ARMISelLowering.cpp revision 515fe3a58877c745a922252a4492e866a2f1e42e
1//===-- ARMISelLowering.cpp - ARM DAG Lowering Implementation -------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines the interfaces that ARM uses to lower LLVM code into a
11// selection DAG.
12//
13//===----------------------------------------------------------------------===//
14
15#define DEBUG_TYPE "arm-isel"
16#include "ARM.h"
17#include "ARMAddressingModes.h"
18#include "ARMConstantPoolValue.h"
19#include "ARMISelLowering.h"
20#include "ARMMachineFunctionInfo.h"
21#include "ARMPerfectShuffle.h"
22#include "ARMRegisterInfo.h"
23#include "ARMSubtarget.h"
24#include "ARMTargetMachine.h"
25#include "ARMTargetObjectFile.h"
26#include "llvm/CallingConv.h"
27#include "llvm/Constants.h"
28#include "llvm/Function.h"
29#include "llvm/GlobalValue.h"
30#include "llvm/Instruction.h"
31#include "llvm/Intrinsics.h"
32#include "llvm/Type.h"
33#include "llvm/CodeGen/CallingConvLower.h"
34#include "llvm/CodeGen/MachineBasicBlock.h"
35#include "llvm/CodeGen/MachineFrameInfo.h"
36#include "llvm/CodeGen/MachineFunction.h"
37#include "llvm/CodeGen/MachineInstrBuilder.h"
38#include "llvm/CodeGen/MachineRegisterInfo.h"
39#include "llvm/CodeGen/PseudoSourceValue.h"
40#include "llvm/CodeGen/SelectionDAG.h"
41#include "llvm/MC/MCSectionMachO.h"
42#include "llvm/Target/TargetOptions.h"
43#include "llvm/ADT/VectorExtras.h"
44#include "llvm/ADT/Statistic.h"
45#include "llvm/Support/CommandLine.h"
46#include "llvm/Support/ErrorHandling.h"
47#include "llvm/Support/MathExtras.h"
48#include "llvm/Support/raw_ostream.h"
49#include <sstream>
50using namespace llvm;
51
52STATISTIC(NumTailCalls, "Number of tail calls");
53
54// This option should go away when tail calls fully work.
55static cl::opt<bool>
56EnableARMTailCalls("arm-tail-calls", cl::Hidden,
57  cl::desc("Generate tail calls (TEMPORARY OPTION)."),
58  cl::init(true));
59
60static cl::opt<bool>
61EnableARMLongCalls("arm-long-calls", cl::Hidden,
62  cl::desc("Generate calls via indirect call instructions"),
63  cl::init(false));
64
65static cl::opt<bool>
66ARMInterworking("arm-interworking", cl::Hidden,
67  cl::desc("Enable / disable ARM interworking (for debugging only)"),
68  cl::init(true));
69
70static cl::opt<bool>
71EnableARMCodePlacement("arm-code-placement", cl::Hidden,
72  cl::desc("Enable code placement pass for ARM"),
73  cl::init(false));
74
75static bool CC_ARM_APCS_Custom_f64(unsigned &ValNo, EVT &ValVT, EVT &LocVT,
76                                   CCValAssign::LocInfo &LocInfo,
77                                   ISD::ArgFlagsTy &ArgFlags,
78                                   CCState &State);
79static bool CC_ARM_AAPCS_Custom_f64(unsigned &ValNo, EVT &ValVT, EVT &LocVT,
80                                    CCValAssign::LocInfo &LocInfo,
81                                    ISD::ArgFlagsTy &ArgFlags,
82                                    CCState &State);
83static bool RetCC_ARM_APCS_Custom_f64(unsigned &ValNo, EVT &ValVT, EVT &LocVT,
84                                      CCValAssign::LocInfo &LocInfo,
85                                      ISD::ArgFlagsTy &ArgFlags,
86                                      CCState &State);
87static bool RetCC_ARM_AAPCS_Custom_f64(unsigned &ValNo, EVT &ValVT, EVT &LocVT,
88                                       CCValAssign::LocInfo &LocInfo,
89                                       ISD::ArgFlagsTy &ArgFlags,
90                                       CCState &State);
91
92void ARMTargetLowering::addTypeForNEON(EVT VT, EVT PromotedLdStVT,
93                                       EVT PromotedBitwiseVT) {
94  if (VT != PromotedLdStVT) {
95    setOperationAction(ISD::LOAD, VT.getSimpleVT(), Promote);
96    AddPromotedToType (ISD::LOAD, VT.getSimpleVT(),
97                       PromotedLdStVT.getSimpleVT());
98
99    setOperationAction(ISD::STORE, VT.getSimpleVT(), Promote);
100    AddPromotedToType (ISD::STORE, VT.getSimpleVT(),
101                       PromotedLdStVT.getSimpleVT());
102  }
103
104  EVT ElemTy = VT.getVectorElementType();
105  if (ElemTy != MVT::i64 && ElemTy != MVT::f64)
106    setOperationAction(ISD::VSETCC, VT.getSimpleVT(), Custom);
107  if (ElemTy == MVT::i8 || ElemTy == MVT::i16)
108    setOperationAction(ISD::EXTRACT_VECTOR_ELT, VT.getSimpleVT(), Custom);
109  if (ElemTy != MVT::i32) {
110    setOperationAction(ISD::SINT_TO_FP, VT.getSimpleVT(), Expand);
111    setOperationAction(ISD::UINT_TO_FP, VT.getSimpleVT(), Expand);
112    setOperationAction(ISD::FP_TO_SINT, VT.getSimpleVT(), Expand);
113    setOperationAction(ISD::FP_TO_UINT, VT.getSimpleVT(), Expand);
114  }
115  setOperationAction(ISD::BUILD_VECTOR, VT.getSimpleVT(), Custom);
116  setOperationAction(ISD::VECTOR_SHUFFLE, VT.getSimpleVT(), Custom);
117  setOperationAction(ISD::CONCAT_VECTORS, VT.getSimpleVT(), Legal);
118  setOperationAction(ISD::EXTRACT_SUBVECTOR, VT.getSimpleVT(), Expand);
119  setOperationAction(ISD::SELECT, VT.getSimpleVT(), Expand);
120  setOperationAction(ISD::SELECT_CC, VT.getSimpleVT(), Expand);
121  if (VT.isInteger()) {
122    setOperationAction(ISD::SHL, VT.getSimpleVT(), Custom);
123    setOperationAction(ISD::SRA, VT.getSimpleVT(), Custom);
124    setOperationAction(ISD::SRL, VT.getSimpleVT(), Custom);
125  }
126
127  // Promote all bit-wise operations.
128  if (VT.isInteger() && VT != PromotedBitwiseVT) {
129    setOperationAction(ISD::AND, VT.getSimpleVT(), Promote);
130    AddPromotedToType (ISD::AND, VT.getSimpleVT(),
131                       PromotedBitwiseVT.getSimpleVT());
132    setOperationAction(ISD::OR,  VT.getSimpleVT(), Promote);
133    AddPromotedToType (ISD::OR,  VT.getSimpleVT(),
134                       PromotedBitwiseVT.getSimpleVT());
135    setOperationAction(ISD::XOR, VT.getSimpleVT(), Promote);
136    AddPromotedToType (ISD::XOR, VT.getSimpleVT(),
137                       PromotedBitwiseVT.getSimpleVT());
138  }
139
140  // Neon does not support vector divide/remainder operations.
141  setOperationAction(ISD::SDIV, VT.getSimpleVT(), Expand);
142  setOperationAction(ISD::UDIV, VT.getSimpleVT(), Expand);
143  setOperationAction(ISD::FDIV, VT.getSimpleVT(), Expand);
144  setOperationAction(ISD::SREM, VT.getSimpleVT(), Expand);
145  setOperationAction(ISD::UREM, VT.getSimpleVT(), Expand);
146  setOperationAction(ISD::FREM, VT.getSimpleVT(), Expand);
147}
148
149void ARMTargetLowering::addDRTypeForNEON(EVT VT) {
150  addRegisterClass(VT, ARM::DPRRegisterClass);
151  addTypeForNEON(VT, MVT::f64, MVT::v2i32);
152}
153
154void ARMTargetLowering::addQRTypeForNEON(EVT VT) {
155  addRegisterClass(VT, ARM::QPRRegisterClass);
156  addTypeForNEON(VT, MVT::v2f64, MVT::v4i32);
157}
158
159static TargetLoweringObjectFile *createTLOF(TargetMachine &TM) {
160  if (TM.getSubtarget<ARMSubtarget>().isTargetDarwin())
161    return new TargetLoweringObjectFileMachO();
162
163  return new ARMElfTargetObjectFile();
164}
165
166ARMTargetLowering::ARMTargetLowering(TargetMachine &TM)
167    : TargetLowering(TM, createTLOF(TM)) {
168  Subtarget = &TM.getSubtarget<ARMSubtarget>();
169
170  if (Subtarget->isTargetDarwin()) {
171    // Uses VFP for Thumb libfuncs if available.
172    if (Subtarget->isThumb() && Subtarget->hasVFP2()) {
173      // Single-precision floating-point arithmetic.
174      setLibcallName(RTLIB::ADD_F32, "__addsf3vfp");
175      setLibcallName(RTLIB::SUB_F32, "__subsf3vfp");
176      setLibcallName(RTLIB::MUL_F32, "__mulsf3vfp");
177      setLibcallName(RTLIB::DIV_F32, "__divsf3vfp");
178
179      // Double-precision floating-point arithmetic.
180      setLibcallName(RTLIB::ADD_F64, "__adddf3vfp");
181      setLibcallName(RTLIB::SUB_F64, "__subdf3vfp");
182      setLibcallName(RTLIB::MUL_F64, "__muldf3vfp");
183      setLibcallName(RTLIB::DIV_F64, "__divdf3vfp");
184
185      // Single-precision comparisons.
186      setLibcallName(RTLIB::OEQ_F32, "__eqsf2vfp");
187      setLibcallName(RTLIB::UNE_F32, "__nesf2vfp");
188      setLibcallName(RTLIB::OLT_F32, "__ltsf2vfp");
189      setLibcallName(RTLIB::OLE_F32, "__lesf2vfp");
190      setLibcallName(RTLIB::OGE_F32, "__gesf2vfp");
191      setLibcallName(RTLIB::OGT_F32, "__gtsf2vfp");
192      setLibcallName(RTLIB::UO_F32,  "__unordsf2vfp");
193      setLibcallName(RTLIB::O_F32,   "__unordsf2vfp");
194
195      setCmpLibcallCC(RTLIB::OEQ_F32, ISD::SETNE);
196      setCmpLibcallCC(RTLIB::UNE_F32, ISD::SETNE);
197      setCmpLibcallCC(RTLIB::OLT_F32, ISD::SETNE);
198      setCmpLibcallCC(RTLIB::OLE_F32, ISD::SETNE);
199      setCmpLibcallCC(RTLIB::OGE_F32, ISD::SETNE);
200      setCmpLibcallCC(RTLIB::OGT_F32, ISD::SETNE);
201      setCmpLibcallCC(RTLIB::UO_F32,  ISD::SETNE);
202      setCmpLibcallCC(RTLIB::O_F32,   ISD::SETEQ);
203
204      // Double-precision comparisons.
205      setLibcallName(RTLIB::OEQ_F64, "__eqdf2vfp");
206      setLibcallName(RTLIB::UNE_F64, "__nedf2vfp");
207      setLibcallName(RTLIB::OLT_F64, "__ltdf2vfp");
208      setLibcallName(RTLIB::OLE_F64, "__ledf2vfp");
209      setLibcallName(RTLIB::OGE_F64, "__gedf2vfp");
210      setLibcallName(RTLIB::OGT_F64, "__gtdf2vfp");
211      setLibcallName(RTLIB::UO_F64,  "__unorddf2vfp");
212      setLibcallName(RTLIB::O_F64,   "__unorddf2vfp");
213
214      setCmpLibcallCC(RTLIB::OEQ_F64, ISD::SETNE);
215      setCmpLibcallCC(RTLIB::UNE_F64, ISD::SETNE);
216      setCmpLibcallCC(RTLIB::OLT_F64, ISD::SETNE);
217      setCmpLibcallCC(RTLIB::OLE_F64, ISD::SETNE);
218      setCmpLibcallCC(RTLIB::OGE_F64, ISD::SETNE);
219      setCmpLibcallCC(RTLIB::OGT_F64, ISD::SETNE);
220      setCmpLibcallCC(RTLIB::UO_F64,  ISD::SETNE);
221      setCmpLibcallCC(RTLIB::O_F64,   ISD::SETEQ);
222
223      // Floating-point to integer conversions.
224      // i64 conversions are done via library routines even when generating VFP
225      // instructions, so use the same ones.
226      setLibcallName(RTLIB::FPTOSINT_F64_I32, "__fixdfsivfp");
227      setLibcallName(RTLIB::FPTOUINT_F64_I32, "__fixunsdfsivfp");
228      setLibcallName(RTLIB::FPTOSINT_F32_I32, "__fixsfsivfp");
229      setLibcallName(RTLIB::FPTOUINT_F32_I32, "__fixunssfsivfp");
230
231      // Conversions between floating types.
232      setLibcallName(RTLIB::FPROUND_F64_F32, "__truncdfsf2vfp");
233      setLibcallName(RTLIB::FPEXT_F32_F64,   "__extendsfdf2vfp");
234
235      // Integer to floating-point conversions.
236      // i64 conversions are done via library routines even when generating VFP
237      // instructions, so use the same ones.
238      // FIXME: There appears to be some naming inconsistency in ARM libgcc:
239      // e.g., __floatunsidf vs. __floatunssidfvfp.
240      setLibcallName(RTLIB::SINTTOFP_I32_F64, "__floatsidfvfp");
241      setLibcallName(RTLIB::UINTTOFP_I32_F64, "__floatunssidfvfp");
242      setLibcallName(RTLIB::SINTTOFP_I32_F32, "__floatsisfvfp");
243      setLibcallName(RTLIB::UINTTOFP_I32_F32, "__floatunssisfvfp");
244    }
245  }
246
247  // These libcalls are not available in 32-bit.
248  setLibcallName(RTLIB::SHL_I128, 0);
249  setLibcallName(RTLIB::SRL_I128, 0);
250  setLibcallName(RTLIB::SRA_I128, 0);
251
252  // Libcalls should use the AAPCS base standard ABI, even if hard float
253  // is in effect, as per the ARM RTABI specification, section 4.1.2.
254  if (Subtarget->isAAPCS_ABI()) {
255    for (int i = 0; i < RTLIB::UNKNOWN_LIBCALL; ++i) {
256      setLibcallCallingConv(static_cast<RTLIB::Libcall>(i),
257                            CallingConv::ARM_AAPCS);
258    }
259  }
260
261  if (Subtarget->isThumb1Only())
262    addRegisterClass(MVT::i32, ARM::tGPRRegisterClass);
263  else
264    addRegisterClass(MVT::i32, ARM::GPRRegisterClass);
265  if (!UseSoftFloat && Subtarget->hasVFP2() && !Subtarget->isThumb1Only()) {
266    addRegisterClass(MVT::f32, ARM::SPRRegisterClass);
267    addRegisterClass(MVT::f64, ARM::DPRRegisterClass);
268
269    setTruncStoreAction(MVT::f64, MVT::f32, Expand);
270  }
271
272  if (Subtarget->hasNEON()) {
273    addDRTypeForNEON(MVT::v2f32);
274    addDRTypeForNEON(MVT::v8i8);
275    addDRTypeForNEON(MVT::v4i16);
276    addDRTypeForNEON(MVT::v2i32);
277    addDRTypeForNEON(MVT::v1i64);
278
279    addQRTypeForNEON(MVT::v4f32);
280    addQRTypeForNEON(MVT::v2f64);
281    addQRTypeForNEON(MVT::v16i8);
282    addQRTypeForNEON(MVT::v8i16);
283    addQRTypeForNEON(MVT::v4i32);
284    addQRTypeForNEON(MVT::v2i64);
285
286    // v2f64 is legal so that QR subregs can be extracted as f64 elements, but
287    // neither Neon nor VFP support any arithmetic operations on it.
288    setOperationAction(ISD::FADD, MVT::v2f64, Expand);
289    setOperationAction(ISD::FSUB, MVT::v2f64, Expand);
290    setOperationAction(ISD::FMUL, MVT::v2f64, Expand);
291    setOperationAction(ISD::FDIV, MVT::v2f64, Expand);
292    setOperationAction(ISD::FREM, MVT::v2f64, Expand);
293    setOperationAction(ISD::FCOPYSIGN, MVT::v2f64, Expand);
294    setOperationAction(ISD::VSETCC, MVT::v2f64, Expand);
295    setOperationAction(ISD::FNEG, MVT::v2f64, Expand);
296    setOperationAction(ISD::FABS, MVT::v2f64, Expand);
297    setOperationAction(ISD::FSQRT, MVT::v2f64, Expand);
298    setOperationAction(ISD::FSIN, MVT::v2f64, Expand);
299    setOperationAction(ISD::FCOS, MVT::v2f64, Expand);
300    setOperationAction(ISD::FPOWI, MVT::v2f64, Expand);
301    setOperationAction(ISD::FPOW, MVT::v2f64, Expand);
302    setOperationAction(ISD::FLOG, MVT::v2f64, Expand);
303    setOperationAction(ISD::FLOG2, MVT::v2f64, Expand);
304    setOperationAction(ISD::FLOG10, MVT::v2f64, Expand);
305    setOperationAction(ISD::FEXP, MVT::v2f64, Expand);
306    setOperationAction(ISD::FEXP2, MVT::v2f64, Expand);
307    setOperationAction(ISD::FCEIL, MVT::v2f64, Expand);
308    setOperationAction(ISD::FTRUNC, MVT::v2f64, Expand);
309    setOperationAction(ISD::FRINT, MVT::v2f64, Expand);
310    setOperationAction(ISD::FNEARBYINT, MVT::v2f64, Expand);
311    setOperationAction(ISD::FFLOOR, MVT::v2f64, Expand);
312
313    // Neon does not support some operations on v1i64 and v2i64 types.
314    setOperationAction(ISD::MUL, MVT::v1i64, Expand);
315    setOperationAction(ISD::MUL, MVT::v2i64, Expand);
316    setOperationAction(ISD::VSETCC, MVT::v1i64, Expand);
317    setOperationAction(ISD::VSETCC, MVT::v2i64, Expand);
318
319    setTargetDAGCombine(ISD::INTRINSIC_WO_CHAIN);
320    setTargetDAGCombine(ISD::SHL);
321    setTargetDAGCombine(ISD::SRL);
322    setTargetDAGCombine(ISD::SRA);
323    setTargetDAGCombine(ISD::SIGN_EXTEND);
324    setTargetDAGCombine(ISD::ZERO_EXTEND);
325    setTargetDAGCombine(ISD::ANY_EXTEND);
326    setTargetDAGCombine(ISD::SELECT_CC);
327  }
328
329  computeRegisterProperties();
330
331  // ARM does not have f32 extending load.
332  setLoadExtAction(ISD::EXTLOAD, MVT::f32, Expand);
333
334  // ARM does not have i1 sign extending load.
335  setLoadExtAction(ISD::SEXTLOAD, MVT::i1, Promote);
336
337  // ARM supports all 4 flavors of integer indexed load / store.
338  if (!Subtarget->isThumb1Only()) {
339    for (unsigned im = (unsigned)ISD::PRE_INC;
340         im != (unsigned)ISD::LAST_INDEXED_MODE; ++im) {
341      setIndexedLoadAction(im,  MVT::i1,  Legal);
342      setIndexedLoadAction(im,  MVT::i8,  Legal);
343      setIndexedLoadAction(im,  MVT::i16, Legal);
344      setIndexedLoadAction(im,  MVT::i32, Legal);
345      setIndexedStoreAction(im, MVT::i1,  Legal);
346      setIndexedStoreAction(im, MVT::i8,  Legal);
347      setIndexedStoreAction(im, MVT::i16, Legal);
348      setIndexedStoreAction(im, MVT::i32, Legal);
349    }
350  }
351
352  // i64 operation support.
353  if (Subtarget->isThumb1Only()) {
354    setOperationAction(ISD::MUL,     MVT::i64, Expand);
355    setOperationAction(ISD::MULHU,   MVT::i32, Expand);
356    setOperationAction(ISD::MULHS,   MVT::i32, Expand);
357    setOperationAction(ISD::UMUL_LOHI, MVT::i32, Expand);
358    setOperationAction(ISD::SMUL_LOHI, MVT::i32, Expand);
359  } else {
360    setOperationAction(ISD::MUL,     MVT::i64, Expand);
361    setOperationAction(ISD::MULHU,   MVT::i32, Expand);
362    if (!Subtarget->hasV6Ops())
363      setOperationAction(ISD::MULHS, MVT::i32, Expand);
364  }
365  setOperationAction(ISD::SHL_PARTS, MVT::i32, Custom);
366  setOperationAction(ISD::SRA_PARTS, MVT::i32, Custom);
367  setOperationAction(ISD::SRL_PARTS, MVT::i32, Custom);
368  setOperationAction(ISD::SRL,       MVT::i64, Custom);
369  setOperationAction(ISD::SRA,       MVT::i64, Custom);
370
371  // ARM does not have ROTL.
372  setOperationAction(ISD::ROTL,  MVT::i32, Expand);
373  setOperationAction(ISD::CTTZ,  MVT::i32, Custom);
374  setOperationAction(ISD::CTPOP, MVT::i32, Expand);
375  if (!Subtarget->hasV5TOps() || Subtarget->isThumb1Only())
376    setOperationAction(ISD::CTLZ, MVT::i32, Expand);
377
378  // Only ARMv6 has BSWAP.
379  if (!Subtarget->hasV6Ops())
380    setOperationAction(ISD::BSWAP, MVT::i32, Expand);
381
382  // These are expanded into libcalls.
383  if (!Subtarget->hasDivide()) {
384    // v7M has a hardware divider
385    setOperationAction(ISD::SDIV,  MVT::i32, Expand);
386    setOperationAction(ISD::UDIV,  MVT::i32, Expand);
387  }
388  setOperationAction(ISD::SREM,  MVT::i32, Expand);
389  setOperationAction(ISD::UREM,  MVT::i32, Expand);
390  setOperationAction(ISD::SDIVREM, MVT::i32, Expand);
391  setOperationAction(ISD::UDIVREM, MVT::i32, Expand);
392
393  setOperationAction(ISD::GlobalAddress, MVT::i32,   Custom);
394  setOperationAction(ISD::ConstantPool,  MVT::i32,   Custom);
395  setOperationAction(ISD::GLOBAL_OFFSET_TABLE, MVT::i32, Custom);
396  setOperationAction(ISD::GlobalTLSAddress, MVT::i32, Custom);
397  setOperationAction(ISD::BlockAddress, MVT::i32, Custom);
398
399  setOperationAction(ISD::TRAP, MVT::Other, Legal);
400
401  // Use the default implementation.
402  setOperationAction(ISD::VASTART,            MVT::Other, Custom);
403  setOperationAction(ISD::VAARG,              MVT::Other, Expand);
404  setOperationAction(ISD::VACOPY,             MVT::Other, Expand);
405  setOperationAction(ISD::VAEND,              MVT::Other, Expand);
406  setOperationAction(ISD::STACKSAVE,          MVT::Other, Expand);
407  setOperationAction(ISD::STACKRESTORE,       MVT::Other, Expand);
408  setOperationAction(ISD::EHSELECTION,        MVT::i32,   Expand);
409  // FIXME: Shouldn't need this, since no register is used, but the legalizer
410  // doesn't yet know how to not do that for SjLj.
411  setExceptionSelectorRegister(ARM::R0);
412  setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32, Expand);
413  // Handle atomics directly for ARMv[67] (except for Thumb1), otherwise
414  // use the default expansion.
415  bool canHandleAtomics =
416    (Subtarget->hasV7Ops() ||
417      (Subtarget->hasV6Ops() && !Subtarget->isThumb1Only()));
418  if (canHandleAtomics) {
419    // membarrier needs custom lowering; the rest are legal and handled
420    // normally.
421    setOperationAction(ISD::MEMBARRIER, MVT::Other, Custom);
422  } else {
423    // Set them all for expansion, which will force libcalls.
424    setOperationAction(ISD::MEMBARRIER, MVT::Other, Expand);
425    setOperationAction(ISD::ATOMIC_CMP_SWAP,  MVT::i8,  Expand);
426    setOperationAction(ISD::ATOMIC_CMP_SWAP,  MVT::i16, Expand);
427    setOperationAction(ISD::ATOMIC_CMP_SWAP,  MVT::i32, Expand);
428    setOperationAction(ISD::ATOMIC_SWAP,      MVT::i8,  Expand);
429    setOperationAction(ISD::ATOMIC_SWAP,      MVT::i16, Expand);
430    setOperationAction(ISD::ATOMIC_SWAP,      MVT::i32, Expand);
431    setOperationAction(ISD::ATOMIC_LOAD_ADD,  MVT::i8,  Expand);
432    setOperationAction(ISD::ATOMIC_LOAD_ADD,  MVT::i16, Expand);
433    setOperationAction(ISD::ATOMIC_LOAD_ADD,  MVT::i32, Expand);
434    setOperationAction(ISD::ATOMIC_LOAD_SUB,  MVT::i8,  Expand);
435    setOperationAction(ISD::ATOMIC_LOAD_SUB,  MVT::i16, Expand);
436    setOperationAction(ISD::ATOMIC_LOAD_SUB,  MVT::i32, Expand);
437    setOperationAction(ISD::ATOMIC_LOAD_AND,  MVT::i8,  Expand);
438    setOperationAction(ISD::ATOMIC_LOAD_AND,  MVT::i16, Expand);
439    setOperationAction(ISD::ATOMIC_LOAD_AND,  MVT::i32, Expand);
440    setOperationAction(ISD::ATOMIC_LOAD_OR,   MVT::i8,  Expand);
441    setOperationAction(ISD::ATOMIC_LOAD_OR,   MVT::i16, Expand);
442    setOperationAction(ISD::ATOMIC_LOAD_OR,   MVT::i32, Expand);
443    setOperationAction(ISD::ATOMIC_LOAD_XOR,  MVT::i8,  Expand);
444    setOperationAction(ISD::ATOMIC_LOAD_XOR,  MVT::i16, Expand);
445    setOperationAction(ISD::ATOMIC_LOAD_XOR,  MVT::i32, Expand);
446    setOperationAction(ISD::ATOMIC_LOAD_NAND, MVT::i8,  Expand);
447    setOperationAction(ISD::ATOMIC_LOAD_NAND, MVT::i16, Expand);
448    setOperationAction(ISD::ATOMIC_LOAD_NAND, MVT::i32, Expand);
449    // Since the libcalls include locking, fold in the fences
450    setShouldFoldAtomicFences(true);
451  }
452  // 64-bit versions are always libcalls (for now)
453  setOperationAction(ISD::ATOMIC_CMP_SWAP,  MVT::i64, Expand);
454  setOperationAction(ISD::ATOMIC_SWAP,      MVT::i64, Expand);
455  setOperationAction(ISD::ATOMIC_LOAD_ADD,  MVT::i64, Expand);
456  setOperationAction(ISD::ATOMIC_LOAD_SUB,  MVT::i64, Expand);
457  setOperationAction(ISD::ATOMIC_LOAD_AND,  MVT::i64, Expand);
458  setOperationAction(ISD::ATOMIC_LOAD_OR,   MVT::i64, Expand);
459  setOperationAction(ISD::ATOMIC_LOAD_XOR,  MVT::i64, Expand);
460  setOperationAction(ISD::ATOMIC_LOAD_NAND, MVT::i64, Expand);
461
462  // Requires SXTB/SXTH, available on v6 and up in both ARM and Thumb modes.
463  if (!Subtarget->hasV6Ops()) {
464    setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16, Expand);
465    setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i8,  Expand);
466  }
467  setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1, Expand);
468
469  if (!UseSoftFloat && Subtarget->hasVFP2() && !Subtarget->isThumb1Only())
470    // Turn f64->i64 into VMOVRRD, i64 -> f64 to VMOVDRR
471    // iff target supports vfp2.
472    setOperationAction(ISD::BIT_CONVERT, MVT::i64, Custom);
473
474  // We want to custom lower some of our intrinsics.
475  setOperationAction(ISD::INTRINSIC_WO_CHAIN, MVT::Other, Custom);
476  if (Subtarget->isTargetDarwin()) {
477    setOperationAction(ISD::EH_SJLJ_SETJMP, MVT::i32, Custom);
478    setOperationAction(ISD::EH_SJLJ_LONGJMP, MVT::Other, Custom);
479  }
480
481  setOperationAction(ISD::SETCC,     MVT::i32, Expand);
482  setOperationAction(ISD::SETCC,     MVT::f32, Expand);
483  setOperationAction(ISD::SETCC,     MVT::f64, Expand);
484  setOperationAction(ISD::SELECT,    MVT::i32, Expand);
485  setOperationAction(ISD::SELECT,    MVT::f32, Expand);
486  setOperationAction(ISD::SELECT,    MVT::f64, Expand);
487  setOperationAction(ISD::SELECT_CC, MVT::i32, Custom);
488  setOperationAction(ISD::SELECT_CC, MVT::f32, Custom);
489  setOperationAction(ISD::SELECT_CC, MVT::f64, Custom);
490
491  setOperationAction(ISD::BRCOND,    MVT::Other, Expand);
492  setOperationAction(ISD::BR_CC,     MVT::i32,   Custom);
493  setOperationAction(ISD::BR_CC,     MVT::f32,   Custom);
494  setOperationAction(ISD::BR_CC,     MVT::f64,   Custom);
495  setOperationAction(ISD::BR_JT,     MVT::Other, Custom);
496
497  // We don't support sin/cos/fmod/copysign/pow
498  setOperationAction(ISD::FSIN,      MVT::f64, Expand);
499  setOperationAction(ISD::FSIN,      MVT::f32, Expand);
500  setOperationAction(ISD::FCOS,      MVT::f32, Expand);
501  setOperationAction(ISD::FCOS,      MVT::f64, Expand);
502  setOperationAction(ISD::FREM,      MVT::f64, Expand);
503  setOperationAction(ISD::FREM,      MVT::f32, Expand);
504  if (!UseSoftFloat && Subtarget->hasVFP2() && !Subtarget->isThumb1Only()) {
505    setOperationAction(ISD::FCOPYSIGN, MVT::f64, Custom);
506    setOperationAction(ISD::FCOPYSIGN, MVT::f32, Custom);
507  }
508  setOperationAction(ISD::FPOW,      MVT::f64, Expand);
509  setOperationAction(ISD::FPOW,      MVT::f32, Expand);
510
511  // Various VFP goodness
512  if (!UseSoftFloat && !Subtarget->isThumb1Only()) {
513    // int <-> fp are custom expanded into bit_convert + ARMISD ops.
514    if (Subtarget->hasVFP2()) {
515      setOperationAction(ISD::SINT_TO_FP, MVT::i32, Custom);
516      setOperationAction(ISD::UINT_TO_FP, MVT::i32, Custom);
517      setOperationAction(ISD::FP_TO_UINT, MVT::i32, Custom);
518      setOperationAction(ISD::FP_TO_SINT, MVT::i32, Custom);
519    }
520    // Special handling for half-precision FP.
521    if (!Subtarget->hasFP16()) {
522      setOperationAction(ISD::FP16_TO_FP32, MVT::f32, Expand);
523      setOperationAction(ISD::FP32_TO_FP16, MVT::i32, Expand);
524    }
525  }
526
527  // We have target-specific dag combine patterns for the following nodes:
528  // ARMISD::VMOVRRD  - No need to call setTargetDAGCombine
529  setTargetDAGCombine(ISD::ADD);
530  setTargetDAGCombine(ISD::SUB);
531  setTargetDAGCombine(ISD::MUL);
532
533  setStackPointerRegisterToSaveRestore(ARM::SP);
534
535  if (UseSoftFloat || Subtarget->isThumb1Only() || !Subtarget->hasVFP2())
536    setSchedulingPreference(Sched::RegPressure);
537  else
538    setSchedulingPreference(Sched::Hybrid);
539
540  maxStoresPerMemcpy = 1;   //// temporary - rewrite interface to use type
541
542  if (EnableARMCodePlacement)
543    benefitFromCodePlacementOpt = true;
544}
545
546const char *ARMTargetLowering::getTargetNodeName(unsigned Opcode) const {
547  switch (Opcode) {
548  default: return 0;
549  case ARMISD::Wrapper:       return "ARMISD::Wrapper";
550  case ARMISD::WrapperJT:     return "ARMISD::WrapperJT";
551  case ARMISD::CALL:          return "ARMISD::CALL";
552  case ARMISD::CALL_PRED:     return "ARMISD::CALL_PRED";
553  case ARMISD::CALL_NOLINK:   return "ARMISD::CALL_NOLINK";
554  case ARMISD::tCALL:         return "ARMISD::tCALL";
555  case ARMISD::BRCOND:        return "ARMISD::BRCOND";
556  case ARMISD::BR_JT:         return "ARMISD::BR_JT";
557  case ARMISD::BR2_JT:        return "ARMISD::BR2_JT";
558  case ARMISD::RET_FLAG:      return "ARMISD::RET_FLAG";
559  case ARMISD::PIC_ADD:       return "ARMISD::PIC_ADD";
560  case ARMISD::CMP:           return "ARMISD::CMP";
561  case ARMISD::CMPZ:          return "ARMISD::CMPZ";
562  case ARMISD::CMPFP:         return "ARMISD::CMPFP";
563  case ARMISD::CMPFPw0:       return "ARMISD::CMPFPw0";
564  case ARMISD::FMSTAT:        return "ARMISD::FMSTAT";
565  case ARMISD::CMOV:          return "ARMISD::CMOV";
566  case ARMISD::CNEG:          return "ARMISD::CNEG";
567
568  case ARMISD::RBIT:          return "ARMISD::RBIT";
569
570  case ARMISD::FTOSI:         return "ARMISD::FTOSI";
571  case ARMISD::FTOUI:         return "ARMISD::FTOUI";
572  case ARMISD::SITOF:         return "ARMISD::SITOF";
573  case ARMISD::UITOF:         return "ARMISD::UITOF";
574
575  case ARMISD::SRL_FLAG:      return "ARMISD::SRL_FLAG";
576  case ARMISD::SRA_FLAG:      return "ARMISD::SRA_FLAG";
577  case ARMISD::RRX:           return "ARMISD::RRX";
578
579  case ARMISD::VMOVRRD:         return "ARMISD::VMOVRRD";
580  case ARMISD::VMOVDRR:         return "ARMISD::VMOVDRR";
581
582  case ARMISD::EH_SJLJ_SETJMP: return "ARMISD::EH_SJLJ_SETJMP";
583  case ARMISD::EH_SJLJ_LONGJMP:return "ARMISD::EH_SJLJ_LONGJMP";
584
585  case ARMISD::TC_RETURN:     return "ARMISD::TC_RETURN";
586
587  case ARMISD::THREAD_POINTER:return "ARMISD::THREAD_POINTER";
588
589  case ARMISD::DYN_ALLOC:     return "ARMISD::DYN_ALLOC";
590
591  case ARMISD::MEMBARRIER:    return "ARMISD::MEMBARRIER";
592  case ARMISD::SYNCBARRIER:   return "ARMISD::SYNCBARRIER";
593
594  case ARMISD::VCEQ:          return "ARMISD::VCEQ";
595  case ARMISD::VCGE:          return "ARMISD::VCGE";
596  case ARMISD::VCGEU:         return "ARMISD::VCGEU";
597  case ARMISD::VCGT:          return "ARMISD::VCGT";
598  case ARMISD::VCGTU:         return "ARMISD::VCGTU";
599  case ARMISD::VTST:          return "ARMISD::VTST";
600
601  case ARMISD::VSHL:          return "ARMISD::VSHL";
602  case ARMISD::VSHRs:         return "ARMISD::VSHRs";
603  case ARMISD::VSHRu:         return "ARMISD::VSHRu";
604  case ARMISD::VSHLLs:        return "ARMISD::VSHLLs";
605  case ARMISD::VSHLLu:        return "ARMISD::VSHLLu";
606  case ARMISD::VSHLLi:        return "ARMISD::VSHLLi";
607  case ARMISD::VSHRN:         return "ARMISD::VSHRN";
608  case ARMISD::VRSHRs:        return "ARMISD::VRSHRs";
609  case ARMISD::VRSHRu:        return "ARMISD::VRSHRu";
610  case ARMISD::VRSHRN:        return "ARMISD::VRSHRN";
611  case ARMISD::VQSHLs:        return "ARMISD::VQSHLs";
612  case ARMISD::VQSHLu:        return "ARMISD::VQSHLu";
613  case ARMISD::VQSHLsu:       return "ARMISD::VQSHLsu";
614  case ARMISD::VQSHRNs:       return "ARMISD::VQSHRNs";
615  case ARMISD::VQSHRNu:       return "ARMISD::VQSHRNu";
616  case ARMISD::VQSHRNsu:      return "ARMISD::VQSHRNsu";
617  case ARMISD::VQRSHRNs:      return "ARMISD::VQRSHRNs";
618  case ARMISD::VQRSHRNu:      return "ARMISD::VQRSHRNu";
619  case ARMISD::VQRSHRNsu:     return "ARMISD::VQRSHRNsu";
620  case ARMISD::VGETLANEu:     return "ARMISD::VGETLANEu";
621  case ARMISD::VGETLANEs:     return "ARMISD::VGETLANEs";
622  case ARMISD::VDUP:          return "ARMISD::VDUP";
623  case ARMISD::VDUPLANE:      return "ARMISD::VDUPLANE";
624  case ARMISD::VEXT:          return "ARMISD::VEXT";
625  case ARMISD::VREV64:        return "ARMISD::VREV64";
626  case ARMISD::VREV32:        return "ARMISD::VREV32";
627  case ARMISD::VREV16:        return "ARMISD::VREV16";
628  case ARMISD::VZIP:          return "ARMISD::VZIP";
629  case ARMISD::VUZP:          return "ARMISD::VUZP";
630  case ARMISD::VTRN:          return "ARMISD::VTRN";
631  case ARMISD::BUILD_VECTOR:  return "ARMISD::BUILD_VECTOR";
632  case ARMISD::FMAX:          return "ARMISD::FMAX";
633  case ARMISD::FMIN:          return "ARMISD::FMIN";
634  }
635}
636
637/// getRegClassFor - Return the register class that should be used for the
638/// specified value type.
639TargetRegisterClass *ARMTargetLowering::getRegClassFor(EVT VT) const {
640  // Map v4i64 to QQ registers but do not make the type legal. Similarly map
641  // v8i64 to QQQQ registers. v4i64 and v8i64 are only used for REG_SEQUENCE to
642  // load / store 4 to 8 consecutive D registers.
643  if (Subtarget->hasNEON()) {
644    if (VT == MVT::v4i64)
645      return ARM::QQPRRegisterClass;
646    else if (VT == MVT::v8i64)
647      return ARM::QQQQPRRegisterClass;
648  }
649  return TargetLowering::getRegClassFor(VT);
650}
651
652/// getFunctionAlignment - Return the Log2 alignment of this function.
653unsigned ARMTargetLowering::getFunctionAlignment(const Function *F) const {
654  return getTargetMachine().getSubtarget<ARMSubtarget>().isThumb() ? 1 : 2;
655}
656
657Sched::Preference ARMTargetLowering::getSchedulingPreference(SDNode *N) const {
658  unsigned NumVals = N->getNumValues();
659  if (!NumVals)
660    return Sched::RegPressure;
661
662  for (unsigned i = 0; i != NumVals; ++i) {
663    EVT VT = N->getValueType(i);
664    if (VT.isFloatingPoint() || VT.isVector())
665      return Sched::Latency;
666  }
667
668  if (!N->isMachineOpcode())
669    return Sched::RegPressure;
670
671  // Load are scheduled for latency even if there instruction itinerary
672  // is not available.
673  const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
674  const TargetInstrDesc &TID = TII->get(N->getMachineOpcode());
675  if (TID.mayLoad())
676    return Sched::Latency;
677
678  const InstrItineraryData &Itins = getTargetMachine().getInstrItineraryData();
679  if (!Itins.isEmpty() && Itins.getStageLatency(TID.getSchedClass()) > 2)
680    return Sched::Latency;
681  return Sched::RegPressure;
682}
683
684//===----------------------------------------------------------------------===//
685// Lowering Code
686//===----------------------------------------------------------------------===//
687
688/// IntCCToARMCC - Convert a DAG integer condition code to an ARM CC
689static ARMCC::CondCodes IntCCToARMCC(ISD::CondCode CC) {
690  switch (CC) {
691  default: llvm_unreachable("Unknown condition code!");
692  case ISD::SETNE:  return ARMCC::NE;
693  case ISD::SETEQ:  return ARMCC::EQ;
694  case ISD::SETGT:  return ARMCC::GT;
695  case ISD::SETGE:  return ARMCC::GE;
696  case ISD::SETLT:  return ARMCC::LT;
697  case ISD::SETLE:  return ARMCC::LE;
698  case ISD::SETUGT: return ARMCC::HI;
699  case ISD::SETUGE: return ARMCC::HS;
700  case ISD::SETULT: return ARMCC::LO;
701  case ISD::SETULE: return ARMCC::LS;
702  }
703}
704
705/// FPCCToARMCC - Convert a DAG fp condition code to an ARM CC.
706static void FPCCToARMCC(ISD::CondCode CC, ARMCC::CondCodes &CondCode,
707                        ARMCC::CondCodes &CondCode2) {
708  CondCode2 = ARMCC::AL;
709  switch (CC) {
710  default: llvm_unreachable("Unknown FP condition!");
711  case ISD::SETEQ:
712  case ISD::SETOEQ: CondCode = ARMCC::EQ; break;
713  case ISD::SETGT:
714  case ISD::SETOGT: CondCode = ARMCC::GT; break;
715  case ISD::SETGE:
716  case ISD::SETOGE: CondCode = ARMCC::GE; break;
717  case ISD::SETOLT: CondCode = ARMCC::MI; break;
718  case ISD::SETOLE: CondCode = ARMCC::LS; break;
719  case ISD::SETONE: CondCode = ARMCC::MI; CondCode2 = ARMCC::GT; break;
720  case ISD::SETO:   CondCode = ARMCC::VC; break;
721  case ISD::SETUO:  CondCode = ARMCC::VS; break;
722  case ISD::SETUEQ: CondCode = ARMCC::EQ; CondCode2 = ARMCC::VS; break;
723  case ISD::SETUGT: CondCode = ARMCC::HI; break;
724  case ISD::SETUGE: CondCode = ARMCC::PL; break;
725  case ISD::SETLT:
726  case ISD::SETULT: CondCode = ARMCC::LT; break;
727  case ISD::SETLE:
728  case ISD::SETULE: CondCode = ARMCC::LE; break;
729  case ISD::SETNE:
730  case ISD::SETUNE: CondCode = ARMCC::NE; break;
731  }
732}
733
734//===----------------------------------------------------------------------===//
735//                      Calling Convention Implementation
736//===----------------------------------------------------------------------===//
737
738#include "ARMGenCallingConv.inc"
739
740// APCS f64 is in register pairs, possibly split to stack
741static bool f64AssignAPCS(unsigned &ValNo, EVT &ValVT, EVT &LocVT,
742                          CCValAssign::LocInfo &LocInfo,
743                          CCState &State, bool CanFail) {
744  static const unsigned RegList[] = { ARM::R0, ARM::R1, ARM::R2, ARM::R3 };
745
746  // Try to get the first register.
747  if (unsigned Reg = State.AllocateReg(RegList, 4))
748    State.addLoc(CCValAssign::getCustomReg(ValNo, ValVT, Reg, LocVT, LocInfo));
749  else {
750    // For the 2nd half of a v2f64, do not fail.
751    if (CanFail)
752      return false;
753
754    // Put the whole thing on the stack.
755    State.addLoc(CCValAssign::getCustomMem(ValNo, ValVT,
756                                           State.AllocateStack(8, 4),
757                                           LocVT, LocInfo));
758    return true;
759  }
760
761  // Try to get the second register.
762  if (unsigned Reg = State.AllocateReg(RegList, 4))
763    State.addLoc(CCValAssign::getCustomReg(ValNo, ValVT, Reg, LocVT, LocInfo));
764  else
765    State.addLoc(CCValAssign::getCustomMem(ValNo, ValVT,
766                                           State.AllocateStack(4, 4),
767                                           LocVT, LocInfo));
768  return true;
769}
770
771static bool CC_ARM_APCS_Custom_f64(unsigned &ValNo, EVT &ValVT, EVT &LocVT,
772                                   CCValAssign::LocInfo &LocInfo,
773                                   ISD::ArgFlagsTy &ArgFlags,
774                                   CCState &State) {
775  if (!f64AssignAPCS(ValNo, ValVT, LocVT, LocInfo, State, true))
776    return false;
777  if (LocVT == MVT::v2f64 &&
778      !f64AssignAPCS(ValNo, ValVT, LocVT, LocInfo, State, false))
779    return false;
780  return true;  // we handled it
781}
782
783// AAPCS f64 is in aligned register pairs
784static bool f64AssignAAPCS(unsigned &ValNo, EVT &ValVT, EVT &LocVT,
785                           CCValAssign::LocInfo &LocInfo,
786                           CCState &State, bool CanFail) {
787  static const unsigned HiRegList[] = { ARM::R0, ARM::R2 };
788  static const unsigned LoRegList[] = { ARM::R1, ARM::R3 };
789
790  unsigned Reg = State.AllocateReg(HiRegList, LoRegList, 2);
791  if (Reg == 0) {
792    // For the 2nd half of a v2f64, do not just fail.
793    if (CanFail)
794      return false;
795
796    // Put the whole thing on the stack.
797    State.addLoc(CCValAssign::getCustomMem(ValNo, ValVT,
798                                           State.AllocateStack(8, 8),
799                                           LocVT, LocInfo));
800    return true;
801  }
802
803  unsigned i;
804  for (i = 0; i < 2; ++i)
805    if (HiRegList[i] == Reg)
806      break;
807
808  State.addLoc(CCValAssign::getCustomReg(ValNo, ValVT, Reg, LocVT, LocInfo));
809  State.addLoc(CCValAssign::getCustomReg(ValNo, ValVT, LoRegList[i],
810                                         LocVT, LocInfo));
811  return true;
812}
813
814static bool CC_ARM_AAPCS_Custom_f64(unsigned &ValNo, EVT &ValVT, EVT &LocVT,
815                                    CCValAssign::LocInfo &LocInfo,
816                                    ISD::ArgFlagsTy &ArgFlags,
817                                    CCState &State) {
818  if (!f64AssignAAPCS(ValNo, ValVT, LocVT, LocInfo, State, true))
819    return false;
820  if (LocVT == MVT::v2f64 &&
821      !f64AssignAAPCS(ValNo, ValVT, LocVT, LocInfo, State, false))
822    return false;
823  return true;  // we handled it
824}
825
826static bool f64RetAssign(unsigned &ValNo, EVT &ValVT, EVT &LocVT,
827                         CCValAssign::LocInfo &LocInfo, CCState &State) {
828  static const unsigned HiRegList[] = { ARM::R0, ARM::R2 };
829  static const unsigned LoRegList[] = { ARM::R1, ARM::R3 };
830
831  unsigned Reg = State.AllocateReg(HiRegList, LoRegList, 2);
832  if (Reg == 0)
833    return false; // we didn't handle it
834
835  unsigned i;
836  for (i = 0; i < 2; ++i)
837    if (HiRegList[i] == Reg)
838      break;
839
840  State.addLoc(CCValAssign::getCustomReg(ValNo, ValVT, Reg, LocVT, LocInfo));
841  State.addLoc(CCValAssign::getCustomReg(ValNo, ValVT, LoRegList[i],
842                                         LocVT, LocInfo));
843  return true;
844}
845
846static bool RetCC_ARM_APCS_Custom_f64(unsigned &ValNo, EVT &ValVT, EVT &LocVT,
847                                      CCValAssign::LocInfo &LocInfo,
848                                      ISD::ArgFlagsTy &ArgFlags,
849                                      CCState &State) {
850  if (!f64RetAssign(ValNo, ValVT, LocVT, LocInfo, State))
851    return false;
852  if (LocVT == MVT::v2f64 && !f64RetAssign(ValNo, ValVT, LocVT, LocInfo, State))
853    return false;
854  return true;  // we handled it
855}
856
857static bool RetCC_ARM_AAPCS_Custom_f64(unsigned &ValNo, EVT &ValVT, EVT &LocVT,
858                                       CCValAssign::LocInfo &LocInfo,
859                                       ISD::ArgFlagsTy &ArgFlags,
860                                       CCState &State) {
861  return RetCC_ARM_APCS_Custom_f64(ValNo, ValVT, LocVT, LocInfo, ArgFlags,
862                                   State);
863}
864
865/// CCAssignFnForNode - Selects the correct CCAssignFn for a the
866/// given CallingConvention value.
867CCAssignFn *ARMTargetLowering::CCAssignFnForNode(CallingConv::ID CC,
868                                                 bool Return,
869                                                 bool isVarArg) const {
870  switch (CC) {
871  default:
872    llvm_unreachable("Unsupported calling convention");
873  case CallingConv::C:
874  case CallingConv::Fast:
875    // Use target triple & subtarget features to do actual dispatch.
876    if (Subtarget->isAAPCS_ABI()) {
877      if (Subtarget->hasVFP2() &&
878          FloatABIType == FloatABI::Hard && !isVarArg)
879        return (Return ? RetCC_ARM_AAPCS_VFP: CC_ARM_AAPCS_VFP);
880      else
881        return (Return ? RetCC_ARM_AAPCS: CC_ARM_AAPCS);
882    } else
883        return (Return ? RetCC_ARM_APCS: CC_ARM_APCS);
884  case CallingConv::ARM_AAPCS_VFP:
885    return (Return ? RetCC_ARM_AAPCS_VFP: CC_ARM_AAPCS_VFP);
886  case CallingConv::ARM_AAPCS:
887    return (Return ? RetCC_ARM_AAPCS: CC_ARM_AAPCS);
888  case CallingConv::ARM_APCS:
889    return (Return ? RetCC_ARM_APCS: CC_ARM_APCS);
890  }
891}
892
893/// LowerCallResult - Lower the result values of a call into the
894/// appropriate copies out of appropriate physical registers.
895SDValue
896ARMTargetLowering::LowerCallResult(SDValue Chain, SDValue InFlag,
897                                   CallingConv::ID CallConv, bool isVarArg,
898                                   const SmallVectorImpl<ISD::InputArg> &Ins,
899                                   DebugLoc dl, SelectionDAG &DAG,
900                                   SmallVectorImpl<SDValue> &InVals) const {
901
902  // Assign locations to each value returned by this call.
903  SmallVector<CCValAssign, 16> RVLocs;
904  CCState CCInfo(CallConv, isVarArg, getTargetMachine(),
905                 RVLocs, *DAG.getContext());
906  CCInfo.AnalyzeCallResult(Ins,
907                           CCAssignFnForNode(CallConv, /* Return*/ true,
908                                             isVarArg));
909
910  // Copy all of the result registers out of their specified physreg.
911  for (unsigned i = 0; i != RVLocs.size(); ++i) {
912    CCValAssign VA = RVLocs[i];
913
914    SDValue Val;
915    if (VA.needsCustom()) {
916      // Handle f64 or half of a v2f64.
917      SDValue Lo = DAG.getCopyFromReg(Chain, dl, VA.getLocReg(), MVT::i32,
918                                      InFlag);
919      Chain = Lo.getValue(1);
920      InFlag = Lo.getValue(2);
921      VA = RVLocs[++i]; // skip ahead to next loc
922      SDValue Hi = DAG.getCopyFromReg(Chain, dl, VA.getLocReg(), MVT::i32,
923                                      InFlag);
924      Chain = Hi.getValue(1);
925      InFlag = Hi.getValue(2);
926      Val = DAG.getNode(ARMISD::VMOVDRR, dl, MVT::f64, Lo, Hi);
927
928      if (VA.getLocVT() == MVT::v2f64) {
929        SDValue Vec = DAG.getNode(ISD::UNDEF, dl, MVT::v2f64);
930        Vec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v2f64, Vec, Val,
931                          DAG.getConstant(0, MVT::i32));
932
933        VA = RVLocs[++i]; // skip ahead to next loc
934        Lo = DAG.getCopyFromReg(Chain, dl, VA.getLocReg(), MVT::i32, InFlag);
935        Chain = Lo.getValue(1);
936        InFlag = Lo.getValue(2);
937        VA = RVLocs[++i]; // skip ahead to next loc
938        Hi = DAG.getCopyFromReg(Chain, dl, VA.getLocReg(), MVT::i32, InFlag);
939        Chain = Hi.getValue(1);
940        InFlag = Hi.getValue(2);
941        Val = DAG.getNode(ARMISD::VMOVDRR, dl, MVT::f64, Lo, Hi);
942        Val = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v2f64, Vec, Val,
943                          DAG.getConstant(1, MVT::i32));
944      }
945    } else {
946      Val = DAG.getCopyFromReg(Chain, dl, VA.getLocReg(), VA.getLocVT(),
947                               InFlag);
948      Chain = Val.getValue(1);
949      InFlag = Val.getValue(2);
950    }
951
952    switch (VA.getLocInfo()) {
953    default: llvm_unreachable("Unknown loc info!");
954    case CCValAssign::Full: break;
955    case CCValAssign::BCvt:
956      Val = DAG.getNode(ISD::BIT_CONVERT, dl, VA.getValVT(), Val);
957      break;
958    }
959
960    InVals.push_back(Val);
961  }
962
963  return Chain;
964}
965
966/// CreateCopyOfByValArgument - Make a copy of an aggregate at address specified
967/// by "Src" to address "Dst" of size "Size".  Alignment information is
968/// specified by the specific parameter attribute.  The copy will be passed as
969/// a byval function parameter.
970/// Sometimes what we are copying is the end of a larger object, the part that
971/// does not fit in registers.
972static SDValue
973CreateCopyOfByValArgument(SDValue Src, SDValue Dst, SDValue Chain,
974                          ISD::ArgFlagsTy Flags, SelectionDAG &DAG,
975                          DebugLoc dl) {
976  SDValue SizeNode = DAG.getConstant(Flags.getByValSize(), MVT::i32);
977  return DAG.getMemcpy(Chain, dl, Dst, Src, SizeNode, Flags.getByValAlign(),
978                       /*isVolatile=*/false, /*AlwaysInline=*/false,
979                       NULL, 0, NULL, 0);
980}
981
982/// LowerMemOpCallTo - Store the argument to the stack.
983SDValue
984ARMTargetLowering::LowerMemOpCallTo(SDValue Chain,
985                                    SDValue StackPtr, SDValue Arg,
986                                    DebugLoc dl, SelectionDAG &DAG,
987                                    const CCValAssign &VA,
988                                    ISD::ArgFlagsTy Flags) const {
989  unsigned LocMemOffset = VA.getLocMemOffset();
990  SDValue PtrOff = DAG.getIntPtrConstant(LocMemOffset);
991  PtrOff = DAG.getNode(ISD::ADD, dl, getPointerTy(), StackPtr, PtrOff);
992  if (Flags.isByVal()) {
993    return CreateCopyOfByValArgument(Arg, PtrOff, Chain, Flags, DAG, dl);
994  }
995  return DAG.getStore(Chain, dl, Arg, PtrOff,
996                      PseudoSourceValue::getStack(), LocMemOffset,
997                      false, false, 0);
998}
999
1000void ARMTargetLowering::PassF64ArgInRegs(DebugLoc dl, SelectionDAG &DAG,
1001                                         SDValue Chain, SDValue &Arg,
1002                                         RegsToPassVector &RegsToPass,
1003                                         CCValAssign &VA, CCValAssign &NextVA,
1004                                         SDValue &StackPtr,
1005                                         SmallVector<SDValue, 8> &MemOpChains,
1006                                         ISD::ArgFlagsTy Flags) const {
1007
1008  SDValue fmrrd = DAG.getNode(ARMISD::VMOVRRD, dl,
1009                              DAG.getVTList(MVT::i32, MVT::i32), Arg);
1010  RegsToPass.push_back(std::make_pair(VA.getLocReg(), fmrrd));
1011
1012  if (NextVA.isRegLoc())
1013    RegsToPass.push_back(std::make_pair(NextVA.getLocReg(), fmrrd.getValue(1)));
1014  else {
1015    assert(NextVA.isMemLoc());
1016    if (StackPtr.getNode() == 0)
1017      StackPtr = DAG.getCopyFromReg(Chain, dl, ARM::SP, getPointerTy());
1018
1019    MemOpChains.push_back(LowerMemOpCallTo(Chain, StackPtr, fmrrd.getValue(1),
1020                                           dl, DAG, NextVA,
1021                                           Flags));
1022  }
1023}
1024
1025/// LowerCall - Lowering a call into a callseq_start <-
1026/// ARMISD:CALL <- callseq_end chain. Also add input and output parameter
1027/// nodes.
1028SDValue
1029ARMTargetLowering::LowerCall(SDValue Chain, SDValue Callee,
1030                             CallingConv::ID CallConv, bool isVarArg,
1031                             bool &isTailCall,
1032                             const SmallVectorImpl<ISD::OutputArg> &Outs,
1033                             const SmallVectorImpl<SDValue> &OutVals,
1034                             const SmallVectorImpl<ISD::InputArg> &Ins,
1035                             DebugLoc dl, SelectionDAG &DAG,
1036                             SmallVectorImpl<SDValue> &InVals) const {
1037  MachineFunction &MF = DAG.getMachineFunction();
1038  bool IsStructRet    = (Outs.empty()) ? false : Outs[0].Flags.isSRet();
1039  bool IsSibCall = false;
1040  // Temporarily disable tail calls so things don't break.
1041  if (!EnableARMTailCalls)
1042    isTailCall = false;
1043  if (isTailCall) {
1044    // Check if it's really possible to do a tail call.
1045    isTailCall = IsEligibleForTailCallOptimization(Callee, CallConv,
1046                    isVarArg, IsStructRet, MF.getFunction()->hasStructRetAttr(),
1047                                                   Outs, OutVals, Ins, DAG);
1048    // We don't support GuaranteedTailCallOpt for ARM, only automatically
1049    // detected sibcalls.
1050    if (isTailCall) {
1051      ++NumTailCalls;
1052      IsSibCall = true;
1053    }
1054  }
1055
1056  // Analyze operands of the call, assigning locations to each operand.
1057  SmallVector<CCValAssign, 16> ArgLocs;
1058  CCState CCInfo(CallConv, isVarArg, getTargetMachine(), ArgLocs,
1059                 *DAG.getContext());
1060  CCInfo.AnalyzeCallOperands(Outs,
1061                             CCAssignFnForNode(CallConv, /* Return*/ false,
1062                                               isVarArg));
1063
1064  // Get a count of how many bytes are to be pushed on the stack.
1065  unsigned NumBytes = CCInfo.getNextStackOffset();
1066
1067  // For tail calls, memory operands are available in our caller's stack.
1068  if (IsSibCall)
1069    NumBytes = 0;
1070
1071  // Adjust the stack pointer for the new arguments...
1072  // These operations are automatically eliminated by the prolog/epilog pass
1073  if (!IsSibCall)
1074    Chain = DAG.getCALLSEQ_START(Chain, DAG.getIntPtrConstant(NumBytes, true));
1075
1076  SDValue StackPtr = DAG.getCopyFromReg(Chain, dl, ARM::SP, getPointerTy());
1077
1078  RegsToPassVector RegsToPass;
1079  SmallVector<SDValue, 8> MemOpChains;
1080
1081  // Walk the register/memloc assignments, inserting copies/loads.  In the case
1082  // of tail call optimization, arguments are handled later.
1083  for (unsigned i = 0, realArgIdx = 0, e = ArgLocs.size();
1084       i != e;
1085       ++i, ++realArgIdx) {
1086    CCValAssign &VA = ArgLocs[i];
1087    SDValue Arg = OutVals[realArgIdx];
1088    ISD::ArgFlagsTy Flags = Outs[realArgIdx].Flags;
1089
1090    // Promote the value if needed.
1091    switch (VA.getLocInfo()) {
1092    default: llvm_unreachable("Unknown loc info!");
1093    case CCValAssign::Full: break;
1094    case CCValAssign::SExt:
1095      Arg = DAG.getNode(ISD::SIGN_EXTEND, dl, VA.getLocVT(), Arg);
1096      break;
1097    case CCValAssign::ZExt:
1098      Arg = DAG.getNode(ISD::ZERO_EXTEND, dl, VA.getLocVT(), Arg);
1099      break;
1100    case CCValAssign::AExt:
1101      Arg = DAG.getNode(ISD::ANY_EXTEND, dl, VA.getLocVT(), Arg);
1102      break;
1103    case CCValAssign::BCvt:
1104      Arg = DAG.getNode(ISD::BIT_CONVERT, dl, VA.getLocVT(), Arg);
1105      break;
1106    }
1107
1108    // f64 and v2f64 might be passed in i32 pairs and must be split into pieces
1109    if (VA.needsCustom()) {
1110      if (VA.getLocVT() == MVT::v2f64) {
1111        SDValue Op0 = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f64, Arg,
1112                                  DAG.getConstant(0, MVT::i32));
1113        SDValue Op1 = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f64, Arg,
1114                                  DAG.getConstant(1, MVT::i32));
1115
1116        PassF64ArgInRegs(dl, DAG, Chain, Op0, RegsToPass,
1117                         VA, ArgLocs[++i], StackPtr, MemOpChains, Flags);
1118
1119        VA = ArgLocs[++i]; // skip ahead to next loc
1120        if (VA.isRegLoc()) {
1121          PassF64ArgInRegs(dl, DAG, Chain, Op1, RegsToPass,
1122                           VA, ArgLocs[++i], StackPtr, MemOpChains, Flags);
1123        } else {
1124          assert(VA.isMemLoc());
1125
1126          MemOpChains.push_back(LowerMemOpCallTo(Chain, StackPtr, Op1,
1127                                                 dl, DAG, VA, Flags));
1128        }
1129      } else {
1130        PassF64ArgInRegs(dl, DAG, Chain, Arg, RegsToPass, VA, ArgLocs[++i],
1131                         StackPtr, MemOpChains, Flags);
1132      }
1133    } else if (VA.isRegLoc()) {
1134      RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
1135    } else if (!IsSibCall) {
1136      assert(VA.isMemLoc());
1137
1138      MemOpChains.push_back(LowerMemOpCallTo(Chain, StackPtr, Arg,
1139                                             dl, DAG, VA, Flags));
1140    }
1141  }
1142
1143  if (!MemOpChains.empty())
1144    Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
1145                        &MemOpChains[0], MemOpChains.size());
1146
1147  // Build a sequence of copy-to-reg nodes chained together with token chain
1148  // and flag operands which copy the outgoing args into the appropriate regs.
1149  SDValue InFlag;
1150  // Tail call byval lowering might overwrite argument registers so in case of
1151  // tail call optimization the copies to registers are lowered later.
1152  if (!isTailCall)
1153    for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
1154      Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first,
1155                               RegsToPass[i].second, InFlag);
1156      InFlag = Chain.getValue(1);
1157    }
1158
1159  // For tail calls lower the arguments to the 'real' stack slot.
1160  if (isTailCall) {
1161    // Force all the incoming stack arguments to be loaded from the stack
1162    // before any new outgoing arguments are stored to the stack, because the
1163    // outgoing stack slots may alias the incoming argument stack slots, and
1164    // the alias isn't otherwise explicit. This is slightly more conservative
1165    // than necessary, because it means that each store effectively depends
1166    // on every argument instead of just those arguments it would clobber.
1167
1168    // Do not flag preceeding copytoreg stuff together with the following stuff.
1169    InFlag = SDValue();
1170    for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
1171      Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first,
1172                               RegsToPass[i].second, InFlag);
1173      InFlag = Chain.getValue(1);
1174    }
1175    InFlag =SDValue();
1176  }
1177
1178  // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
1179  // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
1180  // node so that legalize doesn't hack it.
1181  bool isDirect = false;
1182  bool isARMFunc = false;
1183  bool isLocalARMFunc = false;
1184  ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1185
1186  if (EnableARMLongCalls) {
1187    assert (getTargetMachine().getRelocationModel() == Reloc::Static
1188            && "long-calls with non-static relocation model!");
1189    // Handle a global address or an external symbol. If it's not one of
1190    // those, the target's already in a register, so we don't need to do
1191    // anything extra.
1192    if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
1193      const GlobalValue *GV = G->getGlobal();
1194      // Create a constant pool entry for the callee address
1195      unsigned ARMPCLabelIndex = AFI->createConstPoolEntryUId();
1196      ARMConstantPoolValue *CPV = new ARMConstantPoolValue(GV,
1197                                                           ARMPCLabelIndex,
1198                                                           ARMCP::CPValue, 0);
1199      // Get the address of the callee into a register
1200      SDValue CPAddr = DAG.getTargetConstantPool(CPV, getPointerTy(), 4);
1201      CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
1202      Callee = DAG.getLoad(getPointerTy(), dl,
1203                           DAG.getEntryNode(), CPAddr,
1204                           PseudoSourceValue::getConstantPool(), 0,
1205                           false, false, 0);
1206    } else if (ExternalSymbolSDNode *S=dyn_cast<ExternalSymbolSDNode>(Callee)) {
1207      const char *Sym = S->getSymbol();
1208
1209      // Create a constant pool entry for the callee address
1210      unsigned ARMPCLabelIndex = AFI->createConstPoolEntryUId();
1211      ARMConstantPoolValue *CPV = new ARMConstantPoolValue(*DAG.getContext(),
1212                                                       Sym, ARMPCLabelIndex, 0);
1213      // Get the address of the callee into a register
1214      SDValue CPAddr = DAG.getTargetConstantPool(CPV, getPointerTy(), 4);
1215      CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
1216      Callee = DAG.getLoad(getPointerTy(), dl,
1217                           DAG.getEntryNode(), CPAddr,
1218                           PseudoSourceValue::getConstantPool(), 0,
1219                           false, false, 0);
1220    }
1221  } else if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
1222    const GlobalValue *GV = G->getGlobal();
1223    isDirect = true;
1224    bool isExt = GV->isDeclaration() || GV->isWeakForLinker();
1225    bool isStub = (isExt && Subtarget->isTargetDarwin()) &&
1226                   getTargetMachine().getRelocationModel() != Reloc::Static;
1227    isARMFunc = !Subtarget->isThumb() || isStub;
1228    // ARM call to a local ARM function is predicable.
1229    isLocalARMFunc = !Subtarget->isThumb() && (!isExt || !ARMInterworking);
1230    // tBX takes a register source operand.
1231    if (isARMFunc && Subtarget->isThumb1Only() && !Subtarget->hasV5TOps()) {
1232      unsigned ARMPCLabelIndex = AFI->createConstPoolEntryUId();
1233      ARMConstantPoolValue *CPV = new ARMConstantPoolValue(GV,
1234                                                           ARMPCLabelIndex,
1235                                                           ARMCP::CPValue, 4);
1236      SDValue CPAddr = DAG.getTargetConstantPool(CPV, getPointerTy(), 4);
1237      CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
1238      Callee = DAG.getLoad(getPointerTy(), dl,
1239                           DAG.getEntryNode(), CPAddr,
1240                           PseudoSourceValue::getConstantPool(), 0,
1241                           false, false, 0);
1242      SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, MVT::i32);
1243      Callee = DAG.getNode(ARMISD::PIC_ADD, dl,
1244                           getPointerTy(), Callee, PICLabel);
1245    } else
1246      Callee = DAG.getTargetGlobalAddress(GV, dl, getPointerTy());
1247  } else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) {
1248    isDirect = true;
1249    bool isStub = Subtarget->isTargetDarwin() &&
1250                  getTargetMachine().getRelocationModel() != Reloc::Static;
1251    isARMFunc = !Subtarget->isThumb() || isStub;
1252    // tBX takes a register source operand.
1253    const char *Sym = S->getSymbol();
1254    if (isARMFunc && Subtarget->isThumb1Only() && !Subtarget->hasV5TOps()) {
1255      unsigned ARMPCLabelIndex = AFI->createConstPoolEntryUId();
1256      ARMConstantPoolValue *CPV = new ARMConstantPoolValue(*DAG.getContext(),
1257                                                       Sym, ARMPCLabelIndex, 4);
1258      SDValue CPAddr = DAG.getTargetConstantPool(CPV, getPointerTy(), 4);
1259      CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
1260      Callee = DAG.getLoad(getPointerTy(), dl,
1261                           DAG.getEntryNode(), CPAddr,
1262                           PseudoSourceValue::getConstantPool(), 0,
1263                           false, false, 0);
1264      SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, MVT::i32);
1265      Callee = DAG.getNode(ARMISD::PIC_ADD, dl,
1266                           getPointerTy(), Callee, PICLabel);
1267    } else
1268      Callee = DAG.getTargetExternalSymbol(Sym, getPointerTy());
1269  }
1270
1271  // FIXME: handle tail calls differently.
1272  unsigned CallOpc;
1273  if (Subtarget->isThumb()) {
1274    if ((!isDirect || isARMFunc) && !Subtarget->hasV5TOps())
1275      CallOpc = ARMISD::CALL_NOLINK;
1276    else
1277      CallOpc = isARMFunc ? ARMISD::CALL : ARMISD::tCALL;
1278  } else {
1279    CallOpc = (isDirect || Subtarget->hasV5TOps())
1280      ? (isLocalARMFunc ? ARMISD::CALL_PRED : ARMISD::CALL)
1281      : ARMISD::CALL_NOLINK;
1282  }
1283  if (CallOpc == ARMISD::CALL_NOLINK && !Subtarget->isThumb1Only()) {
1284    // implicit def LR - LR mustn't be allocated as GRP:$dst of CALL_NOLINK
1285    Chain = DAG.getCopyToReg(Chain, dl, ARM::LR, DAG.getUNDEF(MVT::i32),InFlag);
1286    InFlag = Chain.getValue(1);
1287  }
1288
1289  std::vector<SDValue> Ops;
1290  Ops.push_back(Chain);
1291  Ops.push_back(Callee);
1292
1293  // Add argument registers to the end of the list so that they are known live
1294  // into the call.
1295  for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i)
1296    Ops.push_back(DAG.getRegister(RegsToPass[i].first,
1297                                  RegsToPass[i].second.getValueType()));
1298
1299  if (InFlag.getNode())
1300    Ops.push_back(InFlag);
1301
1302  SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Flag);
1303  if (isTailCall)
1304    return DAG.getNode(ARMISD::TC_RETURN, dl, NodeTys, &Ops[0], Ops.size());
1305
1306  // Returns a chain and a flag for retval copy to use.
1307  Chain = DAG.getNode(CallOpc, dl, NodeTys, &Ops[0], Ops.size());
1308  InFlag = Chain.getValue(1);
1309
1310  Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(NumBytes, true),
1311                             DAG.getIntPtrConstant(0, true), InFlag);
1312  if (!Ins.empty())
1313    InFlag = Chain.getValue(1);
1314
1315  // Handle result values, copying them out of physregs into vregs that we
1316  // return.
1317  return LowerCallResult(Chain, InFlag, CallConv, isVarArg, Ins,
1318                         dl, DAG, InVals);
1319}
1320
1321/// MatchingStackOffset - Return true if the given stack call argument is
1322/// already available in the same position (relatively) of the caller's
1323/// incoming argument stack.
1324static
1325bool MatchingStackOffset(SDValue Arg, unsigned Offset, ISD::ArgFlagsTy Flags,
1326                         MachineFrameInfo *MFI, const MachineRegisterInfo *MRI,
1327                         const ARMInstrInfo *TII) {
1328  unsigned Bytes = Arg.getValueType().getSizeInBits() / 8;
1329  int FI = INT_MAX;
1330  if (Arg.getOpcode() == ISD::CopyFromReg) {
1331    unsigned VR = cast<RegisterSDNode>(Arg.getOperand(1))->getReg();
1332    if (!VR || TargetRegisterInfo::isPhysicalRegister(VR))
1333      return false;
1334    MachineInstr *Def = MRI->getVRegDef(VR);
1335    if (!Def)
1336      return false;
1337    if (!Flags.isByVal()) {
1338      if (!TII->isLoadFromStackSlot(Def, FI))
1339        return false;
1340    } else {
1341      return false;
1342    }
1343  } else if (LoadSDNode *Ld = dyn_cast<LoadSDNode>(Arg)) {
1344    if (Flags.isByVal())
1345      // ByVal argument is passed in as a pointer but it's now being
1346      // dereferenced. e.g.
1347      // define @foo(%struct.X* %A) {
1348      //   tail call @bar(%struct.X* byval %A)
1349      // }
1350      return false;
1351    SDValue Ptr = Ld->getBasePtr();
1352    FrameIndexSDNode *FINode = dyn_cast<FrameIndexSDNode>(Ptr);
1353    if (!FINode)
1354      return false;
1355    FI = FINode->getIndex();
1356  } else
1357    return false;
1358
1359  assert(FI != INT_MAX);
1360  if (!MFI->isFixedObjectIndex(FI))
1361    return false;
1362  return Offset == MFI->getObjectOffset(FI) && Bytes == MFI->getObjectSize(FI);
1363}
1364
1365/// IsEligibleForTailCallOptimization - Check whether the call is eligible
1366/// for tail call optimization. Targets which want to do tail call
1367/// optimization should implement this function.
1368bool
1369ARMTargetLowering::IsEligibleForTailCallOptimization(SDValue Callee,
1370                                                     CallingConv::ID CalleeCC,
1371                                                     bool isVarArg,
1372                                                     bool isCalleeStructRet,
1373                                                     bool isCallerStructRet,
1374                                    const SmallVectorImpl<ISD::OutputArg> &Outs,
1375                                    const SmallVectorImpl<SDValue> &OutVals,
1376                                    const SmallVectorImpl<ISD::InputArg> &Ins,
1377                                                     SelectionDAG& DAG) const {
1378  const Function *CallerF = DAG.getMachineFunction().getFunction();
1379  CallingConv::ID CallerCC = CallerF->getCallingConv();
1380  bool CCMatch = CallerCC == CalleeCC;
1381
1382  // Look for obvious safe cases to perform tail call optimization that do not
1383  // require ABI changes. This is what gcc calls sibcall.
1384
1385  // Do not sibcall optimize vararg calls unless the call site is not passing
1386  // any arguments.
1387  if (isVarArg && !Outs.empty())
1388    return false;
1389
1390  // Also avoid sibcall optimization if either caller or callee uses struct
1391  // return semantics.
1392  if (isCalleeStructRet || isCallerStructRet)
1393    return false;
1394
1395  // FIXME: Completely disable sibcall for Thumb1 since Thumb1RegisterInfo::
1396  // emitEpilogue is not ready for them.
1397  // Doing this is tricky, since the LDM/POP instruction on Thumb doesn't take
1398  // LR.  This means if we need to reload LR, it takes an extra instructions,
1399  // which outweighs the value of the tail call; but here we don't know yet
1400  // whether LR is going to be used.  Probably the right approach is to
1401  // generate the tail call here and turn it back into CALL/RET in
1402  // emitEpilogue if LR is used.
1403  if (Subtarget->isThumb1Only())
1404    return false;
1405
1406  // For the moment, we can only do this to functions defined in this
1407  // compilation, or to indirect calls.  A Thumb B to an ARM function,
1408  // or vice versa, is not easily fixed up in the linker unlike BL.
1409  // (We could do this by loading the address of the callee into a register;
1410  // that is an extra instruction over the direct call and burns a register
1411  // as well, so is not likely to be a win.)
1412
1413  // It might be safe to remove this restriction on non-Darwin.
1414
1415  // Thumb1 PIC calls to external symbols use BX, so they can be tail calls,
1416  // but we need to make sure there are enough registers; the only valid
1417  // registers are the 4 used for parameters.  We don't currently do this
1418  // case.
1419  if (isa<ExternalSymbolSDNode>(Callee))
1420      return false;
1421
1422  if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
1423    const GlobalValue *GV = G->getGlobal();
1424    if (GV->isDeclaration() || GV->isWeakForLinker())
1425      return false;
1426  }
1427
1428  // If the calling conventions do not match, then we'd better make sure the
1429  // results are returned in the same way as what the caller expects.
1430  if (!CCMatch) {
1431    SmallVector<CCValAssign, 16> RVLocs1;
1432    CCState CCInfo1(CalleeCC, false, getTargetMachine(),
1433                    RVLocs1, *DAG.getContext());
1434    CCInfo1.AnalyzeCallResult(Ins, CCAssignFnForNode(CalleeCC, true, isVarArg));
1435
1436    SmallVector<CCValAssign, 16> RVLocs2;
1437    CCState CCInfo2(CallerCC, false, getTargetMachine(),
1438                    RVLocs2, *DAG.getContext());
1439    CCInfo2.AnalyzeCallResult(Ins, CCAssignFnForNode(CallerCC, true, isVarArg));
1440
1441    if (RVLocs1.size() != RVLocs2.size())
1442      return false;
1443    for (unsigned i = 0, e = RVLocs1.size(); i != e; ++i) {
1444      if (RVLocs1[i].isRegLoc() != RVLocs2[i].isRegLoc())
1445        return false;
1446      if (RVLocs1[i].getLocInfo() != RVLocs2[i].getLocInfo())
1447        return false;
1448      if (RVLocs1[i].isRegLoc()) {
1449        if (RVLocs1[i].getLocReg() != RVLocs2[i].getLocReg())
1450          return false;
1451      } else {
1452        if (RVLocs1[i].getLocMemOffset() != RVLocs2[i].getLocMemOffset())
1453          return false;
1454      }
1455    }
1456  }
1457
1458  // If the callee takes no arguments then go on to check the results of the
1459  // call.
1460  if (!Outs.empty()) {
1461    // Check if stack adjustment is needed. For now, do not do this if any
1462    // argument is passed on the stack.
1463    SmallVector<CCValAssign, 16> ArgLocs;
1464    CCState CCInfo(CalleeCC, isVarArg, getTargetMachine(),
1465                   ArgLocs, *DAG.getContext());
1466    CCInfo.AnalyzeCallOperands(Outs,
1467                               CCAssignFnForNode(CalleeCC, false, isVarArg));
1468    if (CCInfo.getNextStackOffset()) {
1469      MachineFunction &MF = DAG.getMachineFunction();
1470
1471      // Check if the arguments are already laid out in the right way as
1472      // the caller's fixed stack objects.
1473      MachineFrameInfo *MFI = MF.getFrameInfo();
1474      const MachineRegisterInfo *MRI = &MF.getRegInfo();
1475      const ARMInstrInfo *TII =
1476        ((ARMTargetMachine&)getTargetMachine()).getInstrInfo();
1477      for (unsigned i = 0, realArgIdx = 0, e = ArgLocs.size();
1478           i != e;
1479           ++i, ++realArgIdx) {
1480        CCValAssign &VA = ArgLocs[i];
1481        EVT RegVT = VA.getLocVT();
1482        SDValue Arg = OutVals[realArgIdx];
1483        ISD::ArgFlagsTy Flags = Outs[realArgIdx].Flags;
1484        if (VA.getLocInfo() == CCValAssign::Indirect)
1485          return false;
1486        if (VA.needsCustom()) {
1487          // f64 and vector types are split into multiple registers or
1488          // register/stack-slot combinations.  The types will not match
1489          // the registers; give up on memory f64 refs until we figure
1490          // out what to do about this.
1491          if (!VA.isRegLoc())
1492            return false;
1493          if (!ArgLocs[++i].isRegLoc())
1494            return false;
1495          if (RegVT == MVT::v2f64) {
1496            if (!ArgLocs[++i].isRegLoc())
1497              return false;
1498            if (!ArgLocs[++i].isRegLoc())
1499              return false;
1500          }
1501        } else if (!VA.isRegLoc()) {
1502          if (!MatchingStackOffset(Arg, VA.getLocMemOffset(), Flags,
1503                                   MFI, MRI, TII))
1504            return false;
1505        }
1506      }
1507    }
1508  }
1509
1510  return true;
1511}
1512
1513SDValue
1514ARMTargetLowering::LowerReturn(SDValue Chain,
1515                               CallingConv::ID CallConv, bool isVarArg,
1516                               const SmallVectorImpl<ISD::OutputArg> &Outs,
1517                               const SmallVectorImpl<SDValue> &OutVals,
1518                               DebugLoc dl, SelectionDAG &DAG) const {
1519
1520  // CCValAssign - represent the assignment of the return value to a location.
1521  SmallVector<CCValAssign, 16> RVLocs;
1522
1523  // CCState - Info about the registers and stack slots.
1524  CCState CCInfo(CallConv, isVarArg, getTargetMachine(), RVLocs,
1525                 *DAG.getContext());
1526
1527  // Analyze outgoing return values.
1528  CCInfo.AnalyzeReturn(Outs, CCAssignFnForNode(CallConv, /* Return */ true,
1529                                               isVarArg));
1530
1531  // If this is the first return lowered for this function, add
1532  // the regs to the liveout set for the function.
1533  if (DAG.getMachineFunction().getRegInfo().liveout_empty()) {
1534    for (unsigned i = 0; i != RVLocs.size(); ++i)
1535      if (RVLocs[i].isRegLoc())
1536        DAG.getMachineFunction().getRegInfo().addLiveOut(RVLocs[i].getLocReg());
1537  }
1538
1539  SDValue Flag;
1540
1541  // Copy the result values into the output registers.
1542  for (unsigned i = 0, realRVLocIdx = 0;
1543       i != RVLocs.size();
1544       ++i, ++realRVLocIdx) {
1545    CCValAssign &VA = RVLocs[i];
1546    assert(VA.isRegLoc() && "Can only return in registers!");
1547
1548    SDValue Arg = OutVals[realRVLocIdx];
1549
1550    switch (VA.getLocInfo()) {
1551    default: llvm_unreachable("Unknown loc info!");
1552    case CCValAssign::Full: break;
1553    case CCValAssign::BCvt:
1554      Arg = DAG.getNode(ISD::BIT_CONVERT, dl, VA.getLocVT(), Arg);
1555      break;
1556    }
1557
1558    if (VA.needsCustom()) {
1559      if (VA.getLocVT() == MVT::v2f64) {
1560        // Extract the first half and return it in two registers.
1561        SDValue Half = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f64, Arg,
1562                                   DAG.getConstant(0, MVT::i32));
1563        SDValue HalfGPRs = DAG.getNode(ARMISD::VMOVRRD, dl,
1564                                       DAG.getVTList(MVT::i32, MVT::i32), Half);
1565
1566        Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(), HalfGPRs, Flag);
1567        Flag = Chain.getValue(1);
1568        VA = RVLocs[++i]; // skip ahead to next loc
1569        Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(),
1570                                 HalfGPRs.getValue(1), Flag);
1571        Flag = Chain.getValue(1);
1572        VA = RVLocs[++i]; // skip ahead to next loc
1573
1574        // Extract the 2nd half and fall through to handle it as an f64 value.
1575        Arg = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f64, Arg,
1576                          DAG.getConstant(1, MVT::i32));
1577      }
1578      // Legalize ret f64 -> ret 2 x i32.  We always have fmrrd if f64 is
1579      // available.
1580      SDValue fmrrd = DAG.getNode(ARMISD::VMOVRRD, dl,
1581                                  DAG.getVTList(MVT::i32, MVT::i32), &Arg, 1);
1582      Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(), fmrrd, Flag);
1583      Flag = Chain.getValue(1);
1584      VA = RVLocs[++i]; // skip ahead to next loc
1585      Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(), fmrrd.getValue(1),
1586                               Flag);
1587    } else
1588      Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(), Arg, Flag);
1589
1590    // Guarantee that all emitted copies are
1591    // stuck together, avoiding something bad.
1592    Flag = Chain.getValue(1);
1593  }
1594
1595  SDValue result;
1596  if (Flag.getNode())
1597    result = DAG.getNode(ARMISD::RET_FLAG, dl, MVT::Other, Chain, Flag);
1598  else // Return Void
1599    result = DAG.getNode(ARMISD::RET_FLAG, dl, MVT::Other, Chain);
1600
1601  return result;
1602}
1603
1604// ConstantPool, JumpTable, GlobalAddress, and ExternalSymbol are lowered as
1605// their target counterpart wrapped in the ARMISD::Wrapper node. Suppose N is
1606// one of the above mentioned nodes. It has to be wrapped because otherwise
1607// Select(N) returns N. So the raw TargetGlobalAddress nodes, etc. can only
1608// be used to form addressing mode. These wrapped nodes will be selected
1609// into MOVi.
1610static SDValue LowerConstantPool(SDValue Op, SelectionDAG &DAG) {
1611  EVT PtrVT = Op.getValueType();
1612  // FIXME there is no actual debug info here
1613  DebugLoc dl = Op.getDebugLoc();
1614  ConstantPoolSDNode *CP = cast<ConstantPoolSDNode>(Op);
1615  SDValue Res;
1616  if (CP->isMachineConstantPoolEntry())
1617    Res = DAG.getTargetConstantPool(CP->getMachineCPVal(), PtrVT,
1618                                    CP->getAlignment());
1619  else
1620    Res = DAG.getTargetConstantPool(CP->getConstVal(), PtrVT,
1621                                    CP->getAlignment());
1622  return DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, Res);
1623}
1624
1625SDValue ARMTargetLowering::LowerBlockAddress(SDValue Op,
1626                                             SelectionDAG &DAG) const {
1627  MachineFunction &MF = DAG.getMachineFunction();
1628  ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1629  unsigned ARMPCLabelIndex = 0;
1630  DebugLoc DL = Op.getDebugLoc();
1631  EVT PtrVT = getPointerTy();
1632  const BlockAddress *BA = cast<BlockAddressSDNode>(Op)->getBlockAddress();
1633  Reloc::Model RelocM = getTargetMachine().getRelocationModel();
1634  SDValue CPAddr;
1635  if (RelocM == Reloc::Static) {
1636    CPAddr = DAG.getTargetConstantPool(BA, PtrVT, 4);
1637  } else {
1638    unsigned PCAdj = Subtarget->isThumb() ? 4 : 8;
1639    ARMPCLabelIndex = AFI->createConstPoolEntryUId();
1640    ARMConstantPoolValue *CPV = new ARMConstantPoolValue(BA, ARMPCLabelIndex,
1641                                                         ARMCP::CPBlockAddress,
1642                                                         PCAdj);
1643    CPAddr = DAG.getTargetConstantPool(CPV, PtrVT, 4);
1644  }
1645  CPAddr = DAG.getNode(ARMISD::Wrapper, DL, PtrVT, CPAddr);
1646  SDValue Result = DAG.getLoad(PtrVT, DL, DAG.getEntryNode(), CPAddr,
1647                               PseudoSourceValue::getConstantPool(), 0,
1648                               false, false, 0);
1649  if (RelocM == Reloc::Static)
1650    return Result;
1651  SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, MVT::i32);
1652  return DAG.getNode(ARMISD::PIC_ADD, DL, PtrVT, Result, PICLabel);
1653}
1654
1655// Lower ISD::GlobalTLSAddress using the "general dynamic" model
1656SDValue
1657ARMTargetLowering::LowerToTLSGeneralDynamicModel(GlobalAddressSDNode *GA,
1658                                                 SelectionDAG &DAG) const {
1659  DebugLoc dl = GA->getDebugLoc();
1660  EVT PtrVT = getPointerTy();
1661  unsigned char PCAdj = Subtarget->isThumb() ? 4 : 8;
1662  MachineFunction &MF = DAG.getMachineFunction();
1663  ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1664  unsigned ARMPCLabelIndex = AFI->createConstPoolEntryUId();
1665  ARMConstantPoolValue *CPV =
1666    new ARMConstantPoolValue(GA->getGlobal(), ARMPCLabelIndex,
1667                             ARMCP::CPValue, PCAdj, "tlsgd", true);
1668  SDValue Argument = DAG.getTargetConstantPool(CPV, PtrVT, 4);
1669  Argument = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, Argument);
1670  Argument = DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), Argument,
1671                         PseudoSourceValue::getConstantPool(), 0,
1672                         false, false, 0);
1673  SDValue Chain = Argument.getValue(1);
1674
1675  SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, MVT::i32);
1676  Argument = DAG.getNode(ARMISD::PIC_ADD, dl, PtrVT, Argument, PICLabel);
1677
1678  // call __tls_get_addr.
1679  ArgListTy Args;
1680  ArgListEntry Entry;
1681  Entry.Node = Argument;
1682  Entry.Ty = (const Type *) Type::getInt32Ty(*DAG.getContext());
1683  Args.push_back(Entry);
1684  // FIXME: is there useful debug info available here?
1685  std::pair<SDValue, SDValue> CallResult =
1686    LowerCallTo(Chain, (const Type *) Type::getInt32Ty(*DAG.getContext()),
1687                false, false, false, false,
1688                0, CallingConv::C, false, /*isReturnValueUsed=*/true,
1689                DAG.getExternalSymbol("__tls_get_addr", PtrVT), Args, DAG, dl);
1690  return CallResult.first;
1691}
1692
1693// Lower ISD::GlobalTLSAddress using the "initial exec" or
1694// "local exec" model.
1695SDValue
1696ARMTargetLowering::LowerToTLSExecModels(GlobalAddressSDNode *GA,
1697                                        SelectionDAG &DAG) const {
1698  const GlobalValue *GV = GA->getGlobal();
1699  DebugLoc dl = GA->getDebugLoc();
1700  SDValue Offset;
1701  SDValue Chain = DAG.getEntryNode();
1702  EVT PtrVT = getPointerTy();
1703  // Get the Thread Pointer
1704  SDValue ThreadPointer = DAG.getNode(ARMISD::THREAD_POINTER, dl, PtrVT);
1705
1706  if (GV->isDeclaration()) {
1707    MachineFunction &MF = DAG.getMachineFunction();
1708    ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1709    unsigned ARMPCLabelIndex = AFI->createConstPoolEntryUId();
1710    // Initial exec model.
1711    unsigned char PCAdj = Subtarget->isThumb() ? 4 : 8;
1712    ARMConstantPoolValue *CPV =
1713      new ARMConstantPoolValue(GA->getGlobal(), ARMPCLabelIndex,
1714                               ARMCP::CPValue, PCAdj, "gottpoff", true);
1715    Offset = DAG.getTargetConstantPool(CPV, PtrVT, 4);
1716    Offset = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, Offset);
1717    Offset = DAG.getLoad(PtrVT, dl, Chain, Offset,
1718                         PseudoSourceValue::getConstantPool(), 0,
1719                         false, false, 0);
1720    Chain = Offset.getValue(1);
1721
1722    SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, MVT::i32);
1723    Offset = DAG.getNode(ARMISD::PIC_ADD, dl, PtrVT, Offset, PICLabel);
1724
1725    Offset = DAG.getLoad(PtrVT, dl, Chain, Offset,
1726                         PseudoSourceValue::getConstantPool(), 0,
1727                         false, false, 0);
1728  } else {
1729    // local exec model
1730    ARMConstantPoolValue *CPV = new ARMConstantPoolValue(GV, "tpoff");
1731    Offset = DAG.getTargetConstantPool(CPV, PtrVT, 4);
1732    Offset = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, Offset);
1733    Offset = DAG.getLoad(PtrVT, dl, Chain, Offset,
1734                         PseudoSourceValue::getConstantPool(), 0,
1735                         false, false, 0);
1736  }
1737
1738  // The address of the thread local variable is the add of the thread
1739  // pointer with the offset of the variable.
1740  return DAG.getNode(ISD::ADD, dl, PtrVT, ThreadPointer, Offset);
1741}
1742
1743SDValue
1744ARMTargetLowering::LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const {
1745  // TODO: implement the "local dynamic" model
1746  assert(Subtarget->isTargetELF() &&
1747         "TLS not implemented for non-ELF targets");
1748  GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
1749  // If the relocation model is PIC, use the "General Dynamic" TLS Model,
1750  // otherwise use the "Local Exec" TLS Model
1751  if (getTargetMachine().getRelocationModel() == Reloc::PIC_)
1752    return LowerToTLSGeneralDynamicModel(GA, DAG);
1753  else
1754    return LowerToTLSExecModels(GA, DAG);
1755}
1756
1757SDValue ARMTargetLowering::LowerGlobalAddressELF(SDValue Op,
1758                                                 SelectionDAG &DAG) const {
1759  EVT PtrVT = getPointerTy();
1760  DebugLoc dl = Op.getDebugLoc();
1761  const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
1762  Reloc::Model RelocM = getTargetMachine().getRelocationModel();
1763  if (RelocM == Reloc::PIC_) {
1764    bool UseGOTOFF = GV->hasLocalLinkage() || GV->hasHiddenVisibility();
1765    ARMConstantPoolValue *CPV =
1766      new ARMConstantPoolValue(GV, UseGOTOFF ? "GOTOFF" : "GOT");
1767    SDValue CPAddr = DAG.getTargetConstantPool(CPV, PtrVT, 4);
1768    CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
1769    SDValue Result = DAG.getLoad(PtrVT, dl, DAG.getEntryNode(),
1770                                 CPAddr,
1771                                 PseudoSourceValue::getConstantPool(), 0,
1772                                 false, false, 0);
1773    SDValue Chain = Result.getValue(1);
1774    SDValue GOT = DAG.getGLOBAL_OFFSET_TABLE(PtrVT);
1775    Result = DAG.getNode(ISD::ADD, dl, PtrVT, Result, GOT);
1776    if (!UseGOTOFF)
1777      Result = DAG.getLoad(PtrVT, dl, Chain, Result,
1778                           PseudoSourceValue::getGOT(), 0,
1779                           false, false, 0);
1780    return Result;
1781  } else {
1782    // If we have T2 ops, we can materialize the address directly via movt/movw
1783    // pair. This is always cheaper.
1784    if (Subtarget->useMovt()) {
1785      return DAG.getNode(ARMISD::Wrapper, dl, PtrVT,
1786                         DAG.getTargetGlobalAddress(GV, dl, PtrVT));
1787    } else {
1788      SDValue CPAddr = DAG.getTargetConstantPool(GV, PtrVT, 4);
1789      CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
1790      return DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), CPAddr,
1791                         PseudoSourceValue::getConstantPool(), 0,
1792                         false, false, 0);
1793    }
1794  }
1795}
1796
1797SDValue ARMTargetLowering::LowerGlobalAddressDarwin(SDValue Op,
1798                                                    SelectionDAG &DAG) const {
1799  MachineFunction &MF = DAG.getMachineFunction();
1800  ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1801  unsigned ARMPCLabelIndex = 0;
1802  EVT PtrVT = getPointerTy();
1803  DebugLoc dl = Op.getDebugLoc();
1804  const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
1805  Reloc::Model RelocM = getTargetMachine().getRelocationModel();
1806  SDValue CPAddr;
1807  if (RelocM == Reloc::Static)
1808    CPAddr = DAG.getTargetConstantPool(GV, PtrVT, 4);
1809  else {
1810    ARMPCLabelIndex = AFI->createConstPoolEntryUId();
1811    unsigned PCAdj = (RelocM != Reloc::PIC_) ? 0 : (Subtarget->isThumb()?4:8);
1812    ARMConstantPoolValue *CPV =
1813      new ARMConstantPoolValue(GV, ARMPCLabelIndex, ARMCP::CPValue, PCAdj);
1814    CPAddr = DAG.getTargetConstantPool(CPV, PtrVT, 4);
1815  }
1816  CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
1817
1818  SDValue Result = DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), CPAddr,
1819                               PseudoSourceValue::getConstantPool(), 0,
1820                               false, false, 0);
1821  SDValue Chain = Result.getValue(1);
1822
1823  if (RelocM == Reloc::PIC_) {
1824    SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, MVT::i32);
1825    Result = DAG.getNode(ARMISD::PIC_ADD, dl, PtrVT, Result, PICLabel);
1826  }
1827
1828  if (Subtarget->GVIsIndirectSymbol(GV, RelocM))
1829    Result = DAG.getLoad(PtrVT, dl, Chain, Result,
1830                         PseudoSourceValue::getGOT(), 0,
1831                         false, false, 0);
1832
1833  return Result;
1834}
1835
1836SDValue ARMTargetLowering::LowerGLOBAL_OFFSET_TABLE(SDValue Op,
1837                                                    SelectionDAG &DAG) const {
1838  assert(Subtarget->isTargetELF() &&
1839         "GLOBAL OFFSET TABLE not implemented for non-ELF targets");
1840  MachineFunction &MF = DAG.getMachineFunction();
1841  ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1842  unsigned ARMPCLabelIndex = AFI->createConstPoolEntryUId();
1843  EVT PtrVT = getPointerTy();
1844  DebugLoc dl = Op.getDebugLoc();
1845  unsigned PCAdj = Subtarget->isThumb() ? 4 : 8;
1846  ARMConstantPoolValue *CPV = new ARMConstantPoolValue(*DAG.getContext(),
1847                                                       "_GLOBAL_OFFSET_TABLE_",
1848                                                       ARMPCLabelIndex, PCAdj);
1849  SDValue CPAddr = DAG.getTargetConstantPool(CPV, PtrVT, 4);
1850  CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
1851  SDValue Result = DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), CPAddr,
1852                               PseudoSourceValue::getConstantPool(), 0,
1853                               false, false, 0);
1854  SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, MVT::i32);
1855  return DAG.getNode(ARMISD::PIC_ADD, dl, PtrVT, Result, PICLabel);
1856}
1857
1858SDValue
1859ARMTargetLowering::LowerEH_SJLJ_SETJMP(SDValue Op, SelectionDAG &DAG) const {
1860  DebugLoc dl = Op.getDebugLoc();
1861  SDValue Val = DAG.getConstant(0, MVT::i32);
1862  return DAG.getNode(ARMISD::EH_SJLJ_SETJMP, dl, MVT::i32, Op.getOperand(0),
1863                     Op.getOperand(1), Val);
1864}
1865
1866SDValue
1867ARMTargetLowering::LowerEH_SJLJ_LONGJMP(SDValue Op, SelectionDAG &DAG) const {
1868  DebugLoc dl = Op.getDebugLoc();
1869  return DAG.getNode(ARMISD::EH_SJLJ_LONGJMP, dl, MVT::Other, Op.getOperand(0),
1870                     Op.getOperand(1), DAG.getConstant(0, MVT::i32));
1871}
1872
1873SDValue
1874ARMTargetLowering::LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG,
1875                                          const ARMSubtarget *Subtarget) const {
1876  unsigned IntNo = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
1877  DebugLoc dl = Op.getDebugLoc();
1878  switch (IntNo) {
1879  default: return SDValue();    // Don't custom lower most intrinsics.
1880  case Intrinsic::arm_thread_pointer: {
1881    EVT PtrVT = DAG.getTargetLoweringInfo().getPointerTy();
1882    return DAG.getNode(ARMISD::THREAD_POINTER, dl, PtrVT);
1883  }
1884  case Intrinsic::eh_sjlj_lsda: {
1885    MachineFunction &MF = DAG.getMachineFunction();
1886    ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1887    unsigned ARMPCLabelIndex = AFI->createConstPoolEntryUId();
1888    EVT PtrVT = getPointerTy();
1889    DebugLoc dl = Op.getDebugLoc();
1890    Reloc::Model RelocM = getTargetMachine().getRelocationModel();
1891    SDValue CPAddr;
1892    unsigned PCAdj = (RelocM != Reloc::PIC_)
1893      ? 0 : (Subtarget->isThumb() ? 4 : 8);
1894    ARMConstantPoolValue *CPV =
1895      new ARMConstantPoolValue(MF.getFunction(), ARMPCLabelIndex,
1896                               ARMCP::CPLSDA, PCAdj);
1897    CPAddr = DAG.getTargetConstantPool(CPV, PtrVT, 4);
1898    CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
1899    SDValue Result =
1900      DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), CPAddr,
1901                  PseudoSourceValue::getConstantPool(), 0,
1902                  false, false, 0);
1903
1904    if (RelocM == Reloc::PIC_) {
1905      SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, MVT::i32);
1906      Result = DAG.getNode(ARMISD::PIC_ADD, dl, PtrVT, Result, PICLabel);
1907    }
1908    return Result;
1909  }
1910  }
1911}
1912
1913static SDValue LowerMEMBARRIER(SDValue Op, SelectionDAG &DAG,
1914                               const ARMSubtarget *Subtarget) {
1915  DebugLoc dl = Op.getDebugLoc();
1916  SDValue Op5 = Op.getOperand(5);
1917  unsigned isDeviceBarrier = cast<ConstantSDNode>(Op5)->getZExtValue();
1918  // v6 and v7 can both handle barriers directly, but need handled a bit
1919  // differently. Thumb1 and pre-v6 ARM mode use a libcall instead and should
1920  // never get here.
1921  unsigned Opc = isDeviceBarrier ? ARMISD::SYNCBARRIER : ARMISD::MEMBARRIER;
1922  if (Subtarget->hasV7Ops())
1923    return DAG.getNode(Opc, dl, MVT::Other, Op.getOperand(0));
1924  else if (Subtarget->hasV6Ops() && !Subtarget->isThumb1Only())
1925    return DAG.getNode(Opc, dl, MVT::Other, Op.getOperand(0),
1926                       DAG.getConstant(0, MVT::i32));
1927  assert(0 && "Unexpected ISD::MEMBARRIER encountered. Should be libcall!");
1928  return SDValue();
1929}
1930
1931static SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG) {
1932  MachineFunction &MF = DAG.getMachineFunction();
1933  ARMFunctionInfo *FuncInfo = MF.getInfo<ARMFunctionInfo>();
1934
1935  // vastart just stores the address of the VarArgsFrameIndex slot into the
1936  // memory location argument.
1937  DebugLoc dl = Op.getDebugLoc();
1938  EVT PtrVT = DAG.getTargetLoweringInfo().getPointerTy();
1939  SDValue FR = DAG.getFrameIndex(FuncInfo->getVarArgsFrameIndex(), PtrVT);
1940  const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
1941  return DAG.getStore(Op.getOperand(0), dl, FR, Op.getOperand(1), SV, 0,
1942                      false, false, 0);
1943}
1944
1945SDValue
1946ARMTargetLowering::LowerDYNAMIC_STACKALLOC(SDValue Op,
1947                                           SelectionDAG &DAG) const {
1948  SDNode *Node = Op.getNode();
1949  DebugLoc dl = Node->getDebugLoc();
1950  EVT VT = Node->getValueType(0);
1951  SDValue Chain = Op.getOperand(0);
1952  SDValue Size  = Op.getOperand(1);
1953  SDValue Align = Op.getOperand(2);
1954
1955  // Chain the dynamic stack allocation so that it doesn't modify the stack
1956  // pointer when other instructions are using the stack.
1957  Chain = DAG.getCALLSEQ_START(Chain, DAG.getIntPtrConstant(0, true));
1958
1959  unsigned AlignVal = cast<ConstantSDNode>(Align)->getZExtValue();
1960  unsigned StackAlign = getTargetMachine().getFrameInfo()->getStackAlignment();
1961  if (AlignVal > StackAlign)
1962    // Do this now since selection pass cannot introduce new target
1963    // independent node.
1964    Align = DAG.getConstant(-(uint64_t)AlignVal, VT);
1965
1966  // In Thumb1 mode, there isn't a "sub r, sp, r" instruction, we will end up
1967  // using a "add r, sp, r" instead. Negate the size now so we don't have to
1968  // do even more horrible hack later.
1969  MachineFunction &MF = DAG.getMachineFunction();
1970  ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1971  if (AFI->isThumb1OnlyFunction()) {
1972    bool Negate = true;
1973    ConstantSDNode *C = dyn_cast<ConstantSDNode>(Size);
1974    if (C) {
1975      uint32_t Val = C->getZExtValue();
1976      if (Val <= 508 && ((Val & 3) == 0))
1977        Negate = false;
1978    }
1979    if (Negate)
1980      Size = DAG.getNode(ISD::SUB, dl, VT, DAG.getConstant(0, VT), Size);
1981  }
1982
1983  SDVTList VTList = DAG.getVTList(VT, MVT::Other);
1984  SDValue Ops1[] = { Chain, Size, Align };
1985  SDValue Res = DAG.getNode(ARMISD::DYN_ALLOC, dl, VTList, Ops1, 3);
1986  Chain = Res.getValue(1);
1987  Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(0, true),
1988                             DAG.getIntPtrConstant(0, true), SDValue());
1989  SDValue Ops2[] = { Res, Chain };
1990  return DAG.getMergeValues(Ops2, 2, dl);
1991}
1992
1993SDValue
1994ARMTargetLowering::GetF64FormalArgument(CCValAssign &VA, CCValAssign &NextVA,
1995                                        SDValue &Root, SelectionDAG &DAG,
1996                                        DebugLoc dl) const {
1997  MachineFunction &MF = DAG.getMachineFunction();
1998  ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1999
2000  TargetRegisterClass *RC;
2001  if (AFI->isThumb1OnlyFunction())
2002    RC = ARM::tGPRRegisterClass;
2003  else
2004    RC = ARM::GPRRegisterClass;
2005
2006  // Transform the arguments stored in physical registers into virtual ones.
2007  unsigned Reg = MF.addLiveIn(VA.getLocReg(), RC);
2008  SDValue ArgValue = DAG.getCopyFromReg(Root, dl, Reg, MVT::i32);
2009
2010  SDValue ArgValue2;
2011  if (NextVA.isMemLoc()) {
2012    MachineFrameInfo *MFI = MF.getFrameInfo();
2013    int FI = MFI->CreateFixedObject(4, NextVA.getLocMemOffset(), true);
2014
2015    // Create load node to retrieve arguments from the stack.
2016    SDValue FIN = DAG.getFrameIndex(FI, getPointerTy());
2017    ArgValue2 = DAG.getLoad(MVT::i32, dl, Root, FIN,
2018                            PseudoSourceValue::getFixedStack(FI), 0,
2019                            false, false, 0);
2020  } else {
2021    Reg = MF.addLiveIn(NextVA.getLocReg(), RC);
2022    ArgValue2 = DAG.getCopyFromReg(Root, dl, Reg, MVT::i32);
2023  }
2024
2025  return DAG.getNode(ARMISD::VMOVDRR, dl, MVT::f64, ArgValue, ArgValue2);
2026}
2027
2028SDValue
2029ARMTargetLowering::LowerFormalArguments(SDValue Chain,
2030                                        CallingConv::ID CallConv, bool isVarArg,
2031                                        const SmallVectorImpl<ISD::InputArg>
2032                                          &Ins,
2033                                        DebugLoc dl, SelectionDAG &DAG,
2034                                        SmallVectorImpl<SDValue> &InVals)
2035                                          const {
2036
2037  MachineFunction &MF = DAG.getMachineFunction();
2038  MachineFrameInfo *MFI = MF.getFrameInfo();
2039
2040  ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
2041
2042  // Assign locations to all of the incoming arguments.
2043  SmallVector<CCValAssign, 16> ArgLocs;
2044  CCState CCInfo(CallConv, isVarArg, getTargetMachine(), ArgLocs,
2045                 *DAG.getContext());
2046  CCInfo.AnalyzeFormalArguments(Ins,
2047                                CCAssignFnForNode(CallConv, /* Return*/ false,
2048                                                  isVarArg));
2049
2050  SmallVector<SDValue, 16> ArgValues;
2051
2052  for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
2053    CCValAssign &VA = ArgLocs[i];
2054
2055    // Arguments stored in registers.
2056    if (VA.isRegLoc()) {
2057      EVT RegVT = VA.getLocVT();
2058
2059      SDValue ArgValue;
2060      if (VA.needsCustom()) {
2061        // f64 and vector types are split up into multiple registers or
2062        // combinations of registers and stack slots.
2063        if (VA.getLocVT() == MVT::v2f64) {
2064          SDValue ArgValue1 = GetF64FormalArgument(VA, ArgLocs[++i],
2065                                                   Chain, DAG, dl);
2066          VA = ArgLocs[++i]; // skip ahead to next loc
2067          SDValue ArgValue2;
2068          if (VA.isMemLoc()) {
2069            int FI = MFI->CreateFixedObject(8, VA.getLocMemOffset(), true);
2070            SDValue FIN = DAG.getFrameIndex(FI, getPointerTy());
2071            ArgValue2 = DAG.getLoad(MVT::f64, dl, Chain, FIN,
2072                                    PseudoSourceValue::getFixedStack(FI), 0,
2073                                    false, false, 0);
2074          } else {
2075            ArgValue2 = GetF64FormalArgument(VA, ArgLocs[++i],
2076                                             Chain, DAG, dl);
2077          }
2078          ArgValue = DAG.getNode(ISD::UNDEF, dl, MVT::v2f64);
2079          ArgValue = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v2f64,
2080                                 ArgValue, ArgValue1, DAG.getIntPtrConstant(0));
2081          ArgValue = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v2f64,
2082                                 ArgValue, ArgValue2, DAG.getIntPtrConstant(1));
2083        } else
2084          ArgValue = GetF64FormalArgument(VA, ArgLocs[++i], Chain, DAG, dl);
2085
2086      } else {
2087        TargetRegisterClass *RC;
2088
2089        if (RegVT == MVT::f32)
2090          RC = ARM::SPRRegisterClass;
2091        else if (RegVT == MVT::f64)
2092          RC = ARM::DPRRegisterClass;
2093        else if (RegVT == MVT::v2f64)
2094          RC = ARM::QPRRegisterClass;
2095        else if (RegVT == MVT::i32)
2096          RC = (AFI->isThumb1OnlyFunction() ?
2097                ARM::tGPRRegisterClass : ARM::GPRRegisterClass);
2098        else
2099          llvm_unreachable("RegVT not supported by FORMAL_ARGUMENTS Lowering");
2100
2101        // Transform the arguments in physical registers into virtual ones.
2102        unsigned Reg = MF.addLiveIn(VA.getLocReg(), RC);
2103        ArgValue = DAG.getCopyFromReg(Chain, dl, Reg, RegVT);
2104      }
2105
2106      // If this is an 8 or 16-bit value, it is really passed promoted
2107      // to 32 bits.  Insert an assert[sz]ext to capture this, then
2108      // truncate to the right size.
2109      switch (VA.getLocInfo()) {
2110      default: llvm_unreachable("Unknown loc info!");
2111      case CCValAssign::Full: break;
2112      case CCValAssign::BCvt:
2113        ArgValue = DAG.getNode(ISD::BIT_CONVERT, dl, VA.getValVT(), ArgValue);
2114        break;
2115      case CCValAssign::SExt:
2116        ArgValue = DAG.getNode(ISD::AssertSext, dl, RegVT, ArgValue,
2117                               DAG.getValueType(VA.getValVT()));
2118        ArgValue = DAG.getNode(ISD::TRUNCATE, dl, VA.getValVT(), ArgValue);
2119        break;
2120      case CCValAssign::ZExt:
2121        ArgValue = DAG.getNode(ISD::AssertZext, dl, RegVT, ArgValue,
2122                               DAG.getValueType(VA.getValVT()));
2123        ArgValue = DAG.getNode(ISD::TRUNCATE, dl, VA.getValVT(), ArgValue);
2124        break;
2125      }
2126
2127      InVals.push_back(ArgValue);
2128
2129    } else { // VA.isRegLoc()
2130
2131      // sanity check
2132      assert(VA.isMemLoc());
2133      assert(VA.getValVT() != MVT::i64 && "i64 should already be lowered");
2134
2135      unsigned ArgSize = VA.getLocVT().getSizeInBits()/8;
2136      int FI = MFI->CreateFixedObject(ArgSize, VA.getLocMemOffset(), true);
2137
2138      // Create load nodes to retrieve arguments from the stack.
2139      SDValue FIN = DAG.getFrameIndex(FI, getPointerTy());
2140      InVals.push_back(DAG.getLoad(VA.getValVT(), dl, Chain, FIN,
2141                                   PseudoSourceValue::getFixedStack(FI), 0,
2142                                   false, false, 0));
2143    }
2144  }
2145
2146  // varargs
2147  if (isVarArg) {
2148    static const unsigned GPRArgRegs[] = {
2149      ARM::R0, ARM::R1, ARM::R2, ARM::R3
2150    };
2151
2152    unsigned NumGPRs = CCInfo.getFirstUnallocated
2153      (GPRArgRegs, sizeof(GPRArgRegs) / sizeof(GPRArgRegs[0]));
2154
2155    unsigned Align = MF.getTarget().getFrameInfo()->getStackAlignment();
2156    unsigned VARegSize = (4 - NumGPRs) * 4;
2157    unsigned VARegSaveSize = (VARegSize + Align - 1) & ~(Align - 1);
2158    unsigned ArgOffset = CCInfo.getNextStackOffset();
2159    if (VARegSaveSize) {
2160      // If this function is vararg, store any remaining integer argument regs
2161      // to their spots on the stack so that they may be loaded by deferencing
2162      // the result of va_next.
2163      AFI->setVarArgsRegSaveSize(VARegSaveSize);
2164      AFI->setVarArgsFrameIndex(
2165        MFI->CreateFixedObject(VARegSaveSize,
2166                               ArgOffset + VARegSaveSize - VARegSize,
2167                               true));
2168      SDValue FIN = DAG.getFrameIndex(AFI->getVarArgsFrameIndex(),
2169                                      getPointerTy());
2170
2171      SmallVector<SDValue, 4> MemOps;
2172      for (; NumGPRs < 4; ++NumGPRs) {
2173        TargetRegisterClass *RC;
2174        if (AFI->isThumb1OnlyFunction())
2175          RC = ARM::tGPRRegisterClass;
2176        else
2177          RC = ARM::GPRRegisterClass;
2178
2179        unsigned VReg = MF.addLiveIn(GPRArgRegs[NumGPRs], RC);
2180        SDValue Val = DAG.getCopyFromReg(Chain, dl, VReg, MVT::i32);
2181        SDValue Store =
2182          DAG.getStore(Val.getValue(1), dl, Val, FIN,
2183               PseudoSourceValue::getFixedStack(AFI->getVarArgsFrameIndex()),
2184               0, false, false, 0);
2185        MemOps.push_back(Store);
2186        FIN = DAG.getNode(ISD::ADD, dl, getPointerTy(), FIN,
2187                          DAG.getConstant(4, getPointerTy()));
2188      }
2189      if (!MemOps.empty())
2190        Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
2191                            &MemOps[0], MemOps.size());
2192    } else
2193      // This will point to the next argument passed via stack.
2194      AFI->setVarArgsFrameIndex(MFI->CreateFixedObject(4, ArgOffset, true));
2195  }
2196
2197  return Chain;
2198}
2199
2200/// isFloatingPointZero - Return true if this is +0.0.
2201static bool isFloatingPointZero(SDValue Op) {
2202  if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(Op))
2203    return CFP->getValueAPF().isPosZero();
2204  else if (ISD::isEXTLoad(Op.getNode()) || ISD::isNON_EXTLoad(Op.getNode())) {
2205    // Maybe this has already been legalized into the constant pool?
2206    if (Op.getOperand(1).getOpcode() == ARMISD::Wrapper) {
2207      SDValue WrapperOp = Op.getOperand(1).getOperand(0);
2208      if (ConstantPoolSDNode *CP = dyn_cast<ConstantPoolSDNode>(WrapperOp))
2209        if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CP->getConstVal()))
2210          return CFP->getValueAPF().isPosZero();
2211    }
2212  }
2213  return false;
2214}
2215
2216/// Returns appropriate ARM CMP (cmp) and corresponding condition code for
2217/// the given operands.
2218SDValue
2219ARMTargetLowering::getARMCmp(SDValue LHS, SDValue RHS, ISD::CondCode CC,
2220                             SDValue &ARMCC, SelectionDAG &DAG,
2221                             DebugLoc dl) const {
2222  if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(RHS.getNode())) {
2223    unsigned C = RHSC->getZExtValue();
2224    if (!isLegalICmpImmediate(C)) {
2225      // Constant does not fit, try adjusting it by one?
2226      switch (CC) {
2227      default: break;
2228      case ISD::SETLT:
2229      case ISD::SETGE:
2230        if (isLegalICmpImmediate(C-1)) {
2231          CC = (CC == ISD::SETLT) ? ISD::SETLE : ISD::SETGT;
2232          RHS = DAG.getConstant(C-1, MVT::i32);
2233        }
2234        break;
2235      case ISD::SETULT:
2236      case ISD::SETUGE:
2237        if (C > 0 && isLegalICmpImmediate(C-1)) {
2238          CC = (CC == ISD::SETULT) ? ISD::SETULE : ISD::SETUGT;
2239          RHS = DAG.getConstant(C-1, MVT::i32);
2240        }
2241        break;
2242      case ISD::SETLE:
2243      case ISD::SETGT:
2244        if (isLegalICmpImmediate(C+1)) {
2245          CC = (CC == ISD::SETLE) ? ISD::SETLT : ISD::SETGE;
2246          RHS = DAG.getConstant(C+1, MVT::i32);
2247        }
2248        break;
2249      case ISD::SETULE:
2250      case ISD::SETUGT:
2251        if (C < 0xffffffff && isLegalICmpImmediate(C+1)) {
2252          CC = (CC == ISD::SETULE) ? ISD::SETULT : ISD::SETUGE;
2253          RHS = DAG.getConstant(C+1, MVT::i32);
2254        }
2255        break;
2256      }
2257    }
2258  }
2259
2260  ARMCC::CondCodes CondCode = IntCCToARMCC(CC);
2261  ARMISD::NodeType CompareType;
2262  switch (CondCode) {
2263  default:
2264    CompareType = ARMISD::CMP;
2265    break;
2266  case ARMCC::EQ:
2267  case ARMCC::NE:
2268    // Uses only Z Flag
2269    CompareType = ARMISD::CMPZ;
2270    break;
2271  }
2272  ARMCC = DAG.getConstant(CondCode, MVT::i32);
2273  return DAG.getNode(CompareType, dl, MVT::Flag, LHS, RHS);
2274}
2275
2276static bool canBitcastToInt(SDNode *Op) {
2277  return Op->hasOneUse() &&
2278    ISD::isNormalLoad(Op) &&
2279    Op->getValueType(0) == MVT::f32;
2280}
2281
2282static SDValue bitcastToInt(SDValue Op, SelectionDAG &DAG) {
2283  if (LoadSDNode *Ld = dyn_cast<LoadSDNode>(Op))
2284    return DAG.getLoad(MVT::i32, Op.getDebugLoc(),
2285                       Ld->getChain(), Ld->getBasePtr(),
2286                       Ld->getSrcValue(), Ld->getSrcValueOffset(),
2287                       Ld->isVolatile(), Ld->isNonTemporal(),
2288                       Ld->getAlignment());
2289
2290  llvm_unreachable("Unknown VFP cmp argument!");
2291}
2292
2293/// Returns a appropriate VFP CMP (fcmp{s|d}+fmstat) for the given operands.
2294SDValue
2295ARMTargetLowering::getVFPCmp(SDValue &LHS, SDValue &RHS, ISD::CondCode CC,
2296                             SDValue &ARMCC, SelectionDAG &DAG,
2297                             DebugLoc dl) const {
2298  if ((CC == ISD::SETEQ || CC == ISD::SETOEQ ||
2299       CC == ISD::SETNE || CC == ISD::SETUNE) &&
2300      canBitcastToInt(LHS.getNode()) && canBitcastToInt(RHS.getNode())) {
2301    // If there are no othter uses of the CMP operands, and the condition
2302    // code is EQ oe NE, we can optimize it to an integer comparison.
2303    if (CC == ISD::SETOEQ)
2304      CC = ISD::SETEQ;
2305    else if (CC == ISD::SETUNE)
2306      CC = ISD::SETNE;
2307    LHS = bitcastToInt(LHS, DAG);
2308    RHS = bitcastToInt(RHS, DAG);
2309    return getARMCmp(LHS, RHS, CC, ARMCC, DAG, dl);
2310  }
2311
2312  SDValue Cmp;
2313  if (!isFloatingPointZero(RHS))
2314    Cmp = DAG.getNode(ARMISD::CMPFP, dl, MVT::Flag, LHS, RHS);
2315  else
2316    Cmp = DAG.getNode(ARMISD::CMPFPw0, dl, MVT::Flag, LHS);
2317  return DAG.getNode(ARMISD::FMSTAT, dl, MVT::Flag, Cmp);
2318}
2319
2320SDValue ARMTargetLowering::LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const {
2321  EVT VT = Op.getValueType();
2322  SDValue LHS = Op.getOperand(0);
2323  SDValue RHS = Op.getOperand(1);
2324  ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(4))->get();
2325  SDValue TrueVal = Op.getOperand(2);
2326  SDValue FalseVal = Op.getOperand(3);
2327  DebugLoc dl = Op.getDebugLoc();
2328
2329  if (LHS.getValueType() == MVT::i32) {
2330    SDValue ARMCC;
2331    SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
2332    SDValue Cmp = getARMCmp(LHS, RHS, CC, ARMCC, DAG, dl);
2333    return DAG.getNode(ARMISD::CMOV, dl, VT, FalseVal, TrueVal, ARMCC, CCR,Cmp);
2334  }
2335
2336  ARMCC::CondCodes CondCode, CondCode2;
2337  FPCCToARMCC(CC, CondCode, CondCode2);
2338
2339  SDValue ARMCC = DAG.getConstant(CondCode, MVT::i32);
2340  SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
2341  SDValue Cmp = getVFPCmp(LHS, RHS, CC, ARMCC, DAG, dl);
2342  SDValue Result = DAG.getNode(ARMISD::CMOV, dl, VT, FalseVal, TrueVal,
2343                               ARMCC, CCR, Cmp);
2344  if (CondCode2 != ARMCC::AL) {
2345    SDValue ARMCC2 = DAG.getConstant(CondCode2, MVT::i32);
2346    // FIXME: Needs another CMP because flag can have but one use.
2347    SDValue Cmp2 = getVFPCmp(LHS, RHS, CC, ARMCC2, DAG, dl);
2348    Result = DAG.getNode(ARMISD::CMOV, dl, VT,
2349                         Result, TrueVal, ARMCC2, CCR, Cmp2);
2350  }
2351  return Result;
2352}
2353
2354SDValue ARMTargetLowering::LowerBR_CC(SDValue Op, SelectionDAG &DAG) const {
2355  SDValue  Chain = Op.getOperand(0);
2356  ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(1))->get();
2357  SDValue    LHS = Op.getOperand(2);
2358  SDValue    RHS = Op.getOperand(3);
2359  SDValue   Dest = Op.getOperand(4);
2360  DebugLoc dl = Op.getDebugLoc();
2361
2362  if (LHS.getValueType() == MVT::i32) {
2363    SDValue ARMCC;
2364    SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
2365    SDValue Cmp = getARMCmp(LHS, RHS, CC, ARMCC, DAG, dl);
2366    return DAG.getNode(ARMISD::BRCOND, dl, MVT::Other,
2367                       Chain, Dest, ARMCC, CCR,Cmp);
2368  }
2369
2370  assert(LHS.getValueType() == MVT::f32 || LHS.getValueType() == MVT::f64);
2371  ARMCC::CondCodes CondCode, CondCode2;
2372  FPCCToARMCC(CC, CondCode, CondCode2);
2373
2374  SDValue ARMCC = DAG.getConstant(CondCode, MVT::i32);
2375  SDValue Cmp = getVFPCmp(LHS, RHS, CC, ARMCC, DAG, dl);
2376  SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
2377  SDVTList VTList = DAG.getVTList(MVT::Other, MVT::Flag);
2378  SDValue Ops[] = { Chain, Dest, ARMCC, CCR, Cmp };
2379  SDValue Res = DAG.getNode(ARMISD::BRCOND, dl, VTList, Ops, 5);
2380  if (CondCode2 != ARMCC::AL) {
2381    ARMCC = DAG.getConstant(CondCode2, MVT::i32);
2382    SDValue Ops[] = { Res, Dest, ARMCC, CCR, Res.getValue(1) };
2383    Res = DAG.getNode(ARMISD::BRCOND, dl, VTList, Ops, 5);
2384  }
2385  return Res;
2386}
2387
2388SDValue ARMTargetLowering::LowerBR_JT(SDValue Op, SelectionDAG &DAG) const {
2389  SDValue Chain = Op.getOperand(0);
2390  SDValue Table = Op.getOperand(1);
2391  SDValue Index = Op.getOperand(2);
2392  DebugLoc dl = Op.getDebugLoc();
2393
2394  EVT PTy = getPointerTy();
2395  JumpTableSDNode *JT = cast<JumpTableSDNode>(Table);
2396  ARMFunctionInfo *AFI = DAG.getMachineFunction().getInfo<ARMFunctionInfo>();
2397  SDValue UId = DAG.getConstant(AFI->createJumpTableUId(), PTy);
2398  SDValue JTI = DAG.getTargetJumpTable(JT->getIndex(), PTy);
2399  Table = DAG.getNode(ARMISD::WrapperJT, dl, MVT::i32, JTI, UId);
2400  Index = DAG.getNode(ISD::MUL, dl, PTy, Index, DAG.getConstant(4, PTy));
2401  SDValue Addr = DAG.getNode(ISD::ADD, dl, PTy, Index, Table);
2402  if (Subtarget->isThumb2()) {
2403    // Thumb2 uses a two-level jump. That is, it jumps into the jump table
2404    // which does another jump to the destination. This also makes it easier
2405    // to translate it to TBB / TBH later.
2406    // FIXME: This might not work if the function is extremely large.
2407    return DAG.getNode(ARMISD::BR2_JT, dl, MVT::Other, Chain,
2408                       Addr, Op.getOperand(2), JTI, UId);
2409  }
2410  if (getTargetMachine().getRelocationModel() == Reloc::PIC_) {
2411    Addr = DAG.getLoad((EVT)MVT::i32, dl, Chain, Addr,
2412                       PseudoSourceValue::getJumpTable(), 0,
2413                       false, false, 0);
2414    Chain = Addr.getValue(1);
2415    Addr = DAG.getNode(ISD::ADD, dl, PTy, Addr, Table);
2416    return DAG.getNode(ARMISD::BR_JT, dl, MVT::Other, Chain, Addr, JTI, UId);
2417  } else {
2418    Addr = DAG.getLoad(PTy, dl, Chain, Addr,
2419                       PseudoSourceValue::getJumpTable(), 0, false, false, 0);
2420    Chain = Addr.getValue(1);
2421    return DAG.getNode(ARMISD::BR_JT, dl, MVT::Other, Chain, Addr, JTI, UId);
2422  }
2423}
2424
2425static SDValue LowerFP_TO_INT(SDValue Op, SelectionDAG &DAG) {
2426  DebugLoc dl = Op.getDebugLoc();
2427  unsigned Opc;
2428
2429  switch (Op.getOpcode()) {
2430  default:
2431    assert(0 && "Invalid opcode!");
2432  case ISD::FP_TO_SINT:
2433    Opc = ARMISD::FTOSI;
2434    break;
2435  case ISD::FP_TO_UINT:
2436    Opc = ARMISD::FTOUI;
2437    break;
2438  }
2439  Op = DAG.getNode(Opc, dl, MVT::f32, Op.getOperand(0));
2440  return DAG.getNode(ISD::BIT_CONVERT, dl, MVT::i32, Op);
2441}
2442
2443static SDValue LowerINT_TO_FP(SDValue Op, SelectionDAG &DAG) {
2444  EVT VT = Op.getValueType();
2445  DebugLoc dl = Op.getDebugLoc();
2446  unsigned Opc;
2447
2448  switch (Op.getOpcode()) {
2449  default:
2450    assert(0 && "Invalid opcode!");
2451  case ISD::SINT_TO_FP:
2452    Opc = ARMISD::SITOF;
2453    break;
2454  case ISD::UINT_TO_FP:
2455    Opc = ARMISD::UITOF;
2456    break;
2457  }
2458
2459  Op = DAG.getNode(ISD::BIT_CONVERT, dl, MVT::f32, Op.getOperand(0));
2460  return DAG.getNode(Opc, dl, VT, Op);
2461}
2462
2463SDValue ARMTargetLowering::LowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) const {
2464  // Implement fcopysign with a fabs and a conditional fneg.
2465  SDValue Tmp0 = Op.getOperand(0);
2466  SDValue Tmp1 = Op.getOperand(1);
2467  DebugLoc dl = Op.getDebugLoc();
2468  EVT VT = Op.getValueType();
2469  EVT SrcVT = Tmp1.getValueType();
2470  SDValue AbsVal = DAG.getNode(ISD::FABS, dl, VT, Tmp0);
2471  SDValue ARMCC = DAG.getConstant(ARMCC::LT, MVT::i32);
2472  SDValue FP0 = DAG.getConstantFP(0.0, SrcVT);
2473  SDValue Cmp = getVFPCmp(Tmp1, FP0,
2474                          ISD::SETLT, ARMCC, DAG, dl);
2475  SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
2476  return DAG.getNode(ARMISD::CNEG, dl, VT, AbsVal, AbsVal, ARMCC, CCR, Cmp);
2477}
2478
2479SDValue ARMTargetLowering::LowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const{
2480  MachineFunction &MF = DAG.getMachineFunction();
2481  MachineFrameInfo *MFI = MF.getFrameInfo();
2482  MFI->setReturnAddressIsTaken(true);
2483
2484  EVT VT = Op.getValueType();
2485  DebugLoc dl = Op.getDebugLoc();
2486  unsigned Depth = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
2487  if (Depth) {
2488    SDValue FrameAddr = LowerFRAMEADDR(Op, DAG);
2489    SDValue Offset = DAG.getConstant(4, MVT::i32);
2490    return DAG.getLoad(VT, dl, DAG.getEntryNode(),
2491                       DAG.getNode(ISD::ADD, dl, VT, FrameAddr, Offset),
2492                       NULL, 0, false, false, 0);
2493  }
2494
2495  // Return LR, which contains the return address. Mark it an implicit live-in.
2496  unsigned Reg = MF.addLiveIn(ARM::LR, ARM::GPRRegisterClass);
2497  return DAG.getCopyFromReg(DAG.getEntryNode(), dl, Reg, VT);
2498}
2499
2500SDValue ARMTargetLowering::LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const {
2501  MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
2502  MFI->setFrameAddressIsTaken(true);
2503
2504  EVT VT = Op.getValueType();
2505  DebugLoc dl = Op.getDebugLoc();  // FIXME probably not meaningful
2506  unsigned Depth = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
2507  unsigned FrameReg = (Subtarget->isThumb() || Subtarget->isTargetDarwin())
2508    ? ARM::R7 : ARM::R11;
2509  SDValue FrameAddr = DAG.getCopyFromReg(DAG.getEntryNode(), dl, FrameReg, VT);
2510  while (Depth--)
2511    FrameAddr = DAG.getLoad(VT, dl, DAG.getEntryNode(), FrameAddr, NULL, 0,
2512                            false, false, 0);
2513  return FrameAddr;
2514}
2515
2516/// ExpandBIT_CONVERT - If the target supports VFP, this function is called to
2517/// expand a bit convert where either the source or destination type is i64 to
2518/// use a VMOVDRR or VMOVRRD node.  This should not be done when the non-i64
2519/// operand type is illegal (e.g., v2f32 for a target that doesn't support
2520/// vectors), since the legalizer won't know what to do with that.
2521static SDValue ExpandBIT_CONVERT(SDNode *N, SelectionDAG &DAG) {
2522  const TargetLowering &TLI = DAG.getTargetLoweringInfo();
2523  DebugLoc dl = N->getDebugLoc();
2524  SDValue Op = N->getOperand(0);
2525
2526  // This function is only supposed to be called for i64 types, either as the
2527  // source or destination of the bit convert.
2528  EVT SrcVT = Op.getValueType();
2529  EVT DstVT = N->getValueType(0);
2530  assert((SrcVT == MVT::i64 || DstVT == MVT::i64) &&
2531         "ExpandBIT_CONVERT called for non-i64 type");
2532
2533  // Turn i64->f64 into VMOVDRR.
2534  if (SrcVT == MVT::i64 && TLI.isTypeLegal(DstVT)) {
2535    SDValue Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32, Op,
2536                             DAG.getConstant(0, MVT::i32));
2537    SDValue Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32, Op,
2538                             DAG.getConstant(1, MVT::i32));
2539    return DAG.getNode(ISD::BIT_CONVERT, dl, DstVT,
2540                       DAG.getNode(ARMISD::VMOVDRR, dl, MVT::f64, Lo, Hi));
2541  }
2542
2543  // Turn f64->i64 into VMOVRRD.
2544  if (DstVT == MVT::i64 && TLI.isTypeLegal(SrcVT)) {
2545    SDValue Cvt = DAG.getNode(ARMISD::VMOVRRD, dl,
2546                              DAG.getVTList(MVT::i32, MVT::i32), &Op, 1);
2547    // Merge the pieces into a single i64 value.
2548    return DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, Cvt, Cvt.getValue(1));
2549  }
2550
2551  return SDValue();
2552}
2553
2554/// getZeroVector - Returns a vector of specified type with all zero elements.
2555///
2556static SDValue getZeroVector(EVT VT, SelectionDAG &DAG, DebugLoc dl) {
2557  assert(VT.isVector() && "Expected a vector type");
2558
2559  // Zero vectors are used to represent vector negation and in those cases
2560  // will be implemented with the NEON VNEG instruction.  However, VNEG does
2561  // not support i64 elements, so sometimes the zero vectors will need to be
2562  // explicitly constructed.  For those cases, and potentially other uses in
2563  // the future, always build zero vectors as <16 x i8> or <8 x i8> bitcasted
2564  // to their dest type.  This ensures they get CSE'd.
2565  SDValue Vec;
2566  SDValue Cst = DAG.getTargetConstant(0, MVT::i8);
2567  SmallVector<SDValue, 8> Ops;
2568  MVT TVT;
2569
2570  if (VT.getSizeInBits() == 64) {
2571    Ops.assign(8, Cst); TVT = MVT::v8i8;
2572  } else {
2573    Ops.assign(16, Cst); TVT = MVT::v16i8;
2574  }
2575  Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, TVT, &Ops[0], Ops.size());
2576
2577  return DAG.getNode(ISD::BIT_CONVERT, dl, VT, Vec);
2578}
2579
2580/// getOnesVector - Returns a vector of specified type with all bits set.
2581///
2582static SDValue getOnesVector(EVT VT, SelectionDAG &DAG, DebugLoc dl) {
2583  assert(VT.isVector() && "Expected a vector type");
2584
2585  // Always build ones vectors as <16 x i8> or <8 x i8> bitcasted to their
2586  // dest type. This ensures they get CSE'd.
2587  SDValue Vec;
2588  SDValue Cst = DAG.getTargetConstant(0xFF, MVT::i8);
2589  SmallVector<SDValue, 8> Ops;
2590  MVT TVT;
2591
2592  if (VT.getSizeInBits() == 64) {
2593    Ops.assign(8, Cst); TVT = MVT::v8i8;
2594  } else {
2595    Ops.assign(16, Cst); TVT = MVT::v16i8;
2596  }
2597  Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, TVT, &Ops[0], Ops.size());
2598
2599  return DAG.getNode(ISD::BIT_CONVERT, dl, VT, Vec);
2600}
2601
2602/// LowerShiftRightParts - Lower SRA_PARTS, which returns two
2603/// i32 values and take a 2 x i32 value to shift plus a shift amount.
2604SDValue ARMTargetLowering::LowerShiftRightParts(SDValue Op,
2605                                                SelectionDAG &DAG) const {
2606  assert(Op.getNumOperands() == 3 && "Not a double-shift!");
2607  EVT VT = Op.getValueType();
2608  unsigned VTBits = VT.getSizeInBits();
2609  DebugLoc dl = Op.getDebugLoc();
2610  SDValue ShOpLo = Op.getOperand(0);
2611  SDValue ShOpHi = Op.getOperand(1);
2612  SDValue ShAmt  = Op.getOperand(2);
2613  SDValue ARMCC;
2614  unsigned Opc = (Op.getOpcode() == ISD::SRA_PARTS) ? ISD::SRA : ISD::SRL;
2615
2616  assert(Op.getOpcode() == ISD::SRA_PARTS || Op.getOpcode() == ISD::SRL_PARTS);
2617
2618  SDValue RevShAmt = DAG.getNode(ISD::SUB, dl, MVT::i32,
2619                                 DAG.getConstant(VTBits, MVT::i32), ShAmt);
2620  SDValue Tmp1 = DAG.getNode(ISD::SRL, dl, VT, ShOpLo, ShAmt);
2621  SDValue ExtraShAmt = DAG.getNode(ISD::SUB, dl, MVT::i32, ShAmt,
2622                                   DAG.getConstant(VTBits, MVT::i32));
2623  SDValue Tmp2 = DAG.getNode(ISD::SHL, dl, VT, ShOpHi, RevShAmt);
2624  SDValue FalseVal = DAG.getNode(ISD::OR, dl, VT, Tmp1, Tmp2);
2625  SDValue TrueVal = DAG.getNode(Opc, dl, VT, ShOpHi, ExtraShAmt);
2626
2627  SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
2628  SDValue Cmp = getARMCmp(ExtraShAmt, DAG.getConstant(0, MVT::i32), ISD::SETGE,
2629                          ARMCC, DAG, dl);
2630  SDValue Hi = DAG.getNode(Opc, dl, VT, ShOpHi, ShAmt);
2631  SDValue Lo = DAG.getNode(ARMISD::CMOV, dl, VT, FalseVal, TrueVal, ARMCC,
2632                           CCR, Cmp);
2633
2634  SDValue Ops[2] = { Lo, Hi };
2635  return DAG.getMergeValues(Ops, 2, dl);
2636}
2637
2638/// LowerShiftLeftParts - Lower SHL_PARTS, which returns two
2639/// i32 values and take a 2 x i32 value to shift plus a shift amount.
2640SDValue ARMTargetLowering::LowerShiftLeftParts(SDValue Op,
2641                                               SelectionDAG &DAG) const {
2642  assert(Op.getNumOperands() == 3 && "Not a double-shift!");
2643  EVT VT = Op.getValueType();
2644  unsigned VTBits = VT.getSizeInBits();
2645  DebugLoc dl = Op.getDebugLoc();
2646  SDValue ShOpLo = Op.getOperand(0);
2647  SDValue ShOpHi = Op.getOperand(1);
2648  SDValue ShAmt  = Op.getOperand(2);
2649  SDValue ARMCC;
2650
2651  assert(Op.getOpcode() == ISD::SHL_PARTS);
2652  SDValue RevShAmt = DAG.getNode(ISD::SUB, dl, MVT::i32,
2653                                 DAG.getConstant(VTBits, MVT::i32), ShAmt);
2654  SDValue Tmp1 = DAG.getNode(ISD::SRL, dl, VT, ShOpLo, RevShAmt);
2655  SDValue ExtraShAmt = DAG.getNode(ISD::SUB, dl, MVT::i32, ShAmt,
2656                                   DAG.getConstant(VTBits, MVT::i32));
2657  SDValue Tmp2 = DAG.getNode(ISD::SHL, dl, VT, ShOpHi, ShAmt);
2658  SDValue Tmp3 = DAG.getNode(ISD::SHL, dl, VT, ShOpLo, ExtraShAmt);
2659
2660  SDValue FalseVal = DAG.getNode(ISD::OR, dl, VT, Tmp1, Tmp2);
2661  SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
2662  SDValue Cmp = getARMCmp(ExtraShAmt, DAG.getConstant(0, MVT::i32), ISD::SETGE,
2663                          ARMCC, DAG, dl);
2664  SDValue Lo = DAG.getNode(ISD::SHL, dl, VT, ShOpLo, ShAmt);
2665  SDValue Hi = DAG.getNode(ARMISD::CMOV, dl, VT, FalseVal, Tmp3, ARMCC,
2666                           CCR, Cmp);
2667
2668  SDValue Ops[2] = { Lo, Hi };
2669  return DAG.getMergeValues(Ops, 2, dl);
2670}
2671
2672static SDValue LowerCTTZ(SDNode *N, SelectionDAG &DAG,
2673                         const ARMSubtarget *ST) {
2674  EVT VT = N->getValueType(0);
2675  DebugLoc dl = N->getDebugLoc();
2676
2677  if (!ST->hasV6T2Ops())
2678    return SDValue();
2679
2680  SDValue rbit = DAG.getNode(ARMISD::RBIT, dl, VT, N->getOperand(0));
2681  return DAG.getNode(ISD::CTLZ, dl, VT, rbit);
2682}
2683
2684static SDValue LowerShift(SDNode *N, SelectionDAG &DAG,
2685                          const ARMSubtarget *ST) {
2686  EVT VT = N->getValueType(0);
2687  DebugLoc dl = N->getDebugLoc();
2688
2689  // Lower vector shifts on NEON to use VSHL.
2690  if (VT.isVector()) {
2691    assert(ST->hasNEON() && "unexpected vector shift");
2692
2693    // Left shifts translate directly to the vshiftu intrinsic.
2694    if (N->getOpcode() == ISD::SHL)
2695      return DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, VT,
2696                         DAG.getConstant(Intrinsic::arm_neon_vshiftu, MVT::i32),
2697                         N->getOperand(0), N->getOperand(1));
2698
2699    assert((N->getOpcode() == ISD::SRA ||
2700            N->getOpcode() == ISD::SRL) && "unexpected vector shift opcode");
2701
2702    // NEON uses the same intrinsics for both left and right shifts.  For
2703    // right shifts, the shift amounts are negative, so negate the vector of
2704    // shift amounts.
2705    EVT ShiftVT = N->getOperand(1).getValueType();
2706    SDValue NegatedCount = DAG.getNode(ISD::SUB, dl, ShiftVT,
2707                                       getZeroVector(ShiftVT, DAG, dl),
2708                                       N->getOperand(1));
2709    Intrinsic::ID vshiftInt = (N->getOpcode() == ISD::SRA ?
2710                               Intrinsic::arm_neon_vshifts :
2711                               Intrinsic::arm_neon_vshiftu);
2712    return DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, VT,
2713                       DAG.getConstant(vshiftInt, MVT::i32),
2714                       N->getOperand(0), NegatedCount);
2715  }
2716
2717  // We can get here for a node like i32 = ISD::SHL i32, i64
2718  if (VT != MVT::i64)
2719    return SDValue();
2720
2721  assert((N->getOpcode() == ISD::SRL || N->getOpcode() == ISD::SRA) &&
2722         "Unknown shift to lower!");
2723
2724  // We only lower SRA, SRL of 1 here, all others use generic lowering.
2725  if (!isa<ConstantSDNode>(N->getOperand(1)) ||
2726      cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() != 1)
2727    return SDValue();
2728
2729  // If we are in thumb mode, we don't have RRX.
2730  if (ST->isThumb1Only()) return SDValue();
2731
2732  // Okay, we have a 64-bit SRA or SRL of 1.  Lower this to an RRX expr.
2733  SDValue Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32, N->getOperand(0),
2734                           DAG.getConstant(0, MVT::i32));
2735  SDValue Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32, N->getOperand(0),
2736                           DAG.getConstant(1, MVT::i32));
2737
2738  // First, build a SRA_FLAG/SRL_FLAG op, which shifts the top part by one and
2739  // captures the result into a carry flag.
2740  unsigned Opc = N->getOpcode() == ISD::SRL ? ARMISD::SRL_FLAG:ARMISD::SRA_FLAG;
2741  Hi = DAG.getNode(Opc, dl, DAG.getVTList(MVT::i32, MVT::Flag), &Hi, 1);
2742
2743  // The low part is an ARMISD::RRX operand, which shifts the carry in.
2744  Lo = DAG.getNode(ARMISD::RRX, dl, MVT::i32, Lo, Hi.getValue(1));
2745
2746  // Merge the pieces into a single i64 value.
2747 return DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, Lo, Hi);
2748}
2749
2750static SDValue LowerVSETCC(SDValue Op, SelectionDAG &DAG) {
2751  SDValue TmpOp0, TmpOp1;
2752  bool Invert = false;
2753  bool Swap = false;
2754  unsigned Opc = 0;
2755
2756  SDValue Op0 = Op.getOperand(0);
2757  SDValue Op1 = Op.getOperand(1);
2758  SDValue CC = Op.getOperand(2);
2759  EVT VT = Op.getValueType();
2760  ISD::CondCode SetCCOpcode = cast<CondCodeSDNode>(CC)->get();
2761  DebugLoc dl = Op.getDebugLoc();
2762
2763  if (Op.getOperand(1).getValueType().isFloatingPoint()) {
2764    switch (SetCCOpcode) {
2765    default: llvm_unreachable("Illegal FP comparison"); break;
2766    case ISD::SETUNE:
2767    case ISD::SETNE:  Invert = true; // Fallthrough
2768    case ISD::SETOEQ:
2769    case ISD::SETEQ:  Opc = ARMISD::VCEQ; break;
2770    case ISD::SETOLT:
2771    case ISD::SETLT: Swap = true; // Fallthrough
2772    case ISD::SETOGT:
2773    case ISD::SETGT:  Opc = ARMISD::VCGT; break;
2774    case ISD::SETOLE:
2775    case ISD::SETLE:  Swap = true; // Fallthrough
2776    case ISD::SETOGE:
2777    case ISD::SETGE: Opc = ARMISD::VCGE; break;
2778    case ISD::SETUGE: Swap = true; // Fallthrough
2779    case ISD::SETULE: Invert = true; Opc = ARMISD::VCGT; break;
2780    case ISD::SETUGT: Swap = true; // Fallthrough
2781    case ISD::SETULT: Invert = true; Opc = ARMISD::VCGE; break;
2782    case ISD::SETUEQ: Invert = true; // Fallthrough
2783    case ISD::SETONE:
2784      // Expand this to (OLT | OGT).
2785      TmpOp0 = Op0;
2786      TmpOp1 = Op1;
2787      Opc = ISD::OR;
2788      Op0 = DAG.getNode(ARMISD::VCGT, dl, VT, TmpOp1, TmpOp0);
2789      Op1 = DAG.getNode(ARMISD::VCGT, dl, VT, TmpOp0, TmpOp1);
2790      break;
2791    case ISD::SETUO: Invert = true; // Fallthrough
2792    case ISD::SETO:
2793      // Expand this to (OLT | OGE).
2794      TmpOp0 = Op0;
2795      TmpOp1 = Op1;
2796      Opc = ISD::OR;
2797      Op0 = DAG.getNode(ARMISD::VCGT, dl, VT, TmpOp1, TmpOp0);
2798      Op1 = DAG.getNode(ARMISD::VCGE, dl, VT, TmpOp0, TmpOp1);
2799      break;
2800    }
2801  } else {
2802    // Integer comparisons.
2803    switch (SetCCOpcode) {
2804    default: llvm_unreachable("Illegal integer comparison"); break;
2805    case ISD::SETNE:  Invert = true;
2806    case ISD::SETEQ:  Opc = ARMISD::VCEQ; break;
2807    case ISD::SETLT:  Swap = true;
2808    case ISD::SETGT:  Opc = ARMISD::VCGT; break;
2809    case ISD::SETLE:  Swap = true;
2810    case ISD::SETGE:  Opc = ARMISD::VCGE; break;
2811    case ISD::SETULT: Swap = true;
2812    case ISD::SETUGT: Opc = ARMISD::VCGTU; break;
2813    case ISD::SETULE: Swap = true;
2814    case ISD::SETUGE: Opc = ARMISD::VCGEU; break;
2815    }
2816
2817    // Detect VTST (Vector Test Bits) = icmp ne (and (op0, op1), zero).
2818    if (Opc == ARMISD::VCEQ) {
2819
2820      SDValue AndOp;
2821      if (ISD::isBuildVectorAllZeros(Op1.getNode()))
2822        AndOp = Op0;
2823      else if (ISD::isBuildVectorAllZeros(Op0.getNode()))
2824        AndOp = Op1;
2825
2826      // Ignore bitconvert.
2827      if (AndOp.getNode() && AndOp.getOpcode() == ISD::BIT_CONVERT)
2828        AndOp = AndOp.getOperand(0);
2829
2830      if (AndOp.getNode() && AndOp.getOpcode() == ISD::AND) {
2831        Opc = ARMISD::VTST;
2832        Op0 = DAG.getNode(ISD::BIT_CONVERT, dl, VT, AndOp.getOperand(0));
2833        Op1 = DAG.getNode(ISD::BIT_CONVERT, dl, VT, AndOp.getOperand(1));
2834        Invert = !Invert;
2835      }
2836    }
2837  }
2838
2839  if (Swap)
2840    std::swap(Op0, Op1);
2841
2842  SDValue Result = DAG.getNode(Opc, dl, VT, Op0, Op1);
2843
2844  if (Invert)
2845    Result = DAG.getNOT(dl, Result, VT);
2846
2847  return Result;
2848}
2849
2850/// isNEONModifiedImm - Check if the specified splat value corresponds to a
2851/// valid vector constant for a NEON instruction with a "modified immediate"
2852/// operand (e.g., VMOV).  If so, return either the constant being
2853/// splatted or the encoded value, depending on the DoEncode parameter.  The
2854/// format of the encoded value is: bit12=Op, bits11-8=Cmode,
2855/// bits7-0=Immediate.
2856static SDValue isNEONModifiedImm(uint64_t SplatBits, uint64_t SplatUndef,
2857                                 unsigned SplatBitSize, SelectionDAG &DAG,
2858                                 bool isVMOV, bool DoEncode) {
2859  unsigned Op, Cmode, Imm;
2860  EVT VT;
2861
2862  // SplatBitSize is set to the smallest size that splats the vector, so a
2863  // zero vector will always have SplatBitSize == 8.  However, NEON modified
2864  // immediate instructions others than VMOV do not support the 8-bit encoding
2865  // of a zero vector, and the default encoding of zero is supposed to be the
2866  // 32-bit version.
2867  if (SplatBits == 0)
2868    SplatBitSize = 32;
2869
2870  Op = 0;
2871  switch (SplatBitSize) {
2872  case 8:
2873    // Any 1-byte value is OK.  Op=0, Cmode=1110.
2874    assert((SplatBits & ~0xff) == 0 && "one byte splat value is too big");
2875    Cmode = 0xe;
2876    Imm = SplatBits;
2877    VT = MVT::i8;
2878    break;
2879
2880  case 16:
2881    // NEON's 16-bit VMOV supports splat values where only one byte is nonzero.
2882    VT = MVT::i16;
2883    if ((SplatBits & ~0xff) == 0) {
2884      // Value = 0x00nn: Op=x, Cmode=100x.
2885      Cmode = 0x8;
2886      Imm = SplatBits;
2887      break;
2888    }
2889    if ((SplatBits & ~0xff00) == 0) {
2890      // Value = 0xnn00: Op=x, Cmode=101x.
2891      Cmode = 0xa;
2892      Imm = SplatBits >> 8;
2893      break;
2894    }
2895    return SDValue();
2896
2897  case 32:
2898    // NEON's 32-bit VMOV supports splat values where:
2899    // * only one byte is nonzero, or
2900    // * the least significant byte is 0xff and the second byte is nonzero, or
2901    // * the least significant 2 bytes are 0xff and the third is nonzero.
2902    VT = MVT::i32;
2903    if ((SplatBits & ~0xff) == 0) {
2904      // Value = 0x000000nn: Op=x, Cmode=000x.
2905      Cmode = 0;
2906      Imm = SplatBits;
2907      break;
2908    }
2909    if ((SplatBits & ~0xff00) == 0) {
2910      // Value = 0x0000nn00: Op=x, Cmode=001x.
2911      Cmode = 0x2;
2912      Imm = SplatBits >> 8;
2913      break;
2914    }
2915    if ((SplatBits & ~0xff0000) == 0) {
2916      // Value = 0x00nn0000: Op=x, Cmode=010x.
2917      Cmode = 0x4;
2918      Imm = SplatBits >> 16;
2919      break;
2920    }
2921    if ((SplatBits & ~0xff000000) == 0) {
2922      // Value = 0xnn000000: Op=x, Cmode=011x.
2923      Cmode = 0x6;
2924      Imm = SplatBits >> 24;
2925      break;
2926    }
2927
2928    if ((SplatBits & ~0xffff) == 0 &&
2929        ((SplatBits | SplatUndef) & 0xff) == 0xff) {
2930      // Value = 0x0000nnff: Op=x, Cmode=1100.
2931      Cmode = 0xc;
2932      Imm = SplatBits >> 8;
2933      SplatBits |= 0xff;
2934      break;
2935    }
2936
2937    if ((SplatBits & ~0xffffff) == 0 &&
2938        ((SplatBits | SplatUndef) & 0xffff) == 0xffff) {
2939      // Value = 0x00nnffff: Op=x, Cmode=1101.
2940      Cmode = 0xd;
2941      Imm = SplatBits >> 16;
2942      SplatBits |= 0xffff;
2943      break;
2944    }
2945
2946    // Note: there are a few 32-bit splat values (specifically: 00ffff00,
2947    // ff000000, ff0000ff, and ffff00ff) that are valid for VMOV.I64 but not
2948    // VMOV.I32.  A (very) minor optimization would be to replicate the value
2949    // and fall through here to test for a valid 64-bit splat.  But, then the
2950    // caller would also need to check and handle the change in size.
2951    return SDValue();
2952
2953  case 64: {
2954    // NEON has a 64-bit VMOV splat where each byte is either 0 or 0xff.
2955    if (!isVMOV)
2956      return SDValue();
2957    uint64_t BitMask = 0xff;
2958    uint64_t Val = 0;
2959    unsigned ImmMask = 1;
2960    Imm = 0;
2961    for (int ByteNum = 0; ByteNum < 8; ++ByteNum) {
2962      if (((SplatBits | SplatUndef) & BitMask) == BitMask) {
2963        Val |= BitMask;
2964        Imm |= ImmMask;
2965      } else if ((SplatBits & BitMask) != 0) {
2966        return SDValue();
2967      }
2968      BitMask <<= 8;
2969      ImmMask <<= 1;
2970    }
2971    // Op=1, Cmode=1110.
2972    Op = 1;
2973    Cmode = 0xe;
2974    SplatBits = Val;
2975    VT = MVT::i64;
2976    break;
2977  }
2978
2979  default:
2980    llvm_unreachable("unexpected size for isNEONModifiedImm");
2981    return SDValue();
2982  }
2983
2984  if (DoEncode)
2985    return DAG.getTargetConstant((Op << 12) | (Cmode << 8) | Imm, MVT::i32);
2986  return DAG.getTargetConstant(SplatBits, VT);
2987}
2988
2989
2990/// getNEONModImm - If this is a valid vector constant for a NEON instruction
2991/// with a "modified immediate" operand (e.g., VMOV) of the specified element
2992/// size, return the encoded value for that immediate.  The ByteSize field
2993/// indicates the number of bytes of each element [1248].
2994SDValue ARM::getNEONModImm(SDNode *N, unsigned ByteSize, bool isVMOV,
2995                           SelectionDAG &DAG) {
2996  BuildVectorSDNode *BVN = dyn_cast<BuildVectorSDNode>(N);
2997  APInt SplatBits, SplatUndef;
2998  unsigned SplatBitSize;
2999  bool HasAnyUndefs;
3000  if (! BVN || ! BVN->isConstantSplat(SplatBits, SplatUndef, SplatBitSize,
3001                                      HasAnyUndefs, ByteSize * 8))
3002    return SDValue();
3003
3004  if (SplatBitSize > ByteSize * 8)
3005    return SDValue();
3006
3007  return isNEONModifiedImm(SplatBits.getZExtValue(), SplatUndef.getZExtValue(),
3008                           SplatBitSize, DAG, isVMOV, true);
3009}
3010
3011static bool isVEXTMask(const SmallVectorImpl<int> &M, EVT VT,
3012                       bool &ReverseVEXT, unsigned &Imm) {
3013  unsigned NumElts = VT.getVectorNumElements();
3014  ReverseVEXT = false;
3015  Imm = M[0];
3016
3017  // If this is a VEXT shuffle, the immediate value is the index of the first
3018  // element.  The other shuffle indices must be the successive elements after
3019  // the first one.
3020  unsigned ExpectedElt = Imm;
3021  for (unsigned i = 1; i < NumElts; ++i) {
3022    // Increment the expected index.  If it wraps around, it may still be
3023    // a VEXT but the source vectors must be swapped.
3024    ExpectedElt += 1;
3025    if (ExpectedElt == NumElts * 2) {
3026      ExpectedElt = 0;
3027      ReverseVEXT = true;
3028    }
3029
3030    if (ExpectedElt != static_cast<unsigned>(M[i]))
3031      return false;
3032  }
3033
3034  // Adjust the index value if the source operands will be swapped.
3035  if (ReverseVEXT)
3036    Imm -= NumElts;
3037
3038  return true;
3039}
3040
3041/// isVREVMask - Check if a vector shuffle corresponds to a VREV
3042/// instruction with the specified blocksize.  (The order of the elements
3043/// within each block of the vector is reversed.)
3044static bool isVREVMask(const SmallVectorImpl<int> &M, EVT VT,
3045                       unsigned BlockSize) {
3046  assert((BlockSize==16 || BlockSize==32 || BlockSize==64) &&
3047         "Only possible block sizes for VREV are: 16, 32, 64");
3048
3049  unsigned EltSz = VT.getVectorElementType().getSizeInBits();
3050  if (EltSz == 64)
3051    return false;
3052
3053  unsigned NumElts = VT.getVectorNumElements();
3054  unsigned BlockElts = M[0] + 1;
3055
3056  if (BlockSize <= EltSz || BlockSize != BlockElts * EltSz)
3057    return false;
3058
3059  for (unsigned i = 0; i < NumElts; ++i) {
3060    if ((unsigned) M[i] !=
3061        (i - i%BlockElts) + (BlockElts - 1 - i%BlockElts))
3062      return false;
3063  }
3064
3065  return true;
3066}
3067
3068static bool isVTRNMask(const SmallVectorImpl<int> &M, EVT VT,
3069                       unsigned &WhichResult) {
3070  unsigned EltSz = VT.getVectorElementType().getSizeInBits();
3071  if (EltSz == 64)
3072    return false;
3073
3074  unsigned NumElts = VT.getVectorNumElements();
3075  WhichResult = (M[0] == 0 ? 0 : 1);
3076  for (unsigned i = 0; i < NumElts; i += 2) {
3077    if ((unsigned) M[i] != i + WhichResult ||
3078        (unsigned) M[i+1] != i + NumElts + WhichResult)
3079      return false;
3080  }
3081  return true;
3082}
3083
3084/// isVTRN_v_undef_Mask - Special case of isVTRNMask for canonical form of
3085/// "vector_shuffle v, v", i.e., "vector_shuffle v, undef".
3086/// Mask is e.g., <0, 0, 2, 2> instead of <0, 4, 2, 6>.
3087static bool isVTRN_v_undef_Mask(const SmallVectorImpl<int> &M, EVT VT,
3088                                unsigned &WhichResult) {
3089  unsigned EltSz = VT.getVectorElementType().getSizeInBits();
3090  if (EltSz == 64)
3091    return false;
3092
3093  unsigned NumElts = VT.getVectorNumElements();
3094  WhichResult = (M[0] == 0 ? 0 : 1);
3095  for (unsigned i = 0; i < NumElts; i += 2) {
3096    if ((unsigned) M[i] != i + WhichResult ||
3097        (unsigned) M[i+1] != i + WhichResult)
3098      return false;
3099  }
3100  return true;
3101}
3102
3103static bool isVUZPMask(const SmallVectorImpl<int> &M, EVT VT,
3104                       unsigned &WhichResult) {
3105  unsigned EltSz = VT.getVectorElementType().getSizeInBits();
3106  if (EltSz == 64)
3107    return false;
3108
3109  unsigned NumElts = VT.getVectorNumElements();
3110  WhichResult = (M[0] == 0 ? 0 : 1);
3111  for (unsigned i = 0; i != NumElts; ++i) {
3112    if ((unsigned) M[i] != 2 * i + WhichResult)
3113      return false;
3114  }
3115
3116  // VUZP.32 for 64-bit vectors is a pseudo-instruction alias for VTRN.32.
3117  if (VT.is64BitVector() && EltSz == 32)
3118    return false;
3119
3120  return true;
3121}
3122
3123/// isVUZP_v_undef_Mask - Special case of isVUZPMask for canonical form of
3124/// "vector_shuffle v, v", i.e., "vector_shuffle v, undef".
3125/// Mask is e.g., <0, 2, 0, 2> instead of <0, 2, 4, 6>,
3126static bool isVUZP_v_undef_Mask(const SmallVectorImpl<int> &M, EVT VT,
3127                                unsigned &WhichResult) {
3128  unsigned EltSz = VT.getVectorElementType().getSizeInBits();
3129  if (EltSz == 64)
3130    return false;
3131
3132  unsigned Half = VT.getVectorNumElements() / 2;
3133  WhichResult = (M[0] == 0 ? 0 : 1);
3134  for (unsigned j = 0; j != 2; ++j) {
3135    unsigned Idx = WhichResult;
3136    for (unsigned i = 0; i != Half; ++i) {
3137      if ((unsigned) M[i + j * Half] != Idx)
3138        return false;
3139      Idx += 2;
3140    }
3141  }
3142
3143  // VUZP.32 for 64-bit vectors is a pseudo-instruction alias for VTRN.32.
3144  if (VT.is64BitVector() && EltSz == 32)
3145    return false;
3146
3147  return true;
3148}
3149
3150static bool isVZIPMask(const SmallVectorImpl<int> &M, EVT VT,
3151                       unsigned &WhichResult) {
3152  unsigned EltSz = VT.getVectorElementType().getSizeInBits();
3153  if (EltSz == 64)
3154    return false;
3155
3156  unsigned NumElts = VT.getVectorNumElements();
3157  WhichResult = (M[0] == 0 ? 0 : 1);
3158  unsigned Idx = WhichResult * NumElts / 2;
3159  for (unsigned i = 0; i != NumElts; i += 2) {
3160    if ((unsigned) M[i] != Idx ||
3161        (unsigned) M[i+1] != Idx + NumElts)
3162      return false;
3163    Idx += 1;
3164  }
3165
3166  // VZIP.32 for 64-bit vectors is a pseudo-instruction alias for VTRN.32.
3167  if (VT.is64BitVector() && EltSz == 32)
3168    return false;
3169
3170  return true;
3171}
3172
3173/// isVZIP_v_undef_Mask - Special case of isVZIPMask for canonical form of
3174/// "vector_shuffle v, v", i.e., "vector_shuffle v, undef".
3175/// Mask is e.g., <0, 0, 1, 1> instead of <0, 4, 1, 5>.
3176static bool isVZIP_v_undef_Mask(const SmallVectorImpl<int> &M, EVT VT,
3177                                unsigned &WhichResult) {
3178  unsigned EltSz = VT.getVectorElementType().getSizeInBits();
3179  if (EltSz == 64)
3180    return false;
3181
3182  unsigned NumElts = VT.getVectorNumElements();
3183  WhichResult = (M[0] == 0 ? 0 : 1);
3184  unsigned Idx = WhichResult * NumElts / 2;
3185  for (unsigned i = 0; i != NumElts; i += 2) {
3186    if ((unsigned) M[i] != Idx ||
3187        (unsigned) M[i+1] != Idx)
3188      return false;
3189    Idx += 1;
3190  }
3191
3192  // VZIP.32 for 64-bit vectors is a pseudo-instruction alias for VTRN.32.
3193  if (VT.is64BitVector() && EltSz == 32)
3194    return false;
3195
3196  return true;
3197}
3198
3199
3200static SDValue BuildSplat(SDValue Val, EVT VT, SelectionDAG &DAG, DebugLoc dl) {
3201  // Canonicalize all-zeros and all-ones vectors.
3202  ConstantSDNode *ConstVal = cast<ConstantSDNode>(Val.getNode());
3203  if (ConstVal->isNullValue())
3204    return getZeroVector(VT, DAG, dl);
3205  if (ConstVal->isAllOnesValue())
3206    return getOnesVector(VT, DAG, dl);
3207
3208  EVT CanonicalVT;
3209  if (VT.is64BitVector()) {
3210    switch (Val.getValueType().getSizeInBits()) {
3211    case 8:  CanonicalVT = MVT::v8i8; break;
3212    case 16: CanonicalVT = MVT::v4i16; break;
3213    case 32: CanonicalVT = MVT::v2i32; break;
3214    case 64: CanonicalVT = MVT::v1i64; break;
3215    default: llvm_unreachable("unexpected splat element type"); break;
3216    }
3217  } else {
3218    assert(VT.is128BitVector() && "unknown splat vector size");
3219    switch (Val.getValueType().getSizeInBits()) {
3220    case 8:  CanonicalVT = MVT::v16i8; break;
3221    case 16: CanonicalVT = MVT::v8i16; break;
3222    case 32: CanonicalVT = MVT::v4i32; break;
3223    case 64: CanonicalVT = MVT::v2i64; break;
3224    default: llvm_unreachable("unexpected splat element type"); break;
3225    }
3226  }
3227
3228  // Build a canonical splat for this value.
3229  SmallVector<SDValue, 8> Ops;
3230  Ops.assign(CanonicalVT.getVectorNumElements(), Val);
3231  SDValue Res = DAG.getNode(ISD::BUILD_VECTOR, dl, CanonicalVT, &Ops[0],
3232                            Ops.size());
3233  return DAG.getNode(ISD::BIT_CONVERT, dl, VT, Res);
3234}
3235
3236// If this is a case we can't handle, return null and let the default
3237// expansion code take care of it.
3238static SDValue LowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG) {
3239  BuildVectorSDNode *BVN = cast<BuildVectorSDNode>(Op.getNode());
3240  DebugLoc dl = Op.getDebugLoc();
3241  EVT VT = Op.getValueType();
3242
3243  APInt SplatBits, SplatUndef;
3244  unsigned SplatBitSize;
3245  bool HasAnyUndefs;
3246  if (BVN->isConstantSplat(SplatBits, SplatUndef, SplatBitSize, HasAnyUndefs)) {
3247    if (SplatBitSize <= 64) {
3248      // Check if an immediate VMOV works.
3249      SDValue Val = isNEONModifiedImm(SplatBits.getZExtValue(),
3250                                      SplatUndef.getZExtValue(),
3251                                      SplatBitSize, DAG, true, false);
3252      if (Val.getNode())
3253        return BuildSplat(Val, VT, DAG, dl);
3254    }
3255  }
3256
3257  // Scan through the operands to see if only one value is used.
3258  unsigned NumElts = VT.getVectorNumElements();
3259  bool isOnlyLowElement = true;
3260  bool usesOnlyOneValue = true;
3261  bool isConstant = true;
3262  SDValue Value;
3263  for (unsigned i = 0; i < NumElts; ++i) {
3264    SDValue V = Op.getOperand(i);
3265    if (V.getOpcode() == ISD::UNDEF)
3266      continue;
3267    if (i > 0)
3268      isOnlyLowElement = false;
3269    if (!isa<ConstantFPSDNode>(V) && !isa<ConstantSDNode>(V))
3270      isConstant = false;
3271
3272    if (!Value.getNode())
3273      Value = V;
3274    else if (V != Value)
3275      usesOnlyOneValue = false;
3276  }
3277
3278  if (!Value.getNode())
3279    return DAG.getUNDEF(VT);
3280
3281  if (isOnlyLowElement)
3282    return DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value);
3283
3284  // If all elements are constants, fall back to the default expansion, which
3285  // will generate a load from the constant pool.
3286  if (isConstant)
3287    return SDValue();
3288
3289  // Use VDUP for non-constant splats.
3290  unsigned EltSize = VT.getVectorElementType().getSizeInBits();
3291  if (usesOnlyOneValue && EltSize <= 32)
3292    return DAG.getNode(ARMISD::VDUP, dl, VT, Value);
3293
3294  // Vectors with 32- or 64-bit elements can be built by directly assigning
3295  // the subregisters.  Lower it to an ARMISD::BUILD_VECTOR so the operands
3296  // will be legalized.
3297  if (EltSize >= 32) {
3298    // Do the expansion with floating-point types, since that is what the VFP
3299    // registers are defined to use, and since i64 is not legal.
3300    EVT EltVT = EVT::getFloatingPointVT(EltSize);
3301    EVT VecVT = EVT::getVectorVT(*DAG.getContext(), EltVT, NumElts);
3302    SmallVector<SDValue, 8> Ops;
3303    for (unsigned i = 0; i < NumElts; ++i)
3304      Ops.push_back(DAG.getNode(ISD::BIT_CONVERT, dl, EltVT, Op.getOperand(i)));
3305    SDValue Val = DAG.getNode(ARMISD::BUILD_VECTOR, dl, VecVT, &Ops[0],NumElts);
3306    return DAG.getNode(ISD::BIT_CONVERT, dl, VT, Val);
3307  }
3308
3309  return SDValue();
3310}
3311
3312/// isShuffleMaskLegal - Targets can use this to indicate that they only
3313/// support *some* VECTOR_SHUFFLE operations, those with specific masks.
3314/// By default, if a target supports the VECTOR_SHUFFLE node, all mask values
3315/// are assumed to be legal.
3316bool
3317ARMTargetLowering::isShuffleMaskLegal(const SmallVectorImpl<int> &M,
3318                                      EVT VT) const {
3319  if (VT.getVectorNumElements() == 4 &&
3320      (VT.is128BitVector() || VT.is64BitVector())) {
3321    unsigned PFIndexes[4];
3322    for (unsigned i = 0; i != 4; ++i) {
3323      if (M[i] < 0)
3324        PFIndexes[i] = 8;
3325      else
3326        PFIndexes[i] = M[i];
3327    }
3328
3329    // Compute the index in the perfect shuffle table.
3330    unsigned PFTableIndex =
3331      PFIndexes[0]*9*9*9+PFIndexes[1]*9*9+PFIndexes[2]*9+PFIndexes[3];
3332    unsigned PFEntry = PerfectShuffleTable[PFTableIndex];
3333    unsigned Cost = (PFEntry >> 30);
3334
3335    if (Cost <= 4)
3336      return true;
3337  }
3338
3339  bool ReverseVEXT;
3340  unsigned Imm, WhichResult;
3341
3342  unsigned EltSize = VT.getVectorElementType().getSizeInBits();
3343  return (EltSize >= 32 ||
3344          ShuffleVectorSDNode::isSplatMask(&M[0], VT) ||
3345          isVREVMask(M, VT, 64) ||
3346          isVREVMask(M, VT, 32) ||
3347          isVREVMask(M, VT, 16) ||
3348          isVEXTMask(M, VT, ReverseVEXT, Imm) ||
3349          isVTRNMask(M, VT, WhichResult) ||
3350          isVUZPMask(M, VT, WhichResult) ||
3351          isVZIPMask(M, VT, WhichResult) ||
3352          isVTRN_v_undef_Mask(M, VT, WhichResult) ||
3353          isVUZP_v_undef_Mask(M, VT, WhichResult) ||
3354          isVZIP_v_undef_Mask(M, VT, WhichResult));
3355}
3356
3357/// GeneratePerfectShuffle - Given an entry in the perfect-shuffle table, emit
3358/// the specified operations to build the shuffle.
3359static SDValue GeneratePerfectShuffle(unsigned PFEntry, SDValue LHS,
3360                                      SDValue RHS, SelectionDAG &DAG,
3361                                      DebugLoc dl) {
3362  unsigned OpNum = (PFEntry >> 26) & 0x0F;
3363  unsigned LHSID = (PFEntry >> 13) & ((1 << 13)-1);
3364  unsigned RHSID = (PFEntry >>  0) & ((1 << 13)-1);
3365
3366  enum {
3367    OP_COPY = 0, // Copy, used for things like <u,u,u,3> to say it is <0,1,2,3>
3368    OP_VREV,
3369    OP_VDUP0,
3370    OP_VDUP1,
3371    OP_VDUP2,
3372    OP_VDUP3,
3373    OP_VEXT1,
3374    OP_VEXT2,
3375    OP_VEXT3,
3376    OP_VUZPL, // VUZP, left result
3377    OP_VUZPR, // VUZP, right result
3378    OP_VZIPL, // VZIP, left result
3379    OP_VZIPR, // VZIP, right result
3380    OP_VTRNL, // VTRN, left result
3381    OP_VTRNR  // VTRN, right result
3382  };
3383
3384  if (OpNum == OP_COPY) {
3385    if (LHSID == (1*9+2)*9+3) return LHS;
3386    assert(LHSID == ((4*9+5)*9+6)*9+7 && "Illegal OP_COPY!");
3387    return RHS;
3388  }
3389
3390  SDValue OpLHS, OpRHS;
3391  OpLHS = GeneratePerfectShuffle(PerfectShuffleTable[LHSID], LHS, RHS, DAG, dl);
3392  OpRHS = GeneratePerfectShuffle(PerfectShuffleTable[RHSID], LHS, RHS, DAG, dl);
3393  EVT VT = OpLHS.getValueType();
3394
3395  switch (OpNum) {
3396  default: llvm_unreachable("Unknown shuffle opcode!");
3397  case OP_VREV:
3398    return DAG.getNode(ARMISD::VREV64, dl, VT, OpLHS);
3399  case OP_VDUP0:
3400  case OP_VDUP1:
3401  case OP_VDUP2:
3402  case OP_VDUP3:
3403    return DAG.getNode(ARMISD::VDUPLANE, dl, VT,
3404                       OpLHS, DAG.getConstant(OpNum-OP_VDUP0, MVT::i32));
3405  case OP_VEXT1:
3406  case OP_VEXT2:
3407  case OP_VEXT3:
3408    return DAG.getNode(ARMISD::VEXT, dl, VT,
3409                       OpLHS, OpRHS,
3410                       DAG.getConstant(OpNum-OP_VEXT1+1, MVT::i32));
3411  case OP_VUZPL:
3412  case OP_VUZPR:
3413    return DAG.getNode(ARMISD::VUZP, dl, DAG.getVTList(VT, VT),
3414                       OpLHS, OpRHS).getValue(OpNum-OP_VUZPL);
3415  case OP_VZIPL:
3416  case OP_VZIPR:
3417    return DAG.getNode(ARMISD::VZIP, dl, DAG.getVTList(VT, VT),
3418                       OpLHS, OpRHS).getValue(OpNum-OP_VZIPL);
3419  case OP_VTRNL:
3420  case OP_VTRNR:
3421    return DAG.getNode(ARMISD::VTRN, dl, DAG.getVTList(VT, VT),
3422                       OpLHS, OpRHS).getValue(OpNum-OP_VTRNL);
3423  }
3424}
3425
3426static SDValue LowerVECTOR_SHUFFLE(SDValue Op, SelectionDAG &DAG) {
3427  SDValue V1 = Op.getOperand(0);
3428  SDValue V2 = Op.getOperand(1);
3429  DebugLoc dl = Op.getDebugLoc();
3430  EVT VT = Op.getValueType();
3431  ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(Op.getNode());
3432  SmallVector<int, 8> ShuffleMask;
3433
3434  // Convert shuffles that are directly supported on NEON to target-specific
3435  // DAG nodes, instead of keeping them as shuffles and matching them again
3436  // during code selection.  This is more efficient and avoids the possibility
3437  // of inconsistencies between legalization and selection.
3438  // FIXME: floating-point vectors should be canonicalized to integer vectors
3439  // of the same time so that they get CSEd properly.
3440  SVN->getMask(ShuffleMask);
3441
3442  unsigned EltSize = VT.getVectorElementType().getSizeInBits();
3443  if (EltSize <= 32) {
3444    if (ShuffleVectorSDNode::isSplatMask(&ShuffleMask[0], VT)) {
3445      int Lane = SVN->getSplatIndex();
3446      // If this is undef splat, generate it via "just" vdup, if possible.
3447      if (Lane == -1) Lane = 0;
3448
3449      if (Lane == 0 && V1.getOpcode() == ISD::SCALAR_TO_VECTOR) {
3450        return DAG.getNode(ARMISD::VDUP, dl, VT, V1.getOperand(0));
3451      }
3452      return DAG.getNode(ARMISD::VDUPLANE, dl, VT, V1,
3453                         DAG.getConstant(Lane, MVT::i32));
3454    }
3455
3456    bool ReverseVEXT;
3457    unsigned Imm;
3458    if (isVEXTMask(ShuffleMask, VT, ReverseVEXT, Imm)) {
3459      if (ReverseVEXT)
3460        std::swap(V1, V2);
3461      return DAG.getNode(ARMISD::VEXT, dl, VT, V1, V2,
3462                         DAG.getConstant(Imm, MVT::i32));
3463    }
3464
3465    if (isVREVMask(ShuffleMask, VT, 64))
3466      return DAG.getNode(ARMISD::VREV64, dl, VT, V1);
3467    if (isVREVMask(ShuffleMask, VT, 32))
3468      return DAG.getNode(ARMISD::VREV32, dl, VT, V1);
3469    if (isVREVMask(ShuffleMask, VT, 16))
3470      return DAG.getNode(ARMISD::VREV16, dl, VT, V1);
3471
3472    // Check for Neon shuffles that modify both input vectors in place.
3473    // If both results are used, i.e., if there are two shuffles with the same
3474    // source operands and with masks corresponding to both results of one of
3475    // these operations, DAG memoization will ensure that a single node is
3476    // used for both shuffles.
3477    unsigned WhichResult;
3478    if (isVTRNMask(ShuffleMask, VT, WhichResult))
3479      return DAG.getNode(ARMISD::VTRN, dl, DAG.getVTList(VT, VT),
3480                         V1, V2).getValue(WhichResult);
3481    if (isVUZPMask(ShuffleMask, VT, WhichResult))
3482      return DAG.getNode(ARMISD::VUZP, dl, DAG.getVTList(VT, VT),
3483                         V1, V2).getValue(WhichResult);
3484    if (isVZIPMask(ShuffleMask, VT, WhichResult))
3485      return DAG.getNode(ARMISD::VZIP, dl, DAG.getVTList(VT, VT),
3486                         V1, V2).getValue(WhichResult);
3487
3488    if (isVTRN_v_undef_Mask(ShuffleMask, VT, WhichResult))
3489      return DAG.getNode(ARMISD::VTRN, dl, DAG.getVTList(VT, VT),
3490                         V1, V1).getValue(WhichResult);
3491    if (isVUZP_v_undef_Mask(ShuffleMask, VT, WhichResult))
3492      return DAG.getNode(ARMISD::VUZP, dl, DAG.getVTList(VT, VT),
3493                         V1, V1).getValue(WhichResult);
3494    if (isVZIP_v_undef_Mask(ShuffleMask, VT, WhichResult))
3495      return DAG.getNode(ARMISD::VZIP, dl, DAG.getVTList(VT, VT),
3496                         V1, V1).getValue(WhichResult);
3497  }
3498
3499  // If the shuffle is not directly supported and it has 4 elements, use
3500  // the PerfectShuffle-generated table to synthesize it from other shuffles.
3501  unsigned NumElts = VT.getVectorNumElements();
3502  if (NumElts == 4) {
3503    unsigned PFIndexes[4];
3504    for (unsigned i = 0; i != 4; ++i) {
3505      if (ShuffleMask[i] < 0)
3506        PFIndexes[i] = 8;
3507      else
3508        PFIndexes[i] = ShuffleMask[i];
3509    }
3510
3511    // Compute the index in the perfect shuffle table.
3512    unsigned PFTableIndex =
3513      PFIndexes[0]*9*9*9+PFIndexes[1]*9*9+PFIndexes[2]*9+PFIndexes[3];
3514    unsigned PFEntry = PerfectShuffleTable[PFTableIndex];
3515    unsigned Cost = (PFEntry >> 30);
3516
3517    if (Cost <= 4)
3518      return GeneratePerfectShuffle(PFEntry, V1, V2, DAG, dl);
3519  }
3520
3521  // Implement shuffles with 32- or 64-bit elements as ARMISD::BUILD_VECTORs.
3522  if (EltSize >= 32) {
3523    // Do the expansion with floating-point types, since that is what the VFP
3524    // registers are defined to use, and since i64 is not legal.
3525    EVT EltVT = EVT::getFloatingPointVT(EltSize);
3526    EVT VecVT = EVT::getVectorVT(*DAG.getContext(), EltVT, NumElts);
3527    V1 = DAG.getNode(ISD::BIT_CONVERT, dl, VecVT, V1);
3528    V2 = DAG.getNode(ISD::BIT_CONVERT, dl, VecVT, V2);
3529    SmallVector<SDValue, 8> Ops;
3530    for (unsigned i = 0; i < NumElts; ++i) {
3531      if (ShuffleMask[i] < 0)
3532        Ops.push_back(DAG.getUNDEF(EltVT));
3533      else
3534        Ops.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT,
3535                                  ShuffleMask[i] < (int)NumElts ? V1 : V2,
3536                                  DAG.getConstant(ShuffleMask[i] & (NumElts-1),
3537                                                  MVT::i32)));
3538    }
3539    SDValue Val = DAG.getNode(ARMISD::BUILD_VECTOR, dl, VecVT, &Ops[0],NumElts);
3540    return DAG.getNode(ISD::BIT_CONVERT, dl, VT, Val);
3541  }
3542
3543  return SDValue();
3544}
3545
3546static SDValue LowerEXTRACT_VECTOR_ELT(SDValue Op, SelectionDAG &DAG) {
3547  EVT VT = Op.getValueType();
3548  DebugLoc dl = Op.getDebugLoc();
3549  SDValue Vec = Op.getOperand(0);
3550  SDValue Lane = Op.getOperand(1);
3551  assert(VT == MVT::i32 &&
3552         Vec.getValueType().getVectorElementType().getSizeInBits() < 32 &&
3553         "unexpected type for custom-lowering vector extract");
3554  return DAG.getNode(ARMISD::VGETLANEu, dl, MVT::i32, Vec, Lane);
3555}
3556
3557static SDValue LowerCONCAT_VECTORS(SDValue Op, SelectionDAG &DAG) {
3558  // The only time a CONCAT_VECTORS operation can have legal types is when
3559  // two 64-bit vectors are concatenated to a 128-bit vector.
3560  assert(Op.getValueType().is128BitVector() && Op.getNumOperands() == 2 &&
3561         "unexpected CONCAT_VECTORS");
3562  DebugLoc dl = Op.getDebugLoc();
3563  SDValue Val = DAG.getUNDEF(MVT::v2f64);
3564  SDValue Op0 = Op.getOperand(0);
3565  SDValue Op1 = Op.getOperand(1);
3566  if (Op0.getOpcode() != ISD::UNDEF)
3567    Val = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v2f64, Val,
3568                      DAG.getNode(ISD::BIT_CONVERT, dl, MVT::f64, Op0),
3569                      DAG.getIntPtrConstant(0));
3570  if (Op1.getOpcode() != ISD::UNDEF)
3571    Val = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v2f64, Val,
3572                      DAG.getNode(ISD::BIT_CONVERT, dl, MVT::f64, Op1),
3573                      DAG.getIntPtrConstant(1));
3574  return DAG.getNode(ISD::BIT_CONVERT, dl, Op.getValueType(), Val);
3575}
3576
3577SDValue ARMTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const {
3578  switch (Op.getOpcode()) {
3579  default: llvm_unreachable("Don't know how to custom lower this!");
3580  case ISD::ConstantPool:  return LowerConstantPool(Op, DAG);
3581  case ISD::BlockAddress:  return LowerBlockAddress(Op, DAG);
3582  case ISD::GlobalAddress:
3583    return Subtarget->isTargetDarwin() ? LowerGlobalAddressDarwin(Op, DAG) :
3584      LowerGlobalAddressELF(Op, DAG);
3585  case ISD::GlobalTLSAddress:   return LowerGlobalTLSAddress(Op, DAG);
3586  case ISD::SELECT_CC:     return LowerSELECT_CC(Op, DAG);
3587  case ISD::BR_CC:         return LowerBR_CC(Op, DAG);
3588  case ISD::BR_JT:         return LowerBR_JT(Op, DAG);
3589  case ISD::DYNAMIC_STACKALLOC: return LowerDYNAMIC_STACKALLOC(Op, DAG);
3590  case ISD::VASTART:       return LowerVASTART(Op, DAG);
3591  case ISD::MEMBARRIER:    return LowerMEMBARRIER(Op, DAG, Subtarget);
3592  case ISD::SINT_TO_FP:
3593  case ISD::UINT_TO_FP:    return LowerINT_TO_FP(Op, DAG);
3594  case ISD::FP_TO_SINT:
3595  case ISD::FP_TO_UINT:    return LowerFP_TO_INT(Op, DAG);
3596  case ISD::FCOPYSIGN:     return LowerFCOPYSIGN(Op, DAG);
3597  case ISD::RETURNADDR:    return LowerRETURNADDR(Op, DAG);
3598  case ISD::FRAMEADDR:     return LowerFRAMEADDR(Op, DAG);
3599  case ISD::GLOBAL_OFFSET_TABLE: return LowerGLOBAL_OFFSET_TABLE(Op, DAG);
3600  case ISD::EH_SJLJ_SETJMP: return LowerEH_SJLJ_SETJMP(Op, DAG);
3601  case ISD::EH_SJLJ_LONGJMP: return LowerEH_SJLJ_LONGJMP(Op, DAG);
3602  case ISD::INTRINSIC_WO_CHAIN: return LowerINTRINSIC_WO_CHAIN(Op, DAG,
3603                                                               Subtarget);
3604  case ISD::BIT_CONVERT:   return ExpandBIT_CONVERT(Op.getNode(), DAG);
3605  case ISD::SHL:
3606  case ISD::SRL:
3607  case ISD::SRA:           return LowerShift(Op.getNode(), DAG, Subtarget);
3608  case ISD::SHL_PARTS:     return LowerShiftLeftParts(Op, DAG);
3609  case ISD::SRL_PARTS:
3610  case ISD::SRA_PARTS:     return LowerShiftRightParts(Op, DAG);
3611  case ISD::CTTZ:          return LowerCTTZ(Op.getNode(), DAG, Subtarget);
3612  case ISD::VSETCC:        return LowerVSETCC(Op, DAG);
3613  case ISD::BUILD_VECTOR:  return LowerBUILD_VECTOR(Op, DAG);
3614  case ISD::VECTOR_SHUFFLE: return LowerVECTOR_SHUFFLE(Op, DAG);
3615  case ISD::EXTRACT_VECTOR_ELT: return LowerEXTRACT_VECTOR_ELT(Op, DAG);
3616  case ISD::CONCAT_VECTORS: return LowerCONCAT_VECTORS(Op, DAG);
3617  }
3618  return SDValue();
3619}
3620
3621/// ReplaceNodeResults - Replace the results of node with an illegal result
3622/// type with new values built out of custom code.
3623void ARMTargetLowering::ReplaceNodeResults(SDNode *N,
3624                                           SmallVectorImpl<SDValue>&Results,
3625                                           SelectionDAG &DAG) const {
3626  SDValue Res;
3627  switch (N->getOpcode()) {
3628  default:
3629    llvm_unreachable("Don't know how to custom expand this!");
3630    break;
3631  case ISD::BIT_CONVERT:
3632    Res = ExpandBIT_CONVERT(N, DAG);
3633    break;
3634  case ISD::SRL:
3635  case ISD::SRA:
3636    Res = LowerShift(N, DAG, Subtarget);
3637    break;
3638  }
3639  if (Res.getNode())
3640    Results.push_back(Res);
3641}
3642
3643//===----------------------------------------------------------------------===//
3644//                           ARM Scheduler Hooks
3645//===----------------------------------------------------------------------===//
3646
3647MachineBasicBlock *
3648ARMTargetLowering::EmitAtomicCmpSwap(MachineInstr *MI,
3649                                     MachineBasicBlock *BB,
3650                                     unsigned Size) const {
3651  unsigned dest    = MI->getOperand(0).getReg();
3652  unsigned ptr     = MI->getOperand(1).getReg();
3653  unsigned oldval  = MI->getOperand(2).getReg();
3654  unsigned newval  = MI->getOperand(3).getReg();
3655  unsigned scratch = BB->getParent()->getRegInfo()
3656    .createVirtualRegister(ARM::GPRRegisterClass);
3657  const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
3658  DebugLoc dl = MI->getDebugLoc();
3659  bool isThumb2 = Subtarget->isThumb2();
3660
3661  unsigned ldrOpc, strOpc;
3662  switch (Size) {
3663  default: llvm_unreachable("unsupported size for AtomicCmpSwap!");
3664  case 1:
3665    ldrOpc = isThumb2 ? ARM::t2LDREXB : ARM::LDREXB;
3666    strOpc = isThumb2 ? ARM::t2LDREXB : ARM::STREXB;
3667    break;
3668  case 2:
3669    ldrOpc = isThumb2 ? ARM::t2LDREXH : ARM::LDREXH;
3670    strOpc = isThumb2 ? ARM::t2STREXH : ARM::STREXH;
3671    break;
3672  case 4:
3673    ldrOpc = isThumb2 ? ARM::t2LDREX : ARM::LDREX;
3674    strOpc = isThumb2 ? ARM::t2STREX : ARM::STREX;
3675    break;
3676  }
3677
3678  MachineFunction *MF = BB->getParent();
3679  const BasicBlock *LLVM_BB = BB->getBasicBlock();
3680  MachineFunction::iterator It = BB;
3681  ++It; // insert the new blocks after the current block
3682
3683  MachineBasicBlock *loop1MBB = MF->CreateMachineBasicBlock(LLVM_BB);
3684  MachineBasicBlock *loop2MBB = MF->CreateMachineBasicBlock(LLVM_BB);
3685  MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
3686  MF->insert(It, loop1MBB);
3687  MF->insert(It, loop2MBB);
3688  MF->insert(It, exitMBB);
3689
3690  // Transfer the remainder of BB and its successor edges to exitMBB.
3691  exitMBB->splice(exitMBB->begin(), BB,
3692                  llvm::next(MachineBasicBlock::iterator(MI)),
3693                  BB->end());
3694  exitMBB->transferSuccessorsAndUpdatePHIs(BB);
3695
3696  //  thisMBB:
3697  //   ...
3698  //   fallthrough --> loop1MBB
3699  BB->addSuccessor(loop1MBB);
3700
3701  // loop1MBB:
3702  //   ldrex dest, [ptr]
3703  //   cmp dest, oldval
3704  //   bne exitMBB
3705  BB = loop1MBB;
3706  AddDefaultPred(BuildMI(BB, dl, TII->get(ldrOpc), dest).addReg(ptr));
3707  AddDefaultPred(BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2CMPrr : ARM::CMPrr))
3708                 .addReg(dest).addReg(oldval));
3709  BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2Bcc : ARM::Bcc))
3710    .addMBB(exitMBB).addImm(ARMCC::NE).addReg(ARM::CPSR);
3711  BB->addSuccessor(loop2MBB);
3712  BB->addSuccessor(exitMBB);
3713
3714  // loop2MBB:
3715  //   strex scratch, newval, [ptr]
3716  //   cmp scratch, #0
3717  //   bne loop1MBB
3718  BB = loop2MBB;
3719  AddDefaultPred(BuildMI(BB, dl, TII->get(strOpc), scratch).addReg(newval)
3720                 .addReg(ptr));
3721  AddDefaultPred(BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2CMPri : ARM::CMPri))
3722                 .addReg(scratch).addImm(0));
3723  BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2Bcc : ARM::Bcc))
3724    .addMBB(loop1MBB).addImm(ARMCC::NE).addReg(ARM::CPSR);
3725  BB->addSuccessor(loop1MBB);
3726  BB->addSuccessor(exitMBB);
3727
3728  //  exitMBB:
3729  //   ...
3730  BB = exitMBB;
3731
3732  MI->eraseFromParent();   // The instruction is gone now.
3733
3734  return BB;
3735}
3736
3737MachineBasicBlock *
3738ARMTargetLowering::EmitAtomicBinary(MachineInstr *MI, MachineBasicBlock *BB,
3739                                    unsigned Size, unsigned BinOpcode) const {
3740  // This also handles ATOMIC_SWAP, indicated by BinOpcode==0.
3741  const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
3742
3743  const BasicBlock *LLVM_BB = BB->getBasicBlock();
3744  MachineFunction *MF = BB->getParent();
3745  MachineFunction::iterator It = BB;
3746  ++It;
3747
3748  unsigned dest = MI->getOperand(0).getReg();
3749  unsigned ptr = MI->getOperand(1).getReg();
3750  unsigned incr = MI->getOperand(2).getReg();
3751  DebugLoc dl = MI->getDebugLoc();
3752
3753  bool isThumb2 = Subtarget->isThumb2();
3754  unsigned ldrOpc, strOpc;
3755  switch (Size) {
3756  default: llvm_unreachable("unsupported size for AtomicCmpSwap!");
3757  case 1:
3758    ldrOpc = isThumb2 ? ARM::t2LDREXB : ARM::LDREXB;
3759    strOpc = isThumb2 ? ARM::t2STREXB : ARM::STREXB;
3760    break;
3761  case 2:
3762    ldrOpc = isThumb2 ? ARM::t2LDREXH : ARM::LDREXH;
3763    strOpc = isThumb2 ? ARM::t2STREXH : ARM::STREXH;
3764    break;
3765  case 4:
3766    ldrOpc = isThumb2 ? ARM::t2LDREX : ARM::LDREX;
3767    strOpc = isThumb2 ? ARM::t2STREX : ARM::STREX;
3768    break;
3769  }
3770
3771  MachineBasicBlock *loopMBB = MF->CreateMachineBasicBlock(LLVM_BB);
3772  MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
3773  MF->insert(It, loopMBB);
3774  MF->insert(It, exitMBB);
3775
3776  // Transfer the remainder of BB and its successor edges to exitMBB.
3777  exitMBB->splice(exitMBB->begin(), BB,
3778                  llvm::next(MachineBasicBlock::iterator(MI)),
3779                  BB->end());
3780  exitMBB->transferSuccessorsAndUpdatePHIs(BB);
3781
3782  MachineRegisterInfo &RegInfo = MF->getRegInfo();
3783  unsigned scratch = RegInfo.createVirtualRegister(ARM::GPRRegisterClass);
3784  unsigned scratch2 = (!BinOpcode) ? incr :
3785    RegInfo.createVirtualRegister(ARM::GPRRegisterClass);
3786
3787  //  thisMBB:
3788  //   ...
3789  //   fallthrough --> loopMBB
3790  BB->addSuccessor(loopMBB);
3791
3792  //  loopMBB:
3793  //   ldrex dest, ptr
3794  //   <binop> scratch2, dest, incr
3795  //   strex scratch, scratch2, ptr
3796  //   cmp scratch, #0
3797  //   bne- loopMBB
3798  //   fallthrough --> exitMBB
3799  BB = loopMBB;
3800  AddDefaultPred(BuildMI(BB, dl, TII->get(ldrOpc), dest).addReg(ptr));
3801  if (BinOpcode) {
3802    // operand order needs to go the other way for NAND
3803    if (BinOpcode == ARM::BICrr || BinOpcode == ARM::t2BICrr)
3804      AddDefaultPred(BuildMI(BB, dl, TII->get(BinOpcode), scratch2).
3805                     addReg(incr).addReg(dest)).addReg(0);
3806    else
3807      AddDefaultPred(BuildMI(BB, dl, TII->get(BinOpcode), scratch2).
3808                     addReg(dest).addReg(incr)).addReg(0);
3809  }
3810
3811  AddDefaultPred(BuildMI(BB, dl, TII->get(strOpc), scratch).addReg(scratch2)
3812                 .addReg(ptr));
3813  AddDefaultPred(BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2CMPri : ARM::CMPri))
3814                 .addReg(scratch).addImm(0));
3815  BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2Bcc : ARM::Bcc))
3816    .addMBB(loopMBB).addImm(ARMCC::NE).addReg(ARM::CPSR);
3817
3818  BB->addSuccessor(loopMBB);
3819  BB->addSuccessor(exitMBB);
3820
3821  //  exitMBB:
3822  //   ...
3823  BB = exitMBB;
3824
3825  MI->eraseFromParent();   // The instruction is gone now.
3826
3827  return BB;
3828}
3829
3830MachineBasicBlock *
3831ARMTargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
3832                                               MachineBasicBlock *BB) const {
3833  const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
3834  DebugLoc dl = MI->getDebugLoc();
3835  bool isThumb2 = Subtarget->isThumb2();
3836  switch (MI->getOpcode()) {
3837  default:
3838    MI->dump();
3839    llvm_unreachable("Unexpected instr type to insert");
3840
3841  case ARM::ATOMIC_LOAD_ADD_I8:
3842     return EmitAtomicBinary(MI, BB, 1, isThumb2 ? ARM::t2ADDrr : ARM::ADDrr);
3843  case ARM::ATOMIC_LOAD_ADD_I16:
3844     return EmitAtomicBinary(MI, BB, 2, isThumb2 ? ARM::t2ADDrr : ARM::ADDrr);
3845  case ARM::ATOMIC_LOAD_ADD_I32:
3846     return EmitAtomicBinary(MI, BB, 4, isThumb2 ? ARM::t2ADDrr : ARM::ADDrr);
3847
3848  case ARM::ATOMIC_LOAD_AND_I8:
3849     return EmitAtomicBinary(MI, BB, 1, isThumb2 ? ARM::t2ANDrr : ARM::ANDrr);
3850  case ARM::ATOMIC_LOAD_AND_I16:
3851     return EmitAtomicBinary(MI, BB, 2, isThumb2 ? ARM::t2ANDrr : ARM::ANDrr);
3852  case ARM::ATOMIC_LOAD_AND_I32:
3853     return EmitAtomicBinary(MI, BB, 4, isThumb2 ? ARM::t2ANDrr : ARM::ANDrr);
3854
3855  case ARM::ATOMIC_LOAD_OR_I8:
3856     return EmitAtomicBinary(MI, BB, 1, isThumb2 ? ARM::t2ORRrr : ARM::ORRrr);
3857  case ARM::ATOMIC_LOAD_OR_I16:
3858     return EmitAtomicBinary(MI, BB, 2, isThumb2 ? ARM::t2ORRrr : ARM::ORRrr);
3859  case ARM::ATOMIC_LOAD_OR_I32:
3860     return EmitAtomicBinary(MI, BB, 4, isThumb2 ? ARM::t2ORRrr : ARM::ORRrr);
3861
3862  case ARM::ATOMIC_LOAD_XOR_I8:
3863     return EmitAtomicBinary(MI, BB, 1, isThumb2 ? ARM::t2EORrr : ARM::EORrr);
3864  case ARM::ATOMIC_LOAD_XOR_I16:
3865     return EmitAtomicBinary(MI, BB, 2, isThumb2 ? ARM::t2EORrr : ARM::EORrr);
3866  case ARM::ATOMIC_LOAD_XOR_I32:
3867     return EmitAtomicBinary(MI, BB, 4, isThumb2 ? ARM::t2EORrr : ARM::EORrr);
3868
3869  case ARM::ATOMIC_LOAD_NAND_I8:
3870     return EmitAtomicBinary(MI, BB, 1, isThumb2 ? ARM::t2BICrr : ARM::BICrr);
3871  case ARM::ATOMIC_LOAD_NAND_I16:
3872     return EmitAtomicBinary(MI, BB, 2, isThumb2 ? ARM::t2BICrr : ARM::BICrr);
3873  case ARM::ATOMIC_LOAD_NAND_I32:
3874     return EmitAtomicBinary(MI, BB, 4, isThumb2 ? ARM::t2BICrr : ARM::BICrr);
3875
3876  case ARM::ATOMIC_LOAD_SUB_I8:
3877     return EmitAtomicBinary(MI, BB, 1, isThumb2 ? ARM::t2SUBrr : ARM::SUBrr);
3878  case ARM::ATOMIC_LOAD_SUB_I16:
3879     return EmitAtomicBinary(MI, BB, 2, isThumb2 ? ARM::t2SUBrr : ARM::SUBrr);
3880  case ARM::ATOMIC_LOAD_SUB_I32:
3881     return EmitAtomicBinary(MI, BB, 4, isThumb2 ? ARM::t2SUBrr : ARM::SUBrr);
3882
3883  case ARM::ATOMIC_SWAP_I8:  return EmitAtomicBinary(MI, BB, 1, 0);
3884  case ARM::ATOMIC_SWAP_I16: return EmitAtomicBinary(MI, BB, 2, 0);
3885  case ARM::ATOMIC_SWAP_I32: return EmitAtomicBinary(MI, BB, 4, 0);
3886
3887  case ARM::ATOMIC_CMP_SWAP_I8:  return EmitAtomicCmpSwap(MI, BB, 1);
3888  case ARM::ATOMIC_CMP_SWAP_I16: return EmitAtomicCmpSwap(MI, BB, 2);
3889  case ARM::ATOMIC_CMP_SWAP_I32: return EmitAtomicCmpSwap(MI, BB, 4);
3890
3891  case ARM::tMOVCCr_pseudo: {
3892    // To "insert" a SELECT_CC instruction, we actually have to insert the
3893    // diamond control-flow pattern.  The incoming instruction knows the
3894    // destination vreg to set, the condition code register to branch on, the
3895    // true/false values to select between, and a branch opcode to use.
3896    const BasicBlock *LLVM_BB = BB->getBasicBlock();
3897    MachineFunction::iterator It = BB;
3898    ++It;
3899
3900    //  thisMBB:
3901    //  ...
3902    //   TrueVal = ...
3903    //   cmpTY ccX, r1, r2
3904    //   bCC copy1MBB
3905    //   fallthrough --> copy0MBB
3906    MachineBasicBlock *thisMBB  = BB;
3907    MachineFunction *F = BB->getParent();
3908    MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
3909    MachineBasicBlock *sinkMBB  = F->CreateMachineBasicBlock(LLVM_BB);
3910    F->insert(It, copy0MBB);
3911    F->insert(It, sinkMBB);
3912
3913    // Transfer the remainder of BB and its successor edges to sinkMBB.
3914    sinkMBB->splice(sinkMBB->begin(), BB,
3915                    llvm::next(MachineBasicBlock::iterator(MI)),
3916                    BB->end());
3917    sinkMBB->transferSuccessorsAndUpdatePHIs(BB);
3918
3919    BB->addSuccessor(copy0MBB);
3920    BB->addSuccessor(sinkMBB);
3921
3922    BuildMI(BB, dl, TII->get(ARM::tBcc)).addMBB(sinkMBB)
3923      .addImm(MI->getOperand(3).getImm()).addReg(MI->getOperand(4).getReg());
3924
3925    //  copy0MBB:
3926    //   %FalseValue = ...
3927    //   # fallthrough to sinkMBB
3928    BB = copy0MBB;
3929
3930    // Update machine-CFG edges
3931    BB->addSuccessor(sinkMBB);
3932
3933    //  sinkMBB:
3934    //   %Result = phi [ %FalseValue, copy0MBB ], [ %TrueValue, thisMBB ]
3935    //  ...
3936    BB = sinkMBB;
3937    BuildMI(*BB, BB->begin(), dl,
3938            TII->get(ARM::PHI), MI->getOperand(0).getReg())
3939      .addReg(MI->getOperand(1).getReg()).addMBB(copy0MBB)
3940      .addReg(MI->getOperand(2).getReg()).addMBB(thisMBB);
3941
3942    MI->eraseFromParent();   // The pseudo instruction is gone now.
3943    return BB;
3944  }
3945
3946  case ARM::tANDsp:
3947  case ARM::tADDspr_:
3948  case ARM::tSUBspi_:
3949  case ARM::t2SUBrSPi_:
3950  case ARM::t2SUBrSPi12_:
3951  case ARM::t2SUBrSPs_: {
3952    MachineFunction *MF = BB->getParent();
3953    unsigned DstReg = MI->getOperand(0).getReg();
3954    unsigned SrcReg = MI->getOperand(1).getReg();
3955    bool DstIsDead = MI->getOperand(0).isDead();
3956    bool SrcIsKill = MI->getOperand(1).isKill();
3957
3958    if (SrcReg != ARM::SP) {
3959      // Copy the source to SP from virtual register.
3960      const TargetRegisterClass *RC = MF->getRegInfo().getRegClass(SrcReg);
3961      unsigned CopyOpc = (RC == ARM::tGPRRegisterClass)
3962        ? ARM::tMOVtgpr2gpr : ARM::tMOVgpr2gpr;
3963      BuildMI(*BB, MI, dl, TII->get(CopyOpc), ARM::SP)
3964        .addReg(SrcReg, getKillRegState(SrcIsKill));
3965    }
3966
3967    unsigned OpOpc = 0;
3968    bool NeedPred = false, NeedCC = false, NeedOp3 = false;
3969    switch (MI->getOpcode()) {
3970    default:
3971      llvm_unreachable("Unexpected pseudo instruction!");
3972    case ARM::tANDsp:
3973      OpOpc = ARM::tAND;
3974      NeedPred = true;
3975      break;
3976    case ARM::tADDspr_:
3977      OpOpc = ARM::tADDspr;
3978      break;
3979    case ARM::tSUBspi_:
3980      OpOpc = ARM::tSUBspi;
3981      break;
3982    case ARM::t2SUBrSPi_:
3983      OpOpc = ARM::t2SUBrSPi;
3984      NeedPred = true; NeedCC = true;
3985      break;
3986    case ARM::t2SUBrSPi12_:
3987      OpOpc = ARM::t2SUBrSPi12;
3988      NeedPred = true;
3989      break;
3990    case ARM::t2SUBrSPs_:
3991      OpOpc = ARM::t2SUBrSPs;
3992      NeedPred = true; NeedCC = true; NeedOp3 = true;
3993      break;
3994    }
3995    MachineInstrBuilder MIB = BuildMI(*BB, MI, dl, TII->get(OpOpc), ARM::SP);
3996    if (OpOpc == ARM::tAND)
3997      AddDefaultT1CC(MIB);
3998    MIB.addReg(ARM::SP);
3999    MIB.addOperand(MI->getOperand(2));
4000    if (NeedOp3)
4001      MIB.addOperand(MI->getOperand(3));
4002    if (NeedPred)
4003      AddDefaultPred(MIB);
4004    if (NeedCC)
4005      AddDefaultCC(MIB);
4006
4007    // Copy the result from SP to virtual register.
4008    const TargetRegisterClass *RC = MF->getRegInfo().getRegClass(DstReg);
4009    unsigned CopyOpc = (RC == ARM::tGPRRegisterClass)
4010      ? ARM::tMOVgpr2tgpr : ARM::tMOVgpr2gpr;
4011    BuildMI(*BB, MI, dl, TII->get(CopyOpc))
4012      .addReg(DstReg, getDefRegState(true) | getDeadRegState(DstIsDead))
4013      .addReg(ARM::SP);
4014    MI->eraseFromParent();   // The pseudo instruction is gone now.
4015    return BB;
4016  }
4017  }
4018}
4019
4020//===----------------------------------------------------------------------===//
4021//                           ARM Optimization Hooks
4022//===----------------------------------------------------------------------===//
4023
4024static
4025SDValue combineSelectAndUse(SDNode *N, SDValue Slct, SDValue OtherOp,
4026                            TargetLowering::DAGCombinerInfo &DCI) {
4027  SelectionDAG &DAG = DCI.DAG;
4028  const TargetLowering &TLI = DAG.getTargetLoweringInfo();
4029  EVT VT = N->getValueType(0);
4030  unsigned Opc = N->getOpcode();
4031  bool isSlctCC = Slct.getOpcode() == ISD::SELECT_CC;
4032  SDValue LHS = isSlctCC ? Slct.getOperand(2) : Slct.getOperand(1);
4033  SDValue RHS = isSlctCC ? Slct.getOperand(3) : Slct.getOperand(2);
4034  ISD::CondCode CC = ISD::SETCC_INVALID;
4035
4036  if (isSlctCC) {
4037    CC = cast<CondCodeSDNode>(Slct.getOperand(4))->get();
4038  } else {
4039    SDValue CCOp = Slct.getOperand(0);
4040    if (CCOp.getOpcode() == ISD::SETCC)
4041      CC = cast<CondCodeSDNode>(CCOp.getOperand(2))->get();
4042  }
4043
4044  bool DoXform = false;
4045  bool InvCC = false;
4046  assert ((Opc == ISD::ADD || (Opc == ISD::SUB && Slct == N->getOperand(1))) &&
4047          "Bad input!");
4048
4049  if (LHS.getOpcode() == ISD::Constant &&
4050      cast<ConstantSDNode>(LHS)->isNullValue()) {
4051    DoXform = true;
4052  } else if (CC != ISD::SETCC_INVALID &&
4053             RHS.getOpcode() == ISD::Constant &&
4054             cast<ConstantSDNode>(RHS)->isNullValue()) {
4055    std::swap(LHS, RHS);
4056    SDValue Op0 = Slct.getOperand(0);
4057    EVT OpVT = isSlctCC ? Op0.getValueType() :
4058                          Op0.getOperand(0).getValueType();
4059    bool isInt = OpVT.isInteger();
4060    CC = ISD::getSetCCInverse(CC, isInt);
4061
4062    if (!TLI.isCondCodeLegal(CC, OpVT))
4063      return SDValue();         // Inverse operator isn't legal.
4064
4065    DoXform = true;
4066    InvCC = true;
4067  }
4068
4069  if (DoXform) {
4070    SDValue Result = DAG.getNode(Opc, RHS.getDebugLoc(), VT, OtherOp, RHS);
4071    if (isSlctCC)
4072      return DAG.getSelectCC(N->getDebugLoc(), OtherOp, Result,
4073                             Slct.getOperand(0), Slct.getOperand(1), CC);
4074    SDValue CCOp = Slct.getOperand(0);
4075    if (InvCC)
4076      CCOp = DAG.getSetCC(Slct.getDebugLoc(), CCOp.getValueType(),
4077                          CCOp.getOperand(0), CCOp.getOperand(1), CC);
4078    return DAG.getNode(ISD::SELECT, N->getDebugLoc(), VT,
4079                       CCOp, OtherOp, Result);
4080  }
4081  return SDValue();
4082}
4083
4084/// PerformADDCombine - Target-specific dag combine xforms for ISD::ADD.
4085static SDValue PerformADDCombine(SDNode *N,
4086                                 TargetLowering::DAGCombinerInfo &DCI) {
4087  // added by evan in r37685 with no testcase.
4088  SDValue N0 = N->getOperand(0), N1 = N->getOperand(1);
4089
4090  // fold (add (select cc, 0, c), x) -> (select cc, x, (add, x, c))
4091  if (N0.getOpcode() == ISD::SELECT && N0.getNode()->hasOneUse()) {
4092    SDValue Result = combineSelectAndUse(N, N0, N1, DCI);
4093    if (Result.getNode()) return Result;
4094  }
4095  if (N1.getOpcode() == ISD::SELECT && N1.getNode()->hasOneUse()) {
4096    SDValue Result = combineSelectAndUse(N, N1, N0, DCI);
4097    if (Result.getNode()) return Result;
4098  }
4099
4100  return SDValue();
4101}
4102
4103/// PerformSUBCombine - Target-specific dag combine xforms for ISD::SUB.
4104static SDValue PerformSUBCombine(SDNode *N,
4105                                 TargetLowering::DAGCombinerInfo &DCI) {
4106  // added by evan in r37685 with no testcase.
4107  SDValue N0 = N->getOperand(0), N1 = N->getOperand(1);
4108
4109  // fold (sub x, (select cc, 0, c)) -> (select cc, x, (sub, x, c))
4110  if (N1.getOpcode() == ISD::SELECT && N1.getNode()->hasOneUse()) {
4111    SDValue Result = combineSelectAndUse(N, N1, N0, DCI);
4112    if (Result.getNode()) return Result;
4113  }
4114
4115  return SDValue();
4116}
4117
4118static SDValue PerformMULCombine(SDNode *N,
4119                                 TargetLowering::DAGCombinerInfo &DCI,
4120                                 const ARMSubtarget *Subtarget) {
4121  SelectionDAG &DAG = DCI.DAG;
4122
4123  if (Subtarget->isThumb1Only())
4124    return SDValue();
4125
4126  if (DAG.getMachineFunction().
4127      getFunction()->hasFnAttr(Attribute::OptimizeForSize))
4128    return SDValue();
4129
4130  if (DCI.isBeforeLegalize() || DCI.isCalledByLegalizer())
4131    return SDValue();
4132
4133  EVT VT = N->getValueType(0);
4134  if (VT != MVT::i32)
4135    return SDValue();
4136
4137  ConstantSDNode *C = dyn_cast<ConstantSDNode>(N->getOperand(1));
4138  if (!C)
4139    return SDValue();
4140
4141  uint64_t MulAmt = C->getZExtValue();
4142  unsigned ShiftAmt = CountTrailingZeros_64(MulAmt);
4143  ShiftAmt = ShiftAmt & (32 - 1);
4144  SDValue V = N->getOperand(0);
4145  DebugLoc DL = N->getDebugLoc();
4146
4147  SDValue Res;
4148  MulAmt >>= ShiftAmt;
4149  if (isPowerOf2_32(MulAmt - 1)) {
4150    // (mul x, 2^N + 1) => (add (shl x, N), x)
4151    Res = DAG.getNode(ISD::ADD, DL, VT,
4152                      V, DAG.getNode(ISD::SHL, DL, VT,
4153                                     V, DAG.getConstant(Log2_32(MulAmt-1),
4154                                                        MVT::i32)));
4155  } else if (isPowerOf2_32(MulAmt + 1)) {
4156    // (mul x, 2^N - 1) => (sub (shl x, N), x)
4157    Res = DAG.getNode(ISD::SUB, DL, VT,
4158                      DAG.getNode(ISD::SHL, DL, VT,
4159                                  V, DAG.getConstant(Log2_32(MulAmt+1),
4160                                                     MVT::i32)),
4161                                                     V);
4162  } else
4163    return SDValue();
4164
4165  if (ShiftAmt != 0)
4166    Res = DAG.getNode(ISD::SHL, DL, VT, Res,
4167                      DAG.getConstant(ShiftAmt, MVT::i32));
4168
4169  // Do not add new nodes to DAG combiner worklist.
4170  DCI.CombineTo(N, Res, false);
4171  return SDValue();
4172}
4173
4174/// PerformVMOVRRDCombine - Target-specific dag combine xforms for
4175/// ARMISD::VMOVRRD.
4176static SDValue PerformVMOVRRDCombine(SDNode *N,
4177                                   TargetLowering::DAGCombinerInfo &DCI) {
4178  // fmrrd(fmdrr x, y) -> x,y
4179  SDValue InDouble = N->getOperand(0);
4180  if (InDouble.getOpcode() == ARMISD::VMOVDRR)
4181    return DCI.CombineTo(N, InDouble.getOperand(0), InDouble.getOperand(1));
4182  return SDValue();
4183}
4184
4185/// getVShiftImm - Check if this is a valid build_vector for the immediate
4186/// operand of a vector shift operation, where all the elements of the
4187/// build_vector must have the same constant integer value.
4188static bool getVShiftImm(SDValue Op, unsigned ElementBits, int64_t &Cnt) {
4189  // Ignore bit_converts.
4190  while (Op.getOpcode() == ISD::BIT_CONVERT)
4191    Op = Op.getOperand(0);
4192  BuildVectorSDNode *BVN = dyn_cast<BuildVectorSDNode>(Op.getNode());
4193  APInt SplatBits, SplatUndef;
4194  unsigned SplatBitSize;
4195  bool HasAnyUndefs;
4196  if (! BVN || ! BVN->isConstantSplat(SplatBits, SplatUndef, SplatBitSize,
4197                                      HasAnyUndefs, ElementBits) ||
4198      SplatBitSize > ElementBits)
4199    return false;
4200  Cnt = SplatBits.getSExtValue();
4201  return true;
4202}
4203
4204/// isVShiftLImm - Check if this is a valid build_vector for the immediate
4205/// operand of a vector shift left operation.  That value must be in the range:
4206///   0 <= Value < ElementBits for a left shift; or
4207///   0 <= Value <= ElementBits for a long left shift.
4208static bool isVShiftLImm(SDValue Op, EVT VT, bool isLong, int64_t &Cnt) {
4209  assert(VT.isVector() && "vector shift count is not a vector type");
4210  unsigned ElementBits = VT.getVectorElementType().getSizeInBits();
4211  if (! getVShiftImm(Op, ElementBits, Cnt))
4212    return false;
4213  return (Cnt >= 0 && (isLong ? Cnt-1 : Cnt) < ElementBits);
4214}
4215
4216/// isVShiftRImm - Check if this is a valid build_vector for the immediate
4217/// operand of a vector shift right operation.  For a shift opcode, the value
4218/// is positive, but for an intrinsic the value count must be negative. The
4219/// absolute value must be in the range:
4220///   1 <= |Value| <= ElementBits for a right shift; or
4221///   1 <= |Value| <= ElementBits/2 for a narrow right shift.
4222static bool isVShiftRImm(SDValue Op, EVT VT, bool isNarrow, bool isIntrinsic,
4223                         int64_t &Cnt) {
4224  assert(VT.isVector() && "vector shift count is not a vector type");
4225  unsigned ElementBits = VT.getVectorElementType().getSizeInBits();
4226  if (! getVShiftImm(Op, ElementBits, Cnt))
4227    return false;
4228  if (isIntrinsic)
4229    Cnt = -Cnt;
4230  return (Cnt >= 1 && Cnt <= (isNarrow ? ElementBits/2 : ElementBits));
4231}
4232
4233/// PerformIntrinsicCombine - ARM-specific DAG combining for intrinsics.
4234static SDValue PerformIntrinsicCombine(SDNode *N, SelectionDAG &DAG) {
4235  unsigned IntNo = cast<ConstantSDNode>(N->getOperand(0))->getZExtValue();
4236  switch (IntNo) {
4237  default:
4238    // Don't do anything for most intrinsics.
4239    break;
4240
4241  // Vector shifts: check for immediate versions and lower them.
4242  // Note: This is done during DAG combining instead of DAG legalizing because
4243  // the build_vectors for 64-bit vector element shift counts are generally
4244  // not legal, and it is hard to see their values after they get legalized to
4245  // loads from a constant pool.
4246  case Intrinsic::arm_neon_vshifts:
4247  case Intrinsic::arm_neon_vshiftu:
4248  case Intrinsic::arm_neon_vshiftls:
4249  case Intrinsic::arm_neon_vshiftlu:
4250  case Intrinsic::arm_neon_vshiftn:
4251  case Intrinsic::arm_neon_vrshifts:
4252  case Intrinsic::arm_neon_vrshiftu:
4253  case Intrinsic::arm_neon_vrshiftn:
4254  case Intrinsic::arm_neon_vqshifts:
4255  case Intrinsic::arm_neon_vqshiftu:
4256  case Intrinsic::arm_neon_vqshiftsu:
4257  case Intrinsic::arm_neon_vqshiftns:
4258  case Intrinsic::arm_neon_vqshiftnu:
4259  case Intrinsic::arm_neon_vqshiftnsu:
4260  case Intrinsic::arm_neon_vqrshiftns:
4261  case Intrinsic::arm_neon_vqrshiftnu:
4262  case Intrinsic::arm_neon_vqrshiftnsu: {
4263    EVT VT = N->getOperand(1).getValueType();
4264    int64_t Cnt;
4265    unsigned VShiftOpc = 0;
4266
4267    switch (IntNo) {
4268    case Intrinsic::arm_neon_vshifts:
4269    case Intrinsic::arm_neon_vshiftu:
4270      if (isVShiftLImm(N->getOperand(2), VT, false, Cnt)) {
4271        VShiftOpc = ARMISD::VSHL;
4272        break;
4273      }
4274      if (isVShiftRImm(N->getOperand(2), VT, false, true, Cnt)) {
4275        VShiftOpc = (IntNo == Intrinsic::arm_neon_vshifts ?
4276                     ARMISD::VSHRs : ARMISD::VSHRu);
4277        break;
4278      }
4279      return SDValue();
4280
4281    case Intrinsic::arm_neon_vshiftls:
4282    case Intrinsic::arm_neon_vshiftlu:
4283      if (isVShiftLImm(N->getOperand(2), VT, true, Cnt))
4284        break;
4285      llvm_unreachable("invalid shift count for vshll intrinsic");
4286
4287    case Intrinsic::arm_neon_vrshifts:
4288    case Intrinsic::arm_neon_vrshiftu:
4289      if (isVShiftRImm(N->getOperand(2), VT, false, true, Cnt))
4290        break;
4291      return SDValue();
4292
4293    case Intrinsic::arm_neon_vqshifts:
4294    case Intrinsic::arm_neon_vqshiftu:
4295      if (isVShiftLImm(N->getOperand(2), VT, false, Cnt))
4296        break;
4297      return SDValue();
4298
4299    case Intrinsic::arm_neon_vqshiftsu:
4300      if (isVShiftLImm(N->getOperand(2), VT, false, Cnt))
4301        break;
4302      llvm_unreachable("invalid shift count for vqshlu intrinsic");
4303
4304    case Intrinsic::arm_neon_vshiftn:
4305    case Intrinsic::arm_neon_vrshiftn:
4306    case Intrinsic::arm_neon_vqshiftns:
4307    case Intrinsic::arm_neon_vqshiftnu:
4308    case Intrinsic::arm_neon_vqshiftnsu:
4309    case Intrinsic::arm_neon_vqrshiftns:
4310    case Intrinsic::arm_neon_vqrshiftnu:
4311    case Intrinsic::arm_neon_vqrshiftnsu:
4312      // Narrowing shifts require an immediate right shift.
4313      if (isVShiftRImm(N->getOperand(2), VT, true, true, Cnt))
4314        break;
4315      llvm_unreachable("invalid shift count for narrowing vector shift "
4316                       "intrinsic");
4317
4318    default:
4319      llvm_unreachable("unhandled vector shift");
4320    }
4321
4322    switch (IntNo) {
4323    case Intrinsic::arm_neon_vshifts:
4324    case Intrinsic::arm_neon_vshiftu:
4325      // Opcode already set above.
4326      break;
4327    case Intrinsic::arm_neon_vshiftls:
4328    case Intrinsic::arm_neon_vshiftlu:
4329      if (Cnt == VT.getVectorElementType().getSizeInBits())
4330        VShiftOpc = ARMISD::VSHLLi;
4331      else
4332        VShiftOpc = (IntNo == Intrinsic::arm_neon_vshiftls ?
4333                     ARMISD::VSHLLs : ARMISD::VSHLLu);
4334      break;
4335    case Intrinsic::arm_neon_vshiftn:
4336      VShiftOpc = ARMISD::VSHRN; break;
4337    case Intrinsic::arm_neon_vrshifts:
4338      VShiftOpc = ARMISD::VRSHRs; break;
4339    case Intrinsic::arm_neon_vrshiftu:
4340      VShiftOpc = ARMISD::VRSHRu; break;
4341    case Intrinsic::arm_neon_vrshiftn:
4342      VShiftOpc = ARMISD::VRSHRN; break;
4343    case Intrinsic::arm_neon_vqshifts:
4344      VShiftOpc = ARMISD::VQSHLs; break;
4345    case Intrinsic::arm_neon_vqshiftu:
4346      VShiftOpc = ARMISD::VQSHLu; break;
4347    case Intrinsic::arm_neon_vqshiftsu:
4348      VShiftOpc = ARMISD::VQSHLsu; break;
4349    case Intrinsic::arm_neon_vqshiftns:
4350      VShiftOpc = ARMISD::VQSHRNs; break;
4351    case Intrinsic::arm_neon_vqshiftnu:
4352      VShiftOpc = ARMISD::VQSHRNu; break;
4353    case Intrinsic::arm_neon_vqshiftnsu:
4354      VShiftOpc = ARMISD::VQSHRNsu; break;
4355    case Intrinsic::arm_neon_vqrshiftns:
4356      VShiftOpc = ARMISD::VQRSHRNs; break;
4357    case Intrinsic::arm_neon_vqrshiftnu:
4358      VShiftOpc = ARMISD::VQRSHRNu; break;
4359    case Intrinsic::arm_neon_vqrshiftnsu:
4360      VShiftOpc = ARMISD::VQRSHRNsu; break;
4361    }
4362
4363    return DAG.getNode(VShiftOpc, N->getDebugLoc(), N->getValueType(0),
4364                       N->getOperand(1), DAG.getConstant(Cnt, MVT::i32));
4365  }
4366
4367  case Intrinsic::arm_neon_vshiftins: {
4368    EVT VT = N->getOperand(1).getValueType();
4369    int64_t Cnt;
4370    unsigned VShiftOpc = 0;
4371
4372    if (isVShiftLImm(N->getOperand(3), VT, false, Cnt))
4373      VShiftOpc = ARMISD::VSLI;
4374    else if (isVShiftRImm(N->getOperand(3), VT, false, true, Cnt))
4375      VShiftOpc = ARMISD::VSRI;
4376    else {
4377      llvm_unreachable("invalid shift count for vsli/vsri intrinsic");
4378    }
4379
4380    return DAG.getNode(VShiftOpc, N->getDebugLoc(), N->getValueType(0),
4381                       N->getOperand(1), N->getOperand(2),
4382                       DAG.getConstant(Cnt, MVT::i32));
4383  }
4384
4385  case Intrinsic::arm_neon_vqrshifts:
4386  case Intrinsic::arm_neon_vqrshiftu:
4387    // No immediate versions of these to check for.
4388    break;
4389  }
4390
4391  return SDValue();
4392}
4393
4394/// PerformShiftCombine - Checks for immediate versions of vector shifts and
4395/// lowers them.  As with the vector shift intrinsics, this is done during DAG
4396/// combining instead of DAG legalizing because the build_vectors for 64-bit
4397/// vector element shift counts are generally not legal, and it is hard to see
4398/// their values after they get legalized to loads from a constant pool.
4399static SDValue PerformShiftCombine(SDNode *N, SelectionDAG &DAG,
4400                                   const ARMSubtarget *ST) {
4401  EVT VT = N->getValueType(0);
4402
4403  // Nothing to be done for scalar shifts.
4404  if (! VT.isVector())
4405    return SDValue();
4406
4407  assert(ST->hasNEON() && "unexpected vector shift");
4408  int64_t Cnt;
4409
4410  switch (N->getOpcode()) {
4411  default: llvm_unreachable("unexpected shift opcode");
4412
4413  case ISD::SHL:
4414    if (isVShiftLImm(N->getOperand(1), VT, false, Cnt))
4415      return DAG.getNode(ARMISD::VSHL, N->getDebugLoc(), VT, N->getOperand(0),
4416                         DAG.getConstant(Cnt, MVT::i32));
4417    break;
4418
4419  case ISD::SRA:
4420  case ISD::SRL:
4421    if (isVShiftRImm(N->getOperand(1), VT, false, false, Cnt)) {
4422      unsigned VShiftOpc = (N->getOpcode() == ISD::SRA ?
4423                            ARMISD::VSHRs : ARMISD::VSHRu);
4424      return DAG.getNode(VShiftOpc, N->getDebugLoc(), VT, N->getOperand(0),
4425                         DAG.getConstant(Cnt, MVT::i32));
4426    }
4427  }
4428  return SDValue();
4429}
4430
4431/// PerformExtendCombine - Target-specific DAG combining for ISD::SIGN_EXTEND,
4432/// ISD::ZERO_EXTEND, and ISD::ANY_EXTEND.
4433static SDValue PerformExtendCombine(SDNode *N, SelectionDAG &DAG,
4434                                    const ARMSubtarget *ST) {
4435  SDValue N0 = N->getOperand(0);
4436
4437  // Check for sign- and zero-extensions of vector extract operations of 8-
4438  // and 16-bit vector elements.  NEON supports these directly.  They are
4439  // handled during DAG combining because type legalization will promote them
4440  // to 32-bit types and it is messy to recognize the operations after that.
4441  if (ST->hasNEON() && N0.getOpcode() == ISD::EXTRACT_VECTOR_ELT) {
4442    SDValue Vec = N0.getOperand(0);
4443    SDValue Lane = N0.getOperand(1);
4444    EVT VT = N->getValueType(0);
4445    EVT EltVT = N0.getValueType();
4446    const TargetLowering &TLI = DAG.getTargetLoweringInfo();
4447
4448    if (VT == MVT::i32 &&
4449        (EltVT == MVT::i8 || EltVT == MVT::i16) &&
4450        TLI.isTypeLegal(Vec.getValueType())) {
4451
4452      unsigned Opc = 0;
4453      switch (N->getOpcode()) {
4454      default: llvm_unreachable("unexpected opcode");
4455      case ISD::SIGN_EXTEND:
4456        Opc = ARMISD::VGETLANEs;
4457        break;
4458      case ISD::ZERO_EXTEND:
4459      case ISD::ANY_EXTEND:
4460        Opc = ARMISD::VGETLANEu;
4461        break;
4462      }
4463      return DAG.getNode(Opc, N->getDebugLoc(), VT, Vec, Lane);
4464    }
4465  }
4466
4467  return SDValue();
4468}
4469
4470/// PerformSELECT_CCCombine - Target-specific DAG combining for ISD::SELECT_CC
4471/// to match f32 max/min patterns to use NEON vmax/vmin instructions.
4472static SDValue PerformSELECT_CCCombine(SDNode *N, SelectionDAG &DAG,
4473                                       const ARMSubtarget *ST) {
4474  // If the target supports NEON, try to use vmax/vmin instructions for f32
4475  // selects like "x < y ? x : y".  Unless the FiniteOnlyFPMath option is set,
4476  // be careful about NaNs:  NEON's vmax/vmin return NaN if either operand is
4477  // a NaN; only do the transformation when it matches that behavior.
4478
4479  // For now only do this when using NEON for FP operations; if using VFP, it
4480  // is not obvious that the benefit outweighs the cost of switching to the
4481  // NEON pipeline.
4482  if (!ST->hasNEON() || !ST->useNEONForSinglePrecisionFP() ||
4483      N->getValueType(0) != MVT::f32)
4484    return SDValue();
4485
4486  SDValue CondLHS = N->getOperand(0);
4487  SDValue CondRHS = N->getOperand(1);
4488  SDValue LHS = N->getOperand(2);
4489  SDValue RHS = N->getOperand(3);
4490  ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(4))->get();
4491
4492  unsigned Opcode = 0;
4493  bool IsReversed;
4494  if (DAG.isEqualTo(LHS, CondLHS) && DAG.isEqualTo(RHS, CondRHS)) {
4495    IsReversed = false; // x CC y ? x : y
4496  } else if (DAG.isEqualTo(LHS, CondRHS) && DAG.isEqualTo(RHS, CondLHS)) {
4497    IsReversed = true ; // x CC y ? y : x
4498  } else {
4499    return SDValue();
4500  }
4501
4502  bool IsUnordered;
4503  switch (CC) {
4504  default: break;
4505  case ISD::SETOLT:
4506  case ISD::SETOLE:
4507  case ISD::SETLT:
4508  case ISD::SETLE:
4509  case ISD::SETULT:
4510  case ISD::SETULE:
4511    // If LHS is NaN, an ordered comparison will be false and the result will
4512    // be the RHS, but vmin(NaN, RHS) = NaN.  Avoid this by checking that LHS
4513    // != NaN.  Likewise, for unordered comparisons, check for RHS != NaN.
4514    IsUnordered = (CC == ISD::SETULT || CC == ISD::SETULE);
4515    if (!DAG.isKnownNeverNaN(IsUnordered ? RHS : LHS))
4516      break;
4517    // For less-than-or-equal comparisons, "+0 <= -0" will be true but vmin
4518    // will return -0, so vmin can only be used for unsafe math or if one of
4519    // the operands is known to be nonzero.
4520    if ((CC == ISD::SETLE || CC == ISD::SETOLE || CC == ISD::SETULE) &&
4521        !UnsafeFPMath &&
4522        !(DAG.isKnownNeverZero(LHS) || DAG.isKnownNeverZero(RHS)))
4523      break;
4524    Opcode = IsReversed ? ARMISD::FMAX : ARMISD::FMIN;
4525    break;
4526
4527  case ISD::SETOGT:
4528  case ISD::SETOGE:
4529  case ISD::SETGT:
4530  case ISD::SETGE:
4531  case ISD::SETUGT:
4532  case ISD::SETUGE:
4533    // If LHS is NaN, an ordered comparison will be false and the result will
4534    // be the RHS, but vmax(NaN, RHS) = NaN.  Avoid this by checking that LHS
4535    // != NaN.  Likewise, for unordered comparisons, check for RHS != NaN.
4536    IsUnordered = (CC == ISD::SETUGT || CC == ISD::SETUGE);
4537    if (!DAG.isKnownNeverNaN(IsUnordered ? RHS : LHS))
4538      break;
4539    // For greater-than-or-equal comparisons, "-0 >= +0" will be true but vmax
4540    // will return +0, so vmax can only be used for unsafe math or if one of
4541    // the operands is known to be nonzero.
4542    if ((CC == ISD::SETGE || CC == ISD::SETOGE || CC == ISD::SETUGE) &&
4543        !UnsafeFPMath &&
4544        !(DAG.isKnownNeverZero(LHS) || DAG.isKnownNeverZero(RHS)))
4545      break;
4546    Opcode = IsReversed ? ARMISD::FMIN : ARMISD::FMAX;
4547    break;
4548  }
4549
4550  if (!Opcode)
4551    return SDValue();
4552  return DAG.getNode(Opcode, N->getDebugLoc(), N->getValueType(0), LHS, RHS);
4553}
4554
4555SDValue ARMTargetLowering::PerformDAGCombine(SDNode *N,
4556                                             DAGCombinerInfo &DCI) const {
4557  switch (N->getOpcode()) {
4558  default: break;
4559  case ISD::ADD:        return PerformADDCombine(N, DCI);
4560  case ISD::SUB:        return PerformSUBCombine(N, DCI);
4561  case ISD::MUL:        return PerformMULCombine(N, DCI, Subtarget);
4562  case ARMISD::VMOVRRD: return PerformVMOVRRDCombine(N, DCI);
4563  case ISD::INTRINSIC_WO_CHAIN: return PerformIntrinsicCombine(N, DCI.DAG);
4564  case ISD::SHL:
4565  case ISD::SRA:
4566  case ISD::SRL:        return PerformShiftCombine(N, DCI.DAG, Subtarget);
4567  case ISD::SIGN_EXTEND:
4568  case ISD::ZERO_EXTEND:
4569  case ISD::ANY_EXTEND: return PerformExtendCombine(N, DCI.DAG, Subtarget);
4570  case ISD::SELECT_CC:  return PerformSELECT_CCCombine(N, DCI.DAG, Subtarget);
4571  }
4572  return SDValue();
4573}
4574
4575bool ARMTargetLowering::allowsUnalignedMemoryAccesses(EVT VT) const {
4576  if (!Subtarget->hasV6Ops())
4577    // Pre-v6 does not support unaligned mem access.
4578    return false;
4579
4580  // v6+ may or may not support unaligned mem access depending on the system
4581  // configuration.
4582  // FIXME: This is pretty conservative. Should we provide cmdline option to
4583  // control the behaviour?
4584  if (!Subtarget->isTargetDarwin())
4585    return false;
4586
4587  switch (VT.getSimpleVT().SimpleTy) {
4588  default:
4589    return false;
4590  case MVT::i8:
4591  case MVT::i16:
4592  case MVT::i32:
4593    return true;
4594  // FIXME: VLD1 etc with standard alignment is legal.
4595  }
4596}
4597
4598static bool isLegalT1AddressImmediate(int64_t V, EVT VT) {
4599  if (V < 0)
4600    return false;
4601
4602  unsigned Scale = 1;
4603  switch (VT.getSimpleVT().SimpleTy) {
4604  default: return false;
4605  case MVT::i1:
4606  case MVT::i8:
4607    // Scale == 1;
4608    break;
4609  case MVT::i16:
4610    // Scale == 2;
4611    Scale = 2;
4612    break;
4613  case MVT::i32:
4614    // Scale == 4;
4615    Scale = 4;
4616    break;
4617  }
4618
4619  if ((V & (Scale - 1)) != 0)
4620    return false;
4621  V /= Scale;
4622  return V == (V & ((1LL << 5) - 1));
4623}
4624
4625static bool isLegalT2AddressImmediate(int64_t V, EVT VT,
4626                                      const ARMSubtarget *Subtarget) {
4627  bool isNeg = false;
4628  if (V < 0) {
4629    isNeg = true;
4630    V = - V;
4631  }
4632
4633  switch (VT.getSimpleVT().SimpleTy) {
4634  default: return false;
4635  case MVT::i1:
4636  case MVT::i8:
4637  case MVT::i16:
4638  case MVT::i32:
4639    // + imm12 or - imm8
4640    if (isNeg)
4641      return V == (V & ((1LL << 8) - 1));
4642    return V == (V & ((1LL << 12) - 1));
4643  case MVT::f32:
4644  case MVT::f64:
4645    // Same as ARM mode. FIXME: NEON?
4646    if (!Subtarget->hasVFP2())
4647      return false;
4648    if ((V & 3) != 0)
4649      return false;
4650    V >>= 2;
4651    return V == (V & ((1LL << 8) - 1));
4652  }
4653}
4654
4655/// isLegalAddressImmediate - Return true if the integer value can be used
4656/// as the offset of the target addressing mode for load / store of the
4657/// given type.
4658static bool isLegalAddressImmediate(int64_t V, EVT VT,
4659                                    const ARMSubtarget *Subtarget) {
4660  if (V == 0)
4661    return true;
4662
4663  if (!VT.isSimple())
4664    return false;
4665
4666  if (Subtarget->isThumb1Only())
4667    return isLegalT1AddressImmediate(V, VT);
4668  else if (Subtarget->isThumb2())
4669    return isLegalT2AddressImmediate(V, VT, Subtarget);
4670
4671  // ARM mode.
4672  if (V < 0)
4673    V = - V;
4674  switch (VT.getSimpleVT().SimpleTy) {
4675  default: return false;
4676  case MVT::i1:
4677  case MVT::i8:
4678  case MVT::i32:
4679    // +- imm12
4680    return V == (V & ((1LL << 12) - 1));
4681  case MVT::i16:
4682    // +- imm8
4683    return V == (V & ((1LL << 8) - 1));
4684  case MVT::f32:
4685  case MVT::f64:
4686    if (!Subtarget->hasVFP2()) // FIXME: NEON?
4687      return false;
4688    if ((V & 3) != 0)
4689      return false;
4690    V >>= 2;
4691    return V == (V & ((1LL << 8) - 1));
4692  }
4693}
4694
4695bool ARMTargetLowering::isLegalT2ScaledAddressingMode(const AddrMode &AM,
4696                                                      EVT VT) const {
4697  int Scale = AM.Scale;
4698  if (Scale < 0)
4699    return false;
4700
4701  switch (VT.getSimpleVT().SimpleTy) {
4702  default: return false;
4703  case MVT::i1:
4704  case MVT::i8:
4705  case MVT::i16:
4706  case MVT::i32:
4707    if (Scale == 1)
4708      return true;
4709    // r + r << imm
4710    Scale = Scale & ~1;
4711    return Scale == 2 || Scale == 4 || Scale == 8;
4712  case MVT::i64:
4713    // r + r
4714    if (((unsigned)AM.HasBaseReg + Scale) <= 2)
4715      return true;
4716    return false;
4717  case MVT::isVoid:
4718    // Note, we allow "void" uses (basically, uses that aren't loads or
4719    // stores), because arm allows folding a scale into many arithmetic
4720    // operations.  This should be made more precise and revisited later.
4721
4722    // Allow r << imm, but the imm has to be a multiple of two.
4723    if (Scale & 1) return false;
4724    return isPowerOf2_32(Scale);
4725  }
4726}
4727
4728/// isLegalAddressingMode - Return true if the addressing mode represented
4729/// by AM is legal for this target, for a load/store of the specified type.
4730bool ARMTargetLowering::isLegalAddressingMode(const AddrMode &AM,
4731                                              const Type *Ty) const {
4732  EVT VT = getValueType(Ty, true);
4733  if (!isLegalAddressImmediate(AM.BaseOffs, VT, Subtarget))
4734    return false;
4735
4736  // Can never fold addr of global into load/store.
4737  if (AM.BaseGV)
4738    return false;
4739
4740  switch (AM.Scale) {
4741  case 0:  // no scale reg, must be "r+i" or "r", or "i".
4742    break;
4743  case 1:
4744    if (Subtarget->isThumb1Only())
4745      return false;
4746    // FALL THROUGH.
4747  default:
4748    // ARM doesn't support any R+R*scale+imm addr modes.
4749    if (AM.BaseOffs)
4750      return false;
4751
4752    if (!VT.isSimple())
4753      return false;
4754
4755    if (Subtarget->isThumb2())
4756      return isLegalT2ScaledAddressingMode(AM, VT);
4757
4758    int Scale = AM.Scale;
4759    switch (VT.getSimpleVT().SimpleTy) {
4760    default: return false;
4761    case MVT::i1:
4762    case MVT::i8:
4763    case MVT::i32:
4764      if (Scale < 0) Scale = -Scale;
4765      if (Scale == 1)
4766        return true;
4767      // r + r << imm
4768      return isPowerOf2_32(Scale & ~1);
4769    case MVT::i16:
4770    case MVT::i64:
4771      // r + r
4772      if (((unsigned)AM.HasBaseReg + Scale) <= 2)
4773        return true;
4774      return false;
4775
4776    case MVT::isVoid:
4777      // Note, we allow "void" uses (basically, uses that aren't loads or
4778      // stores), because arm allows folding a scale into many arithmetic
4779      // operations.  This should be made more precise and revisited later.
4780
4781      // Allow r << imm, but the imm has to be a multiple of two.
4782      if (Scale & 1) return false;
4783      return isPowerOf2_32(Scale);
4784    }
4785    break;
4786  }
4787  return true;
4788}
4789
4790/// isLegalICmpImmediate - Return true if the specified immediate is legal
4791/// icmp immediate, that is the target has icmp instructions which can compare
4792/// a register against the immediate without having to materialize the
4793/// immediate into a register.
4794bool ARMTargetLowering::isLegalICmpImmediate(int64_t Imm) const {
4795  if (!Subtarget->isThumb())
4796    return ARM_AM::getSOImmVal(Imm) != -1;
4797  if (Subtarget->isThumb2())
4798    return ARM_AM::getT2SOImmVal(Imm) != -1;
4799  return Imm >= 0 && Imm <= 255;
4800}
4801
4802static bool getARMIndexedAddressParts(SDNode *Ptr, EVT VT,
4803                                      bool isSEXTLoad, SDValue &Base,
4804                                      SDValue &Offset, bool &isInc,
4805                                      SelectionDAG &DAG) {
4806  if (Ptr->getOpcode() != ISD::ADD && Ptr->getOpcode() != ISD::SUB)
4807    return false;
4808
4809  if (VT == MVT::i16 || ((VT == MVT::i8 || VT == MVT::i1) && isSEXTLoad)) {
4810    // AddressingMode 3
4811    Base = Ptr->getOperand(0);
4812    if (ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(Ptr->getOperand(1))) {
4813      int RHSC = (int)RHS->getZExtValue();
4814      if (RHSC < 0 && RHSC > -256) {
4815        assert(Ptr->getOpcode() == ISD::ADD);
4816        isInc = false;
4817        Offset = DAG.getConstant(-RHSC, RHS->getValueType(0));
4818        return true;
4819      }
4820    }
4821    isInc = (Ptr->getOpcode() == ISD::ADD);
4822    Offset = Ptr->getOperand(1);
4823    return true;
4824  } else if (VT == MVT::i32 || VT == MVT::i8 || VT == MVT::i1) {
4825    // AddressingMode 2
4826    if (ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(Ptr->getOperand(1))) {
4827      int RHSC = (int)RHS->getZExtValue();
4828      if (RHSC < 0 && RHSC > -0x1000) {
4829        assert(Ptr->getOpcode() == ISD::ADD);
4830        isInc = false;
4831        Offset = DAG.getConstant(-RHSC, RHS->getValueType(0));
4832        Base = Ptr->getOperand(0);
4833        return true;
4834      }
4835    }
4836
4837    if (Ptr->getOpcode() == ISD::ADD) {
4838      isInc = true;
4839      ARM_AM::ShiftOpc ShOpcVal= ARM_AM::getShiftOpcForNode(Ptr->getOperand(0));
4840      if (ShOpcVal != ARM_AM::no_shift) {
4841        Base = Ptr->getOperand(1);
4842        Offset = Ptr->getOperand(0);
4843      } else {
4844        Base = Ptr->getOperand(0);
4845        Offset = Ptr->getOperand(1);
4846      }
4847      return true;
4848    }
4849
4850    isInc = (Ptr->getOpcode() == ISD::ADD);
4851    Base = Ptr->getOperand(0);
4852    Offset = Ptr->getOperand(1);
4853    return true;
4854  }
4855
4856  // FIXME: Use VLDM / VSTM to emulate indexed FP load / store.
4857  return false;
4858}
4859
4860static bool getT2IndexedAddressParts(SDNode *Ptr, EVT VT,
4861                                     bool isSEXTLoad, SDValue &Base,
4862                                     SDValue &Offset, bool &isInc,
4863                                     SelectionDAG &DAG) {
4864  if (Ptr->getOpcode() != ISD::ADD && Ptr->getOpcode() != ISD::SUB)
4865    return false;
4866
4867  Base = Ptr->getOperand(0);
4868  if (ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(Ptr->getOperand(1))) {
4869    int RHSC = (int)RHS->getZExtValue();
4870    if (RHSC < 0 && RHSC > -0x100) { // 8 bits.
4871      assert(Ptr->getOpcode() == ISD::ADD);
4872      isInc = false;
4873      Offset = DAG.getConstant(-RHSC, RHS->getValueType(0));
4874      return true;
4875    } else if (RHSC > 0 && RHSC < 0x100) { // 8 bit, no zero.
4876      isInc = Ptr->getOpcode() == ISD::ADD;
4877      Offset = DAG.getConstant(RHSC, RHS->getValueType(0));
4878      return true;
4879    }
4880  }
4881
4882  return false;
4883}
4884
4885/// getPreIndexedAddressParts - returns true by value, base pointer and
4886/// offset pointer and addressing mode by reference if the node's address
4887/// can be legally represented as pre-indexed load / store address.
4888bool
4889ARMTargetLowering::getPreIndexedAddressParts(SDNode *N, SDValue &Base,
4890                                             SDValue &Offset,
4891                                             ISD::MemIndexedMode &AM,
4892                                             SelectionDAG &DAG) const {
4893  if (Subtarget->isThumb1Only())
4894    return false;
4895
4896  EVT VT;
4897  SDValue Ptr;
4898  bool isSEXTLoad = false;
4899  if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
4900    Ptr = LD->getBasePtr();
4901    VT  = LD->getMemoryVT();
4902    isSEXTLoad = LD->getExtensionType() == ISD::SEXTLOAD;
4903  } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
4904    Ptr = ST->getBasePtr();
4905    VT  = ST->getMemoryVT();
4906  } else
4907    return false;
4908
4909  bool isInc;
4910  bool isLegal = false;
4911  if (Subtarget->isThumb2())
4912    isLegal = getT2IndexedAddressParts(Ptr.getNode(), VT, isSEXTLoad, Base,
4913                                       Offset, isInc, DAG);
4914  else
4915    isLegal = getARMIndexedAddressParts(Ptr.getNode(), VT, isSEXTLoad, Base,
4916                                        Offset, isInc, DAG);
4917  if (!isLegal)
4918    return false;
4919
4920  AM = isInc ? ISD::PRE_INC : ISD::PRE_DEC;
4921  return true;
4922}
4923
4924/// getPostIndexedAddressParts - returns true by value, base pointer and
4925/// offset pointer and addressing mode by reference if this node can be
4926/// combined with a load / store to form a post-indexed load / store.
4927bool ARMTargetLowering::getPostIndexedAddressParts(SDNode *N, SDNode *Op,
4928                                                   SDValue &Base,
4929                                                   SDValue &Offset,
4930                                                   ISD::MemIndexedMode &AM,
4931                                                   SelectionDAG &DAG) const {
4932  if (Subtarget->isThumb1Only())
4933    return false;
4934
4935  EVT VT;
4936  SDValue Ptr;
4937  bool isSEXTLoad = false;
4938  if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
4939    VT  = LD->getMemoryVT();
4940    Ptr = LD->getBasePtr();
4941    isSEXTLoad = LD->getExtensionType() == ISD::SEXTLOAD;
4942  } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
4943    VT  = ST->getMemoryVT();
4944    Ptr = ST->getBasePtr();
4945  } else
4946    return false;
4947
4948  bool isInc;
4949  bool isLegal = false;
4950  if (Subtarget->isThumb2())
4951    isLegal = getT2IndexedAddressParts(Op, VT, isSEXTLoad, Base, Offset,
4952                                       isInc, DAG);
4953  else
4954    isLegal = getARMIndexedAddressParts(Op, VT, isSEXTLoad, Base, Offset,
4955                                        isInc, DAG);
4956  if (!isLegal)
4957    return false;
4958
4959  if (Ptr != Base) {
4960    // Swap base ptr and offset to catch more post-index load / store when
4961    // it's legal. In Thumb2 mode, offset must be an immediate.
4962    if (Ptr == Offset && Op->getOpcode() == ISD::ADD &&
4963        !Subtarget->isThumb2())
4964      std::swap(Base, Offset);
4965
4966    // Post-indexed load / store update the base pointer.
4967    if (Ptr != Base)
4968      return false;
4969  }
4970
4971  AM = isInc ? ISD::POST_INC : ISD::POST_DEC;
4972  return true;
4973}
4974
4975void ARMTargetLowering::computeMaskedBitsForTargetNode(const SDValue Op,
4976                                                       const APInt &Mask,
4977                                                       APInt &KnownZero,
4978                                                       APInt &KnownOne,
4979                                                       const SelectionDAG &DAG,
4980                                                       unsigned Depth) const {
4981  KnownZero = KnownOne = APInt(Mask.getBitWidth(), 0);
4982  switch (Op.getOpcode()) {
4983  default: break;
4984  case ARMISD::CMOV: {
4985    // Bits are known zero/one if known on the LHS and RHS.
4986    DAG.ComputeMaskedBits(Op.getOperand(0), Mask, KnownZero, KnownOne, Depth+1);
4987    if (KnownZero == 0 && KnownOne == 0) return;
4988
4989    APInt KnownZeroRHS, KnownOneRHS;
4990    DAG.ComputeMaskedBits(Op.getOperand(1), Mask,
4991                          KnownZeroRHS, KnownOneRHS, Depth+1);
4992    KnownZero &= KnownZeroRHS;
4993    KnownOne  &= KnownOneRHS;
4994    return;
4995  }
4996  }
4997}
4998
4999//===----------------------------------------------------------------------===//
5000//                           ARM Inline Assembly Support
5001//===----------------------------------------------------------------------===//
5002
5003/// getConstraintType - Given a constraint letter, return the type of
5004/// constraint it is for this target.
5005ARMTargetLowering::ConstraintType
5006ARMTargetLowering::getConstraintType(const std::string &Constraint) const {
5007  if (Constraint.size() == 1) {
5008    switch (Constraint[0]) {
5009    default:  break;
5010    case 'l': return C_RegisterClass;
5011    case 'w': return C_RegisterClass;
5012    }
5013  }
5014  return TargetLowering::getConstraintType(Constraint);
5015}
5016
5017std::pair<unsigned, const TargetRegisterClass*>
5018ARMTargetLowering::getRegForInlineAsmConstraint(const std::string &Constraint,
5019                                                EVT VT) const {
5020  if (Constraint.size() == 1) {
5021    // GCC ARM Constraint Letters
5022    switch (Constraint[0]) {
5023    case 'l':
5024      if (Subtarget->isThumb())
5025        return std::make_pair(0U, ARM::tGPRRegisterClass);
5026      else
5027        return std::make_pair(0U, ARM::GPRRegisterClass);
5028    case 'r':
5029      return std::make_pair(0U, ARM::GPRRegisterClass);
5030    case 'w':
5031      if (VT == MVT::f32)
5032        return std::make_pair(0U, ARM::SPRRegisterClass);
5033      if (VT.getSizeInBits() == 64)
5034        return std::make_pair(0U, ARM::DPRRegisterClass);
5035      if (VT.getSizeInBits() == 128)
5036        return std::make_pair(0U, ARM::QPRRegisterClass);
5037      break;
5038    }
5039  }
5040  if (StringRef("{cc}").equals_lower(Constraint))
5041    return std::make_pair(unsigned(ARM::CPSR), ARM::CCRRegisterClass);
5042
5043  return TargetLowering::getRegForInlineAsmConstraint(Constraint, VT);
5044}
5045
5046std::vector<unsigned> ARMTargetLowering::
5047getRegClassForInlineAsmConstraint(const std::string &Constraint,
5048                                  EVT VT) const {
5049  if (Constraint.size() != 1)
5050    return std::vector<unsigned>();
5051
5052  switch (Constraint[0]) {      // GCC ARM Constraint Letters
5053  default: break;
5054  case 'l':
5055    return make_vector<unsigned>(ARM::R0, ARM::R1, ARM::R2, ARM::R3,
5056                                 ARM::R4, ARM::R5, ARM::R6, ARM::R7,
5057                                 0);
5058  case 'r':
5059    return make_vector<unsigned>(ARM::R0, ARM::R1, ARM::R2, ARM::R3,
5060                                 ARM::R4, ARM::R5, ARM::R6, ARM::R7,
5061                                 ARM::R8, ARM::R9, ARM::R10, ARM::R11,
5062                                 ARM::R12, ARM::LR, 0);
5063  case 'w':
5064    if (VT == MVT::f32)
5065      return make_vector<unsigned>(ARM::S0, ARM::S1, ARM::S2, ARM::S3,
5066                                   ARM::S4, ARM::S5, ARM::S6, ARM::S7,
5067                                   ARM::S8, ARM::S9, ARM::S10, ARM::S11,
5068                                   ARM::S12,ARM::S13,ARM::S14,ARM::S15,
5069                                   ARM::S16,ARM::S17,ARM::S18,ARM::S19,
5070                                   ARM::S20,ARM::S21,ARM::S22,ARM::S23,
5071                                   ARM::S24,ARM::S25,ARM::S26,ARM::S27,
5072                                   ARM::S28,ARM::S29,ARM::S30,ARM::S31, 0);
5073    if (VT.getSizeInBits() == 64)
5074      return make_vector<unsigned>(ARM::D0, ARM::D1, ARM::D2, ARM::D3,
5075                                   ARM::D4, ARM::D5, ARM::D6, ARM::D7,
5076                                   ARM::D8, ARM::D9, ARM::D10,ARM::D11,
5077                                   ARM::D12,ARM::D13,ARM::D14,ARM::D15, 0);
5078    if (VT.getSizeInBits() == 128)
5079      return make_vector<unsigned>(ARM::Q0, ARM::Q1, ARM::Q2, ARM::Q3,
5080                                   ARM::Q4, ARM::Q5, ARM::Q6, ARM::Q7, 0);
5081      break;
5082  }
5083
5084  return std::vector<unsigned>();
5085}
5086
5087/// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
5088/// vector.  If it is invalid, don't add anything to Ops.
5089void ARMTargetLowering::LowerAsmOperandForConstraint(SDValue Op,
5090                                                     char Constraint,
5091                                                     std::vector<SDValue>&Ops,
5092                                                     SelectionDAG &DAG) const {
5093  SDValue Result(0, 0);
5094
5095  switch (Constraint) {
5096  default: break;
5097  case 'I': case 'J': case 'K': case 'L':
5098  case 'M': case 'N': case 'O':
5099    ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op);
5100    if (!C)
5101      return;
5102
5103    int64_t CVal64 = C->getSExtValue();
5104    int CVal = (int) CVal64;
5105    // None of these constraints allow values larger than 32 bits.  Check
5106    // that the value fits in an int.
5107    if (CVal != CVal64)
5108      return;
5109
5110    switch (Constraint) {
5111      case 'I':
5112        if (Subtarget->isThumb1Only()) {
5113          // This must be a constant between 0 and 255, for ADD
5114          // immediates.
5115          if (CVal >= 0 && CVal <= 255)
5116            break;
5117        } else if (Subtarget->isThumb2()) {
5118          // A constant that can be used as an immediate value in a
5119          // data-processing instruction.
5120          if (ARM_AM::getT2SOImmVal(CVal) != -1)
5121            break;
5122        } else {
5123          // A constant that can be used as an immediate value in a
5124          // data-processing instruction.
5125          if (ARM_AM::getSOImmVal(CVal) != -1)
5126            break;
5127        }
5128        return;
5129
5130      case 'J':
5131        if (Subtarget->isThumb()) {  // FIXME thumb2
5132          // This must be a constant between -255 and -1, for negated ADD
5133          // immediates. This can be used in GCC with an "n" modifier that
5134          // prints the negated value, for use with SUB instructions. It is
5135          // not useful otherwise but is implemented for compatibility.
5136          if (CVal >= -255 && CVal <= -1)
5137            break;
5138        } else {
5139          // This must be a constant between -4095 and 4095. It is not clear
5140          // what this constraint is intended for. Implemented for
5141          // compatibility with GCC.
5142          if (CVal >= -4095 && CVal <= 4095)
5143            break;
5144        }
5145        return;
5146
5147      case 'K':
5148        if (Subtarget->isThumb1Only()) {
5149          // A 32-bit value where only one byte has a nonzero value. Exclude
5150          // zero to match GCC. This constraint is used by GCC internally for
5151          // constants that can be loaded with a move/shift combination.
5152          // It is not useful otherwise but is implemented for compatibility.
5153          if (CVal != 0 && ARM_AM::isThumbImmShiftedVal(CVal))
5154            break;
5155        } else if (Subtarget->isThumb2()) {
5156          // A constant whose bitwise inverse can be used as an immediate
5157          // value in a data-processing instruction. This can be used in GCC
5158          // with a "B" modifier that prints the inverted value, for use with
5159          // BIC and MVN instructions. It is not useful otherwise but is
5160          // implemented for compatibility.
5161          if (ARM_AM::getT2SOImmVal(~CVal) != -1)
5162            break;
5163        } else {
5164          // A constant whose bitwise inverse can be used as an immediate
5165          // value in a data-processing instruction. This can be used in GCC
5166          // with a "B" modifier that prints the inverted value, for use with
5167          // BIC and MVN instructions. It is not useful otherwise but is
5168          // implemented for compatibility.
5169          if (ARM_AM::getSOImmVal(~CVal) != -1)
5170            break;
5171        }
5172        return;
5173
5174      case 'L':
5175        if (Subtarget->isThumb1Only()) {
5176          // This must be a constant between -7 and 7,
5177          // for 3-operand ADD/SUB immediate instructions.
5178          if (CVal >= -7 && CVal < 7)
5179            break;
5180        } else if (Subtarget->isThumb2()) {
5181          // A constant whose negation can be used as an immediate value in a
5182          // data-processing instruction. This can be used in GCC with an "n"
5183          // modifier that prints the negated value, for use with SUB
5184          // instructions. It is not useful otherwise but is implemented for
5185          // compatibility.
5186          if (ARM_AM::getT2SOImmVal(-CVal) != -1)
5187            break;
5188        } else {
5189          // A constant whose negation can be used as an immediate value in a
5190          // data-processing instruction. This can be used in GCC with an "n"
5191          // modifier that prints the negated value, for use with SUB
5192          // instructions. It is not useful otherwise but is implemented for
5193          // compatibility.
5194          if (ARM_AM::getSOImmVal(-CVal) != -1)
5195            break;
5196        }
5197        return;
5198
5199      case 'M':
5200        if (Subtarget->isThumb()) { // FIXME thumb2
5201          // This must be a multiple of 4 between 0 and 1020, for
5202          // ADD sp + immediate.
5203          if ((CVal >= 0 && CVal <= 1020) && ((CVal & 3) == 0))
5204            break;
5205        } else {
5206          // A power of two or a constant between 0 and 32.  This is used in
5207          // GCC for the shift amount on shifted register operands, but it is
5208          // useful in general for any shift amounts.
5209          if ((CVal >= 0 && CVal <= 32) || ((CVal & (CVal - 1)) == 0))
5210            break;
5211        }
5212        return;
5213
5214      case 'N':
5215        if (Subtarget->isThumb()) {  // FIXME thumb2
5216          // This must be a constant between 0 and 31, for shift amounts.
5217          if (CVal >= 0 && CVal <= 31)
5218            break;
5219        }
5220        return;
5221
5222      case 'O':
5223        if (Subtarget->isThumb()) {  // FIXME thumb2
5224          // This must be a multiple of 4 between -508 and 508, for
5225          // ADD/SUB sp = sp + immediate.
5226          if ((CVal >= -508 && CVal <= 508) && ((CVal & 3) == 0))
5227            break;
5228        }
5229        return;
5230    }
5231    Result = DAG.getTargetConstant(CVal, Op.getValueType());
5232    break;
5233  }
5234
5235  if (Result.getNode()) {
5236    Ops.push_back(Result);
5237    return;
5238  }
5239  return TargetLowering::LowerAsmOperandForConstraint(Op, Constraint, Ops, DAG);
5240}
5241
5242bool
5243ARMTargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
5244  // The ARM target isn't yet aware of offsets.
5245  return false;
5246}
5247
5248int ARM::getVFPf32Imm(const APFloat &FPImm) {
5249  APInt Imm = FPImm.bitcastToAPInt();
5250  uint32_t Sign = Imm.lshr(31).getZExtValue() & 1;
5251  int32_t Exp = (Imm.lshr(23).getSExtValue() & 0xff) - 127;  // -126 to 127
5252  int64_t Mantissa = Imm.getZExtValue() & 0x7fffff;  // 23 bits
5253
5254  // We can handle 4 bits of mantissa.
5255  // mantissa = (16+UInt(e:f:g:h))/16.
5256  if (Mantissa & 0x7ffff)
5257    return -1;
5258  Mantissa >>= 19;
5259  if ((Mantissa & 0xf) != Mantissa)
5260    return -1;
5261
5262  // We can handle 3 bits of exponent: exp == UInt(NOT(b):c:d)-3
5263  if (Exp < -3 || Exp > 4)
5264    return -1;
5265  Exp = ((Exp+3) & 0x7) ^ 4;
5266
5267  return ((int)Sign << 7) | (Exp << 4) | Mantissa;
5268}
5269
5270int ARM::getVFPf64Imm(const APFloat &FPImm) {
5271  APInt Imm = FPImm.bitcastToAPInt();
5272  uint64_t Sign = Imm.lshr(63).getZExtValue() & 1;
5273  int64_t Exp = (Imm.lshr(52).getSExtValue() & 0x7ff) - 1023;   // -1022 to 1023
5274  uint64_t Mantissa = Imm.getZExtValue() & 0xfffffffffffffLL;
5275
5276  // We can handle 4 bits of mantissa.
5277  // mantissa = (16+UInt(e:f:g:h))/16.
5278  if (Mantissa & 0xffffffffffffLL)
5279    return -1;
5280  Mantissa >>= 48;
5281  if ((Mantissa & 0xf) != Mantissa)
5282    return -1;
5283
5284  // We can handle 3 bits of exponent: exp == UInt(NOT(b):c:d)-3
5285  if (Exp < -3 || Exp > 4)
5286    return -1;
5287  Exp = ((Exp+3) & 0x7) ^ 4;
5288
5289  return ((int)Sign << 7) | (Exp << 4) | Mantissa;
5290}
5291
5292/// isFPImmLegal - Returns true if the target can instruction select the
5293/// specified FP immediate natively. If false, the legalizer will
5294/// materialize the FP immediate as a load from a constant pool.
5295bool ARMTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT) const {
5296  if (!Subtarget->hasVFP3())
5297    return false;
5298  if (VT == MVT::f32)
5299    return ARM::getVFPf32Imm(Imm) != -1;
5300  if (VT == MVT::f64)
5301    return ARM::getVFPf64Imm(Imm) != -1;
5302  return false;
5303}
5304