ARMISelLowering.cpp revision c9403659a98bf6487ab6fbf40b81628b5695c02e
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//      unsigned Opcode = Def->getOpcode();
1342//      if ((Opcode == X86::LEA32r || Opcode == X86::LEA64r) &&
1343//          Def->getOperand(1).isFI()) {
1344//        FI = Def->getOperand(1).getIndex();
1345//        Bytes = Flags.getByValSize();
1346//      } else
1347        return false;
1348    }
1349  } else if (LoadSDNode *Ld = dyn_cast<LoadSDNode>(Arg)) {
1350    if (Flags.isByVal())
1351      // ByVal argument is passed in as a pointer but it's now being
1352      // dereferenced. e.g.
1353      // define @foo(%struct.X* %A) {
1354      //   tail call @bar(%struct.X* byval %A)
1355      // }
1356      return false;
1357    SDValue Ptr = Ld->getBasePtr();
1358    FrameIndexSDNode *FINode = dyn_cast<FrameIndexSDNode>(Ptr);
1359    if (!FINode)
1360      return false;
1361    FI = FINode->getIndex();
1362  } else
1363    return false;
1364
1365  assert(FI != INT_MAX);
1366  if (!MFI->isFixedObjectIndex(FI))
1367    return false;
1368  return Offset == MFI->getObjectOffset(FI) && Bytes == MFI->getObjectSize(FI);
1369}
1370
1371/// IsEligibleForTailCallOptimization - Check whether the call is eligible
1372/// for tail call optimization. Targets which want to do tail call
1373/// optimization should implement this function.
1374bool
1375ARMTargetLowering::IsEligibleForTailCallOptimization(SDValue Callee,
1376                                                     CallingConv::ID CalleeCC,
1377                                                     bool isVarArg,
1378                                                     bool isCalleeStructRet,
1379                                                     bool isCallerStructRet,
1380                                    const SmallVectorImpl<ISD::OutputArg> &Outs,
1381                                    const SmallVectorImpl<SDValue> &OutVals,
1382                                    const SmallVectorImpl<ISD::InputArg> &Ins,
1383                                                     SelectionDAG& DAG) const {
1384  const Function *CallerF = DAG.getMachineFunction().getFunction();
1385  CallingConv::ID CallerCC = CallerF->getCallingConv();
1386  bool CCMatch = CallerCC == CalleeCC;
1387
1388  // Look for obvious safe cases to perform tail call optimization that do not
1389  // require ABI changes. This is what gcc calls sibcall.
1390
1391  // Do not sibcall optimize vararg calls unless the call site is not passing
1392  // any arguments.
1393  if (isVarArg && !Outs.empty())
1394    return false;
1395
1396  // Also avoid sibcall optimization if either caller or callee uses struct
1397  // return semantics.
1398  if (isCalleeStructRet || isCallerStructRet)
1399    return false;
1400
1401  // FIXME: Completely disable sibcall for Thumb1 since Thumb1RegisterInfo::
1402  // emitEpilogue is not ready for them.
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  if (isa<ExternalSymbolSDNode>(Callee))
1413      return false;
1414
1415  if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
1416    const GlobalValue *GV = G->getGlobal();
1417    if (GV->isDeclaration() || GV->isWeakForLinker())
1418      return false;
1419  }
1420
1421  // If the calling conventions do not match, then we'd better make sure the
1422  // results are returned in the same way as what the caller expects.
1423  if (!CCMatch) {
1424    SmallVector<CCValAssign, 16> RVLocs1;
1425    CCState CCInfo1(CalleeCC, false, getTargetMachine(),
1426                    RVLocs1, *DAG.getContext());
1427    CCInfo1.AnalyzeCallResult(Ins, CCAssignFnForNode(CalleeCC, true, isVarArg));
1428
1429    SmallVector<CCValAssign, 16> RVLocs2;
1430    CCState CCInfo2(CallerCC, false, getTargetMachine(),
1431                    RVLocs2, *DAG.getContext());
1432    CCInfo2.AnalyzeCallResult(Ins, CCAssignFnForNode(CallerCC, true, isVarArg));
1433
1434    if (RVLocs1.size() != RVLocs2.size())
1435      return false;
1436    for (unsigned i = 0, e = RVLocs1.size(); i != e; ++i) {
1437      if (RVLocs1[i].isRegLoc() != RVLocs2[i].isRegLoc())
1438        return false;
1439      if (RVLocs1[i].getLocInfo() != RVLocs2[i].getLocInfo())
1440        return false;
1441      if (RVLocs1[i].isRegLoc()) {
1442        if (RVLocs1[i].getLocReg() != RVLocs2[i].getLocReg())
1443          return false;
1444      } else {
1445        if (RVLocs1[i].getLocMemOffset() != RVLocs2[i].getLocMemOffset())
1446          return false;
1447      }
1448    }
1449  }
1450
1451  // If the callee takes no arguments then go on to check the results of the
1452  // call.
1453  if (!Outs.empty()) {
1454    // Check if stack adjustment is needed. For now, do not do this if any
1455    // argument is passed on the stack.
1456    SmallVector<CCValAssign, 16> ArgLocs;
1457    CCState CCInfo(CalleeCC, isVarArg, getTargetMachine(),
1458                   ArgLocs, *DAG.getContext());
1459    CCInfo.AnalyzeCallOperands(Outs,
1460                               CCAssignFnForNode(CalleeCC, false, isVarArg));
1461    if (CCInfo.getNextStackOffset()) {
1462      MachineFunction &MF = DAG.getMachineFunction();
1463
1464      // Check if the arguments are already laid out in the right way as
1465      // the caller's fixed stack objects.
1466      MachineFrameInfo *MFI = MF.getFrameInfo();
1467      const MachineRegisterInfo *MRI = &MF.getRegInfo();
1468      const ARMInstrInfo *TII =
1469        ((ARMTargetMachine&)getTargetMachine()).getInstrInfo();
1470      for (unsigned i = 0, realArgIdx = 0, e = ArgLocs.size();
1471           i != e;
1472           ++i, ++realArgIdx) {
1473        CCValAssign &VA = ArgLocs[i];
1474        EVT RegVT = VA.getLocVT();
1475        SDValue Arg = OutVals[realArgIdx];
1476        ISD::ArgFlagsTy Flags = Outs[realArgIdx].Flags;
1477        if (VA.getLocInfo() == CCValAssign::Indirect)
1478          return false;
1479        if (VA.needsCustom()) {
1480          // f64 and vector types are split into multiple registers or
1481          // register/stack-slot combinations.  The types will not match
1482          // the registers; give up on memory f64 refs until we figure
1483          // out what to do about this.
1484          if (!VA.isRegLoc())
1485            return false;
1486          if (!ArgLocs[++i].isRegLoc())
1487            return false;
1488          if (RegVT == MVT::v2f64) {
1489            if (!ArgLocs[++i].isRegLoc())
1490              return false;
1491            if (!ArgLocs[++i].isRegLoc())
1492              return false;
1493          }
1494        } else if (!VA.isRegLoc()) {
1495          if (!MatchingStackOffset(Arg, VA.getLocMemOffset(), Flags,
1496                                   MFI, MRI, TII))
1497            return false;
1498        }
1499      }
1500    }
1501  }
1502
1503  return true;
1504}
1505
1506SDValue
1507ARMTargetLowering::LowerReturn(SDValue Chain,
1508                               CallingConv::ID CallConv, bool isVarArg,
1509                               const SmallVectorImpl<ISD::OutputArg> &Outs,
1510                               const SmallVectorImpl<SDValue> &OutVals,
1511                               DebugLoc dl, SelectionDAG &DAG) const {
1512
1513  // CCValAssign - represent the assignment of the return value to a location.
1514  SmallVector<CCValAssign, 16> RVLocs;
1515
1516  // CCState - Info about the registers and stack slots.
1517  CCState CCInfo(CallConv, isVarArg, getTargetMachine(), RVLocs,
1518                 *DAG.getContext());
1519
1520  // Analyze outgoing return values.
1521  CCInfo.AnalyzeReturn(Outs, CCAssignFnForNode(CallConv, /* Return */ true,
1522                                               isVarArg));
1523
1524  // If this is the first return lowered for this function, add
1525  // the regs to the liveout set for the function.
1526  if (DAG.getMachineFunction().getRegInfo().liveout_empty()) {
1527    for (unsigned i = 0; i != RVLocs.size(); ++i)
1528      if (RVLocs[i].isRegLoc())
1529        DAG.getMachineFunction().getRegInfo().addLiveOut(RVLocs[i].getLocReg());
1530  }
1531
1532  SDValue Flag;
1533
1534  // Copy the result values into the output registers.
1535  for (unsigned i = 0, realRVLocIdx = 0;
1536       i != RVLocs.size();
1537       ++i, ++realRVLocIdx) {
1538    CCValAssign &VA = RVLocs[i];
1539    assert(VA.isRegLoc() && "Can only return in registers!");
1540
1541    SDValue Arg = OutVals[realRVLocIdx];
1542
1543    switch (VA.getLocInfo()) {
1544    default: llvm_unreachable("Unknown loc info!");
1545    case CCValAssign::Full: break;
1546    case CCValAssign::BCvt:
1547      Arg = DAG.getNode(ISD::BIT_CONVERT, dl, VA.getLocVT(), Arg);
1548      break;
1549    }
1550
1551    if (VA.needsCustom()) {
1552      if (VA.getLocVT() == MVT::v2f64) {
1553        // Extract the first half and return it in two registers.
1554        SDValue Half = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f64, Arg,
1555                                   DAG.getConstant(0, MVT::i32));
1556        SDValue HalfGPRs = DAG.getNode(ARMISD::VMOVRRD, dl,
1557                                       DAG.getVTList(MVT::i32, MVT::i32), Half);
1558
1559        Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(), HalfGPRs, Flag);
1560        Flag = Chain.getValue(1);
1561        VA = RVLocs[++i]; // skip ahead to next loc
1562        Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(),
1563                                 HalfGPRs.getValue(1), Flag);
1564        Flag = Chain.getValue(1);
1565        VA = RVLocs[++i]; // skip ahead to next loc
1566
1567        // Extract the 2nd half and fall through to handle it as an f64 value.
1568        Arg = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f64, Arg,
1569                          DAG.getConstant(1, MVT::i32));
1570      }
1571      // Legalize ret f64 -> ret 2 x i32.  We always have fmrrd if f64 is
1572      // available.
1573      SDValue fmrrd = DAG.getNode(ARMISD::VMOVRRD, dl,
1574                                  DAG.getVTList(MVT::i32, MVT::i32), &Arg, 1);
1575      Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(), fmrrd, Flag);
1576      Flag = Chain.getValue(1);
1577      VA = RVLocs[++i]; // skip ahead to next loc
1578      Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(), fmrrd.getValue(1),
1579                               Flag);
1580    } else
1581      Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(), Arg, Flag);
1582
1583    // Guarantee that all emitted copies are
1584    // stuck together, avoiding something bad.
1585    Flag = Chain.getValue(1);
1586  }
1587
1588  SDValue result;
1589  if (Flag.getNode())
1590    result = DAG.getNode(ARMISD::RET_FLAG, dl, MVT::Other, Chain, Flag);
1591  else // Return Void
1592    result = DAG.getNode(ARMISD::RET_FLAG, dl, MVT::Other, Chain);
1593
1594  return result;
1595}
1596
1597// ConstantPool, JumpTable, GlobalAddress, and ExternalSymbol are lowered as
1598// their target counterpart wrapped in the ARMISD::Wrapper node. Suppose N is
1599// one of the above mentioned nodes. It has to be wrapped because otherwise
1600// Select(N) returns N. So the raw TargetGlobalAddress nodes, etc. can only
1601// be used to form addressing mode. These wrapped nodes will be selected
1602// into MOVi.
1603static SDValue LowerConstantPool(SDValue Op, SelectionDAG &DAG) {
1604  EVT PtrVT = Op.getValueType();
1605  // FIXME there is no actual debug info here
1606  DebugLoc dl = Op.getDebugLoc();
1607  ConstantPoolSDNode *CP = cast<ConstantPoolSDNode>(Op);
1608  SDValue Res;
1609  if (CP->isMachineConstantPoolEntry())
1610    Res = DAG.getTargetConstantPool(CP->getMachineCPVal(), PtrVT,
1611                                    CP->getAlignment());
1612  else
1613    Res = DAG.getTargetConstantPool(CP->getConstVal(), PtrVT,
1614                                    CP->getAlignment());
1615  return DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, Res);
1616}
1617
1618SDValue ARMTargetLowering::LowerBlockAddress(SDValue Op,
1619                                             SelectionDAG &DAG) const {
1620  MachineFunction &MF = DAG.getMachineFunction();
1621  ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1622  unsigned ARMPCLabelIndex = 0;
1623  DebugLoc DL = Op.getDebugLoc();
1624  EVT PtrVT = getPointerTy();
1625  const BlockAddress *BA = cast<BlockAddressSDNode>(Op)->getBlockAddress();
1626  Reloc::Model RelocM = getTargetMachine().getRelocationModel();
1627  SDValue CPAddr;
1628  if (RelocM == Reloc::Static) {
1629    CPAddr = DAG.getTargetConstantPool(BA, PtrVT, 4);
1630  } else {
1631    unsigned PCAdj = Subtarget->isThumb() ? 4 : 8;
1632    ARMPCLabelIndex = AFI->createConstPoolEntryUId();
1633    ARMConstantPoolValue *CPV = new ARMConstantPoolValue(BA, ARMPCLabelIndex,
1634                                                         ARMCP::CPBlockAddress,
1635                                                         PCAdj);
1636    CPAddr = DAG.getTargetConstantPool(CPV, PtrVT, 4);
1637  }
1638  CPAddr = DAG.getNode(ARMISD::Wrapper, DL, PtrVT, CPAddr);
1639  SDValue Result = DAG.getLoad(PtrVT, DL, DAG.getEntryNode(), CPAddr,
1640                               PseudoSourceValue::getConstantPool(), 0,
1641                               false, false, 0);
1642  if (RelocM == Reloc::Static)
1643    return Result;
1644  SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, MVT::i32);
1645  return DAG.getNode(ARMISD::PIC_ADD, DL, PtrVT, Result, PICLabel);
1646}
1647
1648// Lower ISD::GlobalTLSAddress using the "general dynamic" model
1649SDValue
1650ARMTargetLowering::LowerToTLSGeneralDynamicModel(GlobalAddressSDNode *GA,
1651                                                 SelectionDAG &DAG) const {
1652  DebugLoc dl = GA->getDebugLoc();
1653  EVT PtrVT = getPointerTy();
1654  unsigned char PCAdj = Subtarget->isThumb() ? 4 : 8;
1655  MachineFunction &MF = DAG.getMachineFunction();
1656  ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1657  unsigned ARMPCLabelIndex = AFI->createConstPoolEntryUId();
1658  ARMConstantPoolValue *CPV =
1659    new ARMConstantPoolValue(GA->getGlobal(), ARMPCLabelIndex,
1660                             ARMCP::CPValue, PCAdj, "tlsgd", true);
1661  SDValue Argument = DAG.getTargetConstantPool(CPV, PtrVT, 4);
1662  Argument = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, Argument);
1663  Argument = DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), Argument,
1664                         PseudoSourceValue::getConstantPool(), 0,
1665                         false, false, 0);
1666  SDValue Chain = Argument.getValue(1);
1667
1668  SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, MVT::i32);
1669  Argument = DAG.getNode(ARMISD::PIC_ADD, dl, PtrVT, Argument, PICLabel);
1670
1671  // call __tls_get_addr.
1672  ArgListTy Args;
1673  ArgListEntry Entry;
1674  Entry.Node = Argument;
1675  Entry.Ty = (const Type *) Type::getInt32Ty(*DAG.getContext());
1676  Args.push_back(Entry);
1677  // FIXME: is there useful debug info available here?
1678  std::pair<SDValue, SDValue> CallResult =
1679    LowerCallTo(Chain, (const Type *) Type::getInt32Ty(*DAG.getContext()),
1680                false, false, false, false,
1681                0, CallingConv::C, false, /*isReturnValueUsed=*/true,
1682                DAG.getExternalSymbol("__tls_get_addr", PtrVT), Args, DAG, dl);
1683  return CallResult.first;
1684}
1685
1686// Lower ISD::GlobalTLSAddress using the "initial exec" or
1687// "local exec" model.
1688SDValue
1689ARMTargetLowering::LowerToTLSExecModels(GlobalAddressSDNode *GA,
1690                                        SelectionDAG &DAG) const {
1691  const GlobalValue *GV = GA->getGlobal();
1692  DebugLoc dl = GA->getDebugLoc();
1693  SDValue Offset;
1694  SDValue Chain = DAG.getEntryNode();
1695  EVT PtrVT = getPointerTy();
1696  // Get the Thread Pointer
1697  SDValue ThreadPointer = DAG.getNode(ARMISD::THREAD_POINTER, dl, PtrVT);
1698
1699  if (GV->isDeclaration()) {
1700    MachineFunction &MF = DAG.getMachineFunction();
1701    ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1702    unsigned ARMPCLabelIndex = AFI->createConstPoolEntryUId();
1703    // Initial exec model.
1704    unsigned char PCAdj = Subtarget->isThumb() ? 4 : 8;
1705    ARMConstantPoolValue *CPV =
1706      new ARMConstantPoolValue(GA->getGlobal(), ARMPCLabelIndex,
1707                               ARMCP::CPValue, PCAdj, "gottpoff", true);
1708    Offset = DAG.getTargetConstantPool(CPV, PtrVT, 4);
1709    Offset = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, Offset);
1710    Offset = DAG.getLoad(PtrVT, dl, Chain, Offset,
1711                         PseudoSourceValue::getConstantPool(), 0,
1712                         false, false, 0);
1713    Chain = Offset.getValue(1);
1714
1715    SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, MVT::i32);
1716    Offset = DAG.getNode(ARMISD::PIC_ADD, dl, PtrVT, Offset, PICLabel);
1717
1718    Offset = DAG.getLoad(PtrVT, dl, Chain, Offset,
1719                         PseudoSourceValue::getConstantPool(), 0,
1720                         false, false, 0);
1721  } else {
1722    // local exec model
1723    ARMConstantPoolValue *CPV = new ARMConstantPoolValue(GV, "tpoff");
1724    Offset = DAG.getTargetConstantPool(CPV, PtrVT, 4);
1725    Offset = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, Offset);
1726    Offset = DAG.getLoad(PtrVT, dl, Chain, Offset,
1727                         PseudoSourceValue::getConstantPool(), 0,
1728                         false, false, 0);
1729  }
1730
1731  // The address of the thread local variable is the add of the thread
1732  // pointer with the offset of the variable.
1733  return DAG.getNode(ISD::ADD, dl, PtrVT, ThreadPointer, Offset);
1734}
1735
1736SDValue
1737ARMTargetLowering::LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const {
1738  // TODO: implement the "local dynamic" model
1739  assert(Subtarget->isTargetELF() &&
1740         "TLS not implemented for non-ELF targets");
1741  GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
1742  // If the relocation model is PIC, use the "General Dynamic" TLS Model,
1743  // otherwise use the "Local Exec" TLS Model
1744  if (getTargetMachine().getRelocationModel() == Reloc::PIC_)
1745    return LowerToTLSGeneralDynamicModel(GA, DAG);
1746  else
1747    return LowerToTLSExecModels(GA, DAG);
1748}
1749
1750SDValue ARMTargetLowering::LowerGlobalAddressELF(SDValue Op,
1751                                                 SelectionDAG &DAG) const {
1752  EVT PtrVT = getPointerTy();
1753  DebugLoc dl = Op.getDebugLoc();
1754  const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
1755  Reloc::Model RelocM = getTargetMachine().getRelocationModel();
1756  if (RelocM == Reloc::PIC_) {
1757    bool UseGOTOFF = GV->hasLocalLinkage() || GV->hasHiddenVisibility();
1758    ARMConstantPoolValue *CPV =
1759      new ARMConstantPoolValue(GV, UseGOTOFF ? "GOTOFF" : "GOT");
1760    SDValue CPAddr = DAG.getTargetConstantPool(CPV, PtrVT, 4);
1761    CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
1762    SDValue Result = DAG.getLoad(PtrVT, dl, DAG.getEntryNode(),
1763                                 CPAddr,
1764                                 PseudoSourceValue::getConstantPool(), 0,
1765                                 false, false, 0);
1766    SDValue Chain = Result.getValue(1);
1767    SDValue GOT = DAG.getGLOBAL_OFFSET_TABLE(PtrVT);
1768    Result = DAG.getNode(ISD::ADD, dl, PtrVT, Result, GOT);
1769    if (!UseGOTOFF)
1770      Result = DAG.getLoad(PtrVT, dl, Chain, Result,
1771                           PseudoSourceValue::getGOT(), 0,
1772                           false, false, 0);
1773    return Result;
1774  } else {
1775    // If we have T2 ops, we can materialize the address directly via movt/movw
1776    // pair. This is always cheaper.
1777    if (Subtarget->useMovt()) {
1778      return DAG.getNode(ARMISD::Wrapper, dl, PtrVT,
1779                         DAG.getTargetGlobalAddress(GV, dl, PtrVT));
1780    } else {
1781      SDValue CPAddr = DAG.getTargetConstantPool(GV, PtrVT, 4);
1782      CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
1783      return DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), CPAddr,
1784                         PseudoSourceValue::getConstantPool(), 0,
1785                         false, false, 0);
1786    }
1787  }
1788}
1789
1790SDValue ARMTargetLowering::LowerGlobalAddressDarwin(SDValue Op,
1791                                                    SelectionDAG &DAG) const {
1792  MachineFunction &MF = DAG.getMachineFunction();
1793  ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1794  unsigned ARMPCLabelIndex = 0;
1795  EVT PtrVT = getPointerTy();
1796  DebugLoc dl = Op.getDebugLoc();
1797  const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
1798  Reloc::Model RelocM = getTargetMachine().getRelocationModel();
1799  SDValue CPAddr;
1800  if (RelocM == Reloc::Static)
1801    CPAddr = DAG.getTargetConstantPool(GV, PtrVT, 4);
1802  else {
1803    ARMPCLabelIndex = AFI->createConstPoolEntryUId();
1804    unsigned PCAdj = (RelocM != Reloc::PIC_) ? 0 : (Subtarget->isThumb()?4:8);
1805    ARMConstantPoolValue *CPV =
1806      new ARMConstantPoolValue(GV, ARMPCLabelIndex, ARMCP::CPValue, PCAdj);
1807    CPAddr = DAG.getTargetConstantPool(CPV, PtrVT, 4);
1808  }
1809  CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
1810
1811  SDValue Result = DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), CPAddr,
1812                               PseudoSourceValue::getConstantPool(), 0,
1813                               false, false, 0);
1814  SDValue Chain = Result.getValue(1);
1815
1816  if (RelocM == Reloc::PIC_) {
1817    SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, MVT::i32);
1818    Result = DAG.getNode(ARMISD::PIC_ADD, dl, PtrVT, Result, PICLabel);
1819  }
1820
1821  if (Subtarget->GVIsIndirectSymbol(GV, RelocM))
1822    Result = DAG.getLoad(PtrVT, dl, Chain, Result,
1823                         PseudoSourceValue::getGOT(), 0,
1824                         false, false, 0);
1825
1826  return Result;
1827}
1828
1829SDValue ARMTargetLowering::LowerGLOBAL_OFFSET_TABLE(SDValue Op,
1830                                                    SelectionDAG &DAG) const {
1831  assert(Subtarget->isTargetELF() &&
1832         "GLOBAL OFFSET TABLE not implemented for non-ELF targets");
1833  MachineFunction &MF = DAG.getMachineFunction();
1834  ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1835  unsigned ARMPCLabelIndex = AFI->createConstPoolEntryUId();
1836  EVT PtrVT = getPointerTy();
1837  DebugLoc dl = Op.getDebugLoc();
1838  unsigned PCAdj = Subtarget->isThumb() ? 4 : 8;
1839  ARMConstantPoolValue *CPV = new ARMConstantPoolValue(*DAG.getContext(),
1840                                                       "_GLOBAL_OFFSET_TABLE_",
1841                                                       ARMPCLabelIndex, PCAdj);
1842  SDValue CPAddr = DAG.getTargetConstantPool(CPV, PtrVT, 4);
1843  CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
1844  SDValue Result = DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), CPAddr,
1845                               PseudoSourceValue::getConstantPool(), 0,
1846                               false, false, 0);
1847  SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, MVT::i32);
1848  return DAG.getNode(ARMISD::PIC_ADD, dl, PtrVT, Result, PICLabel);
1849}
1850
1851SDValue
1852ARMTargetLowering::LowerEH_SJLJ_SETJMP(SDValue Op, SelectionDAG &DAG) const {
1853  DebugLoc dl = Op.getDebugLoc();
1854  SDValue Val = DAG.getConstant(0, MVT::i32);
1855  return DAG.getNode(ARMISD::EH_SJLJ_SETJMP, dl, MVT::i32, Op.getOperand(0),
1856                     Op.getOperand(1), Val);
1857}
1858
1859SDValue
1860ARMTargetLowering::LowerEH_SJLJ_LONGJMP(SDValue Op, SelectionDAG &DAG) const {
1861  DebugLoc dl = Op.getDebugLoc();
1862  return DAG.getNode(ARMISD::EH_SJLJ_LONGJMP, dl, MVT::Other, Op.getOperand(0),
1863                     Op.getOperand(1), DAG.getConstant(0, MVT::i32));
1864}
1865
1866SDValue
1867ARMTargetLowering::LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG,
1868                                          const ARMSubtarget *Subtarget) const {
1869  unsigned IntNo = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
1870  DebugLoc dl = Op.getDebugLoc();
1871  switch (IntNo) {
1872  default: return SDValue();    // Don't custom lower most intrinsics.
1873  case Intrinsic::arm_thread_pointer: {
1874    EVT PtrVT = DAG.getTargetLoweringInfo().getPointerTy();
1875    return DAG.getNode(ARMISD::THREAD_POINTER, dl, PtrVT);
1876  }
1877  case Intrinsic::eh_sjlj_lsda: {
1878    MachineFunction &MF = DAG.getMachineFunction();
1879    ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1880    unsigned ARMPCLabelIndex = AFI->createConstPoolEntryUId();
1881    EVT PtrVT = getPointerTy();
1882    DebugLoc dl = Op.getDebugLoc();
1883    Reloc::Model RelocM = getTargetMachine().getRelocationModel();
1884    SDValue CPAddr;
1885    unsigned PCAdj = (RelocM != Reloc::PIC_)
1886      ? 0 : (Subtarget->isThumb() ? 4 : 8);
1887    ARMConstantPoolValue *CPV =
1888      new ARMConstantPoolValue(MF.getFunction(), ARMPCLabelIndex,
1889                               ARMCP::CPLSDA, PCAdj);
1890    CPAddr = DAG.getTargetConstantPool(CPV, PtrVT, 4);
1891    CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
1892    SDValue Result =
1893      DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), CPAddr,
1894                  PseudoSourceValue::getConstantPool(), 0,
1895                  false, false, 0);
1896
1897    if (RelocM == Reloc::PIC_) {
1898      SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, MVT::i32);
1899      Result = DAG.getNode(ARMISD::PIC_ADD, dl, PtrVT, Result, PICLabel);
1900    }
1901    return Result;
1902  }
1903  }
1904}
1905
1906static SDValue LowerMEMBARRIER(SDValue Op, SelectionDAG &DAG,
1907                               const ARMSubtarget *Subtarget) {
1908  DebugLoc dl = Op.getDebugLoc();
1909  SDValue Op5 = Op.getOperand(5);
1910  unsigned isDeviceBarrier = cast<ConstantSDNode>(Op5)->getZExtValue();
1911  // v6 and v7 can both handle barriers directly, but need handled a bit
1912  // differently. Thumb1 and pre-v6 ARM mode use a libcall instead and should
1913  // never get here.
1914  unsigned Opc = isDeviceBarrier ? ARMISD::SYNCBARRIER : ARMISD::MEMBARRIER;
1915  if (Subtarget->hasV7Ops())
1916    return DAG.getNode(Opc, dl, MVT::Other, Op.getOperand(0));
1917  else if (Subtarget->hasV6Ops() && !Subtarget->isThumb1Only())
1918    return DAG.getNode(Opc, dl, MVT::Other, Op.getOperand(0),
1919                       DAG.getConstant(0, MVT::i32));
1920  assert(0 && "Unexpected ISD::MEMBARRIER encountered. Should be libcall!");
1921  return SDValue();
1922}
1923
1924static SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG) {
1925  MachineFunction &MF = DAG.getMachineFunction();
1926  ARMFunctionInfo *FuncInfo = MF.getInfo<ARMFunctionInfo>();
1927
1928  // vastart just stores the address of the VarArgsFrameIndex slot into the
1929  // memory location argument.
1930  DebugLoc dl = Op.getDebugLoc();
1931  EVT PtrVT = DAG.getTargetLoweringInfo().getPointerTy();
1932  SDValue FR = DAG.getFrameIndex(FuncInfo->getVarArgsFrameIndex(), PtrVT);
1933  const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
1934  return DAG.getStore(Op.getOperand(0), dl, FR, Op.getOperand(1), SV, 0,
1935                      false, false, 0);
1936}
1937
1938SDValue
1939ARMTargetLowering::LowerDYNAMIC_STACKALLOC(SDValue Op,
1940                                           SelectionDAG &DAG) const {
1941  SDNode *Node = Op.getNode();
1942  DebugLoc dl = Node->getDebugLoc();
1943  EVT VT = Node->getValueType(0);
1944  SDValue Chain = Op.getOperand(0);
1945  SDValue Size  = Op.getOperand(1);
1946  SDValue Align = Op.getOperand(2);
1947
1948  // Chain the dynamic stack allocation so that it doesn't modify the stack
1949  // pointer when other instructions are using the stack.
1950  Chain = DAG.getCALLSEQ_START(Chain, DAG.getIntPtrConstant(0, true));
1951
1952  unsigned AlignVal = cast<ConstantSDNode>(Align)->getZExtValue();
1953  unsigned StackAlign = getTargetMachine().getFrameInfo()->getStackAlignment();
1954  if (AlignVal > StackAlign)
1955    // Do this now since selection pass cannot introduce new target
1956    // independent node.
1957    Align = DAG.getConstant(-(uint64_t)AlignVal, VT);
1958
1959  // In Thumb1 mode, there isn't a "sub r, sp, r" instruction, we will end up
1960  // using a "add r, sp, r" instead. Negate the size now so we don't have to
1961  // do even more horrible hack later.
1962  MachineFunction &MF = DAG.getMachineFunction();
1963  ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1964  if (AFI->isThumb1OnlyFunction()) {
1965    bool Negate = true;
1966    ConstantSDNode *C = dyn_cast<ConstantSDNode>(Size);
1967    if (C) {
1968      uint32_t Val = C->getZExtValue();
1969      if (Val <= 508 && ((Val & 3) == 0))
1970        Negate = false;
1971    }
1972    if (Negate)
1973      Size = DAG.getNode(ISD::SUB, dl, VT, DAG.getConstant(0, VT), Size);
1974  }
1975
1976  SDVTList VTList = DAG.getVTList(VT, MVT::Other);
1977  SDValue Ops1[] = { Chain, Size, Align };
1978  SDValue Res = DAG.getNode(ARMISD::DYN_ALLOC, dl, VTList, Ops1, 3);
1979  Chain = Res.getValue(1);
1980  Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(0, true),
1981                             DAG.getIntPtrConstant(0, true), SDValue());
1982  SDValue Ops2[] = { Res, Chain };
1983  return DAG.getMergeValues(Ops2, 2, dl);
1984}
1985
1986SDValue
1987ARMTargetLowering::GetF64FormalArgument(CCValAssign &VA, CCValAssign &NextVA,
1988                                        SDValue &Root, SelectionDAG &DAG,
1989                                        DebugLoc dl) const {
1990  MachineFunction &MF = DAG.getMachineFunction();
1991  ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1992
1993  TargetRegisterClass *RC;
1994  if (AFI->isThumb1OnlyFunction())
1995    RC = ARM::tGPRRegisterClass;
1996  else
1997    RC = ARM::GPRRegisterClass;
1998
1999  // Transform the arguments stored in physical registers into virtual ones.
2000  unsigned Reg = MF.addLiveIn(VA.getLocReg(), RC);
2001  SDValue ArgValue = DAG.getCopyFromReg(Root, dl, Reg, MVT::i32);
2002
2003  SDValue ArgValue2;
2004  if (NextVA.isMemLoc()) {
2005    MachineFrameInfo *MFI = MF.getFrameInfo();
2006    int FI = MFI->CreateFixedObject(4, NextVA.getLocMemOffset(), true);
2007
2008    // Create load node to retrieve arguments from the stack.
2009    SDValue FIN = DAG.getFrameIndex(FI, getPointerTy());
2010    ArgValue2 = DAG.getLoad(MVT::i32, dl, Root, FIN,
2011                            PseudoSourceValue::getFixedStack(FI), 0,
2012                            false, false, 0);
2013  } else {
2014    Reg = MF.addLiveIn(NextVA.getLocReg(), RC);
2015    ArgValue2 = DAG.getCopyFromReg(Root, dl, Reg, MVT::i32);
2016  }
2017
2018  return DAG.getNode(ARMISD::VMOVDRR, dl, MVT::f64, ArgValue, ArgValue2);
2019}
2020
2021SDValue
2022ARMTargetLowering::LowerFormalArguments(SDValue Chain,
2023                                        CallingConv::ID CallConv, bool isVarArg,
2024                                        const SmallVectorImpl<ISD::InputArg>
2025                                          &Ins,
2026                                        DebugLoc dl, SelectionDAG &DAG,
2027                                        SmallVectorImpl<SDValue> &InVals)
2028                                          const {
2029
2030  MachineFunction &MF = DAG.getMachineFunction();
2031  MachineFrameInfo *MFI = MF.getFrameInfo();
2032
2033  ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
2034
2035  // Assign locations to all of the incoming arguments.
2036  SmallVector<CCValAssign, 16> ArgLocs;
2037  CCState CCInfo(CallConv, isVarArg, getTargetMachine(), ArgLocs,
2038                 *DAG.getContext());
2039  CCInfo.AnalyzeFormalArguments(Ins,
2040                                CCAssignFnForNode(CallConv, /* Return*/ false,
2041                                                  isVarArg));
2042
2043  SmallVector<SDValue, 16> ArgValues;
2044
2045  for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
2046    CCValAssign &VA = ArgLocs[i];
2047
2048    // Arguments stored in registers.
2049    if (VA.isRegLoc()) {
2050      EVT RegVT = VA.getLocVT();
2051
2052      SDValue ArgValue;
2053      if (VA.needsCustom()) {
2054        // f64 and vector types are split up into multiple registers or
2055        // combinations of registers and stack slots.
2056        if (VA.getLocVT() == MVT::v2f64) {
2057          SDValue ArgValue1 = GetF64FormalArgument(VA, ArgLocs[++i],
2058                                                   Chain, DAG, dl);
2059          VA = ArgLocs[++i]; // skip ahead to next loc
2060          SDValue ArgValue2;
2061          if (VA.isMemLoc()) {
2062            int FI = MFI->CreateFixedObject(8, VA.getLocMemOffset(), true);
2063            SDValue FIN = DAG.getFrameIndex(FI, getPointerTy());
2064            ArgValue2 = DAG.getLoad(MVT::f64, dl, Chain, FIN,
2065                                    PseudoSourceValue::getFixedStack(FI), 0,
2066                                    false, false, 0);
2067          } else {
2068            ArgValue2 = GetF64FormalArgument(VA, ArgLocs[++i],
2069                                             Chain, DAG, dl);
2070          }
2071          ArgValue = DAG.getNode(ISD::UNDEF, dl, MVT::v2f64);
2072          ArgValue = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v2f64,
2073                                 ArgValue, ArgValue1, DAG.getIntPtrConstant(0));
2074          ArgValue = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v2f64,
2075                                 ArgValue, ArgValue2, DAG.getIntPtrConstant(1));
2076        } else
2077          ArgValue = GetF64FormalArgument(VA, ArgLocs[++i], Chain, DAG, dl);
2078
2079      } else {
2080        TargetRegisterClass *RC;
2081
2082        if (RegVT == MVT::f32)
2083          RC = ARM::SPRRegisterClass;
2084        else if (RegVT == MVT::f64)
2085          RC = ARM::DPRRegisterClass;
2086        else if (RegVT == MVT::v2f64)
2087          RC = ARM::QPRRegisterClass;
2088        else if (RegVT == MVT::i32)
2089          RC = (AFI->isThumb1OnlyFunction() ?
2090                ARM::tGPRRegisterClass : ARM::GPRRegisterClass);
2091        else
2092          llvm_unreachable("RegVT not supported by FORMAL_ARGUMENTS Lowering");
2093
2094        // Transform the arguments in physical registers into virtual ones.
2095        unsigned Reg = MF.addLiveIn(VA.getLocReg(), RC);
2096        ArgValue = DAG.getCopyFromReg(Chain, dl, Reg, RegVT);
2097      }
2098
2099      // If this is an 8 or 16-bit value, it is really passed promoted
2100      // to 32 bits.  Insert an assert[sz]ext to capture this, then
2101      // truncate to the right size.
2102      switch (VA.getLocInfo()) {
2103      default: llvm_unreachable("Unknown loc info!");
2104      case CCValAssign::Full: break;
2105      case CCValAssign::BCvt:
2106        ArgValue = DAG.getNode(ISD::BIT_CONVERT, dl, VA.getValVT(), ArgValue);
2107        break;
2108      case CCValAssign::SExt:
2109        ArgValue = DAG.getNode(ISD::AssertSext, dl, RegVT, ArgValue,
2110                               DAG.getValueType(VA.getValVT()));
2111        ArgValue = DAG.getNode(ISD::TRUNCATE, dl, VA.getValVT(), ArgValue);
2112        break;
2113      case CCValAssign::ZExt:
2114        ArgValue = DAG.getNode(ISD::AssertZext, dl, RegVT, ArgValue,
2115                               DAG.getValueType(VA.getValVT()));
2116        ArgValue = DAG.getNode(ISD::TRUNCATE, dl, VA.getValVT(), ArgValue);
2117        break;
2118      }
2119
2120      InVals.push_back(ArgValue);
2121
2122    } else { // VA.isRegLoc()
2123
2124      // sanity check
2125      assert(VA.isMemLoc());
2126      assert(VA.getValVT() != MVT::i64 && "i64 should already be lowered");
2127
2128      unsigned ArgSize = VA.getLocVT().getSizeInBits()/8;
2129      int FI = MFI->CreateFixedObject(ArgSize, VA.getLocMemOffset(), true);
2130
2131      // Create load nodes to retrieve arguments from the stack.
2132      SDValue FIN = DAG.getFrameIndex(FI, getPointerTy());
2133      InVals.push_back(DAG.getLoad(VA.getValVT(), dl, Chain, FIN,
2134                                   PseudoSourceValue::getFixedStack(FI), 0,
2135                                   false, false, 0));
2136    }
2137  }
2138
2139  // varargs
2140  if (isVarArg) {
2141    static const unsigned GPRArgRegs[] = {
2142      ARM::R0, ARM::R1, ARM::R2, ARM::R3
2143    };
2144
2145    unsigned NumGPRs = CCInfo.getFirstUnallocated
2146      (GPRArgRegs, sizeof(GPRArgRegs) / sizeof(GPRArgRegs[0]));
2147
2148    unsigned Align = MF.getTarget().getFrameInfo()->getStackAlignment();
2149    unsigned VARegSize = (4 - NumGPRs) * 4;
2150    unsigned VARegSaveSize = (VARegSize + Align - 1) & ~(Align - 1);
2151    unsigned ArgOffset = CCInfo.getNextStackOffset();
2152    if (VARegSaveSize) {
2153      // If this function is vararg, store any remaining integer argument regs
2154      // to their spots on the stack so that they may be loaded by deferencing
2155      // the result of va_next.
2156      AFI->setVarArgsRegSaveSize(VARegSaveSize);
2157      AFI->setVarArgsFrameIndex(
2158        MFI->CreateFixedObject(VARegSaveSize,
2159                               ArgOffset + VARegSaveSize - VARegSize,
2160                               true));
2161      SDValue FIN = DAG.getFrameIndex(AFI->getVarArgsFrameIndex(),
2162                                      getPointerTy());
2163
2164      SmallVector<SDValue, 4> MemOps;
2165      for (; NumGPRs < 4; ++NumGPRs) {
2166        TargetRegisterClass *RC;
2167        if (AFI->isThumb1OnlyFunction())
2168          RC = ARM::tGPRRegisterClass;
2169        else
2170          RC = ARM::GPRRegisterClass;
2171
2172        unsigned VReg = MF.addLiveIn(GPRArgRegs[NumGPRs], RC);
2173        SDValue Val = DAG.getCopyFromReg(Chain, dl, VReg, MVT::i32);
2174        SDValue Store =
2175          DAG.getStore(Val.getValue(1), dl, Val, FIN,
2176               PseudoSourceValue::getFixedStack(AFI->getVarArgsFrameIndex()),
2177               0, false, false, 0);
2178        MemOps.push_back(Store);
2179        FIN = DAG.getNode(ISD::ADD, dl, getPointerTy(), FIN,
2180                          DAG.getConstant(4, getPointerTy()));
2181      }
2182      if (!MemOps.empty())
2183        Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
2184                            &MemOps[0], MemOps.size());
2185    } else
2186      // This will point to the next argument passed via stack.
2187      AFI->setVarArgsFrameIndex(MFI->CreateFixedObject(4, ArgOffset, true));
2188  }
2189
2190  return Chain;
2191}
2192
2193/// isFloatingPointZero - Return true if this is +0.0.
2194static bool isFloatingPointZero(SDValue Op) {
2195  if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(Op))
2196    return CFP->getValueAPF().isPosZero();
2197  else if (ISD::isEXTLoad(Op.getNode()) || ISD::isNON_EXTLoad(Op.getNode())) {
2198    // Maybe this has already been legalized into the constant pool?
2199    if (Op.getOperand(1).getOpcode() == ARMISD::Wrapper) {
2200      SDValue WrapperOp = Op.getOperand(1).getOperand(0);
2201      if (ConstantPoolSDNode *CP = dyn_cast<ConstantPoolSDNode>(WrapperOp))
2202        if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CP->getConstVal()))
2203          return CFP->getValueAPF().isPosZero();
2204    }
2205  }
2206  return false;
2207}
2208
2209/// Returns appropriate ARM CMP (cmp) and corresponding condition code for
2210/// the given operands.
2211SDValue
2212ARMTargetLowering::getARMCmp(SDValue LHS, SDValue RHS, ISD::CondCode CC,
2213                             SDValue &ARMCC, SelectionDAG &DAG,
2214                             DebugLoc dl) const {
2215  if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(RHS.getNode())) {
2216    unsigned C = RHSC->getZExtValue();
2217    if (!isLegalICmpImmediate(C)) {
2218      // Constant does not fit, try adjusting it by one?
2219      switch (CC) {
2220      default: break;
2221      case ISD::SETLT:
2222      case ISD::SETGE:
2223        if (isLegalICmpImmediate(C-1)) {
2224          CC = (CC == ISD::SETLT) ? ISD::SETLE : ISD::SETGT;
2225          RHS = DAG.getConstant(C-1, MVT::i32);
2226        }
2227        break;
2228      case ISD::SETULT:
2229      case ISD::SETUGE:
2230        if (C > 0 && isLegalICmpImmediate(C-1)) {
2231          CC = (CC == ISD::SETULT) ? ISD::SETULE : ISD::SETUGT;
2232          RHS = DAG.getConstant(C-1, MVT::i32);
2233        }
2234        break;
2235      case ISD::SETLE:
2236      case ISD::SETGT:
2237        if (isLegalICmpImmediate(C+1)) {
2238          CC = (CC == ISD::SETLE) ? ISD::SETLT : ISD::SETGE;
2239          RHS = DAG.getConstant(C+1, MVT::i32);
2240        }
2241        break;
2242      case ISD::SETULE:
2243      case ISD::SETUGT:
2244        if (C < 0xffffffff && isLegalICmpImmediate(C+1)) {
2245          CC = (CC == ISD::SETULE) ? ISD::SETULT : ISD::SETUGE;
2246          RHS = DAG.getConstant(C+1, MVT::i32);
2247        }
2248        break;
2249      }
2250    }
2251  }
2252
2253  ARMCC::CondCodes CondCode = IntCCToARMCC(CC);
2254  ARMISD::NodeType CompareType;
2255  switch (CondCode) {
2256  default:
2257    CompareType = ARMISD::CMP;
2258    break;
2259  case ARMCC::EQ:
2260  case ARMCC::NE:
2261    // Uses only Z Flag
2262    CompareType = ARMISD::CMPZ;
2263    break;
2264  }
2265  ARMCC = DAG.getConstant(CondCode, MVT::i32);
2266  return DAG.getNode(CompareType, dl, MVT::Flag, LHS, RHS);
2267}
2268
2269/// Returns a appropriate VFP CMP (fcmp{s|d}+fmstat) for the given operands.
2270static SDValue getVFPCmp(SDValue LHS, SDValue RHS, SelectionDAG &DAG,
2271                         DebugLoc dl) {
2272  SDValue Cmp;
2273  if (!isFloatingPointZero(RHS))
2274    Cmp = DAG.getNode(ARMISD::CMPFP, dl, MVT::Flag, LHS, RHS);
2275  else
2276    Cmp = DAG.getNode(ARMISD::CMPFPw0, dl, MVT::Flag, LHS);
2277  return DAG.getNode(ARMISD::FMSTAT, dl, MVT::Flag, Cmp);
2278}
2279
2280SDValue ARMTargetLowering::LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const {
2281  EVT VT = Op.getValueType();
2282  SDValue LHS = Op.getOperand(0);
2283  SDValue RHS = Op.getOperand(1);
2284  ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(4))->get();
2285  SDValue TrueVal = Op.getOperand(2);
2286  SDValue FalseVal = Op.getOperand(3);
2287  DebugLoc dl = Op.getDebugLoc();
2288
2289  if (LHS.getValueType() == MVT::i32) {
2290    SDValue ARMCC;
2291    SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
2292    SDValue Cmp = getARMCmp(LHS, RHS, CC, ARMCC, DAG, dl);
2293    return DAG.getNode(ARMISD::CMOV, dl, VT, FalseVal, TrueVal, ARMCC, CCR,Cmp);
2294  }
2295
2296  ARMCC::CondCodes CondCode, CondCode2;
2297  FPCCToARMCC(CC, CondCode, CondCode2);
2298
2299  SDValue ARMCC = DAG.getConstant(CondCode, MVT::i32);
2300  SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
2301  SDValue Cmp = getVFPCmp(LHS, RHS, DAG, dl);
2302  SDValue Result = DAG.getNode(ARMISD::CMOV, dl, VT, FalseVal, TrueVal,
2303                                 ARMCC, CCR, Cmp);
2304  if (CondCode2 != ARMCC::AL) {
2305    SDValue ARMCC2 = DAG.getConstant(CondCode2, MVT::i32);
2306    // FIXME: Needs another CMP because flag can have but one use.
2307    SDValue Cmp2 = getVFPCmp(LHS, RHS, DAG, dl);
2308    Result = DAG.getNode(ARMISD::CMOV, dl, VT,
2309                         Result, TrueVal, ARMCC2, CCR, Cmp2);
2310  }
2311  return Result;
2312}
2313
2314SDValue ARMTargetLowering::LowerBR_CC(SDValue Op, SelectionDAG &DAG) const {
2315  SDValue  Chain = Op.getOperand(0);
2316  ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(1))->get();
2317  SDValue    LHS = Op.getOperand(2);
2318  SDValue    RHS = Op.getOperand(3);
2319  SDValue   Dest = Op.getOperand(4);
2320  DebugLoc dl = Op.getDebugLoc();
2321
2322  if (LHS.getValueType() == MVT::i32) {
2323    SDValue ARMCC;
2324    SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
2325    SDValue Cmp = getARMCmp(LHS, RHS, CC, ARMCC, DAG, dl);
2326    return DAG.getNode(ARMISD::BRCOND, dl, MVT::Other,
2327                       Chain, Dest, ARMCC, CCR,Cmp);
2328  }
2329
2330  assert(LHS.getValueType() == MVT::f32 || LHS.getValueType() == MVT::f64);
2331  ARMCC::CondCodes CondCode, CondCode2;
2332  FPCCToARMCC(CC, CondCode, CondCode2);
2333
2334  SDValue Cmp = getVFPCmp(LHS, RHS, DAG, dl);
2335  SDValue ARMCC = DAG.getConstant(CondCode, MVT::i32);
2336  SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
2337  SDVTList VTList = DAG.getVTList(MVT::Other, MVT::Flag);
2338  SDValue Ops[] = { Chain, Dest, ARMCC, CCR, Cmp };
2339  SDValue Res = DAG.getNode(ARMISD::BRCOND, dl, VTList, Ops, 5);
2340  if (CondCode2 != ARMCC::AL) {
2341    ARMCC = DAG.getConstant(CondCode2, MVT::i32);
2342    SDValue Ops[] = { Res, Dest, ARMCC, CCR, Res.getValue(1) };
2343    Res = DAG.getNode(ARMISD::BRCOND, dl, VTList, Ops, 5);
2344  }
2345  return Res;
2346}
2347
2348SDValue ARMTargetLowering::LowerBR_JT(SDValue Op, SelectionDAG &DAG) const {
2349  SDValue Chain = Op.getOperand(0);
2350  SDValue Table = Op.getOperand(1);
2351  SDValue Index = Op.getOperand(2);
2352  DebugLoc dl = Op.getDebugLoc();
2353
2354  EVT PTy = getPointerTy();
2355  JumpTableSDNode *JT = cast<JumpTableSDNode>(Table);
2356  ARMFunctionInfo *AFI = DAG.getMachineFunction().getInfo<ARMFunctionInfo>();
2357  SDValue UId = DAG.getConstant(AFI->createJumpTableUId(), PTy);
2358  SDValue JTI = DAG.getTargetJumpTable(JT->getIndex(), PTy);
2359  Table = DAG.getNode(ARMISD::WrapperJT, dl, MVT::i32, JTI, UId);
2360  Index = DAG.getNode(ISD::MUL, dl, PTy, Index, DAG.getConstant(4, PTy));
2361  SDValue Addr = DAG.getNode(ISD::ADD, dl, PTy, Index, Table);
2362  if (Subtarget->isThumb2()) {
2363    // Thumb2 uses a two-level jump. That is, it jumps into the jump table
2364    // which does another jump to the destination. This also makes it easier
2365    // to translate it to TBB / TBH later.
2366    // FIXME: This might not work if the function is extremely large.
2367    return DAG.getNode(ARMISD::BR2_JT, dl, MVT::Other, Chain,
2368                       Addr, Op.getOperand(2), JTI, UId);
2369  }
2370  if (getTargetMachine().getRelocationModel() == Reloc::PIC_) {
2371    Addr = DAG.getLoad((EVT)MVT::i32, dl, Chain, Addr,
2372                       PseudoSourceValue::getJumpTable(), 0,
2373                       false, false, 0);
2374    Chain = Addr.getValue(1);
2375    Addr = DAG.getNode(ISD::ADD, dl, PTy, Addr, Table);
2376    return DAG.getNode(ARMISD::BR_JT, dl, MVT::Other, Chain, Addr, JTI, UId);
2377  } else {
2378    Addr = DAG.getLoad(PTy, dl, Chain, Addr,
2379                       PseudoSourceValue::getJumpTable(), 0, false, false, 0);
2380    Chain = Addr.getValue(1);
2381    return DAG.getNode(ARMISD::BR_JT, dl, MVT::Other, Chain, Addr, JTI, UId);
2382  }
2383}
2384
2385static SDValue LowerFP_TO_INT(SDValue Op, SelectionDAG &DAG) {
2386  DebugLoc dl = Op.getDebugLoc();
2387  unsigned Opc;
2388
2389  switch (Op.getOpcode()) {
2390  default:
2391    assert(0 && "Invalid opcode!");
2392  case ISD::FP_TO_SINT:
2393    Opc = ARMISD::FTOSI;
2394    break;
2395  case ISD::FP_TO_UINT:
2396    Opc = ARMISD::FTOUI;
2397    break;
2398  }
2399  Op = DAG.getNode(Opc, dl, MVT::f32, Op.getOperand(0));
2400  return DAG.getNode(ISD::BIT_CONVERT, dl, MVT::i32, Op);
2401}
2402
2403static SDValue LowerINT_TO_FP(SDValue Op, SelectionDAG &DAG) {
2404  EVT VT = Op.getValueType();
2405  DebugLoc dl = Op.getDebugLoc();
2406  unsigned Opc;
2407
2408  switch (Op.getOpcode()) {
2409  default:
2410    assert(0 && "Invalid opcode!");
2411  case ISD::SINT_TO_FP:
2412    Opc = ARMISD::SITOF;
2413    break;
2414  case ISD::UINT_TO_FP:
2415    Opc = ARMISD::UITOF;
2416    break;
2417  }
2418
2419  Op = DAG.getNode(ISD::BIT_CONVERT, dl, MVT::f32, Op.getOperand(0));
2420  return DAG.getNode(Opc, dl, VT, Op);
2421}
2422
2423static SDValue LowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) {
2424  // Implement fcopysign with a fabs and a conditional fneg.
2425  SDValue Tmp0 = Op.getOperand(0);
2426  SDValue Tmp1 = Op.getOperand(1);
2427  DebugLoc dl = Op.getDebugLoc();
2428  EVT VT = Op.getValueType();
2429  EVT SrcVT = Tmp1.getValueType();
2430  SDValue AbsVal = DAG.getNode(ISD::FABS, dl, VT, Tmp0);
2431  SDValue Cmp = getVFPCmp(Tmp1, DAG.getConstantFP(0.0, SrcVT), DAG, dl);
2432  SDValue ARMCC = DAG.getConstant(ARMCC::LT, MVT::i32);
2433  SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
2434  return DAG.getNode(ARMISD::CNEG, dl, VT, AbsVal, AbsVal, ARMCC, CCR, Cmp);
2435}
2436
2437SDValue ARMTargetLowering::LowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const{
2438  MachineFunction &MF = DAG.getMachineFunction();
2439  MachineFrameInfo *MFI = MF.getFrameInfo();
2440  MFI->setReturnAddressIsTaken(true);
2441
2442  EVT VT = Op.getValueType();
2443  DebugLoc dl = Op.getDebugLoc();
2444  unsigned Depth = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
2445  if (Depth) {
2446    SDValue FrameAddr = LowerFRAMEADDR(Op, DAG);
2447    SDValue Offset = DAG.getConstant(4, MVT::i32);
2448    return DAG.getLoad(VT, dl, DAG.getEntryNode(),
2449                       DAG.getNode(ISD::ADD, dl, VT, FrameAddr, Offset),
2450                       NULL, 0, false, false, 0);
2451  }
2452
2453  // Return LR, which contains the return address. Mark it an implicit live-in.
2454  unsigned Reg = MF.addLiveIn(ARM::LR, ARM::GPRRegisterClass);
2455  return DAG.getCopyFromReg(DAG.getEntryNode(), dl, Reg, VT);
2456}
2457
2458SDValue ARMTargetLowering::LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const {
2459  MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
2460  MFI->setFrameAddressIsTaken(true);
2461
2462  EVT VT = Op.getValueType();
2463  DebugLoc dl = Op.getDebugLoc();  // FIXME probably not meaningful
2464  unsigned Depth = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
2465  unsigned FrameReg = (Subtarget->isThumb() || Subtarget->isTargetDarwin())
2466    ? ARM::R7 : ARM::R11;
2467  SDValue FrameAddr = DAG.getCopyFromReg(DAG.getEntryNode(), dl, FrameReg, VT);
2468  while (Depth--)
2469    FrameAddr = DAG.getLoad(VT, dl, DAG.getEntryNode(), FrameAddr, NULL, 0,
2470                            false, false, 0);
2471  return FrameAddr;
2472}
2473
2474/// ExpandBIT_CONVERT - If the target supports VFP, this function is called to
2475/// expand a bit convert where either the source or destination type is i64 to
2476/// use a VMOVDRR or VMOVRRD node.  This should not be done when the non-i64
2477/// operand type is illegal (e.g., v2f32 for a target that doesn't support
2478/// vectors), since the legalizer won't know what to do with that.
2479static SDValue ExpandBIT_CONVERT(SDNode *N, SelectionDAG &DAG) {
2480  const TargetLowering &TLI = DAG.getTargetLoweringInfo();
2481  DebugLoc dl = N->getDebugLoc();
2482  SDValue Op = N->getOperand(0);
2483
2484  // This function is only supposed to be called for i64 types, either as the
2485  // source or destination of the bit convert.
2486  EVT SrcVT = Op.getValueType();
2487  EVT DstVT = N->getValueType(0);
2488  assert((SrcVT == MVT::i64 || DstVT == MVT::i64) &&
2489         "ExpandBIT_CONVERT called for non-i64 type");
2490
2491  // Turn i64->f64 into VMOVDRR.
2492  if (SrcVT == MVT::i64 && TLI.isTypeLegal(DstVT)) {
2493    SDValue Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32, Op,
2494                             DAG.getConstant(0, MVT::i32));
2495    SDValue Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32, Op,
2496                             DAG.getConstant(1, MVT::i32));
2497    return DAG.getNode(ISD::BIT_CONVERT, dl, DstVT,
2498                       DAG.getNode(ARMISD::VMOVDRR, dl, MVT::f64, Lo, Hi));
2499  }
2500
2501  // Turn f64->i64 into VMOVRRD.
2502  if (DstVT == MVT::i64 && TLI.isTypeLegal(SrcVT)) {
2503    SDValue Cvt = DAG.getNode(ARMISD::VMOVRRD, dl,
2504                              DAG.getVTList(MVT::i32, MVT::i32), &Op, 1);
2505    // Merge the pieces into a single i64 value.
2506    return DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, Cvt, Cvt.getValue(1));
2507  }
2508
2509  return SDValue();
2510}
2511
2512/// getZeroVector - Returns a vector of specified type with all zero elements.
2513///
2514static SDValue getZeroVector(EVT VT, SelectionDAG &DAG, DebugLoc dl) {
2515  assert(VT.isVector() && "Expected a vector type");
2516
2517  // Zero vectors are used to represent vector negation and in those cases
2518  // will be implemented with the NEON VNEG instruction.  However, VNEG does
2519  // not support i64 elements, so sometimes the zero vectors will need to be
2520  // explicitly constructed.  For those cases, and potentially other uses in
2521  // the future, always build zero vectors as <16 x i8> or <8 x i8> bitcasted
2522  // to their dest type.  This ensures they get CSE'd.
2523  SDValue Vec;
2524  SDValue Cst = DAG.getTargetConstant(0, MVT::i8);
2525  SmallVector<SDValue, 8> Ops;
2526  MVT TVT;
2527
2528  if (VT.getSizeInBits() == 64) {
2529    Ops.assign(8, Cst); TVT = MVT::v8i8;
2530  } else {
2531    Ops.assign(16, Cst); TVT = MVT::v16i8;
2532  }
2533  Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, TVT, &Ops[0], Ops.size());
2534
2535  return DAG.getNode(ISD::BIT_CONVERT, dl, VT, Vec);
2536}
2537
2538/// getOnesVector - Returns a vector of specified type with all bits set.
2539///
2540static SDValue getOnesVector(EVT VT, SelectionDAG &DAG, DebugLoc dl) {
2541  assert(VT.isVector() && "Expected a vector type");
2542
2543  // Always build ones vectors as <16 x i8> or <8 x i8> bitcasted to their
2544  // dest type. This ensures they get CSE'd.
2545  SDValue Vec;
2546  SDValue Cst = DAG.getTargetConstant(0xFF, MVT::i8);
2547  SmallVector<SDValue, 8> Ops;
2548  MVT TVT;
2549
2550  if (VT.getSizeInBits() == 64) {
2551    Ops.assign(8, Cst); TVT = MVT::v8i8;
2552  } else {
2553    Ops.assign(16, Cst); TVT = MVT::v16i8;
2554  }
2555  Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, TVT, &Ops[0], Ops.size());
2556
2557  return DAG.getNode(ISD::BIT_CONVERT, dl, VT, Vec);
2558}
2559
2560/// LowerShiftRightParts - Lower SRA_PARTS, which returns two
2561/// i32 values and take a 2 x i32 value to shift plus a shift amount.
2562SDValue ARMTargetLowering::LowerShiftRightParts(SDValue Op,
2563                                                SelectionDAG &DAG) const {
2564  assert(Op.getNumOperands() == 3 && "Not a double-shift!");
2565  EVT VT = Op.getValueType();
2566  unsigned VTBits = VT.getSizeInBits();
2567  DebugLoc dl = Op.getDebugLoc();
2568  SDValue ShOpLo = Op.getOperand(0);
2569  SDValue ShOpHi = Op.getOperand(1);
2570  SDValue ShAmt  = Op.getOperand(2);
2571  SDValue ARMCC;
2572  unsigned Opc = (Op.getOpcode() == ISD::SRA_PARTS) ? ISD::SRA : ISD::SRL;
2573
2574  assert(Op.getOpcode() == ISD::SRA_PARTS || Op.getOpcode() == ISD::SRL_PARTS);
2575
2576  SDValue RevShAmt = DAG.getNode(ISD::SUB, dl, MVT::i32,
2577                                 DAG.getConstant(VTBits, MVT::i32), ShAmt);
2578  SDValue Tmp1 = DAG.getNode(ISD::SRL, dl, VT, ShOpLo, ShAmt);
2579  SDValue ExtraShAmt = DAG.getNode(ISD::SUB, dl, MVT::i32, ShAmt,
2580                                   DAG.getConstant(VTBits, MVT::i32));
2581  SDValue Tmp2 = DAG.getNode(ISD::SHL, dl, VT, ShOpHi, RevShAmt);
2582  SDValue FalseVal = DAG.getNode(ISD::OR, dl, VT, Tmp1, Tmp2);
2583  SDValue TrueVal = DAG.getNode(Opc, dl, VT, ShOpHi, ExtraShAmt);
2584
2585  SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
2586  SDValue Cmp = getARMCmp(ExtraShAmt, DAG.getConstant(0, MVT::i32), ISD::SETGE,
2587                          ARMCC, DAG, dl);
2588  SDValue Hi = DAG.getNode(Opc, dl, VT, ShOpHi, ShAmt);
2589  SDValue Lo = DAG.getNode(ARMISD::CMOV, dl, VT, FalseVal, TrueVal, ARMCC,
2590                           CCR, Cmp);
2591
2592  SDValue Ops[2] = { Lo, Hi };
2593  return DAG.getMergeValues(Ops, 2, dl);
2594}
2595
2596/// LowerShiftLeftParts - Lower SHL_PARTS, which returns two
2597/// i32 values and take a 2 x i32 value to shift plus a shift amount.
2598SDValue ARMTargetLowering::LowerShiftLeftParts(SDValue Op,
2599                                               SelectionDAG &DAG) const {
2600  assert(Op.getNumOperands() == 3 && "Not a double-shift!");
2601  EVT VT = Op.getValueType();
2602  unsigned VTBits = VT.getSizeInBits();
2603  DebugLoc dl = Op.getDebugLoc();
2604  SDValue ShOpLo = Op.getOperand(0);
2605  SDValue ShOpHi = Op.getOperand(1);
2606  SDValue ShAmt  = Op.getOperand(2);
2607  SDValue ARMCC;
2608
2609  assert(Op.getOpcode() == ISD::SHL_PARTS);
2610  SDValue RevShAmt = DAG.getNode(ISD::SUB, dl, MVT::i32,
2611                                 DAG.getConstant(VTBits, MVT::i32), ShAmt);
2612  SDValue Tmp1 = DAG.getNode(ISD::SRL, dl, VT, ShOpLo, RevShAmt);
2613  SDValue ExtraShAmt = DAG.getNode(ISD::SUB, dl, MVT::i32, ShAmt,
2614                                   DAG.getConstant(VTBits, MVT::i32));
2615  SDValue Tmp2 = DAG.getNode(ISD::SHL, dl, VT, ShOpHi, ShAmt);
2616  SDValue Tmp3 = DAG.getNode(ISD::SHL, dl, VT, ShOpLo, ExtraShAmt);
2617
2618  SDValue FalseVal = DAG.getNode(ISD::OR, dl, VT, Tmp1, Tmp2);
2619  SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
2620  SDValue Cmp = getARMCmp(ExtraShAmt, DAG.getConstant(0, MVT::i32), ISD::SETGE,
2621                          ARMCC, DAG, dl);
2622  SDValue Lo = DAG.getNode(ISD::SHL, dl, VT, ShOpLo, ShAmt);
2623  SDValue Hi = DAG.getNode(ARMISD::CMOV, dl, VT, FalseVal, Tmp3, ARMCC,
2624                           CCR, Cmp);
2625
2626  SDValue Ops[2] = { Lo, Hi };
2627  return DAG.getMergeValues(Ops, 2, dl);
2628}
2629
2630static SDValue LowerCTTZ(SDNode *N, SelectionDAG &DAG,
2631                         const ARMSubtarget *ST) {
2632  EVT VT = N->getValueType(0);
2633  DebugLoc dl = N->getDebugLoc();
2634
2635  if (!ST->hasV6T2Ops())
2636    return SDValue();
2637
2638  SDValue rbit = DAG.getNode(ARMISD::RBIT, dl, VT, N->getOperand(0));
2639  return DAG.getNode(ISD::CTLZ, dl, VT, rbit);
2640}
2641
2642static SDValue LowerShift(SDNode *N, SelectionDAG &DAG,
2643                          const ARMSubtarget *ST) {
2644  EVT VT = N->getValueType(0);
2645  DebugLoc dl = N->getDebugLoc();
2646
2647  // Lower vector shifts on NEON to use VSHL.
2648  if (VT.isVector()) {
2649    assert(ST->hasNEON() && "unexpected vector shift");
2650
2651    // Left shifts translate directly to the vshiftu intrinsic.
2652    if (N->getOpcode() == ISD::SHL)
2653      return DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, VT,
2654                         DAG.getConstant(Intrinsic::arm_neon_vshiftu, MVT::i32),
2655                         N->getOperand(0), N->getOperand(1));
2656
2657    assert((N->getOpcode() == ISD::SRA ||
2658            N->getOpcode() == ISD::SRL) && "unexpected vector shift opcode");
2659
2660    // NEON uses the same intrinsics for both left and right shifts.  For
2661    // right shifts, the shift amounts are negative, so negate the vector of
2662    // shift amounts.
2663    EVT ShiftVT = N->getOperand(1).getValueType();
2664    SDValue NegatedCount = DAG.getNode(ISD::SUB, dl, ShiftVT,
2665                                       getZeroVector(ShiftVT, DAG, dl),
2666                                       N->getOperand(1));
2667    Intrinsic::ID vshiftInt = (N->getOpcode() == ISD::SRA ?
2668                               Intrinsic::arm_neon_vshifts :
2669                               Intrinsic::arm_neon_vshiftu);
2670    return DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, VT,
2671                       DAG.getConstant(vshiftInt, MVT::i32),
2672                       N->getOperand(0), NegatedCount);
2673  }
2674
2675  // We can get here for a node like i32 = ISD::SHL i32, i64
2676  if (VT != MVT::i64)
2677    return SDValue();
2678
2679  assert((N->getOpcode() == ISD::SRL || N->getOpcode() == ISD::SRA) &&
2680         "Unknown shift to lower!");
2681
2682  // We only lower SRA, SRL of 1 here, all others use generic lowering.
2683  if (!isa<ConstantSDNode>(N->getOperand(1)) ||
2684      cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() != 1)
2685    return SDValue();
2686
2687  // If we are in thumb mode, we don't have RRX.
2688  if (ST->isThumb1Only()) return SDValue();
2689
2690  // Okay, we have a 64-bit SRA or SRL of 1.  Lower this to an RRX expr.
2691  SDValue Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32, N->getOperand(0),
2692                           DAG.getConstant(0, MVT::i32));
2693  SDValue Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32, N->getOperand(0),
2694                           DAG.getConstant(1, MVT::i32));
2695
2696  // First, build a SRA_FLAG/SRL_FLAG op, which shifts the top part by one and
2697  // captures the result into a carry flag.
2698  unsigned Opc = N->getOpcode() == ISD::SRL ? ARMISD::SRL_FLAG:ARMISD::SRA_FLAG;
2699  Hi = DAG.getNode(Opc, dl, DAG.getVTList(MVT::i32, MVT::Flag), &Hi, 1);
2700
2701  // The low part is an ARMISD::RRX operand, which shifts the carry in.
2702  Lo = DAG.getNode(ARMISD::RRX, dl, MVT::i32, Lo, Hi.getValue(1));
2703
2704  // Merge the pieces into a single i64 value.
2705 return DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, Lo, Hi);
2706}
2707
2708static SDValue LowerVSETCC(SDValue Op, SelectionDAG &DAG) {
2709  SDValue TmpOp0, TmpOp1;
2710  bool Invert = false;
2711  bool Swap = false;
2712  unsigned Opc = 0;
2713
2714  SDValue Op0 = Op.getOperand(0);
2715  SDValue Op1 = Op.getOperand(1);
2716  SDValue CC = Op.getOperand(2);
2717  EVT VT = Op.getValueType();
2718  ISD::CondCode SetCCOpcode = cast<CondCodeSDNode>(CC)->get();
2719  DebugLoc dl = Op.getDebugLoc();
2720
2721  if (Op.getOperand(1).getValueType().isFloatingPoint()) {
2722    switch (SetCCOpcode) {
2723    default: llvm_unreachable("Illegal FP comparison"); break;
2724    case ISD::SETUNE:
2725    case ISD::SETNE:  Invert = true; // Fallthrough
2726    case ISD::SETOEQ:
2727    case ISD::SETEQ:  Opc = ARMISD::VCEQ; break;
2728    case ISD::SETOLT:
2729    case ISD::SETLT: Swap = true; // Fallthrough
2730    case ISD::SETOGT:
2731    case ISD::SETGT:  Opc = ARMISD::VCGT; break;
2732    case ISD::SETOLE:
2733    case ISD::SETLE:  Swap = true; // Fallthrough
2734    case ISD::SETOGE:
2735    case ISD::SETGE: Opc = ARMISD::VCGE; break;
2736    case ISD::SETUGE: Swap = true; // Fallthrough
2737    case ISD::SETULE: Invert = true; Opc = ARMISD::VCGT; break;
2738    case ISD::SETUGT: Swap = true; // Fallthrough
2739    case ISD::SETULT: Invert = true; Opc = ARMISD::VCGE; break;
2740    case ISD::SETUEQ: Invert = true; // Fallthrough
2741    case ISD::SETONE:
2742      // Expand this to (OLT | OGT).
2743      TmpOp0 = Op0;
2744      TmpOp1 = Op1;
2745      Opc = ISD::OR;
2746      Op0 = DAG.getNode(ARMISD::VCGT, dl, VT, TmpOp1, TmpOp0);
2747      Op1 = DAG.getNode(ARMISD::VCGT, dl, VT, TmpOp0, TmpOp1);
2748      break;
2749    case ISD::SETUO: Invert = true; // Fallthrough
2750    case ISD::SETO:
2751      // Expand this to (OLT | OGE).
2752      TmpOp0 = Op0;
2753      TmpOp1 = Op1;
2754      Opc = ISD::OR;
2755      Op0 = DAG.getNode(ARMISD::VCGT, dl, VT, TmpOp1, TmpOp0);
2756      Op1 = DAG.getNode(ARMISD::VCGE, dl, VT, TmpOp0, TmpOp1);
2757      break;
2758    }
2759  } else {
2760    // Integer comparisons.
2761    switch (SetCCOpcode) {
2762    default: llvm_unreachable("Illegal integer comparison"); break;
2763    case ISD::SETNE:  Invert = true;
2764    case ISD::SETEQ:  Opc = ARMISD::VCEQ; break;
2765    case ISD::SETLT:  Swap = true;
2766    case ISD::SETGT:  Opc = ARMISD::VCGT; break;
2767    case ISD::SETLE:  Swap = true;
2768    case ISD::SETGE:  Opc = ARMISD::VCGE; break;
2769    case ISD::SETULT: Swap = true;
2770    case ISD::SETUGT: Opc = ARMISD::VCGTU; break;
2771    case ISD::SETULE: Swap = true;
2772    case ISD::SETUGE: Opc = ARMISD::VCGEU; break;
2773    }
2774
2775    // Detect VTST (Vector Test Bits) = icmp ne (and (op0, op1), zero).
2776    if (Opc == ARMISD::VCEQ) {
2777
2778      SDValue AndOp;
2779      if (ISD::isBuildVectorAllZeros(Op1.getNode()))
2780        AndOp = Op0;
2781      else if (ISD::isBuildVectorAllZeros(Op0.getNode()))
2782        AndOp = Op1;
2783
2784      // Ignore bitconvert.
2785      if (AndOp.getNode() && AndOp.getOpcode() == ISD::BIT_CONVERT)
2786        AndOp = AndOp.getOperand(0);
2787
2788      if (AndOp.getNode() && AndOp.getOpcode() == ISD::AND) {
2789        Opc = ARMISD::VTST;
2790        Op0 = DAG.getNode(ISD::BIT_CONVERT, dl, VT, AndOp.getOperand(0));
2791        Op1 = DAG.getNode(ISD::BIT_CONVERT, dl, VT, AndOp.getOperand(1));
2792        Invert = !Invert;
2793      }
2794    }
2795  }
2796
2797  if (Swap)
2798    std::swap(Op0, Op1);
2799
2800  SDValue Result = DAG.getNode(Opc, dl, VT, Op0, Op1);
2801
2802  if (Invert)
2803    Result = DAG.getNOT(dl, Result, VT);
2804
2805  return Result;
2806}
2807
2808/// isNEONModifiedImm - Check if the specified splat value corresponds to a
2809/// valid vector constant for a NEON instruction with a "modified immediate"
2810/// operand (e.g., VMOV).  If so, return either the constant being
2811/// splatted or the encoded value, depending on the DoEncode parameter.  The
2812/// format of the encoded value is: bit12=Op, bits11-8=Cmode,
2813/// bits7-0=Immediate.
2814static SDValue isNEONModifiedImm(uint64_t SplatBits, uint64_t SplatUndef,
2815                                 unsigned SplatBitSize, SelectionDAG &DAG,
2816                                 bool isVMOV, bool DoEncode) {
2817  unsigned Op, Cmode, Imm;
2818  EVT VT;
2819
2820  // SplatBitSize is set to the smallest size that splats the vector, so a
2821  // zero vector will always have SplatBitSize == 8.  However, NEON modified
2822  // immediate instructions others than VMOV do not support the 8-bit encoding
2823  // of a zero vector, and the default encoding of zero is supposed to be the
2824  // 32-bit version.
2825  if (SplatBits == 0)
2826    SplatBitSize = 32;
2827
2828  Op = 0;
2829  switch (SplatBitSize) {
2830  case 8:
2831    // Any 1-byte value is OK.  Op=0, Cmode=1110.
2832    assert((SplatBits & ~0xff) == 0 && "one byte splat value is too big");
2833    Cmode = 0xe;
2834    Imm = SplatBits;
2835    VT = MVT::i8;
2836    break;
2837
2838  case 16:
2839    // NEON's 16-bit VMOV supports splat values where only one byte is nonzero.
2840    VT = MVT::i16;
2841    if ((SplatBits & ~0xff) == 0) {
2842      // Value = 0x00nn: Op=x, Cmode=100x.
2843      Cmode = 0x8;
2844      Imm = SplatBits;
2845      break;
2846    }
2847    if ((SplatBits & ~0xff00) == 0) {
2848      // Value = 0xnn00: Op=x, Cmode=101x.
2849      Cmode = 0xa;
2850      Imm = SplatBits >> 8;
2851      break;
2852    }
2853    return SDValue();
2854
2855  case 32:
2856    // NEON's 32-bit VMOV supports splat values where:
2857    // * only one byte is nonzero, or
2858    // * the least significant byte is 0xff and the second byte is nonzero, or
2859    // * the least significant 2 bytes are 0xff and the third is nonzero.
2860    VT = MVT::i32;
2861    if ((SplatBits & ~0xff) == 0) {
2862      // Value = 0x000000nn: Op=x, Cmode=000x.
2863      Cmode = 0;
2864      Imm = SplatBits;
2865      break;
2866    }
2867    if ((SplatBits & ~0xff00) == 0) {
2868      // Value = 0x0000nn00: Op=x, Cmode=001x.
2869      Cmode = 0x2;
2870      Imm = SplatBits >> 8;
2871      break;
2872    }
2873    if ((SplatBits & ~0xff0000) == 0) {
2874      // Value = 0x00nn0000: Op=x, Cmode=010x.
2875      Cmode = 0x4;
2876      Imm = SplatBits >> 16;
2877      break;
2878    }
2879    if ((SplatBits & ~0xff000000) == 0) {
2880      // Value = 0xnn000000: Op=x, Cmode=011x.
2881      Cmode = 0x6;
2882      Imm = SplatBits >> 24;
2883      break;
2884    }
2885
2886    if ((SplatBits & ~0xffff) == 0 &&
2887        ((SplatBits | SplatUndef) & 0xff) == 0xff) {
2888      // Value = 0x0000nnff: Op=x, Cmode=1100.
2889      Cmode = 0xc;
2890      Imm = SplatBits >> 8;
2891      SplatBits |= 0xff;
2892      break;
2893    }
2894
2895    if ((SplatBits & ~0xffffff) == 0 &&
2896        ((SplatBits | SplatUndef) & 0xffff) == 0xffff) {
2897      // Value = 0x00nnffff: Op=x, Cmode=1101.
2898      Cmode = 0xd;
2899      Imm = SplatBits >> 16;
2900      SplatBits |= 0xffff;
2901      break;
2902    }
2903
2904    // Note: there are a few 32-bit splat values (specifically: 00ffff00,
2905    // ff000000, ff0000ff, and ffff00ff) that are valid for VMOV.I64 but not
2906    // VMOV.I32.  A (very) minor optimization would be to replicate the value
2907    // and fall through here to test for a valid 64-bit splat.  But, then the
2908    // caller would also need to check and handle the change in size.
2909    return SDValue();
2910
2911  case 64: {
2912    // NEON has a 64-bit VMOV splat where each byte is either 0 or 0xff.
2913    if (!isVMOV)
2914      return SDValue();
2915    uint64_t BitMask = 0xff;
2916    uint64_t Val = 0;
2917    unsigned ImmMask = 1;
2918    Imm = 0;
2919    for (int ByteNum = 0; ByteNum < 8; ++ByteNum) {
2920      if (((SplatBits | SplatUndef) & BitMask) == BitMask) {
2921        Val |= BitMask;
2922        Imm |= ImmMask;
2923      } else if ((SplatBits & BitMask) != 0) {
2924        return SDValue();
2925      }
2926      BitMask <<= 8;
2927      ImmMask <<= 1;
2928    }
2929    // Op=1, Cmode=1110.
2930    Op = 1;
2931    Cmode = 0xe;
2932    SplatBits = Val;
2933    VT = MVT::i64;
2934    break;
2935  }
2936
2937  default:
2938    llvm_unreachable("unexpected size for isNEONModifiedImm");
2939    return SDValue();
2940  }
2941
2942  if (DoEncode)
2943    return DAG.getTargetConstant((Op << 12) | (Cmode << 8) | Imm, MVT::i32);
2944  return DAG.getTargetConstant(SplatBits, VT);
2945}
2946
2947
2948/// getNEONModImm - If this is a valid vector constant for a NEON instruction
2949/// with a "modified immediate" operand (e.g., VMOV) of the specified element
2950/// size, return the encoded value for that immediate.  The ByteSize field
2951/// indicates the number of bytes of each element [1248].
2952SDValue ARM::getNEONModImm(SDNode *N, unsigned ByteSize, bool isVMOV,
2953                           SelectionDAG &DAG) {
2954  BuildVectorSDNode *BVN = dyn_cast<BuildVectorSDNode>(N);
2955  APInt SplatBits, SplatUndef;
2956  unsigned SplatBitSize;
2957  bool HasAnyUndefs;
2958  if (! BVN || ! BVN->isConstantSplat(SplatBits, SplatUndef, SplatBitSize,
2959                                      HasAnyUndefs, ByteSize * 8))
2960    return SDValue();
2961
2962  if (SplatBitSize > ByteSize * 8)
2963    return SDValue();
2964
2965  return isNEONModifiedImm(SplatBits.getZExtValue(), SplatUndef.getZExtValue(),
2966                           SplatBitSize, DAG, isVMOV, true);
2967}
2968
2969static bool isVEXTMask(const SmallVectorImpl<int> &M, EVT VT,
2970                       bool &ReverseVEXT, unsigned &Imm) {
2971  unsigned NumElts = VT.getVectorNumElements();
2972  ReverseVEXT = false;
2973  Imm = M[0];
2974
2975  // If this is a VEXT shuffle, the immediate value is the index of the first
2976  // element.  The other shuffle indices must be the successive elements after
2977  // the first one.
2978  unsigned ExpectedElt = Imm;
2979  for (unsigned i = 1; i < NumElts; ++i) {
2980    // Increment the expected index.  If it wraps around, it may still be
2981    // a VEXT but the source vectors must be swapped.
2982    ExpectedElt += 1;
2983    if (ExpectedElt == NumElts * 2) {
2984      ExpectedElt = 0;
2985      ReverseVEXT = true;
2986    }
2987
2988    if (ExpectedElt != static_cast<unsigned>(M[i]))
2989      return false;
2990  }
2991
2992  // Adjust the index value if the source operands will be swapped.
2993  if (ReverseVEXT)
2994    Imm -= NumElts;
2995
2996  return true;
2997}
2998
2999/// isVREVMask - Check if a vector shuffle corresponds to a VREV
3000/// instruction with the specified blocksize.  (The order of the elements
3001/// within each block of the vector is reversed.)
3002static bool isVREVMask(const SmallVectorImpl<int> &M, EVT VT,
3003                       unsigned BlockSize) {
3004  assert((BlockSize==16 || BlockSize==32 || BlockSize==64) &&
3005         "Only possible block sizes for VREV are: 16, 32, 64");
3006
3007  unsigned EltSz = VT.getVectorElementType().getSizeInBits();
3008  if (EltSz == 64)
3009    return false;
3010
3011  unsigned NumElts = VT.getVectorNumElements();
3012  unsigned BlockElts = M[0] + 1;
3013
3014  if (BlockSize <= EltSz || BlockSize != BlockElts * EltSz)
3015    return false;
3016
3017  for (unsigned i = 0; i < NumElts; ++i) {
3018    if ((unsigned) M[i] !=
3019        (i - i%BlockElts) + (BlockElts - 1 - i%BlockElts))
3020      return false;
3021  }
3022
3023  return true;
3024}
3025
3026static bool isVTRNMask(const SmallVectorImpl<int> &M, EVT VT,
3027                       unsigned &WhichResult) {
3028  unsigned EltSz = VT.getVectorElementType().getSizeInBits();
3029  if (EltSz == 64)
3030    return false;
3031
3032  unsigned NumElts = VT.getVectorNumElements();
3033  WhichResult = (M[0] == 0 ? 0 : 1);
3034  for (unsigned i = 0; i < NumElts; i += 2) {
3035    if ((unsigned) M[i] != i + WhichResult ||
3036        (unsigned) M[i+1] != i + NumElts + WhichResult)
3037      return false;
3038  }
3039  return true;
3040}
3041
3042/// isVTRN_v_undef_Mask - Special case of isVTRNMask for canonical form of
3043/// "vector_shuffle v, v", i.e., "vector_shuffle v, undef".
3044/// Mask is e.g., <0, 0, 2, 2> instead of <0, 4, 2, 6>.
3045static bool isVTRN_v_undef_Mask(const SmallVectorImpl<int> &M, EVT VT,
3046                                unsigned &WhichResult) {
3047  unsigned EltSz = VT.getVectorElementType().getSizeInBits();
3048  if (EltSz == 64)
3049    return false;
3050
3051  unsigned NumElts = VT.getVectorNumElements();
3052  WhichResult = (M[0] == 0 ? 0 : 1);
3053  for (unsigned i = 0; i < NumElts; i += 2) {
3054    if ((unsigned) M[i] != i + WhichResult ||
3055        (unsigned) M[i+1] != i + WhichResult)
3056      return false;
3057  }
3058  return true;
3059}
3060
3061static bool isVUZPMask(const SmallVectorImpl<int> &M, EVT VT,
3062                       unsigned &WhichResult) {
3063  unsigned EltSz = VT.getVectorElementType().getSizeInBits();
3064  if (EltSz == 64)
3065    return false;
3066
3067  unsigned NumElts = VT.getVectorNumElements();
3068  WhichResult = (M[0] == 0 ? 0 : 1);
3069  for (unsigned i = 0; i != NumElts; ++i) {
3070    if ((unsigned) M[i] != 2 * i + WhichResult)
3071      return false;
3072  }
3073
3074  // VUZP.32 for 64-bit vectors is a pseudo-instruction alias for VTRN.32.
3075  if (VT.is64BitVector() && EltSz == 32)
3076    return false;
3077
3078  return true;
3079}
3080
3081/// isVUZP_v_undef_Mask - Special case of isVUZPMask for canonical form of
3082/// "vector_shuffle v, v", i.e., "vector_shuffle v, undef".
3083/// Mask is e.g., <0, 2, 0, 2> instead of <0, 2, 4, 6>,
3084static bool isVUZP_v_undef_Mask(const SmallVectorImpl<int> &M, EVT VT,
3085                                unsigned &WhichResult) {
3086  unsigned EltSz = VT.getVectorElementType().getSizeInBits();
3087  if (EltSz == 64)
3088    return false;
3089
3090  unsigned Half = VT.getVectorNumElements() / 2;
3091  WhichResult = (M[0] == 0 ? 0 : 1);
3092  for (unsigned j = 0; j != 2; ++j) {
3093    unsigned Idx = WhichResult;
3094    for (unsigned i = 0; i != Half; ++i) {
3095      if ((unsigned) M[i + j * Half] != Idx)
3096        return false;
3097      Idx += 2;
3098    }
3099  }
3100
3101  // VUZP.32 for 64-bit vectors is a pseudo-instruction alias for VTRN.32.
3102  if (VT.is64BitVector() && EltSz == 32)
3103    return false;
3104
3105  return true;
3106}
3107
3108static bool isVZIPMask(const SmallVectorImpl<int> &M, EVT VT,
3109                       unsigned &WhichResult) {
3110  unsigned EltSz = VT.getVectorElementType().getSizeInBits();
3111  if (EltSz == 64)
3112    return false;
3113
3114  unsigned NumElts = VT.getVectorNumElements();
3115  WhichResult = (M[0] == 0 ? 0 : 1);
3116  unsigned Idx = WhichResult * NumElts / 2;
3117  for (unsigned i = 0; i != NumElts; i += 2) {
3118    if ((unsigned) M[i] != Idx ||
3119        (unsigned) M[i+1] != Idx + NumElts)
3120      return false;
3121    Idx += 1;
3122  }
3123
3124  // VZIP.32 for 64-bit vectors is a pseudo-instruction alias for VTRN.32.
3125  if (VT.is64BitVector() && EltSz == 32)
3126    return false;
3127
3128  return true;
3129}
3130
3131/// isVZIP_v_undef_Mask - Special case of isVZIPMask for canonical form of
3132/// "vector_shuffle v, v", i.e., "vector_shuffle v, undef".
3133/// Mask is e.g., <0, 0, 1, 1> instead of <0, 4, 1, 5>.
3134static bool isVZIP_v_undef_Mask(const SmallVectorImpl<int> &M, EVT VT,
3135                                unsigned &WhichResult) {
3136  unsigned EltSz = VT.getVectorElementType().getSizeInBits();
3137  if (EltSz == 64)
3138    return false;
3139
3140  unsigned NumElts = VT.getVectorNumElements();
3141  WhichResult = (M[0] == 0 ? 0 : 1);
3142  unsigned Idx = WhichResult * NumElts / 2;
3143  for (unsigned i = 0; i != NumElts; i += 2) {
3144    if ((unsigned) M[i] != Idx ||
3145        (unsigned) M[i+1] != Idx)
3146      return false;
3147    Idx += 1;
3148  }
3149
3150  // VZIP.32 for 64-bit vectors is a pseudo-instruction alias for VTRN.32.
3151  if (VT.is64BitVector() && EltSz == 32)
3152    return false;
3153
3154  return true;
3155}
3156
3157
3158static SDValue BuildSplat(SDValue Val, EVT VT, SelectionDAG &DAG, DebugLoc dl) {
3159  // Canonicalize all-zeros and all-ones vectors.
3160  ConstantSDNode *ConstVal = cast<ConstantSDNode>(Val.getNode());
3161  if (ConstVal->isNullValue())
3162    return getZeroVector(VT, DAG, dl);
3163  if (ConstVal->isAllOnesValue())
3164    return getOnesVector(VT, DAG, dl);
3165
3166  EVT CanonicalVT;
3167  if (VT.is64BitVector()) {
3168    switch (Val.getValueType().getSizeInBits()) {
3169    case 8:  CanonicalVT = MVT::v8i8; break;
3170    case 16: CanonicalVT = MVT::v4i16; break;
3171    case 32: CanonicalVT = MVT::v2i32; break;
3172    case 64: CanonicalVT = MVT::v1i64; break;
3173    default: llvm_unreachable("unexpected splat element type"); break;
3174    }
3175  } else {
3176    assert(VT.is128BitVector() && "unknown splat vector size");
3177    switch (Val.getValueType().getSizeInBits()) {
3178    case 8:  CanonicalVT = MVT::v16i8; break;
3179    case 16: CanonicalVT = MVT::v8i16; break;
3180    case 32: CanonicalVT = MVT::v4i32; break;
3181    case 64: CanonicalVT = MVT::v2i64; break;
3182    default: llvm_unreachable("unexpected splat element type"); break;
3183    }
3184  }
3185
3186  // Build a canonical splat for this value.
3187  SmallVector<SDValue, 8> Ops;
3188  Ops.assign(CanonicalVT.getVectorNumElements(), Val);
3189  SDValue Res = DAG.getNode(ISD::BUILD_VECTOR, dl, CanonicalVT, &Ops[0],
3190                            Ops.size());
3191  return DAG.getNode(ISD::BIT_CONVERT, dl, VT, Res);
3192}
3193
3194// If this is a case we can't handle, return null and let the default
3195// expansion code take care of it.
3196static SDValue LowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG) {
3197  BuildVectorSDNode *BVN = cast<BuildVectorSDNode>(Op.getNode());
3198  DebugLoc dl = Op.getDebugLoc();
3199  EVT VT = Op.getValueType();
3200
3201  APInt SplatBits, SplatUndef;
3202  unsigned SplatBitSize;
3203  bool HasAnyUndefs;
3204  if (BVN->isConstantSplat(SplatBits, SplatUndef, SplatBitSize, HasAnyUndefs)) {
3205    if (SplatBitSize <= 64) {
3206      // Check if an immediate VMOV works.
3207      SDValue Val = isNEONModifiedImm(SplatBits.getZExtValue(),
3208                                      SplatUndef.getZExtValue(),
3209                                      SplatBitSize, DAG, true, false);
3210      if (Val.getNode())
3211        return BuildSplat(Val, VT, DAG, dl);
3212    }
3213  }
3214
3215  // Scan through the operands to see if only one value is used.
3216  unsigned NumElts = VT.getVectorNumElements();
3217  bool isOnlyLowElement = true;
3218  bool usesOnlyOneValue = true;
3219  bool isConstant = true;
3220  SDValue Value;
3221  for (unsigned i = 0; i < NumElts; ++i) {
3222    SDValue V = Op.getOperand(i);
3223    if (V.getOpcode() == ISD::UNDEF)
3224      continue;
3225    if (i > 0)
3226      isOnlyLowElement = false;
3227    if (!isa<ConstantFPSDNode>(V) && !isa<ConstantSDNode>(V))
3228      isConstant = false;
3229
3230    if (!Value.getNode())
3231      Value = V;
3232    else if (V != Value)
3233      usesOnlyOneValue = false;
3234  }
3235
3236  if (!Value.getNode())
3237    return DAG.getUNDEF(VT);
3238
3239  if (isOnlyLowElement)
3240    return DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value);
3241
3242  // If all elements are constants, fall back to the default expansion, which
3243  // will generate a load from the constant pool.
3244  if (isConstant)
3245    return SDValue();
3246
3247  // Use VDUP for non-constant splats.
3248  unsigned EltSize = VT.getVectorElementType().getSizeInBits();
3249  if (usesOnlyOneValue && EltSize <= 32)
3250    return DAG.getNode(ARMISD::VDUP, dl, VT, Value);
3251
3252  // Vectors with 32- or 64-bit elements can be built by directly assigning
3253  // the subregisters.  Lower it to an ARMISD::BUILD_VECTOR so the operands
3254  // will be legalized.
3255  if (EltSize >= 32) {
3256    // Do the expansion with floating-point types, since that is what the VFP
3257    // registers are defined to use, and since i64 is not legal.
3258    EVT EltVT = EVT::getFloatingPointVT(EltSize);
3259    EVT VecVT = EVT::getVectorVT(*DAG.getContext(), EltVT, NumElts);
3260    SmallVector<SDValue, 8> Ops;
3261    for (unsigned i = 0; i < NumElts; ++i)
3262      Ops.push_back(DAG.getNode(ISD::BIT_CONVERT, dl, EltVT, Op.getOperand(i)));
3263    SDValue Val = DAG.getNode(ARMISD::BUILD_VECTOR, dl, VecVT, &Ops[0],NumElts);
3264    return DAG.getNode(ISD::BIT_CONVERT, dl, VT, Val);
3265  }
3266
3267  return SDValue();
3268}
3269
3270/// isShuffleMaskLegal - Targets can use this to indicate that they only
3271/// support *some* VECTOR_SHUFFLE operations, those with specific masks.
3272/// By default, if a target supports the VECTOR_SHUFFLE node, all mask values
3273/// are assumed to be legal.
3274bool
3275ARMTargetLowering::isShuffleMaskLegal(const SmallVectorImpl<int> &M,
3276                                      EVT VT) const {
3277  if (VT.getVectorNumElements() == 4 &&
3278      (VT.is128BitVector() || VT.is64BitVector())) {
3279    unsigned PFIndexes[4];
3280    for (unsigned i = 0; i != 4; ++i) {
3281      if (M[i] < 0)
3282        PFIndexes[i] = 8;
3283      else
3284        PFIndexes[i] = M[i];
3285    }
3286
3287    // Compute the index in the perfect shuffle table.
3288    unsigned PFTableIndex =
3289      PFIndexes[0]*9*9*9+PFIndexes[1]*9*9+PFIndexes[2]*9+PFIndexes[3];
3290    unsigned PFEntry = PerfectShuffleTable[PFTableIndex];
3291    unsigned Cost = (PFEntry >> 30);
3292
3293    if (Cost <= 4)
3294      return true;
3295  }
3296
3297  bool ReverseVEXT;
3298  unsigned Imm, WhichResult;
3299
3300  unsigned EltSize = VT.getVectorElementType().getSizeInBits();
3301  return (EltSize >= 32 ||
3302          ShuffleVectorSDNode::isSplatMask(&M[0], VT) ||
3303          isVREVMask(M, VT, 64) ||
3304          isVREVMask(M, VT, 32) ||
3305          isVREVMask(M, VT, 16) ||
3306          isVEXTMask(M, VT, ReverseVEXT, Imm) ||
3307          isVTRNMask(M, VT, WhichResult) ||
3308          isVUZPMask(M, VT, WhichResult) ||
3309          isVZIPMask(M, VT, WhichResult) ||
3310          isVTRN_v_undef_Mask(M, VT, WhichResult) ||
3311          isVUZP_v_undef_Mask(M, VT, WhichResult) ||
3312          isVZIP_v_undef_Mask(M, VT, WhichResult));
3313}
3314
3315/// GeneratePerfectShuffle - Given an entry in the perfect-shuffle table, emit
3316/// the specified operations to build the shuffle.
3317static SDValue GeneratePerfectShuffle(unsigned PFEntry, SDValue LHS,
3318                                      SDValue RHS, SelectionDAG &DAG,
3319                                      DebugLoc dl) {
3320  unsigned OpNum = (PFEntry >> 26) & 0x0F;
3321  unsigned LHSID = (PFEntry >> 13) & ((1 << 13)-1);
3322  unsigned RHSID = (PFEntry >>  0) & ((1 << 13)-1);
3323
3324  enum {
3325    OP_COPY = 0, // Copy, used for things like <u,u,u,3> to say it is <0,1,2,3>
3326    OP_VREV,
3327    OP_VDUP0,
3328    OP_VDUP1,
3329    OP_VDUP2,
3330    OP_VDUP3,
3331    OP_VEXT1,
3332    OP_VEXT2,
3333    OP_VEXT3,
3334    OP_VUZPL, // VUZP, left result
3335    OP_VUZPR, // VUZP, right result
3336    OP_VZIPL, // VZIP, left result
3337    OP_VZIPR, // VZIP, right result
3338    OP_VTRNL, // VTRN, left result
3339    OP_VTRNR  // VTRN, right result
3340  };
3341
3342  if (OpNum == OP_COPY) {
3343    if (LHSID == (1*9+2)*9+3) return LHS;
3344    assert(LHSID == ((4*9+5)*9+6)*9+7 && "Illegal OP_COPY!");
3345    return RHS;
3346  }
3347
3348  SDValue OpLHS, OpRHS;
3349  OpLHS = GeneratePerfectShuffle(PerfectShuffleTable[LHSID], LHS, RHS, DAG, dl);
3350  OpRHS = GeneratePerfectShuffle(PerfectShuffleTable[RHSID], LHS, RHS, DAG, dl);
3351  EVT VT = OpLHS.getValueType();
3352
3353  switch (OpNum) {
3354  default: llvm_unreachable("Unknown shuffle opcode!");
3355  case OP_VREV:
3356    return DAG.getNode(ARMISD::VREV64, dl, VT, OpLHS);
3357  case OP_VDUP0:
3358  case OP_VDUP1:
3359  case OP_VDUP2:
3360  case OP_VDUP3:
3361    return DAG.getNode(ARMISD::VDUPLANE, dl, VT,
3362                       OpLHS, DAG.getConstant(OpNum-OP_VDUP0, MVT::i32));
3363  case OP_VEXT1:
3364  case OP_VEXT2:
3365  case OP_VEXT3:
3366    return DAG.getNode(ARMISD::VEXT, dl, VT,
3367                       OpLHS, OpRHS,
3368                       DAG.getConstant(OpNum-OP_VEXT1+1, MVT::i32));
3369  case OP_VUZPL:
3370  case OP_VUZPR:
3371    return DAG.getNode(ARMISD::VUZP, dl, DAG.getVTList(VT, VT),
3372                       OpLHS, OpRHS).getValue(OpNum-OP_VUZPL);
3373  case OP_VZIPL:
3374  case OP_VZIPR:
3375    return DAG.getNode(ARMISD::VZIP, dl, DAG.getVTList(VT, VT),
3376                       OpLHS, OpRHS).getValue(OpNum-OP_VZIPL);
3377  case OP_VTRNL:
3378  case OP_VTRNR:
3379    return DAG.getNode(ARMISD::VTRN, dl, DAG.getVTList(VT, VT),
3380                       OpLHS, OpRHS).getValue(OpNum-OP_VTRNL);
3381  }
3382}
3383
3384static SDValue LowerVECTOR_SHUFFLE(SDValue Op, SelectionDAG &DAG) {
3385  SDValue V1 = Op.getOperand(0);
3386  SDValue V2 = Op.getOperand(1);
3387  DebugLoc dl = Op.getDebugLoc();
3388  EVT VT = Op.getValueType();
3389  ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(Op.getNode());
3390  SmallVector<int, 8> ShuffleMask;
3391
3392  // Convert shuffles that are directly supported on NEON to target-specific
3393  // DAG nodes, instead of keeping them as shuffles and matching them again
3394  // during code selection.  This is more efficient and avoids the possibility
3395  // of inconsistencies between legalization and selection.
3396  // FIXME: floating-point vectors should be canonicalized to integer vectors
3397  // of the same time so that they get CSEd properly.
3398  SVN->getMask(ShuffleMask);
3399
3400  unsigned EltSize = VT.getVectorElementType().getSizeInBits();
3401  if (EltSize <= 32) {
3402    if (ShuffleVectorSDNode::isSplatMask(&ShuffleMask[0], VT)) {
3403      int Lane = SVN->getSplatIndex();
3404      // If this is undef splat, generate it via "just" vdup, if possible.
3405      if (Lane == -1) Lane = 0;
3406
3407      if (Lane == 0 && V1.getOpcode() == ISD::SCALAR_TO_VECTOR) {
3408        return DAG.getNode(ARMISD::VDUP, dl, VT, V1.getOperand(0));
3409      }
3410      return DAG.getNode(ARMISD::VDUPLANE, dl, VT, V1,
3411                         DAG.getConstant(Lane, MVT::i32));
3412    }
3413
3414    bool ReverseVEXT;
3415    unsigned Imm;
3416    if (isVEXTMask(ShuffleMask, VT, ReverseVEXT, Imm)) {
3417      if (ReverseVEXT)
3418        std::swap(V1, V2);
3419      return DAG.getNode(ARMISD::VEXT, dl, VT, V1, V2,
3420                         DAG.getConstant(Imm, MVT::i32));
3421    }
3422
3423    if (isVREVMask(ShuffleMask, VT, 64))
3424      return DAG.getNode(ARMISD::VREV64, dl, VT, V1);
3425    if (isVREVMask(ShuffleMask, VT, 32))
3426      return DAG.getNode(ARMISD::VREV32, dl, VT, V1);
3427    if (isVREVMask(ShuffleMask, VT, 16))
3428      return DAG.getNode(ARMISD::VREV16, dl, VT, V1);
3429
3430    // Check for Neon shuffles that modify both input vectors in place.
3431    // If both results are used, i.e., if there are two shuffles with the same
3432    // source operands and with masks corresponding to both results of one of
3433    // these operations, DAG memoization will ensure that a single node is
3434    // used for both shuffles.
3435    unsigned WhichResult;
3436    if (isVTRNMask(ShuffleMask, VT, WhichResult))
3437      return DAG.getNode(ARMISD::VTRN, dl, DAG.getVTList(VT, VT),
3438                         V1, V2).getValue(WhichResult);
3439    if (isVUZPMask(ShuffleMask, VT, WhichResult))
3440      return DAG.getNode(ARMISD::VUZP, dl, DAG.getVTList(VT, VT),
3441                         V1, V2).getValue(WhichResult);
3442    if (isVZIPMask(ShuffleMask, VT, WhichResult))
3443      return DAG.getNode(ARMISD::VZIP, dl, DAG.getVTList(VT, VT),
3444                         V1, V2).getValue(WhichResult);
3445
3446    if (isVTRN_v_undef_Mask(ShuffleMask, VT, WhichResult))
3447      return DAG.getNode(ARMISD::VTRN, dl, DAG.getVTList(VT, VT),
3448                         V1, V1).getValue(WhichResult);
3449    if (isVUZP_v_undef_Mask(ShuffleMask, VT, WhichResult))
3450      return DAG.getNode(ARMISD::VUZP, dl, DAG.getVTList(VT, VT),
3451                         V1, V1).getValue(WhichResult);
3452    if (isVZIP_v_undef_Mask(ShuffleMask, VT, WhichResult))
3453      return DAG.getNode(ARMISD::VZIP, dl, DAG.getVTList(VT, VT),
3454                         V1, V1).getValue(WhichResult);
3455  }
3456
3457  // If the shuffle is not directly supported and it has 4 elements, use
3458  // the PerfectShuffle-generated table to synthesize it from other shuffles.
3459  unsigned NumElts = VT.getVectorNumElements();
3460  if (NumElts == 4) {
3461    unsigned PFIndexes[4];
3462    for (unsigned i = 0; i != 4; ++i) {
3463      if (ShuffleMask[i] < 0)
3464        PFIndexes[i] = 8;
3465      else
3466        PFIndexes[i] = ShuffleMask[i];
3467    }
3468
3469    // Compute the index in the perfect shuffle table.
3470    unsigned PFTableIndex =
3471      PFIndexes[0]*9*9*9+PFIndexes[1]*9*9+PFIndexes[2]*9+PFIndexes[3];
3472    unsigned PFEntry = PerfectShuffleTable[PFTableIndex];
3473    unsigned Cost = (PFEntry >> 30);
3474
3475    if (Cost <= 4)
3476      return GeneratePerfectShuffle(PFEntry, V1, V2, DAG, dl);
3477  }
3478
3479  // Implement shuffles with 32- or 64-bit elements as ARMISD::BUILD_VECTORs.
3480  if (EltSize >= 32) {
3481    // Do the expansion with floating-point types, since that is what the VFP
3482    // registers are defined to use, and since i64 is not legal.
3483    EVT EltVT = EVT::getFloatingPointVT(EltSize);
3484    EVT VecVT = EVT::getVectorVT(*DAG.getContext(), EltVT, NumElts);
3485    V1 = DAG.getNode(ISD::BIT_CONVERT, dl, VecVT, V1);
3486    V2 = DAG.getNode(ISD::BIT_CONVERT, dl, VecVT, V2);
3487    SmallVector<SDValue, 8> Ops;
3488    for (unsigned i = 0; i < NumElts; ++i) {
3489      if (ShuffleMask[i] < 0)
3490        Ops.push_back(DAG.getUNDEF(EltVT));
3491      else
3492        Ops.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT,
3493                                  ShuffleMask[i] < (int)NumElts ? V1 : V2,
3494                                  DAG.getConstant(ShuffleMask[i] & (NumElts-1),
3495                                                  MVT::i32)));
3496    }
3497    SDValue Val = DAG.getNode(ARMISD::BUILD_VECTOR, dl, VecVT, &Ops[0],NumElts);
3498    return DAG.getNode(ISD::BIT_CONVERT, dl, VT, Val);
3499  }
3500
3501  return SDValue();
3502}
3503
3504static SDValue LowerEXTRACT_VECTOR_ELT(SDValue Op, SelectionDAG &DAG) {
3505  EVT VT = Op.getValueType();
3506  DebugLoc dl = Op.getDebugLoc();
3507  SDValue Vec = Op.getOperand(0);
3508  SDValue Lane = Op.getOperand(1);
3509  assert(VT == MVT::i32 &&
3510         Vec.getValueType().getVectorElementType().getSizeInBits() < 32 &&
3511         "unexpected type for custom-lowering vector extract");
3512  return DAG.getNode(ARMISD::VGETLANEu, dl, MVT::i32, Vec, Lane);
3513}
3514
3515static SDValue LowerCONCAT_VECTORS(SDValue Op, SelectionDAG &DAG) {
3516  // The only time a CONCAT_VECTORS operation can have legal types is when
3517  // two 64-bit vectors are concatenated to a 128-bit vector.
3518  assert(Op.getValueType().is128BitVector() && Op.getNumOperands() == 2 &&
3519         "unexpected CONCAT_VECTORS");
3520  DebugLoc dl = Op.getDebugLoc();
3521  SDValue Val = DAG.getUNDEF(MVT::v2f64);
3522  SDValue Op0 = Op.getOperand(0);
3523  SDValue Op1 = Op.getOperand(1);
3524  if (Op0.getOpcode() != ISD::UNDEF)
3525    Val = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v2f64, Val,
3526                      DAG.getNode(ISD::BIT_CONVERT, dl, MVT::f64, Op0),
3527                      DAG.getIntPtrConstant(0));
3528  if (Op1.getOpcode() != ISD::UNDEF)
3529    Val = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v2f64, Val,
3530                      DAG.getNode(ISD::BIT_CONVERT, dl, MVT::f64, Op1),
3531                      DAG.getIntPtrConstant(1));
3532  return DAG.getNode(ISD::BIT_CONVERT, dl, Op.getValueType(), Val);
3533}
3534
3535SDValue ARMTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const {
3536  switch (Op.getOpcode()) {
3537  default: llvm_unreachable("Don't know how to custom lower this!");
3538  case ISD::ConstantPool:  return LowerConstantPool(Op, DAG);
3539  case ISD::BlockAddress:  return LowerBlockAddress(Op, DAG);
3540  case ISD::GlobalAddress:
3541    return Subtarget->isTargetDarwin() ? LowerGlobalAddressDarwin(Op, DAG) :
3542      LowerGlobalAddressELF(Op, DAG);
3543  case ISD::GlobalTLSAddress:   return LowerGlobalTLSAddress(Op, DAG);
3544  case ISD::SELECT_CC:     return LowerSELECT_CC(Op, DAG);
3545  case ISD::BR_CC:         return LowerBR_CC(Op, DAG);
3546  case ISD::BR_JT:         return LowerBR_JT(Op, DAG);
3547  case ISD::DYNAMIC_STACKALLOC: return LowerDYNAMIC_STACKALLOC(Op, DAG);
3548  case ISD::VASTART:       return LowerVASTART(Op, DAG);
3549  case ISD::MEMBARRIER:    return LowerMEMBARRIER(Op, DAG, Subtarget);
3550  case ISD::SINT_TO_FP:
3551  case ISD::UINT_TO_FP:    return LowerINT_TO_FP(Op, DAG);
3552  case ISD::FP_TO_SINT:
3553  case ISD::FP_TO_UINT:    return LowerFP_TO_INT(Op, DAG);
3554  case ISD::FCOPYSIGN:     return LowerFCOPYSIGN(Op, DAG);
3555  case ISD::RETURNADDR:    return LowerRETURNADDR(Op, DAG);
3556  case ISD::FRAMEADDR:     return LowerFRAMEADDR(Op, DAG);
3557  case ISD::GLOBAL_OFFSET_TABLE: return LowerGLOBAL_OFFSET_TABLE(Op, DAG);
3558  case ISD::EH_SJLJ_SETJMP: return LowerEH_SJLJ_SETJMP(Op, DAG);
3559  case ISD::EH_SJLJ_LONGJMP: return LowerEH_SJLJ_LONGJMP(Op, DAG);
3560  case ISD::INTRINSIC_WO_CHAIN: return LowerINTRINSIC_WO_CHAIN(Op, DAG,
3561                                                               Subtarget);
3562  case ISD::BIT_CONVERT:   return ExpandBIT_CONVERT(Op.getNode(), DAG);
3563  case ISD::SHL:
3564  case ISD::SRL:
3565  case ISD::SRA:           return LowerShift(Op.getNode(), DAG, Subtarget);
3566  case ISD::SHL_PARTS:     return LowerShiftLeftParts(Op, DAG);
3567  case ISD::SRL_PARTS:
3568  case ISD::SRA_PARTS:     return LowerShiftRightParts(Op, DAG);
3569  case ISD::CTTZ:          return LowerCTTZ(Op.getNode(), DAG, Subtarget);
3570  case ISD::VSETCC:        return LowerVSETCC(Op, DAG);
3571  case ISD::BUILD_VECTOR:  return LowerBUILD_VECTOR(Op, DAG);
3572  case ISD::VECTOR_SHUFFLE: return LowerVECTOR_SHUFFLE(Op, DAG);
3573  case ISD::EXTRACT_VECTOR_ELT: return LowerEXTRACT_VECTOR_ELT(Op, DAG);
3574  case ISD::CONCAT_VECTORS: return LowerCONCAT_VECTORS(Op, DAG);
3575  }
3576  return SDValue();
3577}
3578
3579/// ReplaceNodeResults - Replace the results of node with an illegal result
3580/// type with new values built out of custom code.
3581void ARMTargetLowering::ReplaceNodeResults(SDNode *N,
3582                                           SmallVectorImpl<SDValue>&Results,
3583                                           SelectionDAG &DAG) const {
3584  SDValue Res;
3585  switch (N->getOpcode()) {
3586  default:
3587    llvm_unreachable("Don't know how to custom expand this!");
3588    break;
3589  case ISD::BIT_CONVERT:
3590    Res = ExpandBIT_CONVERT(N, DAG);
3591    break;
3592  case ISD::SRL:
3593  case ISD::SRA:
3594    Res = LowerShift(N, DAG, Subtarget);
3595    break;
3596  }
3597  if (Res.getNode())
3598    Results.push_back(Res);
3599}
3600
3601//===----------------------------------------------------------------------===//
3602//                           ARM Scheduler Hooks
3603//===----------------------------------------------------------------------===//
3604
3605MachineBasicBlock *
3606ARMTargetLowering::EmitAtomicCmpSwap(MachineInstr *MI,
3607                                     MachineBasicBlock *BB,
3608                                     unsigned Size) const {
3609  unsigned dest    = MI->getOperand(0).getReg();
3610  unsigned ptr     = MI->getOperand(1).getReg();
3611  unsigned oldval  = MI->getOperand(2).getReg();
3612  unsigned newval  = MI->getOperand(3).getReg();
3613  unsigned scratch = BB->getParent()->getRegInfo()
3614    .createVirtualRegister(ARM::GPRRegisterClass);
3615  const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
3616  DebugLoc dl = MI->getDebugLoc();
3617  bool isThumb2 = Subtarget->isThumb2();
3618
3619  unsigned ldrOpc, strOpc;
3620  switch (Size) {
3621  default: llvm_unreachable("unsupported size for AtomicCmpSwap!");
3622  case 1:
3623    ldrOpc = isThumb2 ? ARM::t2LDREXB : ARM::LDREXB;
3624    strOpc = isThumb2 ? ARM::t2LDREXB : ARM::STREXB;
3625    break;
3626  case 2:
3627    ldrOpc = isThumb2 ? ARM::t2LDREXH : ARM::LDREXH;
3628    strOpc = isThumb2 ? ARM::t2STREXH : ARM::STREXH;
3629    break;
3630  case 4:
3631    ldrOpc = isThumb2 ? ARM::t2LDREX : ARM::LDREX;
3632    strOpc = isThumb2 ? ARM::t2STREX : ARM::STREX;
3633    break;
3634  }
3635
3636  MachineFunction *MF = BB->getParent();
3637  const BasicBlock *LLVM_BB = BB->getBasicBlock();
3638  MachineFunction::iterator It = BB;
3639  ++It; // insert the new blocks after the current block
3640
3641  MachineBasicBlock *loop1MBB = MF->CreateMachineBasicBlock(LLVM_BB);
3642  MachineBasicBlock *loop2MBB = MF->CreateMachineBasicBlock(LLVM_BB);
3643  MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
3644  MF->insert(It, loop1MBB);
3645  MF->insert(It, loop2MBB);
3646  MF->insert(It, exitMBB);
3647
3648  // Transfer the remainder of BB and its successor edges to exitMBB.
3649  exitMBB->splice(exitMBB->begin(), BB,
3650                  llvm::next(MachineBasicBlock::iterator(MI)),
3651                  BB->end());
3652  exitMBB->transferSuccessorsAndUpdatePHIs(BB);
3653
3654  //  thisMBB:
3655  //   ...
3656  //   fallthrough --> loop1MBB
3657  BB->addSuccessor(loop1MBB);
3658
3659  // loop1MBB:
3660  //   ldrex dest, [ptr]
3661  //   cmp dest, oldval
3662  //   bne exitMBB
3663  BB = loop1MBB;
3664  AddDefaultPred(BuildMI(BB, dl, TII->get(ldrOpc), dest).addReg(ptr));
3665  AddDefaultPred(BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2CMPrr : ARM::CMPrr))
3666                 .addReg(dest).addReg(oldval));
3667  BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2Bcc : ARM::Bcc))
3668    .addMBB(exitMBB).addImm(ARMCC::NE).addReg(ARM::CPSR);
3669  BB->addSuccessor(loop2MBB);
3670  BB->addSuccessor(exitMBB);
3671
3672  // loop2MBB:
3673  //   strex scratch, newval, [ptr]
3674  //   cmp scratch, #0
3675  //   bne loop1MBB
3676  BB = loop2MBB;
3677  AddDefaultPred(BuildMI(BB, dl, TII->get(strOpc), scratch).addReg(newval)
3678                 .addReg(ptr));
3679  AddDefaultPred(BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2CMPri : ARM::CMPri))
3680                 .addReg(scratch).addImm(0));
3681  BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2Bcc : ARM::Bcc))
3682    .addMBB(loop1MBB).addImm(ARMCC::NE).addReg(ARM::CPSR);
3683  BB->addSuccessor(loop1MBB);
3684  BB->addSuccessor(exitMBB);
3685
3686  //  exitMBB:
3687  //   ...
3688  BB = exitMBB;
3689
3690  MI->eraseFromParent();   // The instruction is gone now.
3691
3692  return BB;
3693}
3694
3695MachineBasicBlock *
3696ARMTargetLowering::EmitAtomicBinary(MachineInstr *MI, MachineBasicBlock *BB,
3697                                    unsigned Size, unsigned BinOpcode) const {
3698  // This also handles ATOMIC_SWAP, indicated by BinOpcode==0.
3699  const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
3700
3701  const BasicBlock *LLVM_BB = BB->getBasicBlock();
3702  MachineFunction *MF = BB->getParent();
3703  MachineFunction::iterator It = BB;
3704  ++It;
3705
3706  unsigned dest = MI->getOperand(0).getReg();
3707  unsigned ptr = MI->getOperand(1).getReg();
3708  unsigned incr = MI->getOperand(2).getReg();
3709  DebugLoc dl = MI->getDebugLoc();
3710
3711  bool isThumb2 = Subtarget->isThumb2();
3712  unsigned ldrOpc, strOpc;
3713  switch (Size) {
3714  default: llvm_unreachable("unsupported size for AtomicCmpSwap!");
3715  case 1:
3716    ldrOpc = isThumb2 ? ARM::t2LDREXB : ARM::LDREXB;
3717    strOpc = isThumb2 ? ARM::t2STREXB : ARM::STREXB;
3718    break;
3719  case 2:
3720    ldrOpc = isThumb2 ? ARM::t2LDREXH : ARM::LDREXH;
3721    strOpc = isThumb2 ? ARM::t2STREXH : ARM::STREXH;
3722    break;
3723  case 4:
3724    ldrOpc = isThumb2 ? ARM::t2LDREX : ARM::LDREX;
3725    strOpc = isThumb2 ? ARM::t2STREX : ARM::STREX;
3726    break;
3727  }
3728
3729  MachineBasicBlock *loopMBB = MF->CreateMachineBasicBlock(LLVM_BB);
3730  MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
3731  MF->insert(It, loopMBB);
3732  MF->insert(It, exitMBB);
3733
3734  // Transfer the remainder of BB and its successor edges to exitMBB.
3735  exitMBB->splice(exitMBB->begin(), BB,
3736                  llvm::next(MachineBasicBlock::iterator(MI)),
3737                  BB->end());
3738  exitMBB->transferSuccessorsAndUpdatePHIs(BB);
3739
3740  MachineRegisterInfo &RegInfo = MF->getRegInfo();
3741  unsigned scratch = RegInfo.createVirtualRegister(ARM::GPRRegisterClass);
3742  unsigned scratch2 = (!BinOpcode) ? incr :
3743    RegInfo.createVirtualRegister(ARM::GPRRegisterClass);
3744
3745  //  thisMBB:
3746  //   ...
3747  //   fallthrough --> loopMBB
3748  BB->addSuccessor(loopMBB);
3749
3750  //  loopMBB:
3751  //   ldrex dest, ptr
3752  //   <binop> scratch2, dest, incr
3753  //   strex scratch, scratch2, ptr
3754  //   cmp scratch, #0
3755  //   bne- loopMBB
3756  //   fallthrough --> exitMBB
3757  BB = loopMBB;
3758  AddDefaultPred(BuildMI(BB, dl, TII->get(ldrOpc), dest).addReg(ptr));
3759  if (BinOpcode) {
3760    // operand order needs to go the other way for NAND
3761    if (BinOpcode == ARM::BICrr || BinOpcode == ARM::t2BICrr)
3762      AddDefaultPred(BuildMI(BB, dl, TII->get(BinOpcode), scratch2).
3763                     addReg(incr).addReg(dest)).addReg(0);
3764    else
3765      AddDefaultPred(BuildMI(BB, dl, TII->get(BinOpcode), scratch2).
3766                     addReg(dest).addReg(incr)).addReg(0);
3767  }
3768
3769  AddDefaultPred(BuildMI(BB, dl, TII->get(strOpc), scratch).addReg(scratch2)
3770                 .addReg(ptr));
3771  AddDefaultPred(BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2CMPri : ARM::CMPri))
3772                 .addReg(scratch).addImm(0));
3773  BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2Bcc : ARM::Bcc))
3774    .addMBB(loopMBB).addImm(ARMCC::NE).addReg(ARM::CPSR);
3775
3776  BB->addSuccessor(loopMBB);
3777  BB->addSuccessor(exitMBB);
3778
3779  //  exitMBB:
3780  //   ...
3781  BB = exitMBB;
3782
3783  MI->eraseFromParent();   // The instruction is gone now.
3784
3785  return BB;
3786}
3787
3788MachineBasicBlock *
3789ARMTargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
3790                                               MachineBasicBlock *BB) const {
3791  const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
3792  DebugLoc dl = MI->getDebugLoc();
3793  bool isThumb2 = Subtarget->isThumb2();
3794  switch (MI->getOpcode()) {
3795  default:
3796    MI->dump();
3797    llvm_unreachable("Unexpected instr type to insert");
3798
3799  case ARM::ATOMIC_LOAD_ADD_I8:
3800     return EmitAtomicBinary(MI, BB, 1, isThumb2 ? ARM::t2ADDrr : ARM::ADDrr);
3801  case ARM::ATOMIC_LOAD_ADD_I16:
3802     return EmitAtomicBinary(MI, BB, 2, isThumb2 ? ARM::t2ADDrr : ARM::ADDrr);
3803  case ARM::ATOMIC_LOAD_ADD_I32:
3804     return EmitAtomicBinary(MI, BB, 4, isThumb2 ? ARM::t2ADDrr : ARM::ADDrr);
3805
3806  case ARM::ATOMIC_LOAD_AND_I8:
3807     return EmitAtomicBinary(MI, BB, 1, isThumb2 ? ARM::t2ANDrr : ARM::ANDrr);
3808  case ARM::ATOMIC_LOAD_AND_I16:
3809     return EmitAtomicBinary(MI, BB, 2, isThumb2 ? ARM::t2ANDrr : ARM::ANDrr);
3810  case ARM::ATOMIC_LOAD_AND_I32:
3811     return EmitAtomicBinary(MI, BB, 4, isThumb2 ? ARM::t2ANDrr : ARM::ANDrr);
3812
3813  case ARM::ATOMIC_LOAD_OR_I8:
3814     return EmitAtomicBinary(MI, BB, 1, isThumb2 ? ARM::t2ORRrr : ARM::ORRrr);
3815  case ARM::ATOMIC_LOAD_OR_I16:
3816     return EmitAtomicBinary(MI, BB, 2, isThumb2 ? ARM::t2ORRrr : ARM::ORRrr);
3817  case ARM::ATOMIC_LOAD_OR_I32:
3818     return EmitAtomicBinary(MI, BB, 4, isThumb2 ? ARM::t2ORRrr : ARM::ORRrr);
3819
3820  case ARM::ATOMIC_LOAD_XOR_I8:
3821     return EmitAtomicBinary(MI, BB, 1, isThumb2 ? ARM::t2EORrr : ARM::EORrr);
3822  case ARM::ATOMIC_LOAD_XOR_I16:
3823     return EmitAtomicBinary(MI, BB, 2, isThumb2 ? ARM::t2EORrr : ARM::EORrr);
3824  case ARM::ATOMIC_LOAD_XOR_I32:
3825     return EmitAtomicBinary(MI, BB, 4, isThumb2 ? ARM::t2EORrr : ARM::EORrr);
3826
3827  case ARM::ATOMIC_LOAD_NAND_I8:
3828     return EmitAtomicBinary(MI, BB, 1, isThumb2 ? ARM::t2BICrr : ARM::BICrr);
3829  case ARM::ATOMIC_LOAD_NAND_I16:
3830     return EmitAtomicBinary(MI, BB, 2, isThumb2 ? ARM::t2BICrr : ARM::BICrr);
3831  case ARM::ATOMIC_LOAD_NAND_I32:
3832     return EmitAtomicBinary(MI, BB, 4, isThumb2 ? ARM::t2BICrr : ARM::BICrr);
3833
3834  case ARM::ATOMIC_LOAD_SUB_I8:
3835     return EmitAtomicBinary(MI, BB, 1, isThumb2 ? ARM::t2SUBrr : ARM::SUBrr);
3836  case ARM::ATOMIC_LOAD_SUB_I16:
3837     return EmitAtomicBinary(MI, BB, 2, isThumb2 ? ARM::t2SUBrr : ARM::SUBrr);
3838  case ARM::ATOMIC_LOAD_SUB_I32:
3839     return EmitAtomicBinary(MI, BB, 4, isThumb2 ? ARM::t2SUBrr : ARM::SUBrr);
3840
3841  case ARM::ATOMIC_SWAP_I8:  return EmitAtomicBinary(MI, BB, 1, 0);
3842  case ARM::ATOMIC_SWAP_I16: return EmitAtomicBinary(MI, BB, 2, 0);
3843  case ARM::ATOMIC_SWAP_I32: return EmitAtomicBinary(MI, BB, 4, 0);
3844
3845  case ARM::ATOMIC_CMP_SWAP_I8:  return EmitAtomicCmpSwap(MI, BB, 1);
3846  case ARM::ATOMIC_CMP_SWAP_I16: return EmitAtomicCmpSwap(MI, BB, 2);
3847  case ARM::ATOMIC_CMP_SWAP_I32: return EmitAtomicCmpSwap(MI, BB, 4);
3848
3849  case ARM::tMOVCCr_pseudo: {
3850    // To "insert" a SELECT_CC instruction, we actually have to insert the
3851    // diamond control-flow pattern.  The incoming instruction knows the
3852    // destination vreg to set, the condition code register to branch on, the
3853    // true/false values to select between, and a branch opcode to use.
3854    const BasicBlock *LLVM_BB = BB->getBasicBlock();
3855    MachineFunction::iterator It = BB;
3856    ++It;
3857
3858    //  thisMBB:
3859    //  ...
3860    //   TrueVal = ...
3861    //   cmpTY ccX, r1, r2
3862    //   bCC copy1MBB
3863    //   fallthrough --> copy0MBB
3864    MachineBasicBlock *thisMBB  = BB;
3865    MachineFunction *F = BB->getParent();
3866    MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
3867    MachineBasicBlock *sinkMBB  = F->CreateMachineBasicBlock(LLVM_BB);
3868    F->insert(It, copy0MBB);
3869    F->insert(It, sinkMBB);
3870
3871    // Transfer the remainder of BB and its successor edges to sinkMBB.
3872    sinkMBB->splice(sinkMBB->begin(), BB,
3873                    llvm::next(MachineBasicBlock::iterator(MI)),
3874                    BB->end());
3875    sinkMBB->transferSuccessorsAndUpdatePHIs(BB);
3876
3877    BB->addSuccessor(copy0MBB);
3878    BB->addSuccessor(sinkMBB);
3879
3880    BuildMI(BB, dl, TII->get(ARM::tBcc)).addMBB(sinkMBB)
3881      .addImm(MI->getOperand(3).getImm()).addReg(MI->getOperand(4).getReg());
3882
3883    //  copy0MBB:
3884    //   %FalseValue = ...
3885    //   # fallthrough to sinkMBB
3886    BB = copy0MBB;
3887
3888    // Update machine-CFG edges
3889    BB->addSuccessor(sinkMBB);
3890
3891    //  sinkMBB:
3892    //   %Result = phi [ %FalseValue, copy0MBB ], [ %TrueValue, thisMBB ]
3893    //  ...
3894    BB = sinkMBB;
3895    BuildMI(*BB, BB->begin(), dl,
3896            TII->get(ARM::PHI), MI->getOperand(0).getReg())
3897      .addReg(MI->getOperand(1).getReg()).addMBB(copy0MBB)
3898      .addReg(MI->getOperand(2).getReg()).addMBB(thisMBB);
3899
3900    MI->eraseFromParent();   // The pseudo instruction is gone now.
3901    return BB;
3902  }
3903
3904  case ARM::tANDsp:
3905  case ARM::tADDspr_:
3906  case ARM::tSUBspi_:
3907  case ARM::t2SUBrSPi_:
3908  case ARM::t2SUBrSPi12_:
3909  case ARM::t2SUBrSPs_: {
3910    MachineFunction *MF = BB->getParent();
3911    unsigned DstReg = MI->getOperand(0).getReg();
3912    unsigned SrcReg = MI->getOperand(1).getReg();
3913    bool DstIsDead = MI->getOperand(0).isDead();
3914    bool SrcIsKill = MI->getOperand(1).isKill();
3915
3916    if (SrcReg != ARM::SP) {
3917      // Copy the source to SP from virtual register.
3918      const TargetRegisterClass *RC = MF->getRegInfo().getRegClass(SrcReg);
3919      unsigned CopyOpc = (RC == ARM::tGPRRegisterClass)
3920        ? ARM::tMOVtgpr2gpr : ARM::tMOVgpr2gpr;
3921      BuildMI(*BB, MI, dl, TII->get(CopyOpc), ARM::SP)
3922        .addReg(SrcReg, getKillRegState(SrcIsKill));
3923    }
3924
3925    unsigned OpOpc = 0;
3926    bool NeedPred = false, NeedCC = false, NeedOp3 = false;
3927    switch (MI->getOpcode()) {
3928    default:
3929      llvm_unreachable("Unexpected pseudo instruction!");
3930    case ARM::tANDsp:
3931      OpOpc = ARM::tAND;
3932      NeedPred = true;
3933      break;
3934    case ARM::tADDspr_:
3935      OpOpc = ARM::tADDspr;
3936      break;
3937    case ARM::tSUBspi_:
3938      OpOpc = ARM::tSUBspi;
3939      break;
3940    case ARM::t2SUBrSPi_:
3941      OpOpc = ARM::t2SUBrSPi;
3942      NeedPred = true; NeedCC = true;
3943      break;
3944    case ARM::t2SUBrSPi12_:
3945      OpOpc = ARM::t2SUBrSPi12;
3946      NeedPred = true;
3947      break;
3948    case ARM::t2SUBrSPs_:
3949      OpOpc = ARM::t2SUBrSPs;
3950      NeedPred = true; NeedCC = true; NeedOp3 = true;
3951      break;
3952    }
3953    MachineInstrBuilder MIB = BuildMI(*BB, MI, dl, TII->get(OpOpc), ARM::SP);
3954    if (OpOpc == ARM::tAND)
3955      AddDefaultT1CC(MIB);
3956    MIB.addReg(ARM::SP);
3957    MIB.addOperand(MI->getOperand(2));
3958    if (NeedOp3)
3959      MIB.addOperand(MI->getOperand(3));
3960    if (NeedPred)
3961      AddDefaultPred(MIB);
3962    if (NeedCC)
3963      AddDefaultCC(MIB);
3964
3965    // Copy the result from SP to virtual register.
3966    const TargetRegisterClass *RC = MF->getRegInfo().getRegClass(DstReg);
3967    unsigned CopyOpc = (RC == ARM::tGPRRegisterClass)
3968      ? ARM::tMOVgpr2tgpr : ARM::tMOVgpr2gpr;
3969    BuildMI(*BB, MI, dl, TII->get(CopyOpc))
3970      .addReg(DstReg, getDefRegState(true) | getDeadRegState(DstIsDead))
3971      .addReg(ARM::SP);
3972    MI->eraseFromParent();   // The pseudo instruction is gone now.
3973    return BB;
3974  }
3975  }
3976}
3977
3978//===----------------------------------------------------------------------===//
3979//                           ARM Optimization Hooks
3980//===----------------------------------------------------------------------===//
3981
3982static
3983SDValue combineSelectAndUse(SDNode *N, SDValue Slct, SDValue OtherOp,
3984                            TargetLowering::DAGCombinerInfo &DCI) {
3985  SelectionDAG &DAG = DCI.DAG;
3986  const TargetLowering &TLI = DAG.getTargetLoweringInfo();
3987  EVT VT = N->getValueType(0);
3988  unsigned Opc = N->getOpcode();
3989  bool isSlctCC = Slct.getOpcode() == ISD::SELECT_CC;
3990  SDValue LHS = isSlctCC ? Slct.getOperand(2) : Slct.getOperand(1);
3991  SDValue RHS = isSlctCC ? Slct.getOperand(3) : Slct.getOperand(2);
3992  ISD::CondCode CC = ISD::SETCC_INVALID;
3993
3994  if (isSlctCC) {
3995    CC = cast<CondCodeSDNode>(Slct.getOperand(4))->get();
3996  } else {
3997    SDValue CCOp = Slct.getOperand(0);
3998    if (CCOp.getOpcode() == ISD::SETCC)
3999      CC = cast<CondCodeSDNode>(CCOp.getOperand(2))->get();
4000  }
4001
4002  bool DoXform = false;
4003  bool InvCC = false;
4004  assert ((Opc == ISD::ADD || (Opc == ISD::SUB && Slct == N->getOperand(1))) &&
4005          "Bad input!");
4006
4007  if (LHS.getOpcode() == ISD::Constant &&
4008      cast<ConstantSDNode>(LHS)->isNullValue()) {
4009    DoXform = true;
4010  } else if (CC != ISD::SETCC_INVALID &&
4011             RHS.getOpcode() == ISD::Constant &&
4012             cast<ConstantSDNode>(RHS)->isNullValue()) {
4013    std::swap(LHS, RHS);
4014    SDValue Op0 = Slct.getOperand(0);
4015    EVT OpVT = isSlctCC ? Op0.getValueType() :
4016                          Op0.getOperand(0).getValueType();
4017    bool isInt = OpVT.isInteger();
4018    CC = ISD::getSetCCInverse(CC, isInt);
4019
4020    if (!TLI.isCondCodeLegal(CC, OpVT))
4021      return SDValue();         // Inverse operator isn't legal.
4022
4023    DoXform = true;
4024    InvCC = true;
4025  }
4026
4027  if (DoXform) {
4028    SDValue Result = DAG.getNode(Opc, RHS.getDebugLoc(), VT, OtherOp, RHS);
4029    if (isSlctCC)
4030      return DAG.getSelectCC(N->getDebugLoc(), OtherOp, Result,
4031                             Slct.getOperand(0), Slct.getOperand(1), CC);
4032    SDValue CCOp = Slct.getOperand(0);
4033    if (InvCC)
4034      CCOp = DAG.getSetCC(Slct.getDebugLoc(), CCOp.getValueType(),
4035                          CCOp.getOperand(0), CCOp.getOperand(1), CC);
4036    return DAG.getNode(ISD::SELECT, N->getDebugLoc(), VT,
4037                       CCOp, OtherOp, Result);
4038  }
4039  return SDValue();
4040}
4041
4042/// PerformADDCombine - Target-specific dag combine xforms for ISD::ADD.
4043static SDValue PerformADDCombine(SDNode *N,
4044                                 TargetLowering::DAGCombinerInfo &DCI) {
4045  // added by evan in r37685 with no testcase.
4046  SDValue N0 = N->getOperand(0), N1 = N->getOperand(1);
4047
4048  // fold (add (select cc, 0, c), x) -> (select cc, x, (add, x, c))
4049  if (N0.getOpcode() == ISD::SELECT && N0.getNode()->hasOneUse()) {
4050    SDValue Result = combineSelectAndUse(N, N0, N1, DCI);
4051    if (Result.getNode()) return Result;
4052  }
4053  if (N1.getOpcode() == ISD::SELECT && N1.getNode()->hasOneUse()) {
4054    SDValue Result = combineSelectAndUse(N, N1, N0, DCI);
4055    if (Result.getNode()) return Result;
4056  }
4057
4058  return SDValue();
4059}
4060
4061/// PerformSUBCombine - Target-specific dag combine xforms for ISD::SUB.
4062static SDValue PerformSUBCombine(SDNode *N,
4063                                 TargetLowering::DAGCombinerInfo &DCI) {
4064  // added by evan in r37685 with no testcase.
4065  SDValue N0 = N->getOperand(0), N1 = N->getOperand(1);
4066
4067  // fold (sub x, (select cc, 0, c)) -> (select cc, x, (sub, x, c))
4068  if (N1.getOpcode() == ISD::SELECT && N1.getNode()->hasOneUse()) {
4069    SDValue Result = combineSelectAndUse(N, N1, N0, DCI);
4070    if (Result.getNode()) return Result;
4071  }
4072
4073  return SDValue();
4074}
4075
4076static SDValue PerformMULCombine(SDNode *N,
4077                                 TargetLowering::DAGCombinerInfo &DCI,
4078                                 const ARMSubtarget *Subtarget) {
4079  SelectionDAG &DAG = DCI.DAG;
4080
4081  if (Subtarget->isThumb1Only())
4082    return SDValue();
4083
4084  if (DAG.getMachineFunction().
4085      getFunction()->hasFnAttr(Attribute::OptimizeForSize))
4086    return SDValue();
4087
4088  if (DCI.isBeforeLegalize() || DCI.isCalledByLegalizer())
4089    return SDValue();
4090
4091  EVT VT = N->getValueType(0);
4092  if (VT != MVT::i32)
4093    return SDValue();
4094
4095  ConstantSDNode *C = dyn_cast<ConstantSDNode>(N->getOperand(1));
4096  if (!C)
4097    return SDValue();
4098
4099  uint64_t MulAmt = C->getZExtValue();
4100  unsigned ShiftAmt = CountTrailingZeros_64(MulAmt);
4101  ShiftAmt = ShiftAmt & (32 - 1);
4102  SDValue V = N->getOperand(0);
4103  DebugLoc DL = N->getDebugLoc();
4104
4105  SDValue Res;
4106  MulAmt >>= ShiftAmt;
4107  if (isPowerOf2_32(MulAmt - 1)) {
4108    // (mul x, 2^N + 1) => (add (shl x, N), x)
4109    Res = DAG.getNode(ISD::ADD, DL, VT,
4110                      V, DAG.getNode(ISD::SHL, DL, VT,
4111                                     V, DAG.getConstant(Log2_32(MulAmt-1),
4112                                                        MVT::i32)));
4113  } else if (isPowerOf2_32(MulAmt + 1)) {
4114    // (mul x, 2^N - 1) => (sub (shl x, N), x)
4115    Res = DAG.getNode(ISD::SUB, DL, VT,
4116                      DAG.getNode(ISD::SHL, DL, VT,
4117                                  V, DAG.getConstant(Log2_32(MulAmt+1),
4118                                                     MVT::i32)),
4119                                                     V);
4120  } else
4121    return SDValue();
4122
4123  if (ShiftAmt != 0)
4124    Res = DAG.getNode(ISD::SHL, DL, VT, Res,
4125                      DAG.getConstant(ShiftAmt, MVT::i32));
4126
4127  // Do not add new nodes to DAG combiner worklist.
4128  DCI.CombineTo(N, Res, false);
4129  return SDValue();
4130}
4131
4132/// PerformVMOVRRDCombine - Target-specific dag combine xforms for
4133/// ARMISD::VMOVRRD.
4134static SDValue PerformVMOVRRDCombine(SDNode *N,
4135                                   TargetLowering::DAGCombinerInfo &DCI) {
4136  // fmrrd(fmdrr x, y) -> x,y
4137  SDValue InDouble = N->getOperand(0);
4138  if (InDouble.getOpcode() == ARMISD::VMOVDRR)
4139    return DCI.CombineTo(N, InDouble.getOperand(0), InDouble.getOperand(1));
4140  return SDValue();
4141}
4142
4143/// getVShiftImm - Check if this is a valid build_vector for the immediate
4144/// operand of a vector shift operation, where all the elements of the
4145/// build_vector must have the same constant integer value.
4146static bool getVShiftImm(SDValue Op, unsigned ElementBits, int64_t &Cnt) {
4147  // Ignore bit_converts.
4148  while (Op.getOpcode() == ISD::BIT_CONVERT)
4149    Op = Op.getOperand(0);
4150  BuildVectorSDNode *BVN = dyn_cast<BuildVectorSDNode>(Op.getNode());
4151  APInt SplatBits, SplatUndef;
4152  unsigned SplatBitSize;
4153  bool HasAnyUndefs;
4154  if (! BVN || ! BVN->isConstantSplat(SplatBits, SplatUndef, SplatBitSize,
4155                                      HasAnyUndefs, ElementBits) ||
4156      SplatBitSize > ElementBits)
4157    return false;
4158  Cnt = SplatBits.getSExtValue();
4159  return true;
4160}
4161
4162/// isVShiftLImm - Check if this is a valid build_vector for the immediate
4163/// operand of a vector shift left operation.  That value must be in the range:
4164///   0 <= Value < ElementBits for a left shift; or
4165///   0 <= Value <= ElementBits for a long left shift.
4166static bool isVShiftLImm(SDValue Op, EVT VT, bool isLong, int64_t &Cnt) {
4167  assert(VT.isVector() && "vector shift count is not a vector type");
4168  unsigned ElementBits = VT.getVectorElementType().getSizeInBits();
4169  if (! getVShiftImm(Op, ElementBits, Cnt))
4170    return false;
4171  return (Cnt >= 0 && (isLong ? Cnt-1 : Cnt) < ElementBits);
4172}
4173
4174/// isVShiftRImm - Check if this is a valid build_vector for the immediate
4175/// operand of a vector shift right operation.  For a shift opcode, the value
4176/// is positive, but for an intrinsic the value count must be negative. The
4177/// absolute value must be in the range:
4178///   1 <= |Value| <= ElementBits for a right shift; or
4179///   1 <= |Value| <= ElementBits/2 for a narrow right shift.
4180static bool isVShiftRImm(SDValue Op, EVT VT, bool isNarrow, bool isIntrinsic,
4181                         int64_t &Cnt) {
4182  assert(VT.isVector() && "vector shift count is not a vector type");
4183  unsigned ElementBits = VT.getVectorElementType().getSizeInBits();
4184  if (! getVShiftImm(Op, ElementBits, Cnt))
4185    return false;
4186  if (isIntrinsic)
4187    Cnt = -Cnt;
4188  return (Cnt >= 1 && Cnt <= (isNarrow ? ElementBits/2 : ElementBits));
4189}
4190
4191/// PerformIntrinsicCombine - ARM-specific DAG combining for intrinsics.
4192static SDValue PerformIntrinsicCombine(SDNode *N, SelectionDAG &DAG) {
4193  unsigned IntNo = cast<ConstantSDNode>(N->getOperand(0))->getZExtValue();
4194  switch (IntNo) {
4195  default:
4196    // Don't do anything for most intrinsics.
4197    break;
4198
4199  // Vector shifts: check for immediate versions and lower them.
4200  // Note: This is done during DAG combining instead of DAG legalizing because
4201  // the build_vectors for 64-bit vector element shift counts are generally
4202  // not legal, and it is hard to see their values after they get legalized to
4203  // loads from a constant pool.
4204  case Intrinsic::arm_neon_vshifts:
4205  case Intrinsic::arm_neon_vshiftu:
4206  case Intrinsic::arm_neon_vshiftls:
4207  case Intrinsic::arm_neon_vshiftlu:
4208  case Intrinsic::arm_neon_vshiftn:
4209  case Intrinsic::arm_neon_vrshifts:
4210  case Intrinsic::arm_neon_vrshiftu:
4211  case Intrinsic::arm_neon_vrshiftn:
4212  case Intrinsic::arm_neon_vqshifts:
4213  case Intrinsic::arm_neon_vqshiftu:
4214  case Intrinsic::arm_neon_vqshiftsu:
4215  case Intrinsic::arm_neon_vqshiftns:
4216  case Intrinsic::arm_neon_vqshiftnu:
4217  case Intrinsic::arm_neon_vqshiftnsu:
4218  case Intrinsic::arm_neon_vqrshiftns:
4219  case Intrinsic::arm_neon_vqrshiftnu:
4220  case Intrinsic::arm_neon_vqrshiftnsu: {
4221    EVT VT = N->getOperand(1).getValueType();
4222    int64_t Cnt;
4223    unsigned VShiftOpc = 0;
4224
4225    switch (IntNo) {
4226    case Intrinsic::arm_neon_vshifts:
4227    case Intrinsic::arm_neon_vshiftu:
4228      if (isVShiftLImm(N->getOperand(2), VT, false, Cnt)) {
4229        VShiftOpc = ARMISD::VSHL;
4230        break;
4231      }
4232      if (isVShiftRImm(N->getOperand(2), VT, false, true, Cnt)) {
4233        VShiftOpc = (IntNo == Intrinsic::arm_neon_vshifts ?
4234                     ARMISD::VSHRs : ARMISD::VSHRu);
4235        break;
4236      }
4237      return SDValue();
4238
4239    case Intrinsic::arm_neon_vshiftls:
4240    case Intrinsic::arm_neon_vshiftlu:
4241      if (isVShiftLImm(N->getOperand(2), VT, true, Cnt))
4242        break;
4243      llvm_unreachable("invalid shift count for vshll intrinsic");
4244
4245    case Intrinsic::arm_neon_vrshifts:
4246    case Intrinsic::arm_neon_vrshiftu:
4247      if (isVShiftRImm(N->getOperand(2), VT, false, true, Cnt))
4248        break;
4249      return SDValue();
4250
4251    case Intrinsic::arm_neon_vqshifts:
4252    case Intrinsic::arm_neon_vqshiftu:
4253      if (isVShiftLImm(N->getOperand(2), VT, false, Cnt))
4254        break;
4255      return SDValue();
4256
4257    case Intrinsic::arm_neon_vqshiftsu:
4258      if (isVShiftLImm(N->getOperand(2), VT, false, Cnt))
4259        break;
4260      llvm_unreachable("invalid shift count for vqshlu intrinsic");
4261
4262    case Intrinsic::arm_neon_vshiftn:
4263    case Intrinsic::arm_neon_vrshiftn:
4264    case Intrinsic::arm_neon_vqshiftns:
4265    case Intrinsic::arm_neon_vqshiftnu:
4266    case Intrinsic::arm_neon_vqshiftnsu:
4267    case Intrinsic::arm_neon_vqrshiftns:
4268    case Intrinsic::arm_neon_vqrshiftnu:
4269    case Intrinsic::arm_neon_vqrshiftnsu:
4270      // Narrowing shifts require an immediate right shift.
4271      if (isVShiftRImm(N->getOperand(2), VT, true, true, Cnt))
4272        break;
4273      llvm_unreachable("invalid shift count for narrowing vector shift "
4274                       "intrinsic");
4275
4276    default:
4277      llvm_unreachable("unhandled vector shift");
4278    }
4279
4280    switch (IntNo) {
4281    case Intrinsic::arm_neon_vshifts:
4282    case Intrinsic::arm_neon_vshiftu:
4283      // Opcode already set above.
4284      break;
4285    case Intrinsic::arm_neon_vshiftls:
4286    case Intrinsic::arm_neon_vshiftlu:
4287      if (Cnt == VT.getVectorElementType().getSizeInBits())
4288        VShiftOpc = ARMISD::VSHLLi;
4289      else
4290        VShiftOpc = (IntNo == Intrinsic::arm_neon_vshiftls ?
4291                     ARMISD::VSHLLs : ARMISD::VSHLLu);
4292      break;
4293    case Intrinsic::arm_neon_vshiftn:
4294      VShiftOpc = ARMISD::VSHRN; break;
4295    case Intrinsic::arm_neon_vrshifts:
4296      VShiftOpc = ARMISD::VRSHRs; break;
4297    case Intrinsic::arm_neon_vrshiftu:
4298      VShiftOpc = ARMISD::VRSHRu; break;
4299    case Intrinsic::arm_neon_vrshiftn:
4300      VShiftOpc = ARMISD::VRSHRN; break;
4301    case Intrinsic::arm_neon_vqshifts:
4302      VShiftOpc = ARMISD::VQSHLs; break;
4303    case Intrinsic::arm_neon_vqshiftu:
4304      VShiftOpc = ARMISD::VQSHLu; break;
4305    case Intrinsic::arm_neon_vqshiftsu:
4306      VShiftOpc = ARMISD::VQSHLsu; break;
4307    case Intrinsic::arm_neon_vqshiftns:
4308      VShiftOpc = ARMISD::VQSHRNs; break;
4309    case Intrinsic::arm_neon_vqshiftnu:
4310      VShiftOpc = ARMISD::VQSHRNu; break;
4311    case Intrinsic::arm_neon_vqshiftnsu:
4312      VShiftOpc = ARMISD::VQSHRNsu; break;
4313    case Intrinsic::arm_neon_vqrshiftns:
4314      VShiftOpc = ARMISD::VQRSHRNs; break;
4315    case Intrinsic::arm_neon_vqrshiftnu:
4316      VShiftOpc = ARMISD::VQRSHRNu; break;
4317    case Intrinsic::arm_neon_vqrshiftnsu:
4318      VShiftOpc = ARMISD::VQRSHRNsu; break;
4319    }
4320
4321    return DAG.getNode(VShiftOpc, N->getDebugLoc(), N->getValueType(0),
4322                       N->getOperand(1), DAG.getConstant(Cnt, MVT::i32));
4323  }
4324
4325  case Intrinsic::arm_neon_vshiftins: {
4326    EVT VT = N->getOperand(1).getValueType();
4327    int64_t Cnt;
4328    unsigned VShiftOpc = 0;
4329
4330    if (isVShiftLImm(N->getOperand(3), VT, false, Cnt))
4331      VShiftOpc = ARMISD::VSLI;
4332    else if (isVShiftRImm(N->getOperand(3), VT, false, true, Cnt))
4333      VShiftOpc = ARMISD::VSRI;
4334    else {
4335      llvm_unreachable("invalid shift count for vsli/vsri intrinsic");
4336    }
4337
4338    return DAG.getNode(VShiftOpc, N->getDebugLoc(), N->getValueType(0),
4339                       N->getOperand(1), N->getOperand(2),
4340                       DAG.getConstant(Cnt, MVT::i32));
4341  }
4342
4343  case Intrinsic::arm_neon_vqrshifts:
4344  case Intrinsic::arm_neon_vqrshiftu:
4345    // No immediate versions of these to check for.
4346    break;
4347  }
4348
4349  return SDValue();
4350}
4351
4352/// PerformShiftCombine - Checks for immediate versions of vector shifts and
4353/// lowers them.  As with the vector shift intrinsics, this is done during DAG
4354/// combining instead of DAG legalizing because the build_vectors for 64-bit
4355/// vector element shift counts are generally not legal, and it is hard to see
4356/// their values after they get legalized to loads from a constant pool.
4357static SDValue PerformShiftCombine(SDNode *N, SelectionDAG &DAG,
4358                                   const ARMSubtarget *ST) {
4359  EVT VT = N->getValueType(0);
4360
4361  // Nothing to be done for scalar shifts.
4362  if (! VT.isVector())
4363    return SDValue();
4364
4365  assert(ST->hasNEON() && "unexpected vector shift");
4366  int64_t Cnt;
4367
4368  switch (N->getOpcode()) {
4369  default: llvm_unreachable("unexpected shift opcode");
4370
4371  case ISD::SHL:
4372    if (isVShiftLImm(N->getOperand(1), VT, false, Cnt))
4373      return DAG.getNode(ARMISD::VSHL, N->getDebugLoc(), VT, N->getOperand(0),
4374                         DAG.getConstant(Cnt, MVT::i32));
4375    break;
4376
4377  case ISD::SRA:
4378  case ISD::SRL:
4379    if (isVShiftRImm(N->getOperand(1), VT, false, false, Cnt)) {
4380      unsigned VShiftOpc = (N->getOpcode() == ISD::SRA ?
4381                            ARMISD::VSHRs : ARMISD::VSHRu);
4382      return DAG.getNode(VShiftOpc, N->getDebugLoc(), VT, N->getOperand(0),
4383                         DAG.getConstant(Cnt, MVT::i32));
4384    }
4385  }
4386  return SDValue();
4387}
4388
4389/// PerformExtendCombine - Target-specific DAG combining for ISD::SIGN_EXTEND,
4390/// ISD::ZERO_EXTEND, and ISD::ANY_EXTEND.
4391static SDValue PerformExtendCombine(SDNode *N, SelectionDAG &DAG,
4392                                    const ARMSubtarget *ST) {
4393  SDValue N0 = N->getOperand(0);
4394
4395  // Check for sign- and zero-extensions of vector extract operations of 8-
4396  // and 16-bit vector elements.  NEON supports these directly.  They are
4397  // handled during DAG combining because type legalization will promote them
4398  // to 32-bit types and it is messy to recognize the operations after that.
4399  if (ST->hasNEON() && N0.getOpcode() == ISD::EXTRACT_VECTOR_ELT) {
4400    SDValue Vec = N0.getOperand(0);
4401    SDValue Lane = N0.getOperand(1);
4402    EVT VT = N->getValueType(0);
4403    EVT EltVT = N0.getValueType();
4404    const TargetLowering &TLI = DAG.getTargetLoweringInfo();
4405
4406    if (VT == MVT::i32 &&
4407        (EltVT == MVT::i8 || EltVT == MVT::i16) &&
4408        TLI.isTypeLegal(Vec.getValueType())) {
4409
4410      unsigned Opc = 0;
4411      switch (N->getOpcode()) {
4412      default: llvm_unreachable("unexpected opcode");
4413      case ISD::SIGN_EXTEND:
4414        Opc = ARMISD::VGETLANEs;
4415        break;
4416      case ISD::ZERO_EXTEND:
4417      case ISD::ANY_EXTEND:
4418        Opc = ARMISD::VGETLANEu;
4419        break;
4420      }
4421      return DAG.getNode(Opc, N->getDebugLoc(), VT, Vec, Lane);
4422    }
4423  }
4424
4425  return SDValue();
4426}
4427
4428/// PerformSELECT_CCCombine - Target-specific DAG combining for ISD::SELECT_CC
4429/// to match f32 max/min patterns to use NEON vmax/vmin instructions.
4430static SDValue PerformSELECT_CCCombine(SDNode *N, SelectionDAG &DAG,
4431                                       const ARMSubtarget *ST) {
4432  // If the target supports NEON, try to use vmax/vmin instructions for f32
4433  // selects like "x < y ? x : y".  Unless the FiniteOnlyFPMath option is set,
4434  // be careful about NaNs:  NEON's vmax/vmin return NaN if either operand is
4435  // a NaN; only do the transformation when it matches that behavior.
4436
4437  // For now only do this when using NEON for FP operations; if using VFP, it
4438  // is not obvious that the benefit outweighs the cost of switching to the
4439  // NEON pipeline.
4440  if (!ST->hasNEON() || !ST->useNEONForSinglePrecisionFP() ||
4441      N->getValueType(0) != MVT::f32)
4442    return SDValue();
4443
4444  SDValue CondLHS = N->getOperand(0);
4445  SDValue CondRHS = N->getOperand(1);
4446  SDValue LHS = N->getOperand(2);
4447  SDValue RHS = N->getOperand(3);
4448  ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(4))->get();
4449
4450  unsigned Opcode = 0;
4451  bool IsReversed;
4452  if (DAG.isEqualTo(LHS, CondLHS) && DAG.isEqualTo(RHS, CondRHS)) {
4453    IsReversed = false; // x CC y ? x : y
4454  } else if (DAG.isEqualTo(LHS, CondRHS) && DAG.isEqualTo(RHS, CondLHS)) {
4455    IsReversed = true ; // x CC y ? y : x
4456  } else {
4457    return SDValue();
4458  }
4459
4460  bool IsUnordered;
4461  switch (CC) {
4462  default: break;
4463  case ISD::SETOLT:
4464  case ISD::SETOLE:
4465  case ISD::SETLT:
4466  case ISD::SETLE:
4467  case ISD::SETULT:
4468  case ISD::SETULE:
4469    // If LHS is NaN, an ordered comparison will be false and the result will
4470    // be the RHS, but vmin(NaN, RHS) = NaN.  Avoid this by checking that LHS
4471    // != NaN.  Likewise, for unordered comparisons, check for RHS != NaN.
4472    IsUnordered = (CC == ISD::SETULT || CC == ISD::SETULE);
4473    if (!DAG.isKnownNeverNaN(IsUnordered ? RHS : LHS))
4474      break;
4475    // For less-than-or-equal comparisons, "+0 <= -0" will be true but vmin
4476    // will return -0, so vmin can only be used for unsafe math or if one of
4477    // the operands is known to be nonzero.
4478    if ((CC == ISD::SETLE || CC == ISD::SETOLE || CC == ISD::SETULE) &&
4479        !UnsafeFPMath &&
4480        !(DAG.isKnownNeverZero(LHS) || DAG.isKnownNeverZero(RHS)))
4481      break;
4482    Opcode = IsReversed ? ARMISD::FMAX : ARMISD::FMIN;
4483    break;
4484
4485  case ISD::SETOGT:
4486  case ISD::SETOGE:
4487  case ISD::SETGT:
4488  case ISD::SETGE:
4489  case ISD::SETUGT:
4490  case ISD::SETUGE:
4491    // If LHS is NaN, an ordered comparison will be false and the result will
4492    // be the RHS, but vmax(NaN, RHS) = NaN.  Avoid this by checking that LHS
4493    // != NaN.  Likewise, for unordered comparisons, check for RHS != NaN.
4494    IsUnordered = (CC == ISD::SETUGT || CC == ISD::SETUGE);
4495    if (!DAG.isKnownNeverNaN(IsUnordered ? RHS : LHS))
4496      break;
4497    // For greater-than-or-equal comparisons, "-0 >= +0" will be true but vmax
4498    // will return +0, so vmax can only be used for unsafe math or if one of
4499    // the operands is known to be nonzero.
4500    if ((CC == ISD::SETGE || CC == ISD::SETOGE || CC == ISD::SETUGE) &&
4501        !UnsafeFPMath &&
4502        !(DAG.isKnownNeverZero(LHS) || DAG.isKnownNeverZero(RHS)))
4503      break;
4504    Opcode = IsReversed ? ARMISD::FMIN : ARMISD::FMAX;
4505    break;
4506  }
4507
4508  if (!Opcode)
4509    return SDValue();
4510  return DAG.getNode(Opcode, N->getDebugLoc(), N->getValueType(0), LHS, RHS);
4511}
4512
4513SDValue ARMTargetLowering::PerformDAGCombine(SDNode *N,
4514                                             DAGCombinerInfo &DCI) const {
4515  switch (N->getOpcode()) {
4516  default: break;
4517  case ISD::ADD:        return PerformADDCombine(N, DCI);
4518  case ISD::SUB:        return PerformSUBCombine(N, DCI);
4519  case ISD::MUL:        return PerformMULCombine(N, DCI, Subtarget);
4520  case ARMISD::VMOVRRD: return PerformVMOVRRDCombine(N, DCI);
4521  case ISD::INTRINSIC_WO_CHAIN: return PerformIntrinsicCombine(N, DCI.DAG);
4522  case ISD::SHL:
4523  case ISD::SRA:
4524  case ISD::SRL:        return PerformShiftCombine(N, DCI.DAG, Subtarget);
4525  case ISD::SIGN_EXTEND:
4526  case ISD::ZERO_EXTEND:
4527  case ISD::ANY_EXTEND: return PerformExtendCombine(N, DCI.DAG, Subtarget);
4528  case ISD::SELECT_CC:  return PerformSELECT_CCCombine(N, DCI.DAG, Subtarget);
4529  }
4530  return SDValue();
4531}
4532
4533bool ARMTargetLowering::allowsUnalignedMemoryAccesses(EVT VT) const {
4534  if (!Subtarget->hasV6Ops())
4535    // Pre-v6 does not support unaligned mem access.
4536    return false;
4537
4538  // v6+ may or may not support unaligned mem access depending on the system
4539  // configuration.
4540  // FIXME: This is pretty conservative. Should we provide cmdline option to
4541  // control the behaviour?
4542  if (!Subtarget->isTargetDarwin())
4543    return false;
4544
4545  switch (VT.getSimpleVT().SimpleTy) {
4546  default:
4547    return false;
4548  case MVT::i8:
4549  case MVT::i16:
4550  case MVT::i32:
4551    return true;
4552  // FIXME: VLD1 etc with standard alignment is legal.
4553  }
4554}
4555
4556static bool isLegalT1AddressImmediate(int64_t V, EVT VT) {
4557  if (V < 0)
4558    return false;
4559
4560  unsigned Scale = 1;
4561  switch (VT.getSimpleVT().SimpleTy) {
4562  default: return false;
4563  case MVT::i1:
4564  case MVT::i8:
4565    // Scale == 1;
4566    break;
4567  case MVT::i16:
4568    // Scale == 2;
4569    Scale = 2;
4570    break;
4571  case MVT::i32:
4572    // Scale == 4;
4573    Scale = 4;
4574    break;
4575  }
4576
4577  if ((V & (Scale - 1)) != 0)
4578    return false;
4579  V /= Scale;
4580  return V == (V & ((1LL << 5) - 1));
4581}
4582
4583static bool isLegalT2AddressImmediate(int64_t V, EVT VT,
4584                                      const ARMSubtarget *Subtarget) {
4585  bool isNeg = false;
4586  if (V < 0) {
4587    isNeg = true;
4588    V = - V;
4589  }
4590
4591  switch (VT.getSimpleVT().SimpleTy) {
4592  default: return false;
4593  case MVT::i1:
4594  case MVT::i8:
4595  case MVT::i16:
4596  case MVT::i32:
4597    // + imm12 or - imm8
4598    if (isNeg)
4599      return V == (V & ((1LL << 8) - 1));
4600    return V == (V & ((1LL << 12) - 1));
4601  case MVT::f32:
4602  case MVT::f64:
4603    // Same as ARM mode. FIXME: NEON?
4604    if (!Subtarget->hasVFP2())
4605      return false;
4606    if ((V & 3) != 0)
4607      return false;
4608    V >>= 2;
4609    return V == (V & ((1LL << 8) - 1));
4610  }
4611}
4612
4613/// isLegalAddressImmediate - Return true if the integer value can be used
4614/// as the offset of the target addressing mode for load / store of the
4615/// given type.
4616static bool isLegalAddressImmediate(int64_t V, EVT VT,
4617                                    const ARMSubtarget *Subtarget) {
4618  if (V == 0)
4619    return true;
4620
4621  if (!VT.isSimple())
4622    return false;
4623
4624  if (Subtarget->isThumb1Only())
4625    return isLegalT1AddressImmediate(V, VT);
4626  else if (Subtarget->isThumb2())
4627    return isLegalT2AddressImmediate(V, VT, Subtarget);
4628
4629  // ARM mode.
4630  if (V < 0)
4631    V = - V;
4632  switch (VT.getSimpleVT().SimpleTy) {
4633  default: return false;
4634  case MVT::i1:
4635  case MVT::i8:
4636  case MVT::i32:
4637    // +- imm12
4638    return V == (V & ((1LL << 12) - 1));
4639  case MVT::i16:
4640    // +- imm8
4641    return V == (V & ((1LL << 8) - 1));
4642  case MVT::f32:
4643  case MVT::f64:
4644    if (!Subtarget->hasVFP2()) // FIXME: NEON?
4645      return false;
4646    if ((V & 3) != 0)
4647      return false;
4648    V >>= 2;
4649    return V == (V & ((1LL << 8) - 1));
4650  }
4651}
4652
4653bool ARMTargetLowering::isLegalT2ScaledAddressingMode(const AddrMode &AM,
4654                                                      EVT VT) const {
4655  int Scale = AM.Scale;
4656  if (Scale < 0)
4657    return false;
4658
4659  switch (VT.getSimpleVT().SimpleTy) {
4660  default: return false;
4661  case MVT::i1:
4662  case MVT::i8:
4663  case MVT::i16:
4664  case MVT::i32:
4665    if (Scale == 1)
4666      return true;
4667    // r + r << imm
4668    Scale = Scale & ~1;
4669    return Scale == 2 || Scale == 4 || Scale == 8;
4670  case MVT::i64:
4671    // r + r
4672    if (((unsigned)AM.HasBaseReg + Scale) <= 2)
4673      return true;
4674    return false;
4675  case MVT::isVoid:
4676    // Note, we allow "void" uses (basically, uses that aren't loads or
4677    // stores), because arm allows folding a scale into many arithmetic
4678    // operations.  This should be made more precise and revisited later.
4679
4680    // Allow r << imm, but the imm has to be a multiple of two.
4681    if (Scale & 1) return false;
4682    return isPowerOf2_32(Scale);
4683  }
4684}
4685
4686/// isLegalAddressingMode - Return true if the addressing mode represented
4687/// by AM is legal for this target, for a load/store of the specified type.
4688bool ARMTargetLowering::isLegalAddressingMode(const AddrMode &AM,
4689                                              const Type *Ty) const {
4690  EVT VT = getValueType(Ty, true);
4691  if (!isLegalAddressImmediate(AM.BaseOffs, VT, Subtarget))
4692    return false;
4693
4694  // Can never fold addr of global into load/store.
4695  if (AM.BaseGV)
4696    return false;
4697
4698  switch (AM.Scale) {
4699  case 0:  // no scale reg, must be "r+i" or "r", or "i".
4700    break;
4701  case 1:
4702    if (Subtarget->isThumb1Only())
4703      return false;
4704    // FALL THROUGH.
4705  default:
4706    // ARM doesn't support any R+R*scale+imm addr modes.
4707    if (AM.BaseOffs)
4708      return false;
4709
4710    if (!VT.isSimple())
4711      return false;
4712
4713    if (Subtarget->isThumb2())
4714      return isLegalT2ScaledAddressingMode(AM, VT);
4715
4716    int Scale = AM.Scale;
4717    switch (VT.getSimpleVT().SimpleTy) {
4718    default: return false;
4719    case MVT::i1:
4720    case MVT::i8:
4721    case MVT::i32:
4722      if (Scale < 0) Scale = -Scale;
4723      if (Scale == 1)
4724        return true;
4725      // r + r << imm
4726      return isPowerOf2_32(Scale & ~1);
4727    case MVT::i16:
4728    case MVT::i64:
4729      // r + r
4730      if (((unsigned)AM.HasBaseReg + Scale) <= 2)
4731        return true;
4732      return false;
4733
4734    case MVT::isVoid:
4735      // Note, we allow "void" uses (basically, uses that aren't loads or
4736      // stores), because arm allows folding a scale into many arithmetic
4737      // operations.  This should be made more precise and revisited later.
4738
4739      // Allow r << imm, but the imm has to be a multiple of two.
4740      if (Scale & 1) return false;
4741      return isPowerOf2_32(Scale);
4742    }
4743    break;
4744  }
4745  return true;
4746}
4747
4748/// isLegalICmpImmediate - Return true if the specified immediate is legal
4749/// icmp immediate, that is the target has icmp instructions which can compare
4750/// a register against the immediate without having to materialize the
4751/// immediate into a register.
4752bool ARMTargetLowering::isLegalICmpImmediate(int64_t Imm) const {
4753  if (!Subtarget->isThumb())
4754    return ARM_AM::getSOImmVal(Imm) != -1;
4755  if (Subtarget->isThumb2())
4756    return ARM_AM::getT2SOImmVal(Imm) != -1;
4757  return Imm >= 0 && Imm <= 255;
4758}
4759
4760static bool getARMIndexedAddressParts(SDNode *Ptr, EVT VT,
4761                                      bool isSEXTLoad, SDValue &Base,
4762                                      SDValue &Offset, bool &isInc,
4763                                      SelectionDAG &DAG) {
4764  if (Ptr->getOpcode() != ISD::ADD && Ptr->getOpcode() != ISD::SUB)
4765    return false;
4766
4767  if (VT == MVT::i16 || ((VT == MVT::i8 || VT == MVT::i1) && isSEXTLoad)) {
4768    // AddressingMode 3
4769    Base = Ptr->getOperand(0);
4770    if (ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(Ptr->getOperand(1))) {
4771      int RHSC = (int)RHS->getZExtValue();
4772      if (RHSC < 0 && RHSC > -256) {
4773        assert(Ptr->getOpcode() == ISD::ADD);
4774        isInc = false;
4775        Offset = DAG.getConstant(-RHSC, RHS->getValueType(0));
4776        return true;
4777      }
4778    }
4779    isInc = (Ptr->getOpcode() == ISD::ADD);
4780    Offset = Ptr->getOperand(1);
4781    return true;
4782  } else if (VT == MVT::i32 || VT == MVT::i8 || VT == MVT::i1) {
4783    // AddressingMode 2
4784    if (ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(Ptr->getOperand(1))) {
4785      int RHSC = (int)RHS->getZExtValue();
4786      if (RHSC < 0 && RHSC > -0x1000) {
4787        assert(Ptr->getOpcode() == ISD::ADD);
4788        isInc = false;
4789        Offset = DAG.getConstant(-RHSC, RHS->getValueType(0));
4790        Base = Ptr->getOperand(0);
4791        return true;
4792      }
4793    }
4794
4795    if (Ptr->getOpcode() == ISD::ADD) {
4796      isInc = true;
4797      ARM_AM::ShiftOpc ShOpcVal= ARM_AM::getShiftOpcForNode(Ptr->getOperand(0));
4798      if (ShOpcVal != ARM_AM::no_shift) {
4799        Base = Ptr->getOperand(1);
4800        Offset = Ptr->getOperand(0);
4801      } else {
4802        Base = Ptr->getOperand(0);
4803        Offset = Ptr->getOperand(1);
4804      }
4805      return true;
4806    }
4807
4808    isInc = (Ptr->getOpcode() == ISD::ADD);
4809    Base = Ptr->getOperand(0);
4810    Offset = Ptr->getOperand(1);
4811    return true;
4812  }
4813
4814  // FIXME: Use VLDM / VSTM to emulate indexed FP load / store.
4815  return false;
4816}
4817
4818static bool getT2IndexedAddressParts(SDNode *Ptr, EVT VT,
4819                                     bool isSEXTLoad, SDValue &Base,
4820                                     SDValue &Offset, bool &isInc,
4821                                     SelectionDAG &DAG) {
4822  if (Ptr->getOpcode() != ISD::ADD && Ptr->getOpcode() != ISD::SUB)
4823    return false;
4824
4825  Base = Ptr->getOperand(0);
4826  if (ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(Ptr->getOperand(1))) {
4827    int RHSC = (int)RHS->getZExtValue();
4828    if (RHSC < 0 && RHSC > -0x100) { // 8 bits.
4829      assert(Ptr->getOpcode() == ISD::ADD);
4830      isInc = false;
4831      Offset = DAG.getConstant(-RHSC, RHS->getValueType(0));
4832      return true;
4833    } else if (RHSC > 0 && RHSC < 0x100) { // 8 bit, no zero.
4834      isInc = Ptr->getOpcode() == ISD::ADD;
4835      Offset = DAG.getConstant(RHSC, RHS->getValueType(0));
4836      return true;
4837    }
4838  }
4839
4840  return false;
4841}
4842
4843/// getPreIndexedAddressParts - returns true by value, base pointer and
4844/// offset pointer and addressing mode by reference if the node's address
4845/// can be legally represented as pre-indexed load / store address.
4846bool
4847ARMTargetLowering::getPreIndexedAddressParts(SDNode *N, SDValue &Base,
4848                                             SDValue &Offset,
4849                                             ISD::MemIndexedMode &AM,
4850                                             SelectionDAG &DAG) const {
4851  if (Subtarget->isThumb1Only())
4852    return false;
4853
4854  EVT VT;
4855  SDValue Ptr;
4856  bool isSEXTLoad = false;
4857  if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
4858    Ptr = LD->getBasePtr();
4859    VT  = LD->getMemoryVT();
4860    isSEXTLoad = LD->getExtensionType() == ISD::SEXTLOAD;
4861  } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
4862    Ptr = ST->getBasePtr();
4863    VT  = ST->getMemoryVT();
4864  } else
4865    return false;
4866
4867  bool isInc;
4868  bool isLegal = false;
4869  if (Subtarget->isThumb2())
4870    isLegal = getT2IndexedAddressParts(Ptr.getNode(), VT, isSEXTLoad, Base,
4871                                       Offset, isInc, DAG);
4872  else
4873    isLegal = getARMIndexedAddressParts(Ptr.getNode(), VT, isSEXTLoad, Base,
4874                                        Offset, isInc, DAG);
4875  if (!isLegal)
4876    return false;
4877
4878  AM = isInc ? ISD::PRE_INC : ISD::PRE_DEC;
4879  return true;
4880}
4881
4882/// getPostIndexedAddressParts - returns true by value, base pointer and
4883/// offset pointer and addressing mode by reference if this node can be
4884/// combined with a load / store to form a post-indexed load / store.
4885bool ARMTargetLowering::getPostIndexedAddressParts(SDNode *N, SDNode *Op,
4886                                                   SDValue &Base,
4887                                                   SDValue &Offset,
4888                                                   ISD::MemIndexedMode &AM,
4889                                                   SelectionDAG &DAG) const {
4890  if (Subtarget->isThumb1Only())
4891    return false;
4892
4893  EVT VT;
4894  SDValue Ptr;
4895  bool isSEXTLoad = false;
4896  if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
4897    VT  = LD->getMemoryVT();
4898    Ptr = LD->getBasePtr();
4899    isSEXTLoad = LD->getExtensionType() == ISD::SEXTLOAD;
4900  } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
4901    VT  = ST->getMemoryVT();
4902    Ptr = ST->getBasePtr();
4903  } else
4904    return false;
4905
4906  bool isInc;
4907  bool isLegal = false;
4908  if (Subtarget->isThumb2())
4909    isLegal = getT2IndexedAddressParts(Op, VT, isSEXTLoad, Base, Offset,
4910                                       isInc, DAG);
4911  else
4912    isLegal = getARMIndexedAddressParts(Op, VT, isSEXTLoad, Base, Offset,
4913                                        isInc, DAG);
4914  if (!isLegal)
4915    return false;
4916
4917  if (Ptr != Base) {
4918    // Swap base ptr and offset to catch more post-index load / store when
4919    // it's legal. In Thumb2 mode, offset must be an immediate.
4920    if (Ptr == Offset && Op->getOpcode() == ISD::ADD &&
4921        !Subtarget->isThumb2())
4922      std::swap(Base, Offset);
4923
4924    // Post-indexed load / store update the base pointer.
4925    if (Ptr != Base)
4926      return false;
4927  }
4928
4929  AM = isInc ? ISD::POST_INC : ISD::POST_DEC;
4930  return true;
4931}
4932
4933void ARMTargetLowering::computeMaskedBitsForTargetNode(const SDValue Op,
4934                                                       const APInt &Mask,
4935                                                       APInt &KnownZero,
4936                                                       APInt &KnownOne,
4937                                                       const SelectionDAG &DAG,
4938                                                       unsigned Depth) const {
4939  KnownZero = KnownOne = APInt(Mask.getBitWidth(), 0);
4940  switch (Op.getOpcode()) {
4941  default: break;
4942  case ARMISD::CMOV: {
4943    // Bits are known zero/one if known on the LHS and RHS.
4944    DAG.ComputeMaskedBits(Op.getOperand(0), Mask, KnownZero, KnownOne, Depth+1);
4945    if (KnownZero == 0 && KnownOne == 0) return;
4946
4947    APInt KnownZeroRHS, KnownOneRHS;
4948    DAG.ComputeMaskedBits(Op.getOperand(1), Mask,
4949                          KnownZeroRHS, KnownOneRHS, Depth+1);
4950    KnownZero &= KnownZeroRHS;
4951    KnownOne  &= KnownOneRHS;
4952    return;
4953  }
4954  }
4955}
4956
4957//===----------------------------------------------------------------------===//
4958//                           ARM Inline Assembly Support
4959//===----------------------------------------------------------------------===//
4960
4961/// getConstraintType - Given a constraint letter, return the type of
4962/// constraint it is for this target.
4963ARMTargetLowering::ConstraintType
4964ARMTargetLowering::getConstraintType(const std::string &Constraint) const {
4965  if (Constraint.size() == 1) {
4966    switch (Constraint[0]) {
4967    default:  break;
4968    case 'l': return C_RegisterClass;
4969    case 'w': return C_RegisterClass;
4970    }
4971  }
4972  return TargetLowering::getConstraintType(Constraint);
4973}
4974
4975std::pair<unsigned, const TargetRegisterClass*>
4976ARMTargetLowering::getRegForInlineAsmConstraint(const std::string &Constraint,
4977                                                EVT VT) const {
4978  if (Constraint.size() == 1) {
4979    // GCC ARM Constraint Letters
4980    switch (Constraint[0]) {
4981    case 'l':
4982      if (Subtarget->isThumb())
4983        return std::make_pair(0U, ARM::tGPRRegisterClass);
4984      else
4985        return std::make_pair(0U, ARM::GPRRegisterClass);
4986    case 'r':
4987      return std::make_pair(0U, ARM::GPRRegisterClass);
4988    case 'w':
4989      if (VT == MVT::f32)
4990        return std::make_pair(0U, ARM::SPRRegisterClass);
4991      if (VT.getSizeInBits() == 64)
4992        return std::make_pair(0U, ARM::DPRRegisterClass);
4993      if (VT.getSizeInBits() == 128)
4994        return std::make_pair(0U, ARM::QPRRegisterClass);
4995      break;
4996    }
4997  }
4998  if (StringRef("{cc}").equals_lower(Constraint))
4999    return std::make_pair(unsigned(ARM::CPSR), ARM::CCRRegisterClass);
5000
5001  return TargetLowering::getRegForInlineAsmConstraint(Constraint, VT);
5002}
5003
5004std::vector<unsigned> ARMTargetLowering::
5005getRegClassForInlineAsmConstraint(const std::string &Constraint,
5006                                  EVT VT) const {
5007  if (Constraint.size() != 1)
5008    return std::vector<unsigned>();
5009
5010  switch (Constraint[0]) {      // GCC ARM Constraint Letters
5011  default: break;
5012  case 'l':
5013    return make_vector<unsigned>(ARM::R0, ARM::R1, ARM::R2, ARM::R3,
5014                                 ARM::R4, ARM::R5, ARM::R6, ARM::R7,
5015                                 0);
5016  case 'r':
5017    return make_vector<unsigned>(ARM::R0, ARM::R1, ARM::R2, ARM::R3,
5018                                 ARM::R4, ARM::R5, ARM::R6, ARM::R7,
5019                                 ARM::R8, ARM::R9, ARM::R10, ARM::R11,
5020                                 ARM::R12, ARM::LR, 0);
5021  case 'w':
5022    if (VT == MVT::f32)
5023      return make_vector<unsigned>(ARM::S0, ARM::S1, ARM::S2, ARM::S3,
5024                                   ARM::S4, ARM::S5, ARM::S6, ARM::S7,
5025                                   ARM::S8, ARM::S9, ARM::S10, ARM::S11,
5026                                   ARM::S12,ARM::S13,ARM::S14,ARM::S15,
5027                                   ARM::S16,ARM::S17,ARM::S18,ARM::S19,
5028                                   ARM::S20,ARM::S21,ARM::S22,ARM::S23,
5029                                   ARM::S24,ARM::S25,ARM::S26,ARM::S27,
5030                                   ARM::S28,ARM::S29,ARM::S30,ARM::S31, 0);
5031    if (VT.getSizeInBits() == 64)
5032      return make_vector<unsigned>(ARM::D0, ARM::D1, ARM::D2, ARM::D3,
5033                                   ARM::D4, ARM::D5, ARM::D6, ARM::D7,
5034                                   ARM::D8, ARM::D9, ARM::D10,ARM::D11,
5035                                   ARM::D12,ARM::D13,ARM::D14,ARM::D15, 0);
5036    if (VT.getSizeInBits() == 128)
5037      return make_vector<unsigned>(ARM::Q0, ARM::Q1, ARM::Q2, ARM::Q3,
5038                                   ARM::Q4, ARM::Q5, ARM::Q6, ARM::Q7, 0);
5039      break;
5040  }
5041
5042  return std::vector<unsigned>();
5043}
5044
5045/// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
5046/// vector.  If it is invalid, don't add anything to Ops.
5047void ARMTargetLowering::LowerAsmOperandForConstraint(SDValue Op,
5048                                                     char Constraint,
5049                                                     std::vector<SDValue>&Ops,
5050                                                     SelectionDAG &DAG) const {
5051  SDValue Result(0, 0);
5052
5053  switch (Constraint) {
5054  default: break;
5055  case 'I': case 'J': case 'K': case 'L':
5056  case 'M': case 'N': case 'O':
5057    ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op);
5058    if (!C)
5059      return;
5060
5061    int64_t CVal64 = C->getSExtValue();
5062    int CVal = (int) CVal64;
5063    // None of these constraints allow values larger than 32 bits.  Check
5064    // that the value fits in an int.
5065    if (CVal != CVal64)
5066      return;
5067
5068    switch (Constraint) {
5069      case 'I':
5070        if (Subtarget->isThumb1Only()) {
5071          // This must be a constant between 0 and 255, for ADD
5072          // immediates.
5073          if (CVal >= 0 && CVal <= 255)
5074            break;
5075        } else if (Subtarget->isThumb2()) {
5076          // A constant that can be used as an immediate value in a
5077          // data-processing instruction.
5078          if (ARM_AM::getT2SOImmVal(CVal) != -1)
5079            break;
5080        } else {
5081          // A constant that can be used as an immediate value in a
5082          // data-processing instruction.
5083          if (ARM_AM::getSOImmVal(CVal) != -1)
5084            break;
5085        }
5086        return;
5087
5088      case 'J':
5089        if (Subtarget->isThumb()) {  // FIXME thumb2
5090          // This must be a constant between -255 and -1, for negated ADD
5091          // immediates. This can be used in GCC with an "n" modifier that
5092          // prints the negated value, for use with SUB instructions. It is
5093          // not useful otherwise but is implemented for compatibility.
5094          if (CVal >= -255 && CVal <= -1)
5095            break;
5096        } else {
5097          // This must be a constant between -4095 and 4095. It is not clear
5098          // what this constraint is intended for. Implemented for
5099          // compatibility with GCC.
5100          if (CVal >= -4095 && CVal <= 4095)
5101            break;
5102        }
5103        return;
5104
5105      case 'K':
5106        if (Subtarget->isThumb1Only()) {
5107          // A 32-bit value where only one byte has a nonzero value. Exclude
5108          // zero to match GCC. This constraint is used by GCC internally for
5109          // constants that can be loaded with a move/shift combination.
5110          // It is not useful otherwise but is implemented for compatibility.
5111          if (CVal != 0 && ARM_AM::isThumbImmShiftedVal(CVal))
5112            break;
5113        } else if (Subtarget->isThumb2()) {
5114          // A constant whose bitwise inverse can be used as an immediate
5115          // value in a data-processing instruction. This can be used in GCC
5116          // with a "B" modifier that prints the inverted value, for use with
5117          // BIC and MVN instructions. It is not useful otherwise but is
5118          // implemented for compatibility.
5119          if (ARM_AM::getT2SOImmVal(~CVal) != -1)
5120            break;
5121        } else {
5122          // A constant whose bitwise inverse can be used as an immediate
5123          // value in a data-processing instruction. This can be used in GCC
5124          // with a "B" modifier that prints the inverted value, for use with
5125          // BIC and MVN instructions. It is not useful otherwise but is
5126          // implemented for compatibility.
5127          if (ARM_AM::getSOImmVal(~CVal) != -1)
5128            break;
5129        }
5130        return;
5131
5132      case 'L':
5133        if (Subtarget->isThumb1Only()) {
5134          // This must be a constant between -7 and 7,
5135          // for 3-operand ADD/SUB immediate instructions.
5136          if (CVal >= -7 && CVal < 7)
5137            break;
5138        } else if (Subtarget->isThumb2()) {
5139          // A constant whose negation can be used as an immediate value in a
5140          // data-processing instruction. This can be used in GCC with an "n"
5141          // modifier that prints the negated value, for use with SUB
5142          // instructions. It is not useful otherwise but is implemented for
5143          // compatibility.
5144          if (ARM_AM::getT2SOImmVal(-CVal) != -1)
5145            break;
5146        } else {
5147          // A constant whose negation can be used as an immediate value in a
5148          // data-processing instruction. This can be used in GCC with an "n"
5149          // modifier that prints the negated value, for use with SUB
5150          // instructions. It is not useful otherwise but is implemented for
5151          // compatibility.
5152          if (ARM_AM::getSOImmVal(-CVal) != -1)
5153            break;
5154        }
5155        return;
5156
5157      case 'M':
5158        if (Subtarget->isThumb()) { // FIXME thumb2
5159          // This must be a multiple of 4 between 0 and 1020, for
5160          // ADD sp + immediate.
5161          if ((CVal >= 0 && CVal <= 1020) && ((CVal & 3) == 0))
5162            break;
5163        } else {
5164          // A power of two or a constant between 0 and 32.  This is used in
5165          // GCC for the shift amount on shifted register operands, but it is
5166          // useful in general for any shift amounts.
5167          if ((CVal >= 0 && CVal <= 32) || ((CVal & (CVal - 1)) == 0))
5168            break;
5169        }
5170        return;
5171
5172      case 'N':
5173        if (Subtarget->isThumb()) {  // FIXME thumb2
5174          // This must be a constant between 0 and 31, for shift amounts.
5175          if (CVal >= 0 && CVal <= 31)
5176            break;
5177        }
5178        return;
5179
5180      case 'O':
5181        if (Subtarget->isThumb()) {  // FIXME thumb2
5182          // This must be a multiple of 4 between -508 and 508, for
5183          // ADD/SUB sp = sp + immediate.
5184          if ((CVal >= -508 && CVal <= 508) && ((CVal & 3) == 0))
5185            break;
5186        }
5187        return;
5188    }
5189    Result = DAG.getTargetConstant(CVal, Op.getValueType());
5190    break;
5191  }
5192
5193  if (Result.getNode()) {
5194    Ops.push_back(Result);
5195    return;
5196  }
5197  return TargetLowering::LowerAsmOperandForConstraint(Op, Constraint, Ops, DAG);
5198}
5199
5200bool
5201ARMTargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
5202  // The ARM target isn't yet aware of offsets.
5203  return false;
5204}
5205
5206int ARM::getVFPf32Imm(const APFloat &FPImm) {
5207  APInt Imm = FPImm.bitcastToAPInt();
5208  uint32_t Sign = Imm.lshr(31).getZExtValue() & 1;
5209  int32_t Exp = (Imm.lshr(23).getSExtValue() & 0xff) - 127;  // -126 to 127
5210  int64_t Mantissa = Imm.getZExtValue() & 0x7fffff;  // 23 bits
5211
5212  // We can handle 4 bits of mantissa.
5213  // mantissa = (16+UInt(e:f:g:h))/16.
5214  if (Mantissa & 0x7ffff)
5215    return -1;
5216  Mantissa >>= 19;
5217  if ((Mantissa & 0xf) != Mantissa)
5218    return -1;
5219
5220  // We can handle 3 bits of exponent: exp == UInt(NOT(b):c:d)-3
5221  if (Exp < -3 || Exp > 4)
5222    return -1;
5223  Exp = ((Exp+3) & 0x7) ^ 4;
5224
5225  return ((int)Sign << 7) | (Exp << 4) | Mantissa;
5226}
5227
5228int ARM::getVFPf64Imm(const APFloat &FPImm) {
5229  APInt Imm = FPImm.bitcastToAPInt();
5230  uint64_t Sign = Imm.lshr(63).getZExtValue() & 1;
5231  int64_t Exp = (Imm.lshr(52).getSExtValue() & 0x7ff) - 1023;   // -1022 to 1023
5232  uint64_t Mantissa = Imm.getZExtValue() & 0xfffffffffffffLL;
5233
5234  // We can handle 4 bits of mantissa.
5235  // mantissa = (16+UInt(e:f:g:h))/16.
5236  if (Mantissa & 0xffffffffffffLL)
5237    return -1;
5238  Mantissa >>= 48;
5239  if ((Mantissa & 0xf) != Mantissa)
5240    return -1;
5241
5242  // We can handle 3 bits of exponent: exp == UInt(NOT(b):c:d)-3
5243  if (Exp < -3 || Exp > 4)
5244    return -1;
5245  Exp = ((Exp+3) & 0x7) ^ 4;
5246
5247  return ((int)Sign << 7) | (Exp << 4) | Mantissa;
5248}
5249
5250/// isFPImmLegal - Returns true if the target can instruction select the
5251/// specified FP immediate natively. If false, the legalizer will
5252/// materialize the FP immediate as a load from a constant pool.
5253bool ARMTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT) const {
5254  if (!Subtarget->hasVFP3())
5255    return false;
5256  if (VT == MVT::f32)
5257    return ARM::getVFPf32Imm(Imm) != -1;
5258  if (VT == MVT::f64)
5259    return ARM::getVFPf64Imm(Imm) != -1;
5260  return false;
5261}
5262