ARMISelLowering.cpp revision 8bb9e48752b4a88e512ceb8fb802e2cdf8150e7b 
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#include "ARM.h"
16#include "ARMAddressingModes.h"
17#include "ARMConstantPoolValue.h"
18#include "ARMISelLowering.h"
19#include "ARMMachineFunctionInfo.h"
20#include "ARMRegisterInfo.h"
21#include "ARMSubtarget.h"
22#include "ARMTargetMachine.h"
23#include "llvm/CallingConv.h"
24#include "llvm/Constants.h"
25#include "llvm/Function.h"
26#include "llvm/Instruction.h"
27#include "llvm/Intrinsics.h"
28#include "llvm/GlobalValue.h"
29#include "llvm/CodeGen/CallingConvLower.h"
30#include "llvm/CodeGen/MachineBasicBlock.h"
31#include "llvm/CodeGen/MachineFrameInfo.h"
32#include "llvm/CodeGen/MachineFunction.h"
33#include "llvm/CodeGen/MachineInstrBuilder.h"
34#include "llvm/CodeGen/MachineRegisterInfo.h"
35#include "llvm/CodeGen/PseudoSourceValue.h"
36#include "llvm/CodeGen/SelectionDAG.h"
37#include "llvm/Target/TargetOptions.h"
38#include "llvm/ADT/VectorExtras.h"
39#include "llvm/Support/ErrorHandling.h"
40#include "llvm/Support/MathExtras.h"
41using namespace llvm;
42
43static bool CC_ARM_APCS_Custom_f64(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
44                                   CCValAssign::LocInfo &LocInfo,
45                                   ISD::ArgFlagsTy &ArgFlags,
46                                   CCState &State);
47static bool CC_ARM_AAPCS_Custom_f64(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
48                                    CCValAssign::LocInfo &LocInfo,
49                                    ISD::ArgFlagsTy &ArgFlags,
50                                    CCState &State);
51static bool RetCC_ARM_APCS_Custom_f64(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
52                                      CCValAssign::LocInfo &LocInfo,
53                                      ISD::ArgFlagsTy &ArgFlags,
54                                      CCState &State);
55static bool RetCC_ARM_AAPCS_Custom_f64(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
56                                       CCValAssign::LocInfo &LocInfo,
57                                       ISD::ArgFlagsTy &ArgFlags,
58                                       CCState &State);
59
60void ARMTargetLowering::addTypeForNEON(MVT VT, MVT PromotedLdStVT,
61                                       MVT PromotedBitwiseVT) {
62  if (VT != PromotedLdStVT) {
63    setOperationAction(ISD::LOAD, VT, Promote);
64    AddPromotedToType (ISD::LOAD, VT, PromotedLdStVT);
65
66    setOperationAction(ISD::STORE, VT, Promote);
67    AddPromotedToType (ISD::STORE, VT, PromotedLdStVT);
68  }
69
70  MVT ElemTy = VT.getVectorElementType();
71  if (ElemTy != MVT::i64 && ElemTy != MVT::f64)
72    setOperationAction(ISD::VSETCC, VT, Custom);
73  if (ElemTy == MVT::i8 || ElemTy == MVT::i16)
74    setOperationAction(ISD::EXTRACT_VECTOR_ELT, VT, Custom);
75  setOperationAction(ISD::BUILD_VECTOR, VT, Custom);
76  setOperationAction(ISD::VECTOR_SHUFFLE, VT, Custom);
77  setOperationAction(ISD::SCALAR_TO_VECTOR, VT, Custom);
78  setOperationAction(ISD::CONCAT_VECTORS, VT, Custom);
79  if (VT.isInteger()) {
80    setOperationAction(ISD::SHL, VT, Custom);
81    setOperationAction(ISD::SRA, VT, Custom);
82    setOperationAction(ISD::SRL, VT, Custom);
83  }
84
85  // Promote all bit-wise operations.
86  if (VT.isInteger() && VT != PromotedBitwiseVT) {
87    setOperationAction(ISD::AND, VT, Promote);
88    AddPromotedToType (ISD::AND, VT, PromotedBitwiseVT);
89    setOperationAction(ISD::OR,  VT, Promote);
90    AddPromotedToType (ISD::OR,  VT, PromotedBitwiseVT);
91    setOperationAction(ISD::XOR, VT, Promote);
92    AddPromotedToType (ISD::XOR, VT, PromotedBitwiseVT);
93  }
94}
95
96void ARMTargetLowering::addDRTypeForNEON(MVT VT) {
97  addRegisterClass(VT, ARM::DPRRegisterClass);
98  addTypeForNEON(VT, MVT::f64, MVT::v2i32);
99}
100
101void ARMTargetLowering::addQRTypeForNEON(MVT VT) {
102  addRegisterClass(VT, ARM::QPRRegisterClass);
103  addTypeForNEON(VT, MVT::v2f64, MVT::v4i32);
104}
105
106ARMTargetLowering::ARMTargetLowering(TargetMachine &TM)
107    : TargetLowering(TM), ARMPCLabelIndex(0) {
108  Subtarget = &TM.getSubtarget<ARMSubtarget>();
109
110  if (Subtarget->isTargetDarwin()) {
111    // Uses VFP for Thumb libfuncs if available.
112    if (Subtarget->isThumb() && Subtarget->hasVFP2()) {
113      // Single-precision floating-point arithmetic.
114      setLibcallName(RTLIB::ADD_F32, "__addsf3vfp");
115      setLibcallName(RTLIB::SUB_F32, "__subsf3vfp");
116      setLibcallName(RTLIB::MUL_F32, "__mulsf3vfp");
117      setLibcallName(RTLIB::DIV_F32, "__divsf3vfp");
118
119      // Double-precision floating-point arithmetic.
120      setLibcallName(RTLIB::ADD_F64, "__adddf3vfp");
121      setLibcallName(RTLIB::SUB_F64, "__subdf3vfp");
122      setLibcallName(RTLIB::MUL_F64, "__muldf3vfp");
123      setLibcallName(RTLIB::DIV_F64, "__divdf3vfp");
124
125      // Single-precision comparisons.
126      setLibcallName(RTLIB::OEQ_F32, "__eqsf2vfp");
127      setLibcallName(RTLIB::UNE_F32, "__nesf2vfp");
128      setLibcallName(RTLIB::OLT_F32, "__ltsf2vfp");
129      setLibcallName(RTLIB::OLE_F32, "__lesf2vfp");
130      setLibcallName(RTLIB::OGE_F32, "__gesf2vfp");
131      setLibcallName(RTLIB::OGT_F32, "__gtsf2vfp");
132      setLibcallName(RTLIB::UO_F32,  "__unordsf2vfp");
133      setLibcallName(RTLIB::O_F32,   "__unordsf2vfp");
134
135      setCmpLibcallCC(RTLIB::OEQ_F32, ISD::SETNE);
136      setCmpLibcallCC(RTLIB::UNE_F32, ISD::SETNE);
137      setCmpLibcallCC(RTLIB::OLT_F32, ISD::SETNE);
138      setCmpLibcallCC(RTLIB::OLE_F32, ISD::SETNE);
139      setCmpLibcallCC(RTLIB::OGE_F32, ISD::SETNE);
140      setCmpLibcallCC(RTLIB::OGT_F32, ISD::SETNE);
141      setCmpLibcallCC(RTLIB::UO_F32,  ISD::SETNE);
142      setCmpLibcallCC(RTLIB::O_F32,   ISD::SETEQ);
143
144      // Double-precision comparisons.
145      setLibcallName(RTLIB::OEQ_F64, "__eqdf2vfp");
146      setLibcallName(RTLIB::UNE_F64, "__nedf2vfp");
147      setLibcallName(RTLIB::OLT_F64, "__ltdf2vfp");
148      setLibcallName(RTLIB::OLE_F64, "__ledf2vfp");
149      setLibcallName(RTLIB::OGE_F64, "__gedf2vfp");
150      setLibcallName(RTLIB::OGT_F64, "__gtdf2vfp");
151      setLibcallName(RTLIB::UO_F64,  "__unorddf2vfp");
152      setLibcallName(RTLIB::O_F64,   "__unorddf2vfp");
153
154      setCmpLibcallCC(RTLIB::OEQ_F64, ISD::SETNE);
155      setCmpLibcallCC(RTLIB::UNE_F64, ISD::SETNE);
156      setCmpLibcallCC(RTLIB::OLT_F64, ISD::SETNE);
157      setCmpLibcallCC(RTLIB::OLE_F64, ISD::SETNE);
158      setCmpLibcallCC(RTLIB::OGE_F64, ISD::SETNE);
159      setCmpLibcallCC(RTLIB::OGT_F64, ISD::SETNE);
160      setCmpLibcallCC(RTLIB::UO_F64,  ISD::SETNE);
161      setCmpLibcallCC(RTLIB::O_F64,   ISD::SETEQ);
162
163      // Floating-point to integer conversions.
164      // i64 conversions are done via library routines even when generating VFP
165      // instructions, so use the same ones.
166      setLibcallName(RTLIB::FPTOSINT_F64_I32, "__fixdfsivfp");
167      setLibcallName(RTLIB::FPTOUINT_F64_I32, "__fixunsdfsivfp");
168      setLibcallName(RTLIB::FPTOSINT_F32_I32, "__fixsfsivfp");
169      setLibcallName(RTLIB::FPTOUINT_F32_I32, "__fixunssfsivfp");
170
171      // Conversions between floating types.
172      setLibcallName(RTLIB::FPROUND_F64_F32, "__truncdfsf2vfp");
173      setLibcallName(RTLIB::FPEXT_F32_F64,   "__extendsfdf2vfp");
174
175      // Integer to floating-point conversions.
176      // i64 conversions are done via library routines even when generating VFP
177      // instructions, so use the same ones.
178      // FIXME: There appears to be some naming inconsistency in ARM libgcc:
179      // e.g., __floatunsidf vs. __floatunssidfvfp.
180      setLibcallName(RTLIB::SINTTOFP_I32_F64, "__floatsidfvfp");
181      setLibcallName(RTLIB::UINTTOFP_I32_F64, "__floatunssidfvfp");
182      setLibcallName(RTLIB::SINTTOFP_I32_F32, "__floatsisfvfp");
183      setLibcallName(RTLIB::UINTTOFP_I32_F32, "__floatunssisfvfp");
184    }
185  }
186
187  // These libcalls are not available in 32-bit.
188  setLibcallName(RTLIB::SHL_I128, 0);
189  setLibcallName(RTLIB::SRL_I128, 0);
190  setLibcallName(RTLIB::SRA_I128, 0);
191
192  if (Subtarget->isThumb1Only())
193    addRegisterClass(MVT::i32, ARM::tGPRRegisterClass);
194  else
195    addRegisterClass(MVT::i32, ARM::GPRRegisterClass);
196  if (!UseSoftFloat && Subtarget->hasVFP2() && !Subtarget->isThumb1Only()) {
197    addRegisterClass(MVT::f32, ARM::SPRRegisterClass);
198    addRegisterClass(MVT::f64, ARM::DPRRegisterClass);
199
200    setTruncStoreAction(MVT::f64, MVT::f32, Expand);
201  }
202
203  if (Subtarget->hasNEON()) {
204    addDRTypeForNEON(MVT::v2f32);
205    addDRTypeForNEON(MVT::v8i8);
206    addDRTypeForNEON(MVT::v4i16);
207    addDRTypeForNEON(MVT::v2i32);
208    addDRTypeForNEON(MVT::v1i64);
209
210    addQRTypeForNEON(MVT::v4f32);
211    addQRTypeForNEON(MVT::v2f64);
212    addQRTypeForNEON(MVT::v16i8);
213    addQRTypeForNEON(MVT::v8i16);
214    addQRTypeForNEON(MVT::v4i32);
215    addQRTypeForNEON(MVT::v2i64);
216
217    setTargetDAGCombine(ISD::INTRINSIC_WO_CHAIN);
218    setTargetDAGCombine(ISD::SHL);
219    setTargetDAGCombine(ISD::SRL);
220    setTargetDAGCombine(ISD::SRA);
221    setTargetDAGCombine(ISD::SIGN_EXTEND);
222    setTargetDAGCombine(ISD::ZERO_EXTEND);
223    setTargetDAGCombine(ISD::ANY_EXTEND);
224  }
225
226  computeRegisterProperties();
227
228  // ARM does not have f32 extending load.
229  setLoadExtAction(ISD::EXTLOAD, MVT::f32, Expand);
230
231  // ARM does not have i1 sign extending load.
232  setLoadExtAction(ISD::SEXTLOAD, MVT::i1, Promote);
233
234  // ARM supports all 4 flavors of integer indexed load / store.
235  if (!Subtarget->isThumb1Only()) {
236    for (unsigned im = (unsigned)ISD::PRE_INC;
237         im != (unsigned)ISD::LAST_INDEXED_MODE; ++im) {
238      setIndexedLoadAction(im,  MVT::i1,  Legal);
239      setIndexedLoadAction(im,  MVT::i8,  Legal);
240      setIndexedLoadAction(im,  MVT::i16, Legal);
241      setIndexedLoadAction(im,  MVT::i32, Legal);
242      setIndexedStoreAction(im, MVT::i1,  Legal);
243      setIndexedStoreAction(im, MVT::i8,  Legal);
244      setIndexedStoreAction(im, MVT::i16, Legal);
245      setIndexedStoreAction(im, MVT::i32, Legal);
246    }
247  }
248
249  // i64 operation support.
250  if (Subtarget->isThumb1Only()) {
251    setOperationAction(ISD::MUL,     MVT::i64, Expand);
252    setOperationAction(ISD::MULHU,   MVT::i32, Expand);
253    setOperationAction(ISD::MULHS,   MVT::i32, Expand);
254    setOperationAction(ISD::UMUL_LOHI, MVT::i32, Expand);
255    setOperationAction(ISD::SMUL_LOHI, MVT::i32, Expand);
256  } else {
257    setOperationAction(ISD::MUL,     MVT::i64, Expand);
258    setOperationAction(ISD::MULHU,   MVT::i32, Expand);
259    if (!Subtarget->isThumb1Only() && !Subtarget->hasV6Ops())
260      setOperationAction(ISD::MULHS, MVT::i32, Expand);
261  }
262  setOperationAction(ISD::SHL_PARTS, MVT::i32, Expand);
263  setOperationAction(ISD::SRA_PARTS, MVT::i32, Expand);
264  setOperationAction(ISD::SRL_PARTS, MVT::i32, Expand);
265  setOperationAction(ISD::SRL,       MVT::i64, Custom);
266  setOperationAction(ISD::SRA,       MVT::i64, Custom);
267
268  // ARM does not have ROTL.
269  setOperationAction(ISD::ROTL,  MVT::i32, Expand);
270  setOperationAction(ISD::CTTZ,  MVT::i32, Expand);
271  setOperationAction(ISD::CTPOP, MVT::i32, Expand);
272  if (!Subtarget->hasV5TOps() || Subtarget->isThumb1Only())
273    setOperationAction(ISD::CTLZ, MVT::i32, Expand);
274
275  // Only ARMv6 has BSWAP.
276  if (!Subtarget->hasV6Ops())
277    setOperationAction(ISD::BSWAP, MVT::i32, Expand);
278
279  // These are expanded into libcalls.
280  setOperationAction(ISD::SDIV,  MVT::i32, Expand);
281  setOperationAction(ISD::UDIV,  MVT::i32, Expand);
282  setOperationAction(ISD::SREM,  MVT::i32, Expand);
283  setOperationAction(ISD::UREM,  MVT::i32, Expand);
284  setOperationAction(ISD::SDIVREM, MVT::i32, Expand);
285  setOperationAction(ISD::UDIVREM, MVT::i32, Expand);
286
287  // Support label based line numbers.
288  setOperationAction(ISD::DBG_STOPPOINT, MVT::Other, Expand);
289  setOperationAction(ISD::DEBUG_LOC, MVT::Other, Expand);
290
291  setOperationAction(ISD::RET,           MVT::Other, Custom);
292  setOperationAction(ISD::GlobalAddress, MVT::i32,   Custom);
293  setOperationAction(ISD::ConstantPool,  MVT::i32,   Custom);
294  setOperationAction(ISD::GLOBAL_OFFSET_TABLE, MVT::i32, Custom);
295  setOperationAction(ISD::GlobalTLSAddress, MVT::i32, Custom);
296
297  // Use the default implementation.
298  setOperationAction(ISD::VASTART,            MVT::Other, Custom);
299  setOperationAction(ISD::VAARG,              MVT::Other, Expand);
300  setOperationAction(ISD::VACOPY,             MVT::Other, Expand);
301  setOperationAction(ISD::VAEND,              MVT::Other, Expand);
302  setOperationAction(ISD::STACKSAVE,          MVT::Other, Expand);
303  setOperationAction(ISD::STACKRESTORE,       MVT::Other, Expand);
304  setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32,   Expand);
305  setOperationAction(ISD::MEMBARRIER,         MVT::Other, Expand);
306
307  if (!Subtarget->hasV6Ops() && !Subtarget->isThumb2()) {
308    setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16, Expand);
309    setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i8,  Expand);
310  }
311  setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1, Expand);
312
313  if (!UseSoftFloat && Subtarget->hasVFP2() && !Subtarget->isThumb1Only())
314    // Turn f64->i64 into FMRRD, i64 -> f64 to FMDRR iff target supports vfp2.
315    setOperationAction(ISD::BIT_CONVERT, MVT::i64, Custom);
316
317  // We want to custom lower some of our intrinsics.
318  setOperationAction(ISD::INTRINSIC_WO_CHAIN, MVT::Other, Custom);
319
320  setOperationAction(ISD::SETCC,     MVT::i32, Expand);
321  setOperationAction(ISD::SETCC,     MVT::f32, Expand);
322  setOperationAction(ISD::SETCC,     MVT::f64, Expand);
323  setOperationAction(ISD::SELECT,    MVT::i32, Expand);
324  setOperationAction(ISD::SELECT,    MVT::f32, Expand);
325  setOperationAction(ISD::SELECT,    MVT::f64, Expand);
326  setOperationAction(ISD::SELECT_CC, MVT::i32, Custom);
327  setOperationAction(ISD::SELECT_CC, MVT::f32, Custom);
328  setOperationAction(ISD::SELECT_CC, MVT::f64, Custom);
329
330  setOperationAction(ISD::BRCOND,    MVT::Other, Expand);
331  setOperationAction(ISD::BR_CC,     MVT::i32,   Custom);
332  setOperationAction(ISD::BR_CC,     MVT::f32,   Custom);
333  setOperationAction(ISD::BR_CC,     MVT::f64,   Custom);
334  setOperationAction(ISD::BR_JT,     MVT::Other, Custom);
335
336  // We don't support sin/cos/fmod/copysign/pow
337  setOperationAction(ISD::FSIN,      MVT::f64, Expand);
338  setOperationAction(ISD::FSIN,      MVT::f32, Expand);
339  setOperationAction(ISD::FCOS,      MVT::f32, Expand);
340  setOperationAction(ISD::FCOS,      MVT::f64, Expand);
341  setOperationAction(ISD::FREM,      MVT::f64, Expand);
342  setOperationAction(ISD::FREM,      MVT::f32, Expand);
343  if (!UseSoftFloat && Subtarget->hasVFP2() && !Subtarget->isThumb1Only()) {
344    setOperationAction(ISD::FCOPYSIGN, MVT::f64, Custom);
345    setOperationAction(ISD::FCOPYSIGN, MVT::f32, Custom);
346  }
347  setOperationAction(ISD::FPOW,      MVT::f64, Expand);
348  setOperationAction(ISD::FPOW,      MVT::f32, Expand);
349
350  // int <-> fp are custom expanded into bit_convert + ARMISD ops.
351  if (!UseSoftFloat && Subtarget->hasVFP2() && !Subtarget->isThumb1Only()) {
352    setOperationAction(ISD::SINT_TO_FP, MVT::i32, Custom);
353    setOperationAction(ISD::UINT_TO_FP, MVT::i32, Custom);
354    setOperationAction(ISD::FP_TO_UINT, MVT::i32, Custom);
355    setOperationAction(ISD::FP_TO_SINT, MVT::i32, Custom);
356  }
357
358  // We have target-specific dag combine patterns for the following nodes:
359  // ARMISD::FMRRD  - No need to call setTargetDAGCombine
360  setTargetDAGCombine(ISD::ADD);
361  setTargetDAGCombine(ISD::SUB);
362
363  setStackPointerRegisterToSaveRestore(ARM::SP);
364  setSchedulingPreference(SchedulingForRegPressure);
365  setIfCvtBlockSizeLimit(Subtarget->isThumb() ? 0 : 10);
366  setIfCvtDupBlockSizeLimit(Subtarget->isThumb() ? 0 : 2);
367
368  if (!Subtarget->isThumb()) {
369    // Use branch latency information to determine if-conversion limits.
370    // FIXME: If-converter should use instruction latency of the branch being
371    // eliminated to compute the threshold. For ARMv6, the branch "latency"
372    // varies depending on whether it's dynamically or statically predicted
373    // and on whether the destination is in the prefetch buffer.
374    const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
375    const InstrItineraryData &InstrItins = Subtarget->getInstrItineraryData();
376    unsigned Latency= InstrItins.getLatency(TII->get(ARM::Bcc).getSchedClass());
377    if (Latency > 1) {
378      setIfCvtBlockSizeLimit(Latency-1);
379      if (Latency > 2)
380        setIfCvtDupBlockSizeLimit(Latency-2);
381    } else {
382      setIfCvtBlockSizeLimit(10);
383      setIfCvtDupBlockSizeLimit(2);
384    }
385  }
386
387  maxStoresPerMemcpy = 1;   //// temporary - rewrite interface to use type
388  // Do not enable CodePlacementOpt for now: it currently runs after the
389  // ARMConstantIslandPass and messes up branch relaxation and placement
390  // of constant islands.
391  // benefitFromCodePlacementOpt = true;
392}
393
394const char *ARMTargetLowering::getTargetNodeName(unsigned Opcode) const {
395  switch (Opcode) {
396  default: return 0;
397  case ARMISD::Wrapper:       return "ARMISD::Wrapper";
398  case ARMISD::WrapperJT:     return "ARMISD::WrapperJT";
399  case ARMISD::CALL:          return "ARMISD::CALL";
400  case ARMISD::CALL_PRED:     return "ARMISD::CALL_PRED";
401  case ARMISD::CALL_NOLINK:   return "ARMISD::CALL_NOLINK";
402  case ARMISD::tCALL:         return "ARMISD::tCALL";
403  case ARMISD::BRCOND:        return "ARMISD::BRCOND";
404  case ARMISD::BR_JT:         return "ARMISD::BR_JT";
405  case ARMISD::BR2_JT:        return "ARMISD::BR2_JT";
406  case ARMISD::RET_FLAG:      return "ARMISD::RET_FLAG";
407  case ARMISD::PIC_ADD:       return "ARMISD::PIC_ADD";
408  case ARMISD::CMP:           return "ARMISD::CMP";
409  case ARMISD::CMPZ:          return "ARMISD::CMPZ";
410  case ARMISD::CMPFP:         return "ARMISD::CMPFP";
411  case ARMISD::CMPFPw0:       return "ARMISD::CMPFPw0";
412  case ARMISD::FMSTAT:        return "ARMISD::FMSTAT";
413  case ARMISD::CMOV:          return "ARMISD::CMOV";
414  case ARMISD::CNEG:          return "ARMISD::CNEG";
415
416  case ARMISD::FTOSI:         return "ARMISD::FTOSI";
417  case ARMISD::FTOUI:         return "ARMISD::FTOUI";
418  case ARMISD::SITOF:         return "ARMISD::SITOF";
419  case ARMISD::UITOF:         return "ARMISD::UITOF";
420
421  case ARMISD::SRL_FLAG:      return "ARMISD::SRL_FLAG";
422  case ARMISD::SRA_FLAG:      return "ARMISD::SRA_FLAG";
423  case ARMISD::RRX:           return "ARMISD::RRX";
424
425  case ARMISD::FMRRD:         return "ARMISD::FMRRD";
426  case ARMISD::FMDRR:         return "ARMISD::FMDRR";
427
428  case ARMISD::THREAD_POINTER:return "ARMISD::THREAD_POINTER";
429
430  case ARMISD::VCEQ:          return "ARMISD::VCEQ";
431  case ARMISD::VCGE:          return "ARMISD::VCGE";
432  case ARMISD::VCGEU:         return "ARMISD::VCGEU";
433  case ARMISD::VCGT:          return "ARMISD::VCGT";
434  case ARMISD::VCGTU:         return "ARMISD::VCGTU";
435  case ARMISD::VTST:          return "ARMISD::VTST";
436
437  case ARMISD::VSHL:          return "ARMISD::VSHL";
438  case ARMISD::VSHRs:         return "ARMISD::VSHRs";
439  case ARMISD::VSHRu:         return "ARMISD::VSHRu";
440  case ARMISD::VSHLLs:        return "ARMISD::VSHLLs";
441  case ARMISD::VSHLLu:        return "ARMISD::VSHLLu";
442  case ARMISD::VSHLLi:        return "ARMISD::VSHLLi";
443  case ARMISD::VSHRN:         return "ARMISD::VSHRN";
444  case ARMISD::VRSHRs:        return "ARMISD::VRSHRs";
445  case ARMISD::VRSHRu:        return "ARMISD::VRSHRu";
446  case ARMISD::VRSHRN:        return "ARMISD::VRSHRN";
447  case ARMISD::VQSHLs:        return "ARMISD::VQSHLs";
448  case ARMISD::VQSHLu:        return "ARMISD::VQSHLu";
449  case ARMISD::VQSHLsu:       return "ARMISD::VQSHLsu";
450  case ARMISD::VQSHRNs:       return "ARMISD::VQSHRNs";
451  case ARMISD::VQSHRNu:       return "ARMISD::VQSHRNu";
452  case ARMISD::VQSHRNsu:      return "ARMISD::VQSHRNsu";
453  case ARMISD::VQRSHRNs:      return "ARMISD::VQRSHRNs";
454  case ARMISD::VQRSHRNu:      return "ARMISD::VQRSHRNu";
455  case ARMISD::VQRSHRNsu:     return "ARMISD::VQRSHRNsu";
456  case ARMISD::VGETLANEu:     return "ARMISD::VGETLANEu";
457  case ARMISD::VGETLANEs:     return "ARMISD::VGETLANEs";
458  case ARMISD::VDUPLANEQ:     return "ARMISD::VDUPLANEQ";
459  }
460}
461
462/// getFunctionAlignment - Return the Log2 alignment of this function.
463unsigned ARMTargetLowering::getFunctionAlignment(const Function *F) const {
464  return getTargetMachine().getSubtarget<ARMSubtarget>().isThumb() ? 1 : 2;
465}
466
467//===----------------------------------------------------------------------===//
468// Lowering Code
469//===----------------------------------------------------------------------===//
470
471/// IntCCToARMCC - Convert a DAG integer condition code to an ARM CC
472static ARMCC::CondCodes IntCCToARMCC(ISD::CondCode CC) {
473  switch (CC) {
474  default: llvm_unreachable("Unknown condition code!");
475  case ISD::SETNE:  return ARMCC::NE;
476  case ISD::SETEQ:  return ARMCC::EQ;
477  case ISD::SETGT:  return ARMCC::GT;
478  case ISD::SETGE:  return ARMCC::GE;
479  case ISD::SETLT:  return ARMCC::LT;
480  case ISD::SETLE:  return ARMCC::LE;
481  case ISD::SETUGT: return ARMCC::HI;
482  case ISD::SETUGE: return ARMCC::HS;
483  case ISD::SETULT: return ARMCC::LO;
484  case ISD::SETULE: return ARMCC::LS;
485  }
486}
487
488/// FPCCToARMCC - Convert a DAG fp condition code to an ARM CC. It
489/// returns true if the operands should be inverted to form the proper
490/// comparison.
491static bool FPCCToARMCC(ISD::CondCode CC, ARMCC::CondCodes &CondCode,
492                        ARMCC::CondCodes &CondCode2) {
493  bool Invert = false;
494  CondCode2 = ARMCC::AL;
495  switch (CC) {
496  default: llvm_unreachable("Unknown FP condition!");
497  case ISD::SETEQ:
498  case ISD::SETOEQ: CondCode = ARMCC::EQ; break;
499  case ISD::SETGT:
500  case ISD::SETOGT: CondCode = ARMCC::GT; break;
501  case ISD::SETGE:
502  case ISD::SETOGE: CondCode = ARMCC::GE; break;
503  case ISD::SETOLT: CondCode = ARMCC::MI; break;
504  case ISD::SETOLE: CondCode = ARMCC::GT; Invert = true; break;
505  case ISD::SETONE: CondCode = ARMCC::MI; CondCode2 = ARMCC::GT; break;
506  case ISD::SETO:   CondCode = ARMCC::VC; break;
507  case ISD::SETUO:  CondCode = ARMCC::VS; break;
508  case ISD::SETUEQ: CondCode = ARMCC::EQ; CondCode2 = ARMCC::VS; break;
509  case ISD::SETUGT: CondCode = ARMCC::HI; break;
510  case ISD::SETUGE: CondCode = ARMCC::PL; break;
511  case ISD::SETLT:
512  case ISD::SETULT: CondCode = ARMCC::LT; break;
513  case ISD::SETLE:
514  case ISD::SETULE: CondCode = ARMCC::LE; break;
515  case ISD::SETNE:
516  case ISD::SETUNE: CondCode = ARMCC::NE; break;
517  }
518  return Invert;
519}
520
521//===----------------------------------------------------------------------===//
522//                      Calling Convention Implementation
523//
524//  The lower operations present on calling convention works on this order:
525//      LowerCALL (virt regs --> phys regs, virt regs --> stack)
526//      LowerFORMAL_ARGUMENTS (phys --> virt regs, stack --> virt regs)
527//      LowerRET (virt regs --> phys regs)
528//      LowerCALL (phys regs --> virt regs)
529//
530//===----------------------------------------------------------------------===//
531
532#include "ARMGenCallingConv.inc"
533
534// APCS f64 is in register pairs, possibly split to stack
535static bool f64AssignAPCS(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
536                          CCValAssign::LocInfo &LocInfo,
537                          CCState &State, bool CanFail) {
538  static const unsigned RegList[] = { ARM::R0, ARM::R1, ARM::R2, ARM::R3 };
539
540  // Try to get the first register.
541  if (unsigned Reg = State.AllocateReg(RegList, 4))
542    State.addLoc(CCValAssign::getCustomReg(ValNo, ValVT, Reg, LocVT, LocInfo));
543  else {
544    // For the 2nd half of a v2f64, do not fail.
545    if (CanFail)
546      return false;
547
548    // Put the whole thing on the stack.
549    State.addLoc(CCValAssign::getCustomMem(ValNo, ValVT,
550                                           State.AllocateStack(8, 4),
551                                           LocVT, LocInfo));
552    return true;
553  }
554
555  // Try to get the second register.
556  if (unsigned Reg = State.AllocateReg(RegList, 4))
557    State.addLoc(CCValAssign::getCustomReg(ValNo, ValVT, Reg, LocVT, LocInfo));
558  else
559    State.addLoc(CCValAssign::getCustomMem(ValNo, ValVT,
560                                           State.AllocateStack(4, 4),
561                                           LocVT, LocInfo));
562  return true;
563}
564
565static bool CC_ARM_APCS_Custom_f64(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
566                                   CCValAssign::LocInfo &LocInfo,
567                                   ISD::ArgFlagsTy &ArgFlags,
568                                   CCState &State) {
569  if (!f64AssignAPCS(ValNo, ValVT, LocVT, LocInfo, State, true))
570    return false;
571  if (LocVT == MVT::v2f64 &&
572      !f64AssignAPCS(ValNo, ValVT, LocVT, LocInfo, State, false))
573    return false;
574  return true;  // we handled it
575}
576
577// AAPCS f64 is in aligned register pairs
578static bool f64AssignAAPCS(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
579                           CCValAssign::LocInfo &LocInfo,
580                           CCState &State, bool CanFail) {
581  static const unsigned HiRegList[] = { ARM::R0, ARM::R2 };
582  static const unsigned LoRegList[] = { ARM::R1, ARM::R3 };
583
584  unsigned Reg = State.AllocateReg(HiRegList, LoRegList, 2);
585  if (Reg == 0) {
586    // For the 2nd half of a v2f64, do not just fail.
587    if (CanFail)
588      return false;
589
590    // Put the whole thing on the stack.
591    State.addLoc(CCValAssign::getCustomMem(ValNo, ValVT,
592                                           State.AllocateStack(8, 8),
593                                           LocVT, LocInfo));
594    return true;
595  }
596
597  unsigned i;
598  for (i = 0; i < 2; ++i)
599    if (HiRegList[i] == Reg)
600      break;
601
602  State.addLoc(CCValAssign::getCustomReg(ValNo, ValVT, Reg, LocVT, LocInfo));
603  State.addLoc(CCValAssign::getCustomReg(ValNo, ValVT, LoRegList[i],
604                                         LocVT, LocInfo));
605  return true;
606}
607
608static bool CC_ARM_AAPCS_Custom_f64(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
609                                    CCValAssign::LocInfo &LocInfo,
610                                    ISD::ArgFlagsTy &ArgFlags,
611                                    CCState &State) {
612  if (!f64AssignAAPCS(ValNo, ValVT, LocVT, LocInfo, State, true))
613    return false;
614  if (LocVT == MVT::v2f64 &&
615      !f64AssignAAPCS(ValNo, ValVT, LocVT, LocInfo, State, false))
616    return false;
617  return true;  // we handled it
618}
619
620static bool f64RetAssign(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
621                         CCValAssign::LocInfo &LocInfo, CCState &State) {
622  static const unsigned HiRegList[] = { ARM::R0, ARM::R2 };
623  static const unsigned LoRegList[] = { ARM::R1, ARM::R3 };
624
625  unsigned Reg = State.AllocateReg(HiRegList, LoRegList, 2);
626  if (Reg == 0)
627    return false; // we didn't handle it
628
629  unsigned i;
630  for (i = 0; i < 2; ++i)
631    if (HiRegList[i] == Reg)
632      break;
633
634  State.addLoc(CCValAssign::getCustomReg(ValNo, ValVT, Reg, LocVT, LocInfo));
635  State.addLoc(CCValAssign::getCustomReg(ValNo, ValVT, LoRegList[i],
636                                         LocVT, LocInfo));
637  return true;
638}
639
640static bool RetCC_ARM_APCS_Custom_f64(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
641                                      CCValAssign::LocInfo &LocInfo,
642                                      ISD::ArgFlagsTy &ArgFlags,
643                                      CCState &State) {
644  if (!f64RetAssign(ValNo, ValVT, LocVT, LocInfo, State))
645    return false;
646  if (LocVT == MVT::v2f64 && !f64RetAssign(ValNo, ValVT, LocVT, LocInfo, State))
647    return false;
648  return true;  // we handled it
649}
650
651static bool RetCC_ARM_AAPCS_Custom_f64(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
652                                       CCValAssign::LocInfo &LocInfo,
653                                       ISD::ArgFlagsTy &ArgFlags,
654                                       CCState &State) {
655  return RetCC_ARM_APCS_Custom_f64(ValNo, ValVT, LocVT, LocInfo, ArgFlags,
656                                   State);
657}
658
659/// CCAssignFnForNode - Selects the correct CCAssignFn for a the
660/// given CallingConvention value.
661CCAssignFn *ARMTargetLowering::CCAssignFnForNode(unsigned CC,
662                                                 bool Return) const {
663  switch (CC) {
664  default:
665   llvm_unreachable("Unsupported calling convention");
666  case CallingConv::C:
667  case CallingConv::Fast:
668   // Use target triple & subtarget features to do actual dispatch.
669   if (Subtarget->isAAPCS_ABI()) {
670     if (Subtarget->hasVFP2() &&
671         FloatABIType == FloatABI::Hard)
672       return (Return ? RetCC_ARM_AAPCS_VFP: CC_ARM_AAPCS_VFP);
673     else
674       return (Return ? RetCC_ARM_AAPCS: CC_ARM_AAPCS);
675   } else
676     return (Return ? RetCC_ARM_APCS: CC_ARM_APCS);
677  case CallingConv::ARM_AAPCS_VFP:
678   return (Return ? RetCC_ARM_AAPCS_VFP: CC_ARM_AAPCS_VFP);
679  case CallingConv::ARM_AAPCS:
680   return (Return ? RetCC_ARM_AAPCS: CC_ARM_AAPCS);
681  case CallingConv::ARM_APCS:
682   return (Return ? RetCC_ARM_APCS: CC_ARM_APCS);
683  }
684}
685
686/// LowerCallResult - Lower the result values of an ISD::CALL into the
687/// appropriate copies out of appropriate physical registers.  This assumes that
688/// Chain/InFlag are the input chain/flag to use, and that TheCall is the call
689/// being lowered.  The returns a SDNode with the same number of values as the
690/// ISD::CALL.
691SDNode *ARMTargetLowering::
692LowerCallResult(SDValue Chain, SDValue InFlag, CallSDNode *TheCall,
693                unsigned CallingConv, SelectionDAG &DAG) {
694
695  DebugLoc dl = TheCall->getDebugLoc();
696  // Assign locations to each value returned by this call.
697  SmallVector<CCValAssign, 16> RVLocs;
698  bool isVarArg = TheCall->isVarArg();
699  CCState CCInfo(CallingConv, isVarArg, getTargetMachine(),
700                 RVLocs, *DAG.getContext());
701  CCInfo.AnalyzeCallResult(TheCall,
702                           CCAssignFnForNode(CallingConv, /* Return*/ true));
703
704  SmallVector<SDValue, 8> ResultVals;
705
706  // Copy all of the result registers out of their specified physreg.
707  for (unsigned i = 0; i != RVLocs.size(); ++i) {
708    CCValAssign VA = RVLocs[i];
709
710    SDValue Val;
711    if (VA.needsCustom()) {
712      // Handle f64 or half of a v2f64.
713      SDValue Lo = DAG.getCopyFromReg(Chain, dl, VA.getLocReg(), MVT::i32,
714                                      InFlag);
715      Chain = Lo.getValue(1);
716      InFlag = Lo.getValue(2);
717      VA = RVLocs[++i]; // skip ahead to next loc
718      SDValue Hi = DAG.getCopyFromReg(Chain, dl, VA.getLocReg(), MVT::i32,
719                                      InFlag);
720      Chain = Hi.getValue(1);
721      InFlag = Hi.getValue(2);
722      Val = DAG.getNode(ARMISD::FMDRR, dl, MVT::f64, Lo, Hi);
723
724      if (VA.getLocVT() == MVT::v2f64) {
725        SDValue Vec = DAG.getNode(ISD::UNDEF, dl, MVT::v2f64);
726        Vec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v2f64, Vec, Val,
727                          DAG.getConstant(0, MVT::i32));
728
729        VA = RVLocs[++i]; // skip ahead to next loc
730        Lo = DAG.getCopyFromReg(Chain, dl, VA.getLocReg(), MVT::i32, InFlag);
731        Chain = Lo.getValue(1);
732        InFlag = Lo.getValue(2);
733        VA = RVLocs[++i]; // skip ahead to next loc
734        Hi = DAG.getCopyFromReg(Chain, dl, VA.getLocReg(), MVT::i32, InFlag);
735        Chain = Hi.getValue(1);
736        InFlag = Hi.getValue(2);
737        Val = DAG.getNode(ARMISD::FMDRR, dl, MVT::f64, Lo, Hi);
738        Val = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v2f64, Vec, Val,
739                          DAG.getConstant(1, MVT::i32));
740      }
741    } else {
742      Val = DAG.getCopyFromReg(Chain, dl, VA.getLocReg(), VA.getLocVT(),
743                               InFlag);
744      Chain = Val.getValue(1);
745      InFlag = Val.getValue(2);
746    }
747
748    switch (VA.getLocInfo()) {
749    default: llvm_unreachable("Unknown loc info!");
750    case CCValAssign::Full: break;
751    case CCValAssign::BCvt:
752      Val = DAG.getNode(ISD::BIT_CONVERT, dl, VA.getValVT(), Val);
753      break;
754    }
755
756    ResultVals.push_back(Val);
757  }
758
759  // Merge everything together with a MERGE_VALUES node.
760  ResultVals.push_back(Chain);
761  return DAG.getNode(ISD::MERGE_VALUES, dl, TheCall->getVTList(),
762                     &ResultVals[0], ResultVals.size()).getNode();
763}
764
765/// CreateCopyOfByValArgument - Make a copy of an aggregate at address specified
766/// by "Src" to address "Dst" of size "Size".  Alignment information is
767/// specified by the specific parameter attribute.  The copy will be passed as
768/// a byval function parameter.
769/// Sometimes what we are copying is the end of a larger object, the part that
770/// does not fit in registers.
771static SDValue
772CreateCopyOfByValArgument(SDValue Src, SDValue Dst, SDValue Chain,
773                          ISD::ArgFlagsTy Flags, SelectionDAG &DAG,
774                          DebugLoc dl) {
775  SDValue SizeNode = DAG.getConstant(Flags.getByValSize(), MVT::i32);
776  return DAG.getMemcpy(Chain, dl, Dst, Src, SizeNode, Flags.getByValAlign(),
777                       /*AlwaysInline=*/false, NULL, 0, NULL, 0);
778}
779
780/// LowerMemOpCallTo - Store the argument to the stack.
781SDValue
782ARMTargetLowering::LowerMemOpCallTo(CallSDNode *TheCall, SelectionDAG &DAG,
783                                    const SDValue &StackPtr,
784                                    const CCValAssign &VA, SDValue Chain,
785                                    SDValue Arg, ISD::ArgFlagsTy Flags) {
786  DebugLoc dl = TheCall->getDebugLoc();
787  unsigned LocMemOffset = VA.getLocMemOffset();
788  SDValue PtrOff = DAG.getIntPtrConstant(LocMemOffset);
789  PtrOff = DAG.getNode(ISD::ADD, dl, getPointerTy(), StackPtr, PtrOff);
790  if (Flags.isByVal()) {
791    return CreateCopyOfByValArgument(Arg, PtrOff, Chain, Flags, DAG, dl);
792  }
793  return DAG.getStore(Chain, dl, Arg, PtrOff,
794                      PseudoSourceValue::getStack(), LocMemOffset);
795}
796
797void ARMTargetLowering::PassF64ArgInRegs(CallSDNode *TheCall, SelectionDAG &DAG,
798                                         SDValue Chain, SDValue &Arg,
799                                         RegsToPassVector &RegsToPass,
800                                         CCValAssign &VA, CCValAssign &NextVA,
801                                         SDValue &StackPtr,
802                                         SmallVector<SDValue, 8> &MemOpChains,
803                                         ISD::ArgFlagsTy Flags) {
804  DebugLoc dl = TheCall->getDebugLoc();
805
806  SDValue fmrrd = DAG.getNode(ARMISD::FMRRD, dl,
807                              DAG.getVTList(MVT::i32, MVT::i32), Arg);
808  RegsToPass.push_back(std::make_pair(VA.getLocReg(), fmrrd));
809
810  if (NextVA.isRegLoc())
811    RegsToPass.push_back(std::make_pair(NextVA.getLocReg(), fmrrd.getValue(1)));
812  else {
813    assert(NextVA.isMemLoc());
814    if (StackPtr.getNode() == 0)
815      StackPtr = DAG.getCopyFromReg(Chain, dl, ARM::SP, getPointerTy());
816
817    MemOpChains.push_back(LowerMemOpCallTo(TheCall, DAG, StackPtr, NextVA,
818                                           Chain, fmrrd.getValue(1), Flags));
819  }
820}
821
822/// LowerCALL - Lowering a ISD::CALL node into a callseq_start <-
823/// ARMISD:CALL <- callseq_end chain. Also add input and output parameter
824/// nodes.
825SDValue ARMTargetLowering::LowerCALL(SDValue Op, SelectionDAG &DAG) {
826  CallSDNode *TheCall = cast<CallSDNode>(Op.getNode());
827  MVT RetVT           = TheCall->getRetValType(0);
828  SDValue Chain       = TheCall->getChain();
829  unsigned CC         = TheCall->getCallingConv();
830  bool isVarArg       = TheCall->isVarArg();
831  SDValue Callee      = TheCall->getCallee();
832  DebugLoc dl         = TheCall->getDebugLoc();
833
834  // Analyze operands of the call, assigning locations to each operand.
835  SmallVector<CCValAssign, 16> ArgLocs;
836  CCState CCInfo(CC, isVarArg, getTargetMachine(), ArgLocs, *DAG.getContext());
837  CCInfo.AnalyzeCallOperands(TheCall, CCAssignFnForNode(CC, /* Return*/ false));
838
839  // Get a count of how many bytes are to be pushed on the stack.
840  unsigned NumBytes = CCInfo.getNextStackOffset();
841
842  // Adjust the stack pointer for the new arguments...
843  // These operations are automatically eliminated by the prolog/epilog pass
844  Chain = DAG.getCALLSEQ_START(Chain, DAG.getIntPtrConstant(NumBytes, true));
845
846  SDValue StackPtr = DAG.getRegister(ARM::SP, MVT::i32);
847
848  RegsToPassVector RegsToPass;
849  SmallVector<SDValue, 8> MemOpChains;
850
851  // Walk the register/memloc assignments, inserting copies/loads.  In the case
852  // of tail call optimization, arguments are handled later.
853  for (unsigned i = 0, realArgIdx = 0, e = ArgLocs.size();
854       i != e;
855       ++i, ++realArgIdx) {
856    CCValAssign &VA = ArgLocs[i];
857    SDValue Arg = TheCall->getArg(realArgIdx);
858    ISD::ArgFlagsTy Flags = TheCall->getArgFlags(realArgIdx);
859
860    // Promote the value if needed.
861    switch (VA.getLocInfo()) {
862    default: llvm_unreachable("Unknown loc info!");
863    case CCValAssign::Full: break;
864    case CCValAssign::SExt:
865      Arg = DAG.getNode(ISD::SIGN_EXTEND, dl, VA.getLocVT(), Arg);
866      break;
867    case CCValAssign::ZExt:
868      Arg = DAG.getNode(ISD::ZERO_EXTEND, dl, VA.getLocVT(), Arg);
869      break;
870    case CCValAssign::AExt:
871      Arg = DAG.getNode(ISD::ANY_EXTEND, dl, VA.getLocVT(), Arg);
872      break;
873    case CCValAssign::BCvt:
874      Arg = DAG.getNode(ISD::BIT_CONVERT, dl, VA.getLocVT(), Arg);
875      break;
876    }
877
878    // f64 and v2f64 are passed in i32 pairs and must be split into pieces
879    if (VA.needsCustom()) {
880      if (VA.getLocVT() == MVT::v2f64) {
881        SDValue Op0 = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f64, Arg,
882                                  DAG.getConstant(0, MVT::i32));
883        SDValue Op1 = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f64, Arg,
884                                  DAG.getConstant(1, MVT::i32));
885
886        PassF64ArgInRegs(TheCall, DAG, Chain, Op0, RegsToPass,
887                         VA, ArgLocs[++i], StackPtr, MemOpChains, Flags);
888
889        VA = ArgLocs[++i]; // skip ahead to next loc
890        if (VA.isRegLoc()) {
891          PassF64ArgInRegs(TheCall, DAG, Chain, Op1, RegsToPass,
892                           VA, ArgLocs[++i], StackPtr, MemOpChains, Flags);
893        } else {
894          assert(VA.isMemLoc());
895          if (StackPtr.getNode() == 0)
896            StackPtr = DAG.getCopyFromReg(Chain, dl, ARM::SP, getPointerTy());
897
898          MemOpChains.push_back(LowerMemOpCallTo(TheCall, DAG, StackPtr, VA,
899                                                 Chain, Op1, Flags));
900        }
901      } else {
902        PassF64ArgInRegs(TheCall, DAG, Chain, Arg, RegsToPass, VA, ArgLocs[++i],
903                         StackPtr, MemOpChains, Flags);
904      }
905    } else if (VA.isRegLoc()) {
906      RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
907    } else {
908      assert(VA.isMemLoc());
909      if (StackPtr.getNode() == 0)
910        StackPtr = DAG.getCopyFromReg(Chain, dl, ARM::SP, getPointerTy());
911
912      MemOpChains.push_back(LowerMemOpCallTo(TheCall, DAG, StackPtr, VA,
913                                             Chain, Arg, Flags));
914    }
915  }
916
917  if (!MemOpChains.empty())
918    Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
919                        &MemOpChains[0], MemOpChains.size());
920
921  // Build a sequence of copy-to-reg nodes chained together with token chain
922  // and flag operands which copy the outgoing args into the appropriate regs.
923  SDValue InFlag;
924  for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
925    Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first,
926                             RegsToPass[i].second, InFlag);
927    InFlag = Chain.getValue(1);
928  }
929
930  // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
931  // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
932  // node so that legalize doesn't hack it.
933  bool isDirect = false;
934  bool isARMFunc = false;
935  bool isLocalARMFunc = false;
936  if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
937    GlobalValue *GV = G->getGlobal();
938    isDirect = true;
939    bool isExt = GV->isDeclaration() || GV->isWeakForLinker();
940    bool isStub = (isExt && Subtarget->isTargetDarwin()) &&
941                   getTargetMachine().getRelocationModel() != Reloc::Static;
942    isARMFunc = !Subtarget->isThumb() || isStub;
943    // ARM call to a local ARM function is predicable.
944    isLocalARMFunc = !Subtarget->isThumb() && !isExt;
945    // tBX takes a register source operand.
946    if (isARMFunc && Subtarget->isThumb1Only() && !Subtarget->hasV5TOps()) {
947      ARMConstantPoolValue *CPV = new ARMConstantPoolValue(GV, ARMPCLabelIndex,
948                                                           ARMCP::CPStub, 4);
949      SDValue CPAddr = DAG.getTargetConstantPool(CPV, getPointerTy(), 4);
950      CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
951      Callee = DAG.getLoad(getPointerTy(), dl,
952                           DAG.getEntryNode(), CPAddr, NULL, 0);
953      SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex++, MVT::i32);
954      Callee = DAG.getNode(ARMISD::PIC_ADD, dl,
955                           getPointerTy(), Callee, PICLabel);
956   } else
957      Callee = DAG.getTargetGlobalAddress(GV, getPointerTy());
958  } else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) {
959    isDirect = true;
960    bool isStub = Subtarget->isTargetDarwin() &&
961                  getTargetMachine().getRelocationModel() != Reloc::Static;
962    isARMFunc = !Subtarget->isThumb() || isStub;
963    // tBX takes a register source operand.
964    const char *Sym = S->getSymbol();
965    if (isARMFunc && Subtarget->isThumb1Only() && !Subtarget->hasV5TOps()) {
966      ARMConstantPoolValue *CPV = new ARMConstantPoolValue(Sym, ARMPCLabelIndex,
967                                                           ARMCP::CPStub, 4);
968      SDValue CPAddr = DAG.getTargetConstantPool(CPV, getPointerTy(), 4);
969      CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
970      Callee = DAG.getLoad(getPointerTy(), dl,
971                           DAG.getEntryNode(), CPAddr, NULL, 0);
972      SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex++, MVT::i32);
973      Callee = DAG.getNode(ARMISD::PIC_ADD, dl,
974                           getPointerTy(), Callee, PICLabel);
975    } else
976      Callee = DAG.getTargetExternalSymbol(Sym, getPointerTy());
977  }
978
979  // FIXME: handle tail calls differently.
980  unsigned CallOpc;
981  if (Subtarget->isThumb1Only()) {
982    if (!Subtarget->hasV5TOps() && (!isDirect || isARMFunc))
983      CallOpc = ARMISD::CALL_NOLINK;
984    else
985      CallOpc = isARMFunc ? ARMISD::CALL : ARMISD::tCALL;
986  } else {
987    CallOpc = (isDirect || Subtarget->hasV5TOps())
988      ? (isLocalARMFunc ? ARMISD::CALL_PRED : ARMISD::CALL)
989      : ARMISD::CALL_NOLINK;
990  }
991  if (CallOpc == ARMISD::CALL_NOLINK && !Subtarget->isThumb1Only()) {
992    // implicit def LR - LR mustn't be allocated as GRP:$dst of CALL_NOLINK
993    Chain = DAG.getCopyToReg(Chain, dl, ARM::LR, DAG.getUNDEF(MVT::i32),InFlag);
994    InFlag = Chain.getValue(1);
995  }
996
997  std::vector<SDValue> Ops;
998  Ops.push_back(Chain);
999  Ops.push_back(Callee);
1000
1001  // Add argument registers to the end of the list so that they are known live
1002  // into the call.
1003  for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i)
1004    Ops.push_back(DAG.getRegister(RegsToPass[i].first,
1005                                  RegsToPass[i].second.getValueType()));
1006
1007  if (InFlag.getNode())
1008    Ops.push_back(InFlag);
1009  // Returns a chain and a flag for retval copy to use.
1010  Chain = DAG.getNode(CallOpc, dl, DAG.getVTList(MVT::Other, MVT::Flag),
1011                      &Ops[0], Ops.size());
1012  InFlag = Chain.getValue(1);
1013
1014  Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(NumBytes, true),
1015                             DAG.getIntPtrConstant(0, true), InFlag);
1016  if (RetVT != MVT::Other)
1017    InFlag = Chain.getValue(1);
1018
1019  // Handle result values, copying them out of physregs into vregs that we
1020  // return.
1021  return SDValue(LowerCallResult(Chain, InFlag, TheCall, CC, DAG),
1022                                 Op.getResNo());
1023}
1024
1025SDValue ARMTargetLowering::LowerRET(SDValue Op, SelectionDAG &DAG) {
1026  // The chain is always operand #0
1027  SDValue Chain = Op.getOperand(0);
1028  DebugLoc dl = Op.getDebugLoc();
1029
1030  // CCValAssign - represent the assignment of the return value to a location.
1031  SmallVector<CCValAssign, 16> RVLocs;
1032  unsigned CC   = DAG.getMachineFunction().getFunction()->getCallingConv();
1033  bool isVarArg = DAG.getMachineFunction().getFunction()->isVarArg();
1034
1035  // CCState - Info about the registers and stack slots.
1036  CCState CCInfo(CC, isVarArg, getTargetMachine(), RVLocs, *DAG.getContext());
1037
1038  // Analyze return values of ISD::RET.
1039  CCInfo.AnalyzeReturn(Op.getNode(), CCAssignFnForNode(CC, /* Return */ true));
1040
1041  // If this is the first return lowered for this function, add
1042  // the regs to the liveout set for the function.
1043  if (DAG.getMachineFunction().getRegInfo().liveout_empty()) {
1044    for (unsigned i = 0; i != RVLocs.size(); ++i)
1045      if (RVLocs[i].isRegLoc())
1046        DAG.getMachineFunction().getRegInfo().addLiveOut(RVLocs[i].getLocReg());
1047  }
1048
1049  SDValue Flag;
1050
1051  // Copy the result values into the output registers.
1052  for (unsigned i = 0, realRVLocIdx = 0;
1053       i != RVLocs.size();
1054       ++i, ++realRVLocIdx) {
1055    CCValAssign &VA = RVLocs[i];
1056    assert(VA.isRegLoc() && "Can only return in registers!");
1057
1058    // ISD::RET => ret chain, (regnum1,val1), ...
1059    // So i*2+1 index only the regnums
1060    SDValue Arg = Op.getOperand(realRVLocIdx*2+1);
1061
1062    switch (VA.getLocInfo()) {
1063    default: llvm_unreachable("Unknown loc info!");
1064    case CCValAssign::Full: break;
1065    case CCValAssign::BCvt:
1066      Arg = DAG.getNode(ISD::BIT_CONVERT, dl, VA.getLocVT(), Arg);
1067      break;
1068    }
1069
1070    if (VA.needsCustom()) {
1071      if (VA.getLocVT() == MVT::v2f64) {
1072        // Extract the first half and return it in two registers.
1073        SDValue Half = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f64, Arg,
1074                                   DAG.getConstant(0, MVT::i32));
1075        SDValue HalfGPRs = DAG.getNode(ARMISD::FMRRD, dl,
1076                                       DAG.getVTList(MVT::i32, MVT::i32), Half);
1077
1078        Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(), HalfGPRs, Flag);
1079        Flag = Chain.getValue(1);
1080        VA = RVLocs[++i]; // skip ahead to next loc
1081        Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(),
1082                                 HalfGPRs.getValue(1), Flag);
1083        Flag = Chain.getValue(1);
1084        VA = RVLocs[++i]; // skip ahead to next loc
1085
1086        // Extract the 2nd half and fall through to handle it as an f64 value.
1087        Arg = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f64, Arg,
1088                          DAG.getConstant(1, MVT::i32));
1089      }
1090      // Legalize ret f64 -> ret 2 x i32.  We always have fmrrd if f64 is
1091      // available.
1092      SDValue fmrrd = DAG.getNode(ARMISD::FMRRD, dl,
1093                                  DAG.getVTList(MVT::i32, MVT::i32), &Arg, 1);
1094      Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(), fmrrd, Flag);
1095      Flag = Chain.getValue(1);
1096      VA = RVLocs[++i]; // skip ahead to next loc
1097      Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(), fmrrd.getValue(1),
1098                               Flag);
1099    } else
1100      Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(), Arg, Flag);
1101
1102    // Guarantee that all emitted copies are
1103    // stuck together, avoiding something bad.
1104    Flag = Chain.getValue(1);
1105  }
1106
1107  SDValue result;
1108  if (Flag.getNode())
1109    result = DAG.getNode(ARMISD::RET_FLAG, dl, MVT::Other, Chain, Flag);
1110  else // Return Void
1111    result = DAG.getNode(ARMISD::RET_FLAG, dl, MVT::Other, Chain);
1112
1113  return result;
1114}
1115
1116// ConstantPool, JumpTable, GlobalAddress, and ExternalSymbol are lowered as
1117// their target counterpart wrapped in the ARMISD::Wrapper node. Suppose N is
1118// one of the above mentioned nodes. It has to be wrapped because otherwise
1119// Select(N) returns N. So the raw TargetGlobalAddress nodes, etc. can only
1120// be used to form addressing mode. These wrapped nodes will be selected
1121// into MOVi.
1122static SDValue LowerConstantPool(SDValue Op, SelectionDAG &DAG) {
1123  MVT PtrVT = Op.getValueType();
1124  // FIXME there is no actual debug info here
1125  DebugLoc dl = Op.getDebugLoc();
1126  ConstantPoolSDNode *CP = cast<ConstantPoolSDNode>(Op);
1127  SDValue Res;
1128  if (CP->isMachineConstantPoolEntry())
1129    Res = DAG.getTargetConstantPool(CP->getMachineCPVal(), PtrVT,
1130                                    CP->getAlignment());
1131  else
1132    Res = DAG.getTargetConstantPool(CP->getConstVal(), PtrVT,
1133                                    CP->getAlignment());
1134  return DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, Res);
1135}
1136
1137// Lower ISD::GlobalTLSAddress using the "general dynamic" model
1138SDValue
1139ARMTargetLowering::LowerToTLSGeneralDynamicModel(GlobalAddressSDNode *GA,
1140                                                 SelectionDAG &DAG) {
1141  DebugLoc dl = GA->getDebugLoc();
1142  MVT PtrVT = getPointerTy();
1143  unsigned char PCAdj = Subtarget->isThumb() ? 4 : 8;
1144  ARMConstantPoolValue *CPV =
1145    new ARMConstantPoolValue(GA->getGlobal(), ARMPCLabelIndex, ARMCP::CPValue,
1146                             PCAdj, "tlsgd", true);
1147  SDValue Argument = DAG.getTargetConstantPool(CPV, PtrVT, 4);
1148  Argument = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, Argument);
1149  Argument = DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), Argument, NULL, 0);
1150  SDValue Chain = Argument.getValue(1);
1151
1152  SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex++, MVT::i32);
1153  Argument = DAG.getNode(ARMISD::PIC_ADD, dl, PtrVT, Argument, PICLabel);
1154
1155  // call __tls_get_addr.
1156  ArgListTy Args;
1157  ArgListEntry Entry;
1158  Entry.Node = Argument;
1159  Entry.Ty = (const Type *) Type::Int32Ty;
1160  Args.push_back(Entry);
1161  // FIXME: is there useful debug info available here?
1162  std::pair<SDValue, SDValue> CallResult =
1163    LowerCallTo(Chain, (const Type *) Type::Int32Ty, false, false, false, false,
1164                0, CallingConv::C, false,
1165                DAG.getExternalSymbol("__tls_get_addr", PtrVT), Args, DAG, dl);
1166  return CallResult.first;
1167}
1168
1169// Lower ISD::GlobalTLSAddress using the "initial exec" or
1170// "local exec" model.
1171SDValue
1172ARMTargetLowering::LowerToTLSExecModels(GlobalAddressSDNode *GA,
1173                                        SelectionDAG &DAG) {
1174  GlobalValue *GV = GA->getGlobal();
1175  DebugLoc dl = GA->getDebugLoc();
1176  SDValue Offset;
1177  SDValue Chain = DAG.getEntryNode();
1178  MVT PtrVT = getPointerTy();
1179  // Get the Thread Pointer
1180  SDValue ThreadPointer = DAG.getNode(ARMISD::THREAD_POINTER, dl, PtrVT);
1181
1182  if (GV->isDeclaration()) {
1183    // initial exec model
1184    unsigned char PCAdj = Subtarget->isThumb() ? 4 : 8;
1185    ARMConstantPoolValue *CPV =
1186      new ARMConstantPoolValue(GA->getGlobal(), ARMPCLabelIndex, ARMCP::CPValue,
1187                               PCAdj, "gottpoff", true);
1188    Offset = DAG.getTargetConstantPool(CPV, PtrVT, 4);
1189    Offset = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, Offset);
1190    Offset = DAG.getLoad(PtrVT, dl, Chain, Offset, NULL, 0);
1191    Chain = Offset.getValue(1);
1192
1193    SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex++, MVT::i32);
1194    Offset = DAG.getNode(ARMISD::PIC_ADD, dl, PtrVT, Offset, PICLabel);
1195
1196    Offset = DAG.getLoad(PtrVT, dl, Chain, Offset, NULL, 0);
1197  } else {
1198    // local exec model
1199    ARMConstantPoolValue *CPV =
1200      new ARMConstantPoolValue(GV, ARMCP::CPValue, "tpoff");
1201    Offset = DAG.getTargetConstantPool(CPV, PtrVT, 4);
1202    Offset = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, Offset);
1203    Offset = DAG.getLoad(PtrVT, dl, Chain, Offset, NULL, 0);
1204  }
1205
1206  // The address of the thread local variable is the add of the thread
1207  // pointer with the offset of the variable.
1208  return DAG.getNode(ISD::ADD, dl, PtrVT, ThreadPointer, Offset);
1209}
1210
1211SDValue
1212ARMTargetLowering::LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) {
1213  // TODO: implement the "local dynamic" model
1214  assert(Subtarget->isTargetELF() &&
1215         "TLS not implemented for non-ELF targets");
1216  GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
1217  // If the relocation model is PIC, use the "General Dynamic" TLS Model,
1218  // otherwise use the "Local Exec" TLS Model
1219  if (getTargetMachine().getRelocationModel() == Reloc::PIC_)
1220    return LowerToTLSGeneralDynamicModel(GA, DAG);
1221  else
1222    return LowerToTLSExecModels(GA, DAG);
1223}
1224
1225SDValue ARMTargetLowering::LowerGlobalAddressELF(SDValue Op,
1226                                                 SelectionDAG &DAG) {
1227  MVT PtrVT = getPointerTy();
1228  DebugLoc dl = Op.getDebugLoc();
1229  GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
1230  Reloc::Model RelocM = getTargetMachine().getRelocationModel();
1231  if (RelocM == Reloc::PIC_) {
1232    bool UseGOTOFF = GV->hasLocalLinkage() || GV->hasHiddenVisibility();
1233    ARMConstantPoolValue *CPV =
1234      new ARMConstantPoolValue(GV, ARMCP::CPValue, UseGOTOFF ? "GOTOFF":"GOT");
1235    SDValue CPAddr = DAG.getTargetConstantPool(CPV, PtrVT, 4);
1236    CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
1237    SDValue Result = DAG.getLoad(PtrVT, dl, DAG.getEntryNode(),
1238                                 CPAddr, NULL, 0);
1239    SDValue Chain = Result.getValue(1);
1240    SDValue GOT = DAG.getGLOBAL_OFFSET_TABLE(PtrVT);
1241    Result = DAG.getNode(ISD::ADD, dl, PtrVT, Result, GOT);
1242    if (!UseGOTOFF)
1243      Result = DAG.getLoad(PtrVT, dl, Chain, Result, NULL, 0);
1244    return Result;
1245  } else {
1246    SDValue CPAddr = DAG.getTargetConstantPool(GV, PtrVT, 4);
1247    CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
1248    return DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), CPAddr, NULL, 0);
1249  }
1250}
1251
1252/// GVIsIndirectSymbol - true if the GV will be accessed via an indirect symbol
1253/// even in non-static mode.
1254static bool GVIsIndirectSymbol(GlobalValue *GV, Reloc::Model RelocM) {
1255  // If symbol visibility is hidden, the extra load is not needed if
1256  // the symbol is definitely defined in the current translation unit.
1257  bool isDecl = GV->isDeclaration() || GV->hasAvailableExternallyLinkage();
1258  if (GV->hasHiddenVisibility() && (!isDecl && !GV->hasCommonLinkage()))
1259    return false;
1260  return RelocM != Reloc::Static && (isDecl || GV->isWeakForLinker());
1261}
1262
1263SDValue ARMTargetLowering::LowerGlobalAddressDarwin(SDValue Op,
1264                                                    SelectionDAG &DAG) {
1265  MVT PtrVT = getPointerTy();
1266  DebugLoc dl = Op.getDebugLoc();
1267  GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
1268  Reloc::Model RelocM = getTargetMachine().getRelocationModel();
1269  bool IsIndirect = GVIsIndirectSymbol(GV, RelocM);
1270  SDValue CPAddr;
1271  if (RelocM == Reloc::Static)
1272    CPAddr = DAG.getTargetConstantPool(GV, PtrVT, 4);
1273  else {
1274    unsigned PCAdj = (RelocM != Reloc::PIC_)
1275      ? 0 : (Subtarget->isThumb() ? 4 : 8);
1276    ARMCP::ARMCPKind Kind = IsIndirect ? ARMCP::CPNonLazyPtr
1277      : ARMCP::CPValue;
1278    ARMConstantPoolValue *CPV = new ARMConstantPoolValue(GV, ARMPCLabelIndex,
1279                                                         Kind, PCAdj);
1280    CPAddr = DAG.getTargetConstantPool(CPV, PtrVT, 4);
1281  }
1282  CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
1283
1284  SDValue Result = DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), CPAddr, NULL, 0);
1285  SDValue Chain = Result.getValue(1);
1286
1287  if (RelocM == Reloc::PIC_) {
1288    SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex++, MVT::i32);
1289    Result = DAG.getNode(ARMISD::PIC_ADD, dl, PtrVT, Result, PICLabel);
1290  }
1291  if (IsIndirect)
1292    Result = DAG.getLoad(PtrVT, dl, Chain, Result, NULL, 0);
1293
1294  return Result;
1295}
1296
1297SDValue ARMTargetLowering::LowerGLOBAL_OFFSET_TABLE(SDValue Op,
1298                                                    SelectionDAG &DAG){
1299  assert(Subtarget->isTargetELF() &&
1300         "GLOBAL OFFSET TABLE not implemented for non-ELF targets");
1301  MVT PtrVT = getPointerTy();
1302  DebugLoc dl = Op.getDebugLoc();
1303  unsigned PCAdj = Subtarget->isThumb() ? 4 : 8;
1304  ARMConstantPoolValue *CPV = new ARMConstantPoolValue("_GLOBAL_OFFSET_TABLE_",
1305                                                       ARMPCLabelIndex,
1306                                                       ARMCP::CPValue, PCAdj);
1307  SDValue CPAddr = DAG.getTargetConstantPool(CPV, PtrVT, 4);
1308  CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
1309  SDValue Result = DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), CPAddr, NULL, 0);
1310  SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex++, MVT::i32);
1311  return DAG.getNode(ARMISD::PIC_ADD, dl, PtrVT, Result, PICLabel);
1312}
1313
1314SDValue
1315ARMTargetLowering::LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG) {
1316  MVT PtrVT = DAG.getTargetLoweringInfo().getPointerTy();
1317  unsigned IntNo = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
1318  DebugLoc dl = Op.getDebugLoc();
1319  switch (IntNo) {
1320  default: return SDValue();    // Don't custom lower most intrinsics.
1321  case Intrinsic::arm_thread_pointer:
1322      return DAG.getNode(ARMISD::THREAD_POINTER, dl, PtrVT);
1323  case Intrinsic::eh_sjlj_setjmp:
1324      SDValue Res = DAG.getNode(ARMISD::EH_SJLJ_SETJMP, dl, MVT::i32,
1325                         Op.getOperand(1));
1326      return Res;
1327  }
1328}
1329
1330static SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG,
1331                            unsigned VarArgsFrameIndex) {
1332  // vastart just stores the address of the VarArgsFrameIndex slot into the
1333  // memory location argument.
1334  DebugLoc dl = Op.getDebugLoc();
1335  MVT PtrVT = DAG.getTargetLoweringInfo().getPointerTy();
1336  SDValue FR = DAG.getFrameIndex(VarArgsFrameIndex, PtrVT);
1337  const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
1338  return DAG.getStore(Op.getOperand(0), dl, FR, Op.getOperand(1), SV, 0);
1339}
1340
1341SDValue
1342ARMTargetLowering::GetF64FormalArgument(CCValAssign &VA, CCValAssign &NextVA,
1343                                        SDValue &Root, SelectionDAG &DAG,
1344                                        DebugLoc dl) {
1345  MachineFunction &MF = DAG.getMachineFunction();
1346  ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1347
1348  TargetRegisterClass *RC;
1349  if (AFI->isThumb1OnlyFunction())
1350    RC = ARM::tGPRRegisterClass;
1351  else
1352    RC = ARM::GPRRegisterClass;
1353
1354  // Transform the arguments stored in physical registers into virtual ones.
1355  unsigned Reg = MF.addLiveIn(VA.getLocReg(), RC);
1356  SDValue ArgValue = DAG.getCopyFromReg(Root, dl, Reg, MVT::i32);
1357
1358  SDValue ArgValue2;
1359  if (NextVA.isMemLoc()) {
1360    unsigned ArgSize = NextVA.getLocVT().getSizeInBits()/8;
1361    MachineFrameInfo *MFI = MF.getFrameInfo();
1362    int FI = MFI->CreateFixedObject(ArgSize, NextVA.getLocMemOffset());
1363
1364    // Create load node to retrieve arguments from the stack.
1365    SDValue FIN = DAG.getFrameIndex(FI, getPointerTy());
1366    ArgValue2 = DAG.getLoad(MVT::i32, dl, Root, FIN, NULL, 0);
1367  } else {
1368    Reg = MF.addLiveIn(NextVA.getLocReg(), RC);
1369    ArgValue2 = DAG.getCopyFromReg(Root, dl, Reg, MVT::i32);
1370  }
1371
1372  return DAG.getNode(ARMISD::FMDRR, dl, MVT::f64, ArgValue, ArgValue2);
1373}
1374
1375SDValue
1376ARMTargetLowering::LowerFORMAL_ARGUMENTS(SDValue Op, SelectionDAG &DAG) {
1377  MachineFunction &MF = DAG.getMachineFunction();
1378  MachineFrameInfo *MFI = MF.getFrameInfo();
1379
1380  SDValue Root = Op.getOperand(0);
1381  DebugLoc dl = Op.getDebugLoc();
1382  bool isVarArg = cast<ConstantSDNode>(Op.getOperand(2))->getZExtValue() != 0;
1383  unsigned CC = MF.getFunction()->getCallingConv();
1384  ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1385
1386  // Assign locations to all of the incoming arguments.
1387  SmallVector<CCValAssign, 16> ArgLocs;
1388  CCState CCInfo(CC, isVarArg, getTargetMachine(), ArgLocs, *DAG.getContext());
1389  CCInfo.AnalyzeFormalArguments(Op.getNode(),
1390                                CCAssignFnForNode(CC, /* Return*/ false));
1391
1392  SmallVector<SDValue, 16> ArgValues;
1393
1394  for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
1395    CCValAssign &VA = ArgLocs[i];
1396
1397    // Arguments stored in registers.
1398    if (VA.isRegLoc()) {
1399      MVT RegVT = VA.getLocVT();
1400
1401      SDValue ArgValue;
1402      if (VA.needsCustom()) {
1403        // f64 and vector types are split up into multiple registers or
1404        // combinations of registers and stack slots.
1405        RegVT = MVT::i32;
1406
1407        if (VA.getLocVT() == MVT::v2f64) {
1408          SDValue ArgValue1 = GetF64FormalArgument(VA, ArgLocs[++i],
1409                                                   Root, DAG, dl);
1410          VA = ArgLocs[++i]; // skip ahead to next loc
1411          SDValue ArgValue2 = GetF64FormalArgument(VA, ArgLocs[++i],
1412                                                   Root, DAG, dl);
1413          ArgValue = DAG.getNode(ISD::UNDEF, dl, MVT::v2f64);
1414          ArgValue = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v2f64,
1415                                 ArgValue, ArgValue1, DAG.getIntPtrConstant(0));
1416          ArgValue = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v2f64,
1417                                 ArgValue, ArgValue2, DAG.getIntPtrConstant(1));
1418        } else
1419          ArgValue = GetF64FormalArgument(VA, ArgLocs[++i], Root, DAG, dl);
1420
1421      } else {
1422        TargetRegisterClass *RC;
1423        if (FloatABIType == FloatABI::Hard && RegVT == MVT::f32)
1424          RC = ARM::SPRRegisterClass;
1425        else if (FloatABIType == FloatABI::Hard && RegVT == MVT::f64)
1426          RC = ARM::DPRRegisterClass;
1427        else if (AFI->isThumb1OnlyFunction())
1428          RC = ARM::tGPRRegisterClass;
1429        else
1430          RC = ARM::GPRRegisterClass;
1431
1432        assert((RegVT == MVT::i32 || RegVT == MVT::f32 ||
1433                (FloatABIType == FloatABI::Hard && RegVT == MVT::f64)) &&
1434               "RegVT not supported by FORMAL_ARGUMENTS Lowering");
1435
1436        // Transform the arguments in physical registers into virtual ones.
1437        unsigned Reg = MF.addLiveIn(VA.getLocReg(), RC);
1438        ArgValue = DAG.getCopyFromReg(Root, dl, Reg, RegVT);
1439      }
1440
1441      // If this is an 8 or 16-bit value, it is really passed promoted
1442      // to 32 bits.  Insert an assert[sz]ext to capture this, then
1443      // truncate to the right size.
1444      switch (VA.getLocInfo()) {
1445      default: llvm_unreachable("Unknown loc info!");
1446      case CCValAssign::Full: break;
1447      case CCValAssign::BCvt:
1448        ArgValue = DAG.getNode(ISD::BIT_CONVERT, dl, VA.getValVT(), ArgValue);
1449        break;
1450      case CCValAssign::SExt:
1451        ArgValue = DAG.getNode(ISD::AssertSext, dl, RegVT, ArgValue,
1452                               DAG.getValueType(VA.getValVT()));
1453        ArgValue = DAG.getNode(ISD::TRUNCATE, dl, VA.getValVT(), ArgValue);
1454        break;
1455      case CCValAssign::ZExt:
1456        ArgValue = DAG.getNode(ISD::AssertZext, dl, RegVT, ArgValue,
1457                               DAG.getValueType(VA.getValVT()));
1458        ArgValue = DAG.getNode(ISD::TRUNCATE, dl, VA.getValVT(), ArgValue);
1459        break;
1460      }
1461
1462      ArgValues.push_back(ArgValue);
1463
1464    } else { // VA.isRegLoc()
1465
1466      // sanity check
1467      assert(VA.isMemLoc());
1468      assert(VA.getValVT() != MVT::i64 && "i64 should already be lowered");
1469
1470      unsigned ArgSize = VA.getLocVT().getSizeInBits()/8;
1471      int FI = MFI->CreateFixedObject(ArgSize, VA.getLocMemOffset());
1472
1473      // Create load nodes to retrieve arguments from the stack.
1474      SDValue FIN = DAG.getFrameIndex(FI, getPointerTy());
1475      ArgValues.push_back(DAG.getLoad(VA.getValVT(), dl, Root, FIN, NULL, 0));
1476    }
1477  }
1478
1479  // varargs
1480  if (isVarArg) {
1481    static const unsigned GPRArgRegs[] = {
1482      ARM::R0, ARM::R1, ARM::R2, ARM::R3
1483    };
1484
1485    unsigned NumGPRs = CCInfo.getFirstUnallocated
1486      (GPRArgRegs, sizeof(GPRArgRegs) / sizeof(GPRArgRegs[0]));
1487
1488    unsigned Align = MF.getTarget().getFrameInfo()->getStackAlignment();
1489    unsigned VARegSize = (4 - NumGPRs) * 4;
1490    unsigned VARegSaveSize = (VARegSize + Align - 1) & ~(Align - 1);
1491    unsigned ArgOffset = 0;
1492    if (VARegSaveSize) {
1493      // If this function is vararg, store any remaining integer argument regs
1494      // to their spots on the stack so that they may be loaded by deferencing
1495      // the result of va_next.
1496      AFI->setVarArgsRegSaveSize(VARegSaveSize);
1497      ArgOffset = CCInfo.getNextStackOffset();
1498      VarArgsFrameIndex = MFI->CreateFixedObject(VARegSaveSize, ArgOffset +
1499                                                 VARegSaveSize - VARegSize);
1500      SDValue FIN = DAG.getFrameIndex(VarArgsFrameIndex, getPointerTy());
1501
1502      SmallVector<SDValue, 4> MemOps;
1503      for (; NumGPRs < 4; ++NumGPRs) {
1504        TargetRegisterClass *RC;
1505        if (AFI->isThumb1OnlyFunction())
1506          RC = ARM::tGPRRegisterClass;
1507        else
1508          RC = ARM::GPRRegisterClass;
1509
1510        unsigned VReg = MF.addLiveIn(GPRArgRegs[NumGPRs], RC);
1511        SDValue Val = DAG.getCopyFromReg(Root, dl, VReg, MVT::i32);
1512        SDValue Store = DAG.getStore(Val.getValue(1), dl, Val, FIN, NULL, 0);
1513        MemOps.push_back(Store);
1514        FIN = DAG.getNode(ISD::ADD, dl, getPointerTy(), FIN,
1515                          DAG.getConstant(4, getPointerTy()));
1516      }
1517      if (!MemOps.empty())
1518        Root = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
1519                           &MemOps[0], MemOps.size());
1520    } else
1521      // This will point to the next argument passed via stack.
1522      VarArgsFrameIndex = MFI->CreateFixedObject(4, ArgOffset);
1523  }
1524
1525  ArgValues.push_back(Root);
1526
1527  // Return the new list of results.
1528  return DAG.getNode(ISD::MERGE_VALUES, dl, Op.getNode()->getVTList(),
1529                     &ArgValues[0], ArgValues.size()).getValue(Op.getResNo());
1530}
1531
1532/// isFloatingPointZero - Return true if this is +0.0.
1533static bool isFloatingPointZero(SDValue Op) {
1534  if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(Op))
1535    return CFP->getValueAPF().isPosZero();
1536  else if (ISD::isEXTLoad(Op.getNode()) || ISD::isNON_EXTLoad(Op.getNode())) {
1537    // Maybe this has already been legalized into the constant pool?
1538    if (Op.getOperand(1).getOpcode() == ARMISD::Wrapper) {
1539      SDValue WrapperOp = Op.getOperand(1).getOperand(0);
1540      if (ConstantPoolSDNode *CP = dyn_cast<ConstantPoolSDNode>(WrapperOp))
1541        if (ConstantFP *CFP = dyn_cast<ConstantFP>(CP->getConstVal()))
1542          return CFP->getValueAPF().isPosZero();
1543    }
1544  }
1545  return false;
1546}
1547
1548static bool isLegalCmpImmediate(unsigned C, bool isThumb1Only) {
1549  return ( isThumb1Only && (C & ~255U) == 0) ||
1550         (!isThumb1Only && ARM_AM::getSOImmVal(C) != -1);
1551}
1552
1553/// Returns appropriate ARM CMP (cmp) and corresponding condition code for
1554/// the given operands.
1555static SDValue getARMCmp(SDValue LHS, SDValue RHS, ISD::CondCode CC,
1556                         SDValue &ARMCC, SelectionDAG &DAG, bool isThumb1Only,
1557                         DebugLoc dl) {
1558  if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(RHS.getNode())) {
1559    unsigned C = RHSC->getZExtValue();
1560    if (!isLegalCmpImmediate(C, isThumb1Only)) {
1561      // Constant does not fit, try adjusting it by one?
1562      switch (CC) {
1563      default: break;
1564      case ISD::SETLT:
1565      case ISD::SETGE:
1566        if (isLegalCmpImmediate(C-1, isThumb1Only)) {
1567          CC = (CC == ISD::SETLT) ? ISD::SETLE : ISD::SETGT;
1568          RHS = DAG.getConstant(C-1, MVT::i32);
1569        }
1570        break;
1571      case ISD::SETULT:
1572      case ISD::SETUGE:
1573        if (C > 0 && isLegalCmpImmediate(C-1, isThumb1Only)) {
1574          CC = (CC == ISD::SETULT) ? ISD::SETULE : ISD::SETUGT;
1575          RHS = DAG.getConstant(C-1, MVT::i32);
1576        }
1577        break;
1578      case ISD::SETLE:
1579      case ISD::SETGT:
1580        if (isLegalCmpImmediate(C+1, isThumb1Only)) {
1581          CC = (CC == ISD::SETLE) ? ISD::SETLT : ISD::SETGE;
1582          RHS = DAG.getConstant(C+1, MVT::i32);
1583        }
1584        break;
1585      case ISD::SETULE:
1586      case ISD::SETUGT:
1587        if (C < 0xffffffff && isLegalCmpImmediate(C+1, isThumb1Only)) {
1588          CC = (CC == ISD::SETULE) ? ISD::SETULT : ISD::SETUGE;
1589          RHS = DAG.getConstant(C+1, MVT::i32);
1590        }
1591        break;
1592      }
1593    }
1594  }
1595
1596  ARMCC::CondCodes CondCode = IntCCToARMCC(CC);
1597  ARMISD::NodeType CompareType;
1598  switch (CondCode) {
1599  default:
1600    CompareType = ARMISD::CMP;
1601    break;
1602  case ARMCC::EQ:
1603  case ARMCC::NE:
1604    // Uses only Z Flag
1605    CompareType = ARMISD::CMPZ;
1606    break;
1607  }
1608  ARMCC = DAG.getConstant(CondCode, MVT::i32);
1609  return DAG.getNode(CompareType, dl, MVT::Flag, LHS, RHS);
1610}
1611
1612/// Returns a appropriate VFP CMP (fcmp{s|d}+fmstat) for the given operands.
1613static SDValue getVFPCmp(SDValue LHS, SDValue RHS, SelectionDAG &DAG,
1614                         DebugLoc dl) {
1615  SDValue Cmp;
1616  if (!isFloatingPointZero(RHS))
1617    Cmp = DAG.getNode(ARMISD::CMPFP, dl, MVT::Flag, LHS, RHS);
1618  else
1619    Cmp = DAG.getNode(ARMISD::CMPFPw0, dl, MVT::Flag, LHS);
1620  return DAG.getNode(ARMISD::FMSTAT, dl, MVT::Flag, Cmp);
1621}
1622
1623static SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG,
1624                              const ARMSubtarget *ST) {
1625  MVT VT = Op.getValueType();
1626  SDValue LHS = Op.getOperand(0);
1627  SDValue RHS = Op.getOperand(1);
1628  ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(4))->get();
1629  SDValue TrueVal = Op.getOperand(2);
1630  SDValue FalseVal = Op.getOperand(3);
1631  DebugLoc dl = Op.getDebugLoc();
1632
1633  if (LHS.getValueType() == MVT::i32) {
1634    SDValue ARMCC;
1635    SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
1636    SDValue Cmp = getARMCmp(LHS, RHS, CC, ARMCC, DAG, ST->isThumb1Only(), dl);
1637    return DAG.getNode(ARMISD::CMOV, dl, VT, FalseVal, TrueVal, ARMCC, CCR,Cmp);
1638  }
1639
1640  ARMCC::CondCodes CondCode, CondCode2;
1641  if (FPCCToARMCC(CC, CondCode, CondCode2))
1642    std::swap(TrueVal, FalseVal);
1643
1644  SDValue ARMCC = DAG.getConstant(CondCode, MVT::i32);
1645  SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
1646  SDValue Cmp = getVFPCmp(LHS, RHS, DAG, dl);
1647  SDValue Result = DAG.getNode(ARMISD::CMOV, dl, VT, FalseVal, TrueVal,
1648                                 ARMCC, CCR, Cmp);
1649  if (CondCode2 != ARMCC::AL) {
1650    SDValue ARMCC2 = DAG.getConstant(CondCode2, MVT::i32);
1651    // FIXME: Needs another CMP because flag can have but one use.
1652    SDValue Cmp2 = getVFPCmp(LHS, RHS, DAG, dl);
1653    Result = DAG.getNode(ARMISD::CMOV, dl, VT,
1654                         Result, TrueVal, ARMCC2, CCR, Cmp2);
1655  }
1656  return Result;
1657}
1658
1659static SDValue LowerBR_CC(SDValue Op, SelectionDAG &DAG,
1660                          const ARMSubtarget *ST) {
1661  SDValue  Chain = Op.getOperand(0);
1662  ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(1))->get();
1663  SDValue    LHS = Op.getOperand(2);
1664  SDValue    RHS = Op.getOperand(3);
1665  SDValue   Dest = Op.getOperand(4);
1666  DebugLoc dl = Op.getDebugLoc();
1667
1668  if (LHS.getValueType() == MVT::i32) {
1669    SDValue ARMCC;
1670    SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
1671    SDValue Cmp = getARMCmp(LHS, RHS, CC, ARMCC, DAG, ST->isThumb1Only(), dl);
1672    return DAG.getNode(ARMISD::BRCOND, dl, MVT::Other,
1673                       Chain, Dest, ARMCC, CCR,Cmp);
1674  }
1675
1676  assert(LHS.getValueType() == MVT::f32 || LHS.getValueType() == MVT::f64);
1677  ARMCC::CondCodes CondCode, CondCode2;
1678  if (FPCCToARMCC(CC, CondCode, CondCode2))
1679    // Swap the LHS/RHS of the comparison if needed.
1680    std::swap(LHS, RHS);
1681
1682  SDValue Cmp = getVFPCmp(LHS, RHS, DAG, dl);
1683  SDValue ARMCC = DAG.getConstant(CondCode, MVT::i32);
1684  SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
1685  SDVTList VTList = DAG.getVTList(MVT::Other, MVT::Flag);
1686  SDValue Ops[] = { Chain, Dest, ARMCC, CCR, Cmp };
1687  SDValue Res = DAG.getNode(ARMISD::BRCOND, dl, VTList, Ops, 5);
1688  if (CondCode2 != ARMCC::AL) {
1689    ARMCC = DAG.getConstant(CondCode2, MVT::i32);
1690    SDValue Ops[] = { Res, Dest, ARMCC, CCR, Res.getValue(1) };
1691    Res = DAG.getNode(ARMISD::BRCOND, dl, VTList, Ops, 5);
1692  }
1693  return Res;
1694}
1695
1696SDValue ARMTargetLowering::LowerBR_JT(SDValue Op, SelectionDAG &DAG) {
1697  SDValue Chain = Op.getOperand(0);
1698  SDValue Table = Op.getOperand(1);
1699  SDValue Index = Op.getOperand(2);
1700  DebugLoc dl = Op.getDebugLoc();
1701
1702  MVT PTy = getPointerTy();
1703  JumpTableSDNode *JT = cast<JumpTableSDNode>(Table);
1704  ARMFunctionInfo *AFI = DAG.getMachineFunction().getInfo<ARMFunctionInfo>();
1705  SDValue UId = DAG.getConstant(AFI->createJumpTableUId(), PTy);
1706  SDValue JTI = DAG.getTargetJumpTable(JT->getIndex(), PTy);
1707  Table = DAG.getNode(ARMISD::WrapperJT, dl, MVT::i32, JTI, UId);
1708  if (Subtarget->isThumb2()) {
1709    // Thumb2 uses a two-level jump. That is, it jumps into the jump table
1710    // which does another jump to the destination. This also makes it easier
1711    // to translate it to TBB / TBH later.
1712    // FIXME: This might not work if the function is extremely large.
1713    return DAG.getNode(ARMISD::BR2_JT, dl, MVT::Other, Chain, Table, Index,
1714                       JTI, UId);
1715  }
1716
1717  Index = DAG.getNode(ISD::MUL, dl, PTy, Index, DAG.getConstant(4, PTy));
1718  SDValue Addr = DAG.getNode(ISD::ADD, dl, PTy, Index, Table);
1719  if (getTargetMachine().getRelocationModel() == Reloc::PIC_) {
1720    Addr = DAG.getLoad((MVT)MVT::i32, dl, Chain, Addr, NULL, 0);
1721    Chain = Addr.getValue(1);
1722    Addr = DAG.getNode(ISD::ADD, dl, PTy, Addr, Table);
1723    return DAG.getNode(ARMISD::BR_JT, dl, MVT::Other, Chain, Addr, JTI, UId);
1724  } else {
1725    Addr = DAG.getLoad(PTy, dl, Chain, Addr, NULL, 0);
1726    Chain = Addr.getValue(1);
1727    return DAG.getNode(ARMISD::BR_JT, dl, MVT::Other, Chain, Addr, JTI, UId);
1728  }
1729}
1730
1731static SDValue LowerFP_TO_INT(SDValue Op, SelectionDAG &DAG) {
1732  DebugLoc dl = Op.getDebugLoc();
1733  unsigned Opc =
1734    Op.getOpcode() == ISD::FP_TO_SINT ? ARMISD::FTOSI : ARMISD::FTOUI;
1735  Op = DAG.getNode(Opc, dl, MVT::f32, Op.getOperand(0));
1736  return DAG.getNode(ISD::BIT_CONVERT, dl, MVT::i32, Op);
1737}
1738
1739static SDValue LowerINT_TO_FP(SDValue Op, SelectionDAG &DAG) {
1740  MVT VT = Op.getValueType();
1741  DebugLoc dl = Op.getDebugLoc();
1742  unsigned Opc =
1743    Op.getOpcode() == ISD::SINT_TO_FP ? ARMISD::SITOF : ARMISD::UITOF;
1744
1745  Op = DAG.getNode(ISD::BIT_CONVERT, dl, MVT::f32, Op.getOperand(0));
1746  return DAG.getNode(Opc, dl, VT, Op);
1747}
1748
1749static SDValue LowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) {
1750  // Implement fcopysign with a fabs and a conditional fneg.
1751  SDValue Tmp0 = Op.getOperand(0);
1752  SDValue Tmp1 = Op.getOperand(1);
1753  DebugLoc dl = Op.getDebugLoc();
1754  MVT VT = Op.getValueType();
1755  MVT SrcVT = Tmp1.getValueType();
1756  SDValue AbsVal = DAG.getNode(ISD::FABS, dl, VT, Tmp0);
1757  SDValue Cmp = getVFPCmp(Tmp1, DAG.getConstantFP(0.0, SrcVT), DAG, dl);
1758  SDValue ARMCC = DAG.getConstant(ARMCC::LT, MVT::i32);
1759  SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
1760  return DAG.getNode(ARMISD::CNEG, dl, VT, AbsVal, AbsVal, ARMCC, CCR, Cmp);
1761}
1762
1763SDValue ARMTargetLowering::LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) {
1764  MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
1765  MFI->setFrameAddressIsTaken(true);
1766  MVT VT = Op.getValueType();
1767  DebugLoc dl = Op.getDebugLoc();  // FIXME probably not meaningful
1768  unsigned Depth = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
1769  unsigned FrameReg = (Subtarget->isThumb() || Subtarget->isTargetDarwin())
1770    ? ARM::R7 : ARM::R11;
1771  SDValue FrameAddr = DAG.getCopyFromReg(DAG.getEntryNode(), dl, FrameReg, VT);
1772  while (Depth--)
1773    FrameAddr = DAG.getLoad(VT, dl, DAG.getEntryNode(), FrameAddr, NULL, 0);
1774  return FrameAddr;
1775}
1776
1777SDValue
1778ARMTargetLowering::EmitTargetCodeForMemcpy(SelectionDAG &DAG, DebugLoc dl,
1779                                           SDValue Chain,
1780                                           SDValue Dst, SDValue Src,
1781                                           SDValue Size, unsigned Align,
1782                                           bool AlwaysInline,
1783                                         const Value *DstSV, uint64_t DstSVOff,
1784                                         const Value *SrcSV, uint64_t SrcSVOff){
1785  // Do repeated 4-byte loads and stores. To be improved.
1786  // This requires 4-byte alignment.
1787  if ((Align & 3) != 0)
1788    return SDValue();
1789  // This requires the copy size to be a constant, preferrably
1790  // within a subtarget-specific limit.
1791  ConstantSDNode *ConstantSize = dyn_cast<ConstantSDNode>(Size);
1792  if (!ConstantSize)
1793    return SDValue();
1794  uint64_t SizeVal = ConstantSize->getZExtValue();
1795  if (!AlwaysInline && SizeVal > getSubtarget()->getMaxInlineSizeThreshold())
1796    return SDValue();
1797
1798  unsigned BytesLeft = SizeVal & 3;
1799  unsigned NumMemOps = SizeVal >> 2;
1800  unsigned EmittedNumMemOps = 0;
1801  MVT VT = MVT::i32;
1802  unsigned VTSize = 4;
1803  unsigned i = 0;
1804  const unsigned MAX_LOADS_IN_LDM = 6;
1805  SDValue TFOps[MAX_LOADS_IN_LDM];
1806  SDValue Loads[MAX_LOADS_IN_LDM];
1807  uint64_t SrcOff = 0, DstOff = 0;
1808
1809  // Emit up to MAX_LOADS_IN_LDM loads, then a TokenFactor barrier, then the
1810  // same number of stores.  The loads and stores will get combined into
1811  // ldm/stm later on.
1812  while (EmittedNumMemOps < NumMemOps) {
1813    for (i = 0;
1814         i < MAX_LOADS_IN_LDM && EmittedNumMemOps + i < NumMemOps; ++i) {
1815      Loads[i] = DAG.getLoad(VT, dl, Chain,
1816                             DAG.getNode(ISD::ADD, dl, MVT::i32, Src,
1817                                         DAG.getConstant(SrcOff, MVT::i32)),
1818                             SrcSV, SrcSVOff + SrcOff);
1819      TFOps[i] = Loads[i].getValue(1);
1820      SrcOff += VTSize;
1821    }
1822    Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, &TFOps[0], i);
1823
1824    for (i = 0;
1825         i < MAX_LOADS_IN_LDM && EmittedNumMemOps + i < NumMemOps; ++i) {
1826      TFOps[i] = DAG.getStore(Chain, dl, Loads[i],
1827                           DAG.getNode(ISD::ADD, dl, MVT::i32, Dst,
1828                                       DAG.getConstant(DstOff, MVT::i32)),
1829                           DstSV, DstSVOff + DstOff);
1830      DstOff += VTSize;
1831    }
1832    Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, &TFOps[0], i);
1833
1834    EmittedNumMemOps += i;
1835  }
1836
1837  if (BytesLeft == 0)
1838    return Chain;
1839
1840  // Issue loads / stores for the trailing (1 - 3) bytes.
1841  unsigned BytesLeftSave = BytesLeft;
1842  i = 0;
1843  while (BytesLeft) {
1844    if (BytesLeft >= 2) {
1845      VT = MVT::i16;
1846      VTSize = 2;
1847    } else {
1848      VT = MVT::i8;
1849      VTSize = 1;
1850    }
1851
1852    Loads[i] = DAG.getLoad(VT, dl, Chain,
1853                           DAG.getNode(ISD::ADD, dl, MVT::i32, Src,
1854                                       DAG.getConstant(SrcOff, MVT::i32)),
1855                           SrcSV, SrcSVOff + SrcOff);
1856    TFOps[i] = Loads[i].getValue(1);
1857    ++i;
1858    SrcOff += VTSize;
1859    BytesLeft -= VTSize;
1860  }
1861  Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, &TFOps[0], i);
1862
1863  i = 0;
1864  BytesLeft = BytesLeftSave;
1865  while (BytesLeft) {
1866    if (BytesLeft >= 2) {
1867      VT = MVT::i16;
1868      VTSize = 2;
1869    } else {
1870      VT = MVT::i8;
1871      VTSize = 1;
1872    }
1873
1874    TFOps[i] = DAG.getStore(Chain, dl, Loads[i],
1875                            DAG.getNode(ISD::ADD, dl, MVT::i32, Dst,
1876                                        DAG.getConstant(DstOff, MVT::i32)),
1877                            DstSV, DstSVOff + DstOff);
1878    ++i;
1879    DstOff += VTSize;
1880    BytesLeft -= VTSize;
1881  }
1882  return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, &TFOps[0], i);
1883}
1884
1885static SDValue ExpandBIT_CONVERT(SDNode *N, SelectionDAG &DAG) {
1886  SDValue Op = N->getOperand(0);
1887  DebugLoc dl = N->getDebugLoc();
1888  if (N->getValueType(0) == MVT::f64) {
1889    // Turn i64->f64 into FMDRR.
1890    SDValue Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32, Op,
1891                             DAG.getConstant(0, MVT::i32));
1892    SDValue Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32, Op,
1893                             DAG.getConstant(1, MVT::i32));
1894    return DAG.getNode(ARMISD::FMDRR, dl, MVT::f64, Lo, Hi);
1895  }
1896
1897  // Turn f64->i64 into FMRRD.
1898  SDValue Cvt = DAG.getNode(ARMISD::FMRRD, dl,
1899                            DAG.getVTList(MVT::i32, MVT::i32), &Op, 1);
1900
1901  // Merge the pieces into a single i64 value.
1902  return DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, Cvt, Cvt.getValue(1));
1903}
1904
1905/// getZeroVector - Returns a vector of specified type with all zero elements.
1906///
1907static SDValue getZeroVector(MVT VT, SelectionDAG &DAG, DebugLoc dl) {
1908  assert(VT.isVector() && "Expected a vector type");
1909
1910  // Zero vectors are used to represent vector negation and in those cases
1911  // will be implemented with the NEON VNEG instruction.  However, VNEG does
1912  // not support i64 elements, so sometimes the zero vectors will need to be
1913  // explicitly constructed.  For those cases, and potentially other uses in
1914  // the future, always build zero vectors as <4 x i32> or <2 x i32> bitcasted
1915  // to their dest type.  This ensures they get CSE'd.
1916  SDValue Vec;
1917  SDValue Cst = DAG.getTargetConstant(0, MVT::i32);
1918  if (VT.getSizeInBits() == 64)
1919    Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, MVT::v2i32, Cst, Cst);
1920  else
1921    Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, MVT::v4i32, Cst, Cst, Cst, Cst);
1922
1923  return DAG.getNode(ISD::BIT_CONVERT, dl, VT, Vec);
1924}
1925
1926/// getOnesVector - Returns a vector of specified type with all bits set.
1927///
1928static SDValue getOnesVector(MVT VT, SelectionDAG &DAG, DebugLoc dl) {
1929  assert(VT.isVector() && "Expected a vector type");
1930
1931  // Always build ones vectors as <4 x i32> or <2 x i32> bitcasted to their dest
1932  // type.  This ensures they get CSE'd.
1933  SDValue Vec;
1934  SDValue Cst = DAG.getTargetConstant(~0U, MVT::i32);
1935  if (VT.getSizeInBits() == 64)
1936    Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, MVT::v2i32, Cst, Cst);
1937  else
1938    Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, MVT::v4i32, Cst, Cst, Cst, Cst);
1939
1940  return DAG.getNode(ISD::BIT_CONVERT, dl, VT, Vec);
1941}
1942
1943static SDValue LowerShift(SDNode *N, SelectionDAG &DAG,
1944                          const ARMSubtarget *ST) {
1945  MVT VT = N->getValueType(0);
1946  DebugLoc dl = N->getDebugLoc();
1947
1948  // Lower vector shifts on NEON to use VSHL.
1949  if (VT.isVector()) {
1950    assert(ST->hasNEON() && "unexpected vector shift");
1951
1952    // Left shifts translate directly to the vshiftu intrinsic.
1953    if (N->getOpcode() == ISD::SHL)
1954      return DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, VT,
1955                         DAG.getConstant(Intrinsic::arm_neon_vshiftu, MVT::i32),
1956                         N->getOperand(0), N->getOperand(1));
1957
1958    assert((N->getOpcode() == ISD::SRA ||
1959            N->getOpcode() == ISD::SRL) && "unexpected vector shift opcode");
1960
1961    // NEON uses the same intrinsics for both left and right shifts.  For
1962    // right shifts, the shift amounts are negative, so negate the vector of
1963    // shift amounts.
1964    MVT ShiftVT = N->getOperand(1).getValueType();
1965    SDValue NegatedCount = DAG.getNode(ISD::SUB, dl, ShiftVT,
1966                                       getZeroVector(ShiftVT, DAG, dl),
1967                                       N->getOperand(1));
1968    Intrinsic::ID vshiftInt = (N->getOpcode() == ISD::SRA ?
1969                               Intrinsic::arm_neon_vshifts :
1970                               Intrinsic::arm_neon_vshiftu);
1971    return DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, VT,
1972                       DAG.getConstant(vshiftInt, MVT::i32),
1973                       N->getOperand(0), NegatedCount);
1974  }
1975
1976  assert(VT == MVT::i64 &&
1977         (N->getOpcode() == ISD::SRL || N->getOpcode() == ISD::SRA) &&
1978         "Unknown shift to lower!");
1979
1980  // We only lower SRA, SRL of 1 here, all others use generic lowering.
1981  if (!isa<ConstantSDNode>(N->getOperand(1)) ||
1982      cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() != 1)
1983    return SDValue();
1984
1985  // If we are in thumb mode, we don't have RRX.
1986  if (ST->isThumb1Only()) return SDValue();
1987
1988  // Okay, we have a 64-bit SRA or SRL of 1.  Lower this to an RRX expr.
1989  SDValue Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32, N->getOperand(0),
1990                             DAG.getConstant(0, MVT::i32));
1991  SDValue Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32, N->getOperand(0),
1992                             DAG.getConstant(1, MVT::i32));
1993
1994  // First, build a SRA_FLAG/SRL_FLAG op, which shifts the top part by one and
1995  // captures the result into a carry flag.
1996  unsigned Opc = N->getOpcode() == ISD::SRL ? ARMISD::SRL_FLAG:ARMISD::SRA_FLAG;
1997  Hi = DAG.getNode(Opc, dl, DAG.getVTList(MVT::i32, MVT::Flag), &Hi, 1);
1998
1999  // The low part is an ARMISD::RRX operand, which shifts the carry in.
2000  Lo = DAG.getNode(ARMISD::RRX, dl, MVT::i32, Lo, Hi.getValue(1));
2001
2002  // Merge the pieces into a single i64 value.
2003 return DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, Lo, Hi);
2004}
2005
2006static SDValue LowerVSETCC(SDValue Op, SelectionDAG &DAG) {
2007  SDValue TmpOp0, TmpOp1;
2008  bool Invert = false;
2009  bool Swap = false;
2010  unsigned Opc = 0;
2011
2012  SDValue Op0 = Op.getOperand(0);
2013  SDValue Op1 = Op.getOperand(1);
2014  SDValue CC = Op.getOperand(2);
2015  MVT VT = Op.getValueType();
2016  ISD::CondCode SetCCOpcode = cast<CondCodeSDNode>(CC)->get();
2017  DebugLoc dl = Op.getDebugLoc();
2018
2019  if (Op.getOperand(1).getValueType().isFloatingPoint()) {
2020    switch (SetCCOpcode) {
2021    default: llvm_unreachable("Illegal FP comparison"); break;
2022    case ISD::SETUNE:
2023    case ISD::SETNE:  Invert = true; // Fallthrough
2024    case ISD::SETOEQ:
2025    case ISD::SETEQ:  Opc = ARMISD::VCEQ; break;
2026    case ISD::SETOLT:
2027    case ISD::SETLT: Swap = true; // Fallthrough
2028    case ISD::SETOGT:
2029    case ISD::SETGT:  Opc = ARMISD::VCGT; break;
2030    case ISD::SETOLE:
2031    case ISD::SETLE:  Swap = true; // Fallthrough
2032    case ISD::SETOGE:
2033    case ISD::SETGE: Opc = ARMISD::VCGE; break;
2034    case ISD::SETUGE: Swap = true; // Fallthrough
2035    case ISD::SETULE: Invert = true; Opc = ARMISD::VCGT; break;
2036    case ISD::SETUGT: Swap = true; // Fallthrough
2037    case ISD::SETULT: Invert = true; Opc = ARMISD::VCGE; break;
2038    case ISD::SETUEQ: Invert = true; // Fallthrough
2039    case ISD::SETONE:
2040      // Expand this to (OLT | OGT).
2041      TmpOp0 = Op0;
2042      TmpOp1 = Op1;
2043      Opc = ISD::OR;
2044      Op0 = DAG.getNode(ARMISD::VCGT, dl, VT, TmpOp1, TmpOp0);
2045      Op1 = DAG.getNode(ARMISD::VCGT, dl, VT, TmpOp0, TmpOp1);
2046      break;
2047    case ISD::SETUO: Invert = true; // Fallthrough
2048    case ISD::SETO:
2049      // Expand this to (OLT | OGE).
2050      TmpOp0 = Op0;
2051      TmpOp1 = Op1;
2052      Opc = ISD::OR;
2053      Op0 = DAG.getNode(ARMISD::VCGT, dl, VT, TmpOp1, TmpOp0);
2054      Op1 = DAG.getNode(ARMISD::VCGE, dl, VT, TmpOp0, TmpOp1);
2055      break;
2056    }
2057  } else {
2058    // Integer comparisons.
2059    switch (SetCCOpcode) {
2060    default: llvm_unreachable("Illegal integer comparison"); break;
2061    case ISD::SETNE:  Invert = true;
2062    case ISD::SETEQ:  Opc = ARMISD::VCEQ; break;
2063    case ISD::SETLT:  Swap = true;
2064    case ISD::SETGT:  Opc = ARMISD::VCGT; break;
2065    case ISD::SETLE:  Swap = true;
2066    case ISD::SETGE:  Opc = ARMISD::VCGE; break;
2067    case ISD::SETULT: Swap = true;
2068    case ISD::SETUGT: Opc = ARMISD::VCGTU; break;
2069    case ISD::SETULE: Swap = true;
2070    case ISD::SETUGE: Opc = ARMISD::VCGEU; break;
2071    }
2072
2073    // Detect VTST (Vector Test Bits) = icmp ne (and (op0, op1), zero).
2074    if (Opc == ARMISD::VCEQ) {
2075
2076      SDValue AndOp;
2077      if (ISD::isBuildVectorAllZeros(Op1.getNode()))
2078        AndOp = Op0;
2079      else if (ISD::isBuildVectorAllZeros(Op0.getNode()))
2080        AndOp = Op1;
2081
2082      // Ignore bitconvert.
2083      if (AndOp.getNode() && AndOp.getOpcode() == ISD::BIT_CONVERT)
2084        AndOp = AndOp.getOperand(0);
2085
2086      if (AndOp.getNode() && AndOp.getOpcode() == ISD::AND) {
2087        Opc = ARMISD::VTST;
2088        Op0 = DAG.getNode(ISD::BIT_CONVERT, dl, VT, AndOp.getOperand(0));
2089        Op1 = DAG.getNode(ISD::BIT_CONVERT, dl, VT, AndOp.getOperand(1));
2090        Invert = !Invert;
2091      }
2092    }
2093  }
2094
2095  if (Swap)
2096    std::swap(Op0, Op1);
2097
2098  SDValue Result = DAG.getNode(Opc, dl, VT, Op0, Op1);
2099
2100  if (Invert)
2101    Result = DAG.getNOT(dl, Result, VT);
2102
2103  return Result;
2104}
2105
2106/// isVMOVSplat - Check if the specified splat value corresponds to an immediate
2107/// VMOV instruction, and if so, return the constant being splatted.
2108static SDValue isVMOVSplat(uint64_t SplatBits, uint64_t SplatUndef,
2109                           unsigned SplatBitSize, SelectionDAG &DAG) {
2110  switch (SplatBitSize) {
2111  case 8:
2112    // Any 1-byte value is OK.
2113    assert((SplatBits & ~0xff) == 0 && "one byte splat value is too big");
2114    return DAG.getTargetConstant(SplatBits, MVT::i8);
2115
2116  case 16:
2117    // NEON's 16-bit VMOV supports splat values where only one byte is nonzero.
2118    if ((SplatBits & ~0xff) == 0 ||
2119        (SplatBits & ~0xff00) == 0)
2120      return DAG.getTargetConstant(SplatBits, MVT::i16);
2121    break;
2122
2123  case 32:
2124    // NEON's 32-bit VMOV supports splat values where:
2125    // * only one byte is nonzero, or
2126    // * the least significant byte is 0xff and the second byte is nonzero, or
2127    // * the least significant 2 bytes are 0xff and the third is nonzero.
2128    if ((SplatBits & ~0xff) == 0 ||
2129        (SplatBits & ~0xff00) == 0 ||
2130        (SplatBits & ~0xff0000) == 0 ||
2131        (SplatBits & ~0xff000000) == 0)
2132      return DAG.getTargetConstant(SplatBits, MVT::i32);
2133
2134    if ((SplatBits & ~0xffff) == 0 &&
2135        ((SplatBits | SplatUndef) & 0xff) == 0xff)
2136      return DAG.getTargetConstant(SplatBits | 0xff, MVT::i32);
2137
2138    if ((SplatBits & ~0xffffff) == 0 &&
2139        ((SplatBits | SplatUndef) & 0xffff) == 0xffff)
2140      return DAG.getTargetConstant(SplatBits | 0xffff, MVT::i32);
2141
2142    // Note: there are a few 32-bit splat values (specifically: 00ffff00,
2143    // ff000000, ff0000ff, and ffff00ff) that are valid for VMOV.I64 but not
2144    // VMOV.I32.  A (very) minor optimization would be to replicate the value
2145    // and fall through here to test for a valid 64-bit splat.  But, then the
2146    // caller would also need to check and handle the change in size.
2147    break;
2148
2149  case 64: {
2150    // NEON has a 64-bit VMOV splat where each byte is either 0 or 0xff.
2151    uint64_t BitMask = 0xff;
2152    uint64_t Val = 0;
2153    for (int ByteNum = 0; ByteNum < 8; ++ByteNum) {
2154      if (((SplatBits | SplatUndef) & BitMask) == BitMask)
2155        Val |= BitMask;
2156      else if ((SplatBits & BitMask) != 0)
2157        return SDValue();
2158      BitMask <<= 8;
2159    }
2160    return DAG.getTargetConstant(Val, MVT::i64);
2161  }
2162
2163  default:
2164    llvm_unreachable("unexpected size for isVMOVSplat");
2165    break;
2166  }
2167
2168  return SDValue();
2169}
2170
2171/// getVMOVImm - If this is a build_vector of constants which can be
2172/// formed by using a VMOV instruction of the specified element size,
2173/// return the constant being splatted.  The ByteSize field indicates the
2174/// number of bytes of each element [1248].
2175SDValue ARM::getVMOVImm(SDNode *N, unsigned ByteSize, SelectionDAG &DAG) {
2176  BuildVectorSDNode *BVN = dyn_cast<BuildVectorSDNode>(N);
2177  APInt SplatBits, SplatUndef;
2178  unsigned SplatBitSize;
2179  bool HasAnyUndefs;
2180  if (! BVN || ! BVN->isConstantSplat(SplatBits, SplatUndef, SplatBitSize,
2181                                      HasAnyUndefs, ByteSize * 8))
2182    return SDValue();
2183
2184  if (SplatBitSize > ByteSize * 8)
2185    return SDValue();
2186
2187  return isVMOVSplat(SplatBits.getZExtValue(), SplatUndef.getZExtValue(),
2188                     SplatBitSize, DAG);
2189}
2190
2191/// isVREVMask - Check if a vector shuffle corresponds to a VREV
2192/// instruction with the specified blocksize.  (The order of the elements
2193/// within each block of the vector is reversed.)
2194bool ARM::isVREVMask(ShuffleVectorSDNode *N, unsigned BlockSize) {
2195  assert((BlockSize==16 || BlockSize==32 || BlockSize==64) &&
2196         "Only possible block sizes for VREV are: 16, 32, 64");
2197
2198  MVT VT = N->getValueType(0);
2199  unsigned NumElts = VT.getVectorNumElements();
2200  unsigned EltSz = VT.getVectorElementType().getSizeInBits();
2201  unsigned BlockElts = N->getMaskElt(0) + 1;
2202
2203  if (BlockSize <= EltSz || BlockSize != BlockElts * EltSz)
2204    return false;
2205
2206  for (unsigned i = 0; i < NumElts; ++i) {
2207    if ((unsigned) N->getMaskElt(i) !=
2208        (i - i%BlockElts) + (BlockElts - 1 - i%BlockElts))
2209      return false;
2210  }
2211
2212  return true;
2213}
2214
2215static SDValue BuildSplat(SDValue Val, MVT VT, SelectionDAG &DAG, DebugLoc dl) {
2216  // Canonicalize all-zeros and all-ones vectors.
2217  ConstantSDNode *ConstVal = dyn_cast<ConstantSDNode>(Val.getNode());
2218  if (ConstVal->isNullValue())
2219    return getZeroVector(VT, DAG, dl);
2220  if (ConstVal->isAllOnesValue())
2221    return getOnesVector(VT, DAG, dl);
2222
2223  MVT CanonicalVT;
2224  if (VT.is64BitVector()) {
2225    switch (Val.getValueType().getSizeInBits()) {
2226    case 8:  CanonicalVT = MVT::v8i8; break;
2227    case 16: CanonicalVT = MVT::v4i16; break;
2228    case 32: CanonicalVT = MVT::v2i32; break;
2229    case 64: CanonicalVT = MVT::v1i64; break;
2230    default: llvm_unreachable("unexpected splat element type"); break;
2231    }
2232  } else {
2233    assert(VT.is128BitVector() && "unknown splat vector size");
2234    switch (Val.getValueType().getSizeInBits()) {
2235    case 8:  CanonicalVT = MVT::v16i8; break;
2236    case 16: CanonicalVT = MVT::v8i16; break;
2237    case 32: CanonicalVT = MVT::v4i32; break;
2238    case 64: CanonicalVT = MVT::v2i64; break;
2239    default: llvm_unreachable("unexpected splat element type"); break;
2240    }
2241  }
2242
2243  // Build a canonical splat for this value.
2244  SmallVector<SDValue, 8> Ops;
2245  Ops.assign(CanonicalVT.getVectorNumElements(), Val);
2246  SDValue Res = DAG.getNode(ISD::BUILD_VECTOR, dl, CanonicalVT, &Ops[0],
2247                            Ops.size());
2248  return DAG.getNode(ISD::BIT_CONVERT, dl, VT, Res);
2249}
2250
2251// If this is a case we can't handle, return null and let the default
2252// expansion code take care of it.
2253static SDValue LowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG) {
2254  BuildVectorSDNode *BVN = dyn_cast<BuildVectorSDNode>(Op.getNode());
2255  assert(BVN != 0 && "Expected a BuildVectorSDNode in LowerBUILD_VECTOR");
2256  DebugLoc dl = Op.getDebugLoc();
2257
2258  APInt SplatBits, SplatUndef;
2259  unsigned SplatBitSize;
2260  bool HasAnyUndefs;
2261  if (BVN->isConstantSplat(SplatBits, SplatUndef, SplatBitSize, HasAnyUndefs)) {
2262    SDValue Val = isVMOVSplat(SplatBits.getZExtValue(),
2263                              SplatUndef.getZExtValue(), SplatBitSize, DAG);
2264    if (Val.getNode())
2265      return BuildSplat(Val, Op.getValueType(), DAG, dl);
2266  }
2267
2268  return SDValue();
2269}
2270
2271static SDValue LowerVECTOR_SHUFFLE(SDValue Op, SelectionDAG &DAG) {
2272  return Op;
2273}
2274
2275static SDValue LowerSCALAR_TO_VECTOR(SDValue Op, SelectionDAG &DAG) {
2276  return Op;
2277}
2278
2279static SDValue LowerEXTRACT_VECTOR_ELT(SDValue Op, SelectionDAG &DAG) {
2280  MVT VT = Op.getValueType();
2281  DebugLoc dl = Op.getDebugLoc();
2282  assert((VT == MVT::i8 || VT == MVT::i16) &&
2283         "unexpected type for custom-lowering vector extract");
2284  SDValue Vec = Op.getOperand(0);
2285  SDValue Lane = Op.getOperand(1);
2286  Op = DAG.getNode(ARMISD::VGETLANEu, dl, MVT::i32, Vec, Lane);
2287  Op = DAG.getNode(ISD::AssertZext, dl, MVT::i32, Op, DAG.getValueType(VT));
2288  return DAG.getNode(ISD::TRUNCATE, dl, VT, Op);
2289}
2290
2291static SDValue LowerCONCAT_VECTORS(SDValue Op) {
2292  if (Op.getValueType().is128BitVector() && Op.getNumOperands() == 2)
2293    return Op;
2294  return SDValue();
2295}
2296
2297SDValue ARMTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) {
2298  switch (Op.getOpcode()) {
2299  default: llvm_unreachable("Don't know how to custom lower this!");
2300  case ISD::ConstantPool:  return LowerConstantPool(Op, DAG);
2301  case ISD::GlobalAddress:
2302    return Subtarget->isTargetDarwin() ? LowerGlobalAddressDarwin(Op, DAG) :
2303      LowerGlobalAddressELF(Op, DAG);
2304  case ISD::GlobalTLSAddress:   return LowerGlobalTLSAddress(Op, DAG);
2305  case ISD::CALL:          return LowerCALL(Op, DAG);
2306  case ISD::RET:           return LowerRET(Op, DAG);
2307  case ISD::SELECT_CC:     return LowerSELECT_CC(Op, DAG, Subtarget);
2308  case ISD::BR_CC:         return LowerBR_CC(Op, DAG, Subtarget);
2309  case ISD::BR_JT:         return LowerBR_JT(Op, DAG);
2310  case ISD::VASTART:       return LowerVASTART(Op, DAG, VarArgsFrameIndex);
2311  case ISD::SINT_TO_FP:
2312  case ISD::UINT_TO_FP:    return LowerINT_TO_FP(Op, DAG);
2313  case ISD::FP_TO_SINT:
2314  case ISD::FP_TO_UINT:    return LowerFP_TO_INT(Op, DAG);
2315  case ISD::FCOPYSIGN:     return LowerFCOPYSIGN(Op, DAG);
2316  case ISD::FORMAL_ARGUMENTS: return LowerFORMAL_ARGUMENTS(Op, DAG);
2317  case ISD::RETURNADDR:    break;
2318  case ISD::FRAMEADDR:     return LowerFRAMEADDR(Op, DAG);
2319  case ISD::GLOBAL_OFFSET_TABLE: return LowerGLOBAL_OFFSET_TABLE(Op, DAG);
2320  case ISD::INTRINSIC_WO_CHAIN: return LowerINTRINSIC_WO_CHAIN(Op, DAG);
2321  case ISD::BIT_CONVERT:   return ExpandBIT_CONVERT(Op.getNode(), DAG);
2322  case ISD::SHL:
2323  case ISD::SRL:
2324  case ISD::SRA:           return LowerShift(Op.getNode(), DAG, Subtarget);
2325  case ISD::VSETCC:        return LowerVSETCC(Op, DAG);
2326  case ISD::BUILD_VECTOR:  return LowerBUILD_VECTOR(Op, DAG);
2327  case ISD::VECTOR_SHUFFLE: return LowerVECTOR_SHUFFLE(Op, DAG);
2328  case ISD::SCALAR_TO_VECTOR: return LowerSCALAR_TO_VECTOR(Op, DAG);
2329  case ISD::EXTRACT_VECTOR_ELT: return LowerEXTRACT_VECTOR_ELT(Op, DAG);
2330  case ISD::CONCAT_VECTORS: return LowerCONCAT_VECTORS(Op);
2331  }
2332  return SDValue();
2333}
2334
2335/// ReplaceNodeResults - Replace the results of node with an illegal result
2336/// type with new values built out of custom code.
2337void ARMTargetLowering::ReplaceNodeResults(SDNode *N,
2338                                           SmallVectorImpl<SDValue>&Results,
2339                                           SelectionDAG &DAG) {
2340  switch (N->getOpcode()) {
2341  default:
2342    llvm_unreachable("Don't know how to custom expand this!");
2343    return;
2344  case ISD::BIT_CONVERT:
2345    Results.push_back(ExpandBIT_CONVERT(N, DAG));
2346    return;
2347  case ISD::SRL:
2348  case ISD::SRA: {
2349    SDValue Res = LowerShift(N, DAG, Subtarget);
2350    if (Res.getNode())
2351      Results.push_back(Res);
2352    return;
2353  }
2354  }
2355}
2356
2357//===----------------------------------------------------------------------===//
2358//                           ARM Scheduler Hooks
2359//===----------------------------------------------------------------------===//
2360
2361MachineBasicBlock *
2362ARMTargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
2363                                               MachineBasicBlock *BB) const {
2364  const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
2365  DebugLoc dl = MI->getDebugLoc();
2366  switch (MI->getOpcode()) {
2367  default: assert(false && "Unexpected instr type to insert");
2368  case ARM::tMOVCCr: {
2369    // To "insert" a SELECT_CC instruction, we actually have to insert the
2370    // diamond control-flow pattern.  The incoming instruction knows the
2371    // destination vreg to set, the condition code register to branch on, the
2372    // true/false values to select between, and a branch opcode to use.
2373    const BasicBlock *LLVM_BB = BB->getBasicBlock();
2374    MachineFunction::iterator It = BB;
2375    ++It;
2376
2377    //  thisMBB:
2378    //  ...
2379    //   TrueVal = ...
2380    //   cmpTY ccX, r1, r2
2381    //   bCC copy1MBB
2382    //   fallthrough --> copy0MBB
2383    MachineBasicBlock *thisMBB  = BB;
2384    MachineFunction *F = BB->getParent();
2385    MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
2386    MachineBasicBlock *sinkMBB  = F->CreateMachineBasicBlock(LLVM_BB);
2387    BuildMI(BB, dl, TII->get(ARM::tBcc)).addMBB(sinkMBB)
2388      .addImm(MI->getOperand(3).getImm()).addReg(MI->getOperand(4).getReg());
2389    F->insert(It, copy0MBB);
2390    F->insert(It, sinkMBB);
2391    // Update machine-CFG edges by first adding all successors of the current
2392    // block to the new block which will contain the Phi node for the select.
2393    for(MachineBasicBlock::succ_iterator i = BB->succ_begin(),
2394        e = BB->succ_end(); i != e; ++i)
2395      sinkMBB->addSuccessor(*i);
2396    // Next, remove all successors of the current block, and add the true
2397    // and fallthrough blocks as its successors.
2398    while(!BB->succ_empty())
2399      BB->removeSuccessor(BB->succ_begin());
2400    BB->addSuccessor(copy0MBB);
2401    BB->addSuccessor(sinkMBB);
2402
2403    //  copy0MBB:
2404    //   %FalseValue = ...
2405    //   # fallthrough to sinkMBB
2406    BB = copy0MBB;
2407
2408    // Update machine-CFG edges
2409    BB->addSuccessor(sinkMBB);
2410
2411    //  sinkMBB:
2412    //   %Result = phi [ %FalseValue, copy0MBB ], [ %TrueValue, thisMBB ]
2413    //  ...
2414    BB = sinkMBB;
2415    BuildMI(BB, dl, TII->get(ARM::PHI), MI->getOperand(0).getReg())
2416      .addReg(MI->getOperand(1).getReg()).addMBB(copy0MBB)
2417      .addReg(MI->getOperand(2).getReg()).addMBB(thisMBB);
2418
2419    F->DeleteMachineInstr(MI);   // The pseudo instruction is gone now.
2420    return BB;
2421  }
2422  }
2423}
2424
2425//===----------------------------------------------------------------------===//
2426//                           ARM Optimization Hooks
2427//===----------------------------------------------------------------------===//
2428
2429static
2430SDValue combineSelectAndUse(SDNode *N, SDValue Slct, SDValue OtherOp,
2431                            TargetLowering::DAGCombinerInfo &DCI) {
2432  SelectionDAG &DAG = DCI.DAG;
2433  const TargetLowering &TLI = DAG.getTargetLoweringInfo();
2434  MVT VT = N->getValueType(0);
2435  unsigned Opc = N->getOpcode();
2436  bool isSlctCC = Slct.getOpcode() == ISD::SELECT_CC;
2437  SDValue LHS = isSlctCC ? Slct.getOperand(2) : Slct.getOperand(1);
2438  SDValue RHS = isSlctCC ? Slct.getOperand(3) : Slct.getOperand(2);
2439  ISD::CondCode CC = ISD::SETCC_INVALID;
2440
2441  if (isSlctCC) {
2442    CC = cast<CondCodeSDNode>(Slct.getOperand(4))->get();
2443  } else {
2444    SDValue CCOp = Slct.getOperand(0);
2445    if (CCOp.getOpcode() == ISD::SETCC)
2446      CC = cast<CondCodeSDNode>(CCOp.getOperand(2))->get();
2447  }
2448
2449  bool DoXform = false;
2450  bool InvCC = false;
2451  assert ((Opc == ISD::ADD || (Opc == ISD::SUB && Slct == N->getOperand(1))) &&
2452          "Bad input!");
2453
2454  if (LHS.getOpcode() == ISD::Constant &&
2455      cast<ConstantSDNode>(LHS)->isNullValue()) {
2456    DoXform = true;
2457  } else if (CC != ISD::SETCC_INVALID &&
2458             RHS.getOpcode() == ISD::Constant &&
2459             cast<ConstantSDNode>(RHS)->isNullValue()) {
2460    std::swap(LHS, RHS);
2461    SDValue Op0 = Slct.getOperand(0);
2462    MVT OpVT = isSlctCC ? Op0.getValueType() :
2463                          Op0.getOperand(0).getValueType();
2464    bool isInt = OpVT.isInteger();
2465    CC = ISD::getSetCCInverse(CC, isInt);
2466
2467    if (!TLI.isCondCodeLegal(CC, OpVT))
2468      return SDValue();         // Inverse operator isn't legal.
2469
2470    DoXform = true;
2471    InvCC = true;
2472  }
2473
2474  if (DoXform) {
2475    SDValue Result = DAG.getNode(Opc, RHS.getDebugLoc(), VT, OtherOp, RHS);
2476    if (isSlctCC)
2477      return DAG.getSelectCC(N->getDebugLoc(), OtherOp, Result,
2478                             Slct.getOperand(0), Slct.getOperand(1), CC);
2479    SDValue CCOp = Slct.getOperand(0);
2480    if (InvCC)
2481      CCOp = DAG.getSetCC(Slct.getDebugLoc(), CCOp.getValueType(),
2482                          CCOp.getOperand(0), CCOp.getOperand(1), CC);
2483    return DAG.getNode(ISD::SELECT, N->getDebugLoc(), VT,
2484                       CCOp, OtherOp, Result);
2485  }
2486  return SDValue();
2487}
2488
2489/// PerformADDCombine - Target-specific dag combine xforms for ISD::ADD.
2490static SDValue PerformADDCombine(SDNode *N,
2491                                 TargetLowering::DAGCombinerInfo &DCI) {
2492  // added by evan in r37685 with no testcase.
2493  SDValue N0 = N->getOperand(0), N1 = N->getOperand(1);
2494
2495  // fold (add (select cc, 0, c), x) -> (select cc, x, (add, x, c))
2496  if (N0.getOpcode() == ISD::SELECT && N0.getNode()->hasOneUse()) {
2497    SDValue Result = combineSelectAndUse(N, N0, N1, DCI);
2498    if (Result.getNode()) return Result;
2499  }
2500  if (N1.getOpcode() == ISD::SELECT && N1.getNode()->hasOneUse()) {
2501    SDValue Result = combineSelectAndUse(N, N1, N0, DCI);
2502    if (Result.getNode()) return Result;
2503  }
2504
2505  return SDValue();
2506}
2507
2508/// PerformSUBCombine - Target-specific dag combine xforms for ISD::SUB.
2509static SDValue PerformSUBCombine(SDNode *N,
2510                                 TargetLowering::DAGCombinerInfo &DCI) {
2511  // added by evan in r37685 with no testcase.
2512  SDValue N0 = N->getOperand(0), N1 = N->getOperand(1);
2513
2514  // fold (sub x, (select cc, 0, c)) -> (select cc, x, (sub, x, c))
2515  if (N1.getOpcode() == ISD::SELECT && N1.getNode()->hasOneUse()) {
2516    SDValue Result = combineSelectAndUse(N, N1, N0, DCI);
2517    if (Result.getNode()) return Result;
2518  }
2519
2520  return SDValue();
2521}
2522
2523
2524/// PerformFMRRDCombine - Target-specific dag combine xforms for ARMISD::FMRRD.
2525static SDValue PerformFMRRDCombine(SDNode *N,
2526                                   TargetLowering::DAGCombinerInfo &DCI) {
2527  // fmrrd(fmdrr x, y) -> x,y
2528  SDValue InDouble = N->getOperand(0);
2529  if (InDouble.getOpcode() == ARMISD::FMDRR)
2530    return DCI.CombineTo(N, InDouble.getOperand(0), InDouble.getOperand(1));
2531  return SDValue();
2532}
2533
2534/// getVShiftImm - Check if this is a valid build_vector for the immediate
2535/// operand of a vector shift operation, where all the elements of the
2536/// build_vector must have the same constant integer value.
2537static bool getVShiftImm(SDValue Op, unsigned ElementBits, int64_t &Cnt) {
2538  // Ignore bit_converts.
2539  while (Op.getOpcode() == ISD::BIT_CONVERT)
2540    Op = Op.getOperand(0);
2541  BuildVectorSDNode *BVN = dyn_cast<BuildVectorSDNode>(Op.getNode());
2542  APInt SplatBits, SplatUndef;
2543  unsigned SplatBitSize;
2544  bool HasAnyUndefs;
2545  if (! BVN || ! BVN->isConstantSplat(SplatBits, SplatUndef, SplatBitSize,
2546                                      HasAnyUndefs, ElementBits) ||
2547      SplatBitSize > ElementBits)
2548    return false;
2549  Cnt = SplatBits.getSExtValue();
2550  return true;
2551}
2552
2553/// isVShiftLImm - Check if this is a valid build_vector for the immediate
2554/// operand of a vector shift left operation.  That value must be in the range:
2555///   0 <= Value < ElementBits for a left shift; or
2556///   0 <= Value <= ElementBits for a long left shift.
2557static bool isVShiftLImm(SDValue Op, MVT VT, bool isLong, int64_t &Cnt) {
2558  assert(VT.isVector() && "vector shift count is not a vector type");
2559  unsigned ElementBits = VT.getVectorElementType().getSizeInBits();
2560  if (! getVShiftImm(Op, ElementBits, Cnt))
2561    return false;
2562  return (Cnt >= 0 && (isLong ? Cnt-1 : Cnt) < ElementBits);
2563}
2564
2565/// isVShiftRImm - Check if this is a valid build_vector for the immediate
2566/// operand of a vector shift right operation.  For a shift opcode, the value
2567/// is positive, but for an intrinsic the value count must be negative. The
2568/// absolute value must be in the range:
2569///   1 <= |Value| <= ElementBits for a right shift; or
2570///   1 <= |Value| <= ElementBits/2 for a narrow right shift.
2571static bool isVShiftRImm(SDValue Op, MVT VT, bool isNarrow, bool isIntrinsic,
2572                         int64_t &Cnt) {
2573  assert(VT.isVector() && "vector shift count is not a vector type");
2574  unsigned ElementBits = VT.getVectorElementType().getSizeInBits();
2575  if (! getVShiftImm(Op, ElementBits, Cnt))
2576    return false;
2577  if (isIntrinsic)
2578    Cnt = -Cnt;
2579  return (Cnt >= 1 && Cnt <= (isNarrow ? ElementBits/2 : ElementBits));
2580}
2581
2582/// PerformIntrinsicCombine - ARM-specific DAG combining for intrinsics.
2583static SDValue PerformIntrinsicCombine(SDNode *N, SelectionDAG &DAG) {
2584  unsigned IntNo = cast<ConstantSDNode>(N->getOperand(0))->getZExtValue();
2585  switch (IntNo) {
2586  default:
2587    // Don't do anything for most intrinsics.
2588    break;
2589
2590  // Vector shifts: check for immediate versions and lower them.
2591  // Note: This is done during DAG combining instead of DAG legalizing because
2592  // the build_vectors for 64-bit vector element shift counts are generally
2593  // not legal, and it is hard to see their values after they get legalized to
2594  // loads from a constant pool.
2595  case Intrinsic::arm_neon_vshifts:
2596  case Intrinsic::arm_neon_vshiftu:
2597  case Intrinsic::arm_neon_vshiftls:
2598  case Intrinsic::arm_neon_vshiftlu:
2599  case Intrinsic::arm_neon_vshiftn:
2600  case Intrinsic::arm_neon_vrshifts:
2601  case Intrinsic::arm_neon_vrshiftu:
2602  case Intrinsic::arm_neon_vrshiftn:
2603  case Intrinsic::arm_neon_vqshifts:
2604  case Intrinsic::arm_neon_vqshiftu:
2605  case Intrinsic::arm_neon_vqshiftsu:
2606  case Intrinsic::arm_neon_vqshiftns:
2607  case Intrinsic::arm_neon_vqshiftnu:
2608  case Intrinsic::arm_neon_vqshiftnsu:
2609  case Intrinsic::arm_neon_vqrshiftns:
2610  case Intrinsic::arm_neon_vqrshiftnu:
2611  case Intrinsic::arm_neon_vqrshiftnsu: {
2612    MVT VT = N->getOperand(1).getValueType();
2613    int64_t Cnt;
2614    unsigned VShiftOpc = 0;
2615
2616    switch (IntNo) {
2617    case Intrinsic::arm_neon_vshifts:
2618    case Intrinsic::arm_neon_vshiftu:
2619      if (isVShiftLImm(N->getOperand(2), VT, false, Cnt)) {
2620        VShiftOpc = ARMISD::VSHL;
2621        break;
2622      }
2623      if (isVShiftRImm(N->getOperand(2), VT, false, true, Cnt)) {
2624        VShiftOpc = (IntNo == Intrinsic::arm_neon_vshifts ?
2625                     ARMISD::VSHRs : ARMISD::VSHRu);
2626        break;
2627      }
2628      return SDValue();
2629
2630    case Intrinsic::arm_neon_vshiftls:
2631    case Intrinsic::arm_neon_vshiftlu:
2632      if (isVShiftLImm(N->getOperand(2), VT, true, Cnt))
2633        break;
2634      llvm_unreachable("invalid shift count for vshll intrinsic");
2635
2636    case Intrinsic::arm_neon_vrshifts:
2637    case Intrinsic::arm_neon_vrshiftu:
2638      if (isVShiftRImm(N->getOperand(2), VT, false, true, Cnt))
2639        break;
2640      return SDValue();
2641
2642    case Intrinsic::arm_neon_vqshifts:
2643    case Intrinsic::arm_neon_vqshiftu:
2644      if (isVShiftLImm(N->getOperand(2), VT, false, Cnt))
2645        break;
2646      return SDValue();
2647
2648    case Intrinsic::arm_neon_vqshiftsu:
2649      if (isVShiftLImm(N->getOperand(2), VT, false, Cnt))
2650        break;
2651      llvm_unreachable("invalid shift count for vqshlu intrinsic");
2652
2653    case Intrinsic::arm_neon_vshiftn:
2654    case Intrinsic::arm_neon_vrshiftn:
2655    case Intrinsic::arm_neon_vqshiftns:
2656    case Intrinsic::arm_neon_vqshiftnu:
2657    case Intrinsic::arm_neon_vqshiftnsu:
2658    case Intrinsic::arm_neon_vqrshiftns:
2659    case Intrinsic::arm_neon_vqrshiftnu:
2660    case Intrinsic::arm_neon_vqrshiftnsu:
2661      // Narrowing shifts require an immediate right shift.
2662      if (isVShiftRImm(N->getOperand(2), VT, true, true, Cnt))
2663        break;
2664      llvm_unreachable("invalid shift count for narrowing vector shift intrinsic");
2665
2666    default:
2667      llvm_unreachable("unhandled vector shift");
2668    }
2669
2670    switch (IntNo) {
2671    case Intrinsic::arm_neon_vshifts:
2672    case Intrinsic::arm_neon_vshiftu:
2673      // Opcode already set above.
2674      break;
2675    case Intrinsic::arm_neon_vshiftls:
2676    case Intrinsic::arm_neon_vshiftlu:
2677      if (Cnt == VT.getVectorElementType().getSizeInBits())
2678        VShiftOpc = ARMISD::VSHLLi;
2679      else
2680        VShiftOpc = (IntNo == Intrinsic::arm_neon_vshiftls ?
2681                     ARMISD::VSHLLs : ARMISD::VSHLLu);
2682      break;
2683    case Intrinsic::arm_neon_vshiftn:
2684      VShiftOpc = ARMISD::VSHRN; break;
2685    case Intrinsic::arm_neon_vrshifts:
2686      VShiftOpc = ARMISD::VRSHRs; break;
2687    case Intrinsic::arm_neon_vrshiftu:
2688      VShiftOpc = ARMISD::VRSHRu; break;
2689    case Intrinsic::arm_neon_vrshiftn:
2690      VShiftOpc = ARMISD::VRSHRN; break;
2691    case Intrinsic::arm_neon_vqshifts:
2692      VShiftOpc = ARMISD::VQSHLs; break;
2693    case Intrinsic::arm_neon_vqshiftu:
2694      VShiftOpc = ARMISD::VQSHLu; break;
2695    case Intrinsic::arm_neon_vqshiftsu:
2696      VShiftOpc = ARMISD::VQSHLsu; break;
2697    case Intrinsic::arm_neon_vqshiftns:
2698      VShiftOpc = ARMISD::VQSHRNs; break;
2699    case Intrinsic::arm_neon_vqshiftnu:
2700      VShiftOpc = ARMISD::VQSHRNu; break;
2701    case Intrinsic::arm_neon_vqshiftnsu:
2702      VShiftOpc = ARMISD::VQSHRNsu; break;
2703    case Intrinsic::arm_neon_vqrshiftns:
2704      VShiftOpc = ARMISD::VQRSHRNs; break;
2705    case Intrinsic::arm_neon_vqrshiftnu:
2706      VShiftOpc = ARMISD::VQRSHRNu; break;
2707    case Intrinsic::arm_neon_vqrshiftnsu:
2708      VShiftOpc = ARMISD::VQRSHRNsu; break;
2709    }
2710
2711    return DAG.getNode(VShiftOpc, N->getDebugLoc(), N->getValueType(0),
2712                       N->getOperand(1), DAG.getConstant(Cnt, MVT::i32));
2713  }
2714
2715  case Intrinsic::arm_neon_vshiftins: {
2716    MVT VT = N->getOperand(1).getValueType();
2717    int64_t Cnt;
2718    unsigned VShiftOpc = 0;
2719
2720    if (isVShiftLImm(N->getOperand(3), VT, false, Cnt))
2721      VShiftOpc = ARMISD::VSLI;
2722    else if (isVShiftRImm(N->getOperand(3), VT, false, true, Cnt))
2723      VShiftOpc = ARMISD::VSRI;
2724    else {
2725      llvm_unreachable("invalid shift count for vsli/vsri intrinsic");
2726    }
2727
2728    return DAG.getNode(VShiftOpc, N->getDebugLoc(), N->getValueType(0),
2729                       N->getOperand(1), N->getOperand(2),
2730                       DAG.getConstant(Cnt, MVT::i32));
2731  }
2732
2733  case Intrinsic::arm_neon_vqrshifts:
2734  case Intrinsic::arm_neon_vqrshiftu:
2735    // No immediate versions of these to check for.
2736    break;
2737  }
2738
2739  return SDValue();
2740}
2741
2742/// PerformShiftCombine - Checks for immediate versions of vector shifts and
2743/// lowers them.  As with the vector shift intrinsics, this is done during DAG
2744/// combining instead of DAG legalizing because the build_vectors for 64-bit
2745/// vector element shift counts are generally not legal, and it is hard to see
2746/// their values after they get legalized to loads from a constant pool.
2747static SDValue PerformShiftCombine(SDNode *N, SelectionDAG &DAG,
2748                                   const ARMSubtarget *ST) {
2749  MVT VT = N->getValueType(0);
2750
2751  // Nothing to be done for scalar shifts.
2752  if (! VT.isVector())
2753    return SDValue();
2754
2755  assert(ST->hasNEON() && "unexpected vector shift");
2756  int64_t Cnt;
2757
2758  switch (N->getOpcode()) {
2759  default: llvm_unreachable("unexpected shift opcode");
2760
2761  case ISD::SHL:
2762    if (isVShiftLImm(N->getOperand(1), VT, false, Cnt))
2763      return DAG.getNode(ARMISD::VSHL, N->getDebugLoc(), VT, N->getOperand(0),
2764                         DAG.getConstant(Cnt, MVT::i32));
2765    break;
2766
2767  case ISD::SRA:
2768  case ISD::SRL:
2769    if (isVShiftRImm(N->getOperand(1), VT, false, false, Cnt)) {
2770      unsigned VShiftOpc = (N->getOpcode() == ISD::SRA ?
2771                            ARMISD::VSHRs : ARMISD::VSHRu);
2772      return DAG.getNode(VShiftOpc, N->getDebugLoc(), VT, N->getOperand(0),
2773                         DAG.getConstant(Cnt, MVT::i32));
2774    }
2775  }
2776  return SDValue();
2777}
2778
2779/// PerformExtendCombine - Target-specific DAG combining for ISD::SIGN_EXTEND,
2780/// ISD::ZERO_EXTEND, and ISD::ANY_EXTEND.
2781static SDValue PerformExtendCombine(SDNode *N, SelectionDAG &DAG,
2782                                    const ARMSubtarget *ST) {
2783  SDValue N0 = N->getOperand(0);
2784
2785  // Check for sign- and zero-extensions of vector extract operations of 8-
2786  // and 16-bit vector elements.  NEON supports these directly.  They are
2787  // handled during DAG combining because type legalization will promote them
2788  // to 32-bit types and it is messy to recognize the operations after that.
2789  if (ST->hasNEON() && N0.getOpcode() == ISD::EXTRACT_VECTOR_ELT) {
2790    SDValue Vec = N0.getOperand(0);
2791    SDValue Lane = N0.getOperand(1);
2792    MVT VT = N->getValueType(0);
2793    MVT EltVT = N0.getValueType();
2794    const TargetLowering &TLI = DAG.getTargetLoweringInfo();
2795
2796    if (VT == MVT::i32 &&
2797        (EltVT == MVT::i8 || EltVT == MVT::i16) &&
2798        TLI.isTypeLegal(Vec.getValueType())) {
2799
2800      unsigned Opc = 0;
2801      switch (N->getOpcode()) {
2802      default: llvm_unreachable("unexpected opcode");
2803      case ISD::SIGN_EXTEND:
2804        Opc = ARMISD::VGETLANEs;
2805        break;
2806      case ISD::ZERO_EXTEND:
2807      case ISD::ANY_EXTEND:
2808        Opc = ARMISD::VGETLANEu;
2809        break;
2810      }
2811      return DAG.getNode(Opc, N->getDebugLoc(), VT, Vec, Lane);
2812    }
2813  }
2814
2815  return SDValue();
2816}
2817
2818SDValue ARMTargetLowering::PerformDAGCombine(SDNode *N,
2819                                             DAGCombinerInfo &DCI) const {
2820  switch (N->getOpcode()) {
2821  default: break;
2822  case ISD::ADD:      return PerformADDCombine(N, DCI);
2823  case ISD::SUB:      return PerformSUBCombine(N, DCI);
2824  case ARMISD::FMRRD: return PerformFMRRDCombine(N, DCI);
2825  case ISD::INTRINSIC_WO_CHAIN:
2826    return PerformIntrinsicCombine(N, DCI.DAG);
2827  case ISD::SHL:
2828  case ISD::SRA:
2829  case ISD::SRL:
2830    return PerformShiftCombine(N, DCI.DAG, Subtarget);
2831  case ISD::SIGN_EXTEND:
2832  case ISD::ZERO_EXTEND:
2833  case ISD::ANY_EXTEND:
2834    return PerformExtendCombine(N, DCI.DAG, Subtarget);
2835  }
2836  return SDValue();
2837}
2838
2839/// isLegalAddressImmediate - Return true if the integer value can be used
2840/// as the offset of the target addressing mode for load / store of the
2841/// given type.
2842static bool isLegalAddressImmediate(int64_t V, MVT VT,
2843                                    const ARMSubtarget *Subtarget) {
2844  if (V == 0)
2845    return true;
2846
2847  if (!VT.isSimple())
2848    return false;
2849
2850  if (Subtarget->isThumb()) { // FIXME for thumb2
2851    if (V < 0)
2852      return false;
2853
2854    unsigned Scale = 1;
2855    switch (VT.getSimpleVT()) {
2856    default: return false;
2857    case MVT::i1:
2858    case MVT::i8:
2859      // Scale == 1;
2860      break;
2861    case MVT::i16:
2862      // Scale == 2;
2863      Scale = 2;
2864      break;
2865    case MVT::i32:
2866      // Scale == 4;
2867      Scale = 4;
2868      break;
2869    }
2870
2871    if ((V & (Scale - 1)) != 0)
2872      return false;
2873    V /= Scale;
2874    return V == (V & ((1LL << 5) - 1));
2875  }
2876
2877  if (V < 0)
2878    V = - V;
2879  switch (VT.getSimpleVT()) {
2880  default: return false;
2881  case MVT::i1:
2882  case MVT::i8:
2883  case MVT::i32:
2884    // +- imm12
2885    return V == (V & ((1LL << 12) - 1));
2886  case MVT::i16:
2887    // +- imm8
2888    return V == (V & ((1LL << 8) - 1));
2889  case MVT::f32:
2890  case MVT::f64:
2891    if (!Subtarget->hasVFP2())
2892      return false;
2893    if ((V & 3) != 0)
2894      return false;
2895    V >>= 2;
2896    return V == (V & ((1LL << 8) - 1));
2897  }
2898}
2899
2900/// isLegalAddressingMode - Return true if the addressing mode represented
2901/// by AM is legal for this target, for a load/store of the specified type.
2902bool ARMTargetLowering::isLegalAddressingMode(const AddrMode &AM,
2903                                              const Type *Ty) const {
2904  MVT VT = getValueType(Ty, true);
2905  if (!isLegalAddressImmediate(AM.BaseOffs, VT, Subtarget))
2906    return false;
2907
2908  // Can never fold addr of global into load/store.
2909  if (AM.BaseGV)
2910    return false;
2911
2912  switch (AM.Scale) {
2913  case 0:  // no scale reg, must be "r+i" or "r", or "i".
2914    break;
2915  case 1:
2916    if (Subtarget->isThumb())  // FIXME for thumb2
2917      return false;
2918    // FALL THROUGH.
2919  default:
2920    // ARM doesn't support any R+R*scale+imm addr modes.
2921    if (AM.BaseOffs)
2922      return false;
2923
2924    if (!VT.isSimple())
2925      return false;
2926
2927    int Scale = AM.Scale;
2928    switch (VT.getSimpleVT()) {
2929    default: return false;
2930    case MVT::i1:
2931    case MVT::i8:
2932    case MVT::i32:
2933    case MVT::i64:
2934      // This assumes i64 is legalized to a pair of i32. If not (i.e.
2935      // ldrd / strd are used, then its address mode is same as i16.
2936      // r + r
2937      if (Scale < 0) Scale = -Scale;
2938      if (Scale == 1)
2939        return true;
2940      // r + r << imm
2941      return isPowerOf2_32(Scale & ~1);
2942    case MVT::i16:
2943      // r + r
2944      if (((unsigned)AM.HasBaseReg + Scale) <= 2)
2945        return true;
2946      return false;
2947
2948    case MVT::isVoid:
2949      // Note, we allow "void" uses (basically, uses that aren't loads or
2950      // stores), because arm allows folding a scale into many arithmetic
2951      // operations.  This should be made more precise and revisited later.
2952
2953      // Allow r << imm, but the imm has to be a multiple of two.
2954      if (AM.Scale & 1) return false;
2955      return isPowerOf2_32(AM.Scale);
2956    }
2957    break;
2958  }
2959  return true;
2960}
2961
2962static bool getARMIndexedAddressParts(SDNode *Ptr, MVT VT,
2963                                      bool isSEXTLoad, SDValue &Base,
2964                                      SDValue &Offset, bool &isInc,
2965                                      SelectionDAG &DAG) {
2966  if (Ptr->getOpcode() != ISD::ADD && Ptr->getOpcode() != ISD::SUB)
2967    return false;
2968
2969  if (VT == MVT::i16 || ((VT == MVT::i8 || VT == MVT::i1) && isSEXTLoad)) {
2970    // AddressingMode 3
2971    Base = Ptr->getOperand(0);
2972    if (ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(Ptr->getOperand(1))) {
2973      int RHSC = (int)RHS->getZExtValue();
2974      if (RHSC < 0 && RHSC > -256) {
2975        assert(Ptr->getOpcode() == ISD::ADD);
2976        isInc = false;
2977        Offset = DAG.getConstant(-RHSC, RHS->getValueType(0));
2978        return true;
2979      }
2980    }
2981    isInc = (Ptr->getOpcode() == ISD::ADD);
2982    Offset = Ptr->getOperand(1);
2983    return true;
2984  } else if (VT == MVT::i32 || VT == MVT::i8 || VT == MVT::i1) {
2985    // AddressingMode 2
2986    if (ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(Ptr->getOperand(1))) {
2987      int RHSC = (int)RHS->getZExtValue();
2988      if (RHSC < 0 && RHSC > -0x1000) {
2989        assert(Ptr->getOpcode() == ISD::ADD);
2990        isInc = false;
2991        Offset = DAG.getConstant(-RHSC, RHS->getValueType(0));
2992        Base = Ptr->getOperand(0);
2993        return true;
2994      }
2995    }
2996
2997    if (Ptr->getOpcode() == ISD::ADD) {
2998      isInc = true;
2999      ARM_AM::ShiftOpc ShOpcVal= ARM_AM::getShiftOpcForNode(Ptr->getOperand(0));
3000      if (ShOpcVal != ARM_AM::no_shift) {
3001        Base = Ptr->getOperand(1);
3002        Offset = Ptr->getOperand(0);
3003      } else {
3004        Base = Ptr->getOperand(0);
3005        Offset = Ptr->getOperand(1);
3006      }
3007      return true;
3008    }
3009
3010    isInc = (Ptr->getOpcode() == ISD::ADD);
3011    Base = Ptr->getOperand(0);
3012    Offset = Ptr->getOperand(1);
3013    return true;
3014  }
3015
3016  // FIXME: Use FLDM / FSTM to emulate indexed FP load / store.
3017  return false;
3018}
3019
3020static bool getT2IndexedAddressParts(SDNode *Ptr, MVT VT,
3021                                     bool isSEXTLoad, SDValue &Base,
3022                                     SDValue &Offset, bool &isInc,
3023                                     SelectionDAG &DAG) {
3024  if (Ptr->getOpcode() != ISD::ADD && Ptr->getOpcode() != ISD::SUB)
3025    return false;
3026
3027  Base = Ptr->getOperand(0);
3028  if (ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(Ptr->getOperand(1))) {
3029    int RHSC = (int)RHS->getZExtValue();
3030    if (RHSC < 0 && RHSC > -0x100) { // 8 bits.
3031      assert(Ptr->getOpcode() == ISD::ADD);
3032      isInc = false;
3033      Offset = DAG.getConstant(-RHSC, RHS->getValueType(0));
3034      return true;
3035    } else if (RHSC > 0 && RHSC < 0x100) { // 8 bit, no zero.
3036      isInc = Ptr->getOpcode() == ISD::ADD;
3037      Offset = DAG.getConstant(RHSC, RHS->getValueType(0));
3038      return true;
3039    }
3040  }
3041
3042  return false;
3043}
3044
3045/// getPreIndexedAddressParts - returns true by value, base pointer and
3046/// offset pointer and addressing mode by reference if the node's address
3047/// can be legally represented as pre-indexed load / store address.
3048bool
3049ARMTargetLowering::getPreIndexedAddressParts(SDNode *N, SDValue &Base,
3050                                             SDValue &Offset,
3051                                             ISD::MemIndexedMode &AM,
3052                                             SelectionDAG &DAG) const {
3053  if (Subtarget->isThumb1Only())
3054    return false;
3055
3056  MVT VT;
3057  SDValue Ptr;
3058  bool isSEXTLoad = false;
3059  if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
3060    Ptr = LD->getBasePtr();
3061    VT  = LD->getMemoryVT();
3062    isSEXTLoad = LD->getExtensionType() == ISD::SEXTLOAD;
3063  } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
3064    Ptr = ST->getBasePtr();
3065    VT  = ST->getMemoryVT();
3066  } else
3067    return false;
3068
3069  bool isInc;
3070  bool isLegal = false;
3071  if (Subtarget->isThumb() && Subtarget->hasThumb2())
3072    isLegal = getT2IndexedAddressParts(Ptr.getNode(), VT, isSEXTLoad, Base,
3073                                       Offset, isInc, DAG);
3074  else
3075    isLegal = getARMIndexedAddressParts(Ptr.getNode(), VT, isSEXTLoad, Base,
3076                                        Offset, isInc, DAG);
3077  if (!isLegal)
3078    return false;
3079
3080  AM = isInc ? ISD::PRE_INC : ISD::PRE_DEC;
3081  return true;
3082}
3083
3084/// getPostIndexedAddressParts - returns true by value, base pointer and
3085/// offset pointer and addressing mode by reference if this node can be
3086/// combined with a load / store to form a post-indexed load / store.
3087bool ARMTargetLowering::getPostIndexedAddressParts(SDNode *N, SDNode *Op,
3088                                                   SDValue &Base,
3089                                                   SDValue &Offset,
3090                                                   ISD::MemIndexedMode &AM,
3091                                                   SelectionDAG &DAG) const {
3092  if (Subtarget->isThumb1Only())
3093    return false;
3094
3095  MVT VT;
3096  SDValue Ptr;
3097  bool isSEXTLoad = false;
3098  if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
3099    VT  = LD->getMemoryVT();
3100    isSEXTLoad = LD->getExtensionType() == ISD::SEXTLOAD;
3101  } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
3102    VT  = ST->getMemoryVT();
3103  } else
3104    return false;
3105
3106  bool isInc;
3107  bool isLegal = false;
3108  if (Subtarget->isThumb() && Subtarget->hasThumb2())
3109    isLegal = getT2IndexedAddressParts(Op, VT, isSEXTLoad, Base, Offset,
3110                                        isInc, DAG);
3111  else
3112    isLegal = getARMIndexedAddressParts(Op, VT, isSEXTLoad, Base, Offset,
3113                                        isInc, DAG);
3114  if (!isLegal)
3115    return false;
3116
3117  AM = isInc ? ISD::POST_INC : ISD::POST_DEC;
3118  return true;
3119}
3120
3121void ARMTargetLowering::computeMaskedBitsForTargetNode(const SDValue Op,
3122                                                       const APInt &Mask,
3123                                                       APInt &KnownZero,
3124                                                       APInt &KnownOne,
3125                                                       const SelectionDAG &DAG,
3126                                                       unsigned Depth) const {
3127  KnownZero = KnownOne = APInt(Mask.getBitWidth(), 0);
3128  switch (Op.getOpcode()) {
3129  default: break;
3130  case ARMISD::CMOV: {
3131    // Bits are known zero/one if known on the LHS and RHS.
3132    DAG.ComputeMaskedBits(Op.getOperand(0), Mask, KnownZero, KnownOne, Depth+1);
3133    if (KnownZero == 0 && KnownOne == 0) return;
3134
3135    APInt KnownZeroRHS, KnownOneRHS;
3136    DAG.ComputeMaskedBits(Op.getOperand(1), Mask,
3137                          KnownZeroRHS, KnownOneRHS, Depth+1);
3138    KnownZero &= KnownZeroRHS;
3139    KnownOne  &= KnownOneRHS;
3140    return;
3141  }
3142  }
3143}
3144
3145//===----------------------------------------------------------------------===//
3146//                           ARM Inline Assembly Support
3147//===----------------------------------------------------------------------===//
3148
3149/// getConstraintType - Given a constraint letter, return the type of
3150/// constraint it is for this target.
3151ARMTargetLowering::ConstraintType
3152ARMTargetLowering::getConstraintType(const std::string &Constraint) const {
3153  if (Constraint.size() == 1) {
3154    switch (Constraint[0]) {
3155    default:  break;
3156    case 'l': return C_RegisterClass;
3157    case 'w': return C_RegisterClass;
3158    }
3159  }
3160  return TargetLowering::getConstraintType(Constraint);
3161}
3162
3163std::pair<unsigned, const TargetRegisterClass*>
3164ARMTargetLowering::getRegForInlineAsmConstraint(const std::string &Constraint,
3165                                                MVT VT) const {
3166  if (Constraint.size() == 1) {
3167    // GCC RS6000 Constraint Letters
3168    switch (Constraint[0]) {
3169    case 'l':
3170      if (Subtarget->isThumb1Only())
3171        return std::make_pair(0U, ARM::tGPRRegisterClass);
3172      else
3173        return std::make_pair(0U, ARM::GPRRegisterClass);
3174    case 'r':
3175      return std::make_pair(0U, ARM::GPRRegisterClass);
3176    case 'w':
3177      if (VT == MVT::f32)
3178        return std::make_pair(0U, ARM::SPRRegisterClass);
3179      if (VT == MVT::f64)
3180        return std::make_pair(0U, ARM::DPRRegisterClass);
3181      break;
3182    }
3183  }
3184  return TargetLowering::getRegForInlineAsmConstraint(Constraint, VT);
3185}
3186
3187std::vector<unsigned> ARMTargetLowering::
3188getRegClassForInlineAsmConstraint(const std::string &Constraint,
3189                                  MVT VT) const {
3190  if (Constraint.size() != 1)
3191    return std::vector<unsigned>();
3192
3193  switch (Constraint[0]) {      // GCC ARM Constraint Letters
3194  default: break;
3195  case 'l':
3196    return make_vector<unsigned>(ARM::R0, ARM::R1, ARM::R2, ARM::R3,
3197                                 ARM::R4, ARM::R5, ARM::R6, ARM::R7,
3198                                 0);
3199  case 'r':
3200    return make_vector<unsigned>(ARM::R0, ARM::R1, ARM::R2, ARM::R3,
3201                                 ARM::R4, ARM::R5, ARM::R6, ARM::R7,
3202                                 ARM::R8, ARM::R9, ARM::R10, ARM::R11,
3203                                 ARM::R12, ARM::LR, 0);
3204  case 'w':
3205    if (VT == MVT::f32)
3206      return make_vector<unsigned>(ARM::S0, ARM::S1, ARM::S2, ARM::S3,
3207                                   ARM::S4, ARM::S5, ARM::S6, ARM::S7,
3208                                   ARM::S8, ARM::S9, ARM::S10, ARM::S11,
3209                                   ARM::S12,ARM::S13,ARM::S14,ARM::S15,
3210                                   ARM::S16,ARM::S17,ARM::S18,ARM::S19,
3211                                   ARM::S20,ARM::S21,ARM::S22,ARM::S23,
3212                                   ARM::S24,ARM::S25,ARM::S26,ARM::S27,
3213                                   ARM::S28,ARM::S29,ARM::S30,ARM::S31, 0);
3214    if (VT == MVT::f64)
3215      return make_vector<unsigned>(ARM::D0, ARM::D1, ARM::D2, ARM::D3,
3216                                   ARM::D4, ARM::D5, ARM::D6, ARM::D7,
3217                                   ARM::D8, ARM::D9, ARM::D10,ARM::D11,
3218                                   ARM::D12,ARM::D13,ARM::D14,ARM::D15, 0);
3219      break;
3220  }
3221
3222  return std::vector<unsigned>();
3223}
3224
3225/// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
3226/// vector.  If it is invalid, don't add anything to Ops.
3227void ARMTargetLowering::LowerAsmOperandForConstraint(SDValue Op,
3228                                                     char Constraint,
3229                                                     bool hasMemory,
3230                                                     std::vector<SDValue>&Ops,
3231                                                     SelectionDAG &DAG) const {
3232  SDValue Result(0, 0);
3233
3234  switch (Constraint) {
3235  default: break;
3236  case 'I': case 'J': case 'K': case 'L':
3237  case 'M': case 'N': case 'O':
3238    ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op);
3239    if (!C)
3240      return;
3241
3242    int64_t CVal64 = C->getSExtValue();
3243    int CVal = (int) CVal64;
3244    // None of these constraints allow values larger than 32 bits.  Check
3245    // that the value fits in an int.
3246    if (CVal != CVal64)
3247      return;
3248
3249    switch (Constraint) {
3250      case 'I':
3251        if (Subtarget->isThumb1Only()) {
3252          // This must be a constant between 0 and 255, for ADD
3253          // immediates.
3254          if (CVal >= 0 && CVal <= 255)
3255            break;
3256        } else if (Subtarget->isThumb2()) {
3257          // A constant that can be used as an immediate value in a
3258          // data-processing instruction.
3259          if (ARM_AM::getT2SOImmVal(CVal) != -1)
3260            break;
3261        } else {
3262          // A constant that can be used as an immediate value in a
3263          // data-processing instruction.
3264          if (ARM_AM::getSOImmVal(CVal) != -1)
3265            break;
3266        }
3267        return;
3268
3269      case 'J':
3270        if (Subtarget->isThumb()) {  // FIXME thumb2
3271          // This must be a constant between -255 and -1, for negated ADD
3272          // immediates. This can be used in GCC with an "n" modifier that
3273          // prints the negated value, for use with SUB instructions. It is
3274          // not useful otherwise but is implemented for compatibility.
3275          if (CVal >= -255 && CVal <= -1)
3276            break;
3277        } else {
3278          // This must be a constant between -4095 and 4095. It is not clear
3279          // what this constraint is intended for. Implemented for
3280          // compatibility with GCC.
3281          if (CVal >= -4095 && CVal <= 4095)
3282            break;
3283        }
3284        return;
3285
3286      case 'K':
3287        if (Subtarget->isThumb1Only()) {
3288          // A 32-bit value where only one byte has a nonzero value. Exclude
3289          // zero to match GCC. This constraint is used by GCC internally for
3290          // constants that can be loaded with a move/shift combination.
3291          // It is not useful otherwise but is implemented for compatibility.
3292          if (CVal != 0 && ARM_AM::isThumbImmShiftedVal(CVal))
3293            break;
3294        } else if (Subtarget->isThumb2()) {
3295          // A constant whose bitwise inverse can be used as an immediate
3296          // value in a data-processing instruction. This can be used in GCC
3297          // with a "B" modifier that prints the inverted value, for use with
3298          // BIC and MVN instructions. It is not useful otherwise but is
3299          // implemented for compatibility.
3300          if (ARM_AM::getT2SOImmVal(~CVal) != -1)
3301            break;
3302        } else {
3303          // A constant whose bitwise inverse can be used as an immediate
3304          // value in a data-processing instruction. This can be used in GCC
3305          // with a "B" modifier that prints the inverted value, for use with
3306          // BIC and MVN instructions. It is not useful otherwise but is
3307          // implemented for compatibility.
3308          if (ARM_AM::getSOImmVal(~CVal) != -1)
3309            break;
3310        }
3311        return;
3312
3313      case 'L':
3314        if (Subtarget->isThumb1Only()) {
3315          // This must be a constant between -7 and 7,
3316          // for 3-operand ADD/SUB immediate instructions.
3317          if (CVal >= -7 && CVal < 7)
3318            break;
3319        } else if (Subtarget->isThumb2()) {
3320          // A constant whose negation can be used as an immediate value in a
3321          // data-processing instruction. This can be used in GCC with an "n"
3322          // modifier that prints the negated value, for use with SUB
3323          // instructions. It is not useful otherwise but is implemented for
3324          // compatibility.
3325          if (ARM_AM::getT2SOImmVal(-CVal) != -1)
3326            break;
3327        } else {
3328          // A constant whose negation can be used as an immediate value in a
3329          // data-processing instruction. This can be used in GCC with an "n"
3330          // modifier that prints the negated value, for use with SUB
3331          // instructions. It is not useful otherwise but is implemented for
3332          // compatibility.
3333          if (ARM_AM::getSOImmVal(-CVal) != -1)
3334            break;
3335        }
3336        return;
3337
3338      case 'M':
3339        if (Subtarget->isThumb()) { // FIXME thumb2
3340          // This must be a multiple of 4 between 0 and 1020, for
3341          // ADD sp + immediate.
3342          if ((CVal >= 0 && CVal <= 1020) && ((CVal & 3) == 0))
3343            break;
3344        } else {
3345          // A power of two or a constant between 0 and 32.  This is used in
3346          // GCC for the shift amount on shifted register operands, but it is
3347          // useful in general for any shift amounts.
3348          if ((CVal >= 0 && CVal <= 32) || ((CVal & (CVal - 1)) == 0))
3349            break;
3350        }
3351        return;
3352
3353      case 'N':
3354        if (Subtarget->isThumb()) {  // FIXME thumb2
3355          // This must be a constant between 0 and 31, for shift amounts.
3356          if (CVal >= 0 && CVal <= 31)
3357            break;
3358        }
3359        return;
3360
3361      case 'O':
3362        if (Subtarget->isThumb()) {  // FIXME thumb2
3363          // This must be a multiple of 4 between -508 and 508, for
3364          // ADD/SUB sp = sp + immediate.
3365          if ((CVal >= -508 && CVal <= 508) && ((CVal & 3) == 0))
3366            break;
3367        }
3368        return;
3369    }
3370    Result = DAG.getTargetConstant(CVal, Op.getValueType());
3371    break;
3372  }
3373
3374  if (Result.getNode()) {
3375    Ops.push_back(Result);
3376    return;
3377  }
3378  return TargetLowering::LowerAsmOperandForConstraint(Op, Constraint, hasMemory,
3379                                                      Ops, DAG);
3380}
3381