ARMISelLowering.cpp revision 1607f05cb7d77d01ce521a30232faa389dbed4e2
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/Instruction.h"
26#include "llvm/Intrinsics.h"
27#include "llvm/GlobalValue.h"
28#include "llvm/CodeGen/MachineBasicBlock.h"
29#include "llvm/CodeGen/MachineFrameInfo.h"
30#include "llvm/CodeGen/MachineFunction.h"
31#include "llvm/CodeGen/MachineInstrBuilder.h"
32#include "llvm/CodeGen/MachineRegisterInfo.h"
33#include "llvm/CodeGen/SelectionDAG.h"
34#include "llvm/Target/TargetOptions.h"
35#include "llvm/ADT/VectorExtras.h"
36#include "llvm/Support/MathExtras.h"
37using namespace llvm;
38
39ARMTargetLowering::ARMTargetLowering(TargetMachine &TM)
40    : TargetLowering(TM), ARMPCLabelIndex(0) {
41  Subtarget = &TM.getSubtarget<ARMSubtarget>();
42
43  if (Subtarget->isTargetDarwin()) {
44    // Uses VFP for Thumb libfuncs if available.
45    if (Subtarget->isThumb() && Subtarget->hasVFP2()) {
46      // Single-precision floating-point arithmetic.
47      setLibcallName(RTLIB::ADD_F32, "__addsf3vfp");
48      setLibcallName(RTLIB::SUB_F32, "__subsf3vfp");
49      setLibcallName(RTLIB::MUL_F32, "__mulsf3vfp");
50      setLibcallName(RTLIB::DIV_F32, "__divsf3vfp");
51
52      // Double-precision floating-point arithmetic.
53      setLibcallName(RTLIB::ADD_F64, "__adddf3vfp");
54      setLibcallName(RTLIB::SUB_F64, "__subdf3vfp");
55      setLibcallName(RTLIB::MUL_F64, "__muldf3vfp");
56      setLibcallName(RTLIB::DIV_F64, "__divdf3vfp");
57
58      // Single-precision comparisons.
59      setLibcallName(RTLIB::OEQ_F32, "__eqsf2vfp");
60      setLibcallName(RTLIB::UNE_F32, "__nesf2vfp");
61      setLibcallName(RTLIB::OLT_F32, "__ltsf2vfp");
62      setLibcallName(RTLIB::OLE_F32, "__lesf2vfp");
63      setLibcallName(RTLIB::OGE_F32, "__gesf2vfp");
64      setLibcallName(RTLIB::OGT_F32, "__gtsf2vfp");
65      setLibcallName(RTLIB::UO_F32,  "__unordsf2vfp");
66      setLibcallName(RTLIB::O_F32,   "__unordsf2vfp");
67
68      setCmpLibcallCC(RTLIB::OEQ_F32, ISD::SETNE);
69      setCmpLibcallCC(RTLIB::UNE_F32, ISD::SETNE);
70      setCmpLibcallCC(RTLIB::OLT_F32, ISD::SETNE);
71      setCmpLibcallCC(RTLIB::OLE_F32, ISD::SETNE);
72      setCmpLibcallCC(RTLIB::OGE_F32, ISD::SETNE);
73      setCmpLibcallCC(RTLIB::OGT_F32, ISD::SETNE);
74      setCmpLibcallCC(RTLIB::UO_F32,  ISD::SETNE);
75      setCmpLibcallCC(RTLIB::O_F32,   ISD::SETEQ);
76
77      // Double-precision comparisons.
78      setLibcallName(RTLIB::OEQ_F64, "__eqdf2vfp");
79      setLibcallName(RTLIB::UNE_F64, "__nedf2vfp");
80      setLibcallName(RTLIB::OLT_F64, "__ltdf2vfp");
81      setLibcallName(RTLIB::OLE_F64, "__ledf2vfp");
82      setLibcallName(RTLIB::OGE_F64, "__gedf2vfp");
83      setLibcallName(RTLIB::OGT_F64, "__gtdf2vfp");
84      setLibcallName(RTLIB::UO_F64,  "__unorddf2vfp");
85      setLibcallName(RTLIB::O_F64,   "__unorddf2vfp");
86
87      setCmpLibcallCC(RTLIB::OEQ_F64, ISD::SETNE);
88      setCmpLibcallCC(RTLIB::UNE_F64, ISD::SETNE);
89      setCmpLibcallCC(RTLIB::OLT_F64, ISD::SETNE);
90      setCmpLibcallCC(RTLIB::OLE_F64, ISD::SETNE);
91      setCmpLibcallCC(RTLIB::OGE_F64, ISD::SETNE);
92      setCmpLibcallCC(RTLIB::OGT_F64, ISD::SETNE);
93      setCmpLibcallCC(RTLIB::UO_F64,  ISD::SETNE);
94      setCmpLibcallCC(RTLIB::O_F64,   ISD::SETEQ);
95
96      // Floating-point to integer conversions.
97      // i64 conversions are done via library routines even when generating VFP
98      // instructions, so use the same ones.
99      setLibcallName(RTLIB::FPTOSINT_F64_I32, "__fixdfsivfp");
100      setLibcallName(RTLIB::FPTOUINT_F64_I32, "__fixunsdfsivfp");
101      setLibcallName(RTLIB::FPTOSINT_F32_I32, "__fixsfsivfp");
102      setLibcallName(RTLIB::FPTOUINT_F32_I32, "__fixunssfsivfp");
103
104      // Conversions between floating types.
105      setLibcallName(RTLIB::FPROUND_F64_F32, "__truncdfsf2vfp");
106      setLibcallName(RTLIB::FPEXT_F32_F64,   "__extendsfdf2vfp");
107
108      // Integer to floating-point conversions.
109      // i64 conversions are done via library routines even when generating VFP
110      // instructions, so use the same ones.
111      // FIXME: There appears to be some naming inconsistency in ARM libgcc: e.g.
112      // __floatunsidf vs. __floatunssidfvfp.
113      setLibcallName(RTLIB::SINTTOFP_I32_F64, "__floatsidfvfp");
114      setLibcallName(RTLIB::UINTTOFP_I32_F64, "__floatunssidfvfp");
115      setLibcallName(RTLIB::SINTTOFP_I32_F32, "__floatsisfvfp");
116      setLibcallName(RTLIB::UINTTOFP_I32_F32, "__floatunssisfvfp");
117    }
118  }
119
120  addRegisterClass(MVT::i32, ARM::GPRRegisterClass);
121  if (!UseSoftFloat && Subtarget->hasVFP2() && !Subtarget->isThumb()) {
122    addRegisterClass(MVT::f32, ARM::SPRRegisterClass);
123    addRegisterClass(MVT::f64, ARM::DPRRegisterClass);
124
125    setTruncStoreAction(MVT::f64, MVT::f32, Expand);
126  }
127  computeRegisterProperties();
128
129  // ARM does not have f32 extending load.
130  setLoadExtAction(ISD::EXTLOAD, MVT::f32, Expand);
131
132  // ARM does not have i1 sign extending load.
133  setLoadExtAction(ISD::SEXTLOAD, MVT::i1, Promote);
134
135  // ARM supports all 4 flavors of integer indexed load / store.
136  for (unsigned im = (unsigned)ISD::PRE_INC;
137       im != (unsigned)ISD::LAST_INDEXED_MODE; ++im) {
138    setIndexedLoadAction(im,  MVT::i1,  Legal);
139    setIndexedLoadAction(im,  MVT::i8,  Legal);
140    setIndexedLoadAction(im,  MVT::i16, Legal);
141    setIndexedLoadAction(im,  MVT::i32, Legal);
142    setIndexedStoreAction(im, MVT::i1,  Legal);
143    setIndexedStoreAction(im, MVT::i8,  Legal);
144    setIndexedStoreAction(im, MVT::i16, Legal);
145    setIndexedStoreAction(im, MVT::i32, Legal);
146  }
147
148  // i64 operation support.
149  if (Subtarget->isThumb()) {
150    setOperationAction(ISD::MUL,     MVT::i64, Expand);
151    setOperationAction(ISD::MULHU,   MVT::i32, Expand);
152    setOperationAction(ISD::MULHS,   MVT::i32, Expand);
153    setOperationAction(ISD::UMUL_LOHI, MVT::i32, Expand);
154    setOperationAction(ISD::SMUL_LOHI, MVT::i32, Expand);
155  } else {
156    setOperationAction(ISD::MUL,     MVT::i64, Expand);
157    setOperationAction(ISD::MULHU,   MVT::i32, Expand);
158    if (!Subtarget->hasV6Ops())
159      setOperationAction(ISD::MULHS, MVT::i32, Expand);
160  }
161  setOperationAction(ISD::SHL_PARTS, MVT::i32, Expand);
162  setOperationAction(ISD::SRA_PARTS, MVT::i32, Expand);
163  setOperationAction(ISD::SRL_PARTS, MVT::i32, Expand);
164  setOperationAction(ISD::SRL,       MVT::i64, Custom);
165  setOperationAction(ISD::SRA,       MVT::i64, Custom);
166
167  // ARM does not have ROTL.
168  setOperationAction(ISD::ROTL,  MVT::i32, Expand);
169  setOperationAction(ISD::CTTZ , MVT::i32, Expand);
170  setOperationAction(ISD::CTPOP, MVT::i32, Expand);
171  if (!Subtarget->hasV5TOps() || Subtarget->isThumb())
172    setOperationAction(ISD::CTLZ, MVT::i32, Expand);
173
174  // Only ARMv6 has BSWAP.
175  if (!Subtarget->hasV6Ops())
176    setOperationAction(ISD::BSWAP, MVT::i32, Expand);
177
178  // These are expanded into libcalls.
179  setOperationAction(ISD::SDIV,  MVT::i32, Expand);
180  setOperationAction(ISD::UDIV,  MVT::i32, Expand);
181  setOperationAction(ISD::SREM,  MVT::i32, Expand);
182  setOperationAction(ISD::UREM,  MVT::i32, Expand);
183  setOperationAction(ISD::SDIVREM, MVT::i32, Expand);
184  setOperationAction(ISD::UDIVREM, MVT::i32, Expand);
185
186  // Support label based line numbers.
187  setOperationAction(ISD::DBG_STOPPOINT, MVT::Other, Expand);
188  setOperationAction(ISD::DEBUG_LOC, MVT::Other, Expand);
189
190  setOperationAction(ISD::RET,           MVT::Other, Custom);
191  setOperationAction(ISD::GlobalAddress, MVT::i32,   Custom);
192  setOperationAction(ISD::ConstantPool,  MVT::i32,   Custom);
193  setOperationAction(ISD::GLOBAL_OFFSET_TABLE, MVT::i32, Custom);
194  setOperationAction(ISD::GlobalTLSAddress, MVT::i32, Custom);
195
196  // Use the default implementation.
197  setOperationAction(ISD::VASTART           , MVT::Other, Custom);
198  setOperationAction(ISD::VAARG             , MVT::Other, Expand);
199  setOperationAction(ISD::VACOPY            , MVT::Other, Expand);
200  setOperationAction(ISD::VAEND             , MVT::Other, Expand);
201  setOperationAction(ISD::STACKSAVE,          MVT::Other, Expand);
202  setOperationAction(ISD::STACKRESTORE,       MVT::Other, Expand);
203  setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32  , Expand);
204  setOperationAction(ISD::MEMBARRIER        , MVT::Other, Expand);
205
206  if (!Subtarget->hasV6Ops()) {
207    setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16, Expand);
208    setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i8,  Expand);
209  }
210  setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1, Expand);
211
212  if (!UseSoftFloat && Subtarget->hasVFP2() && !Subtarget->isThumb())
213    // Turn f64->i64 into FMRRD, i64 -> f64 to FMDRR iff target supports vfp2.
214    setOperationAction(ISD::BIT_CONVERT, MVT::i64, Custom);
215
216  // We want to custom lower some of our intrinsics.
217  setOperationAction(ISD::INTRINSIC_WO_CHAIN, MVT::Other, Custom);
218
219  setOperationAction(ISD::SETCC    , MVT::i32, Expand);
220  setOperationAction(ISD::SETCC    , MVT::f32, Expand);
221  setOperationAction(ISD::SETCC    , MVT::f64, Expand);
222  setOperationAction(ISD::SELECT   , MVT::i32, Expand);
223  setOperationAction(ISD::SELECT   , MVT::f32, Expand);
224  setOperationAction(ISD::SELECT   , MVT::f64, Expand);
225  setOperationAction(ISD::SELECT_CC, MVT::i32, Custom);
226  setOperationAction(ISD::SELECT_CC, MVT::f32, Custom);
227  setOperationAction(ISD::SELECT_CC, MVT::f64, Custom);
228
229  setOperationAction(ISD::BRCOND   , MVT::Other, Expand);
230  setOperationAction(ISD::BR_CC    , MVT::i32,   Custom);
231  setOperationAction(ISD::BR_CC    , MVT::f32,   Custom);
232  setOperationAction(ISD::BR_CC    , MVT::f64,   Custom);
233  setOperationAction(ISD::BR_JT    , MVT::Other, Custom);
234
235  // We don't support sin/cos/fmod/copysign/pow
236  setOperationAction(ISD::FSIN     , MVT::f64, Expand);
237  setOperationAction(ISD::FSIN     , MVT::f32, Expand);
238  setOperationAction(ISD::FCOS     , MVT::f32, Expand);
239  setOperationAction(ISD::FCOS     , MVT::f64, Expand);
240  setOperationAction(ISD::FREM     , MVT::f64, Expand);
241  setOperationAction(ISD::FREM     , MVT::f32, Expand);
242  if (!UseSoftFloat && Subtarget->hasVFP2() && !Subtarget->isThumb()) {
243    setOperationAction(ISD::FCOPYSIGN, MVT::f64, Custom);
244    setOperationAction(ISD::FCOPYSIGN, MVT::f32, Custom);
245  }
246  setOperationAction(ISD::FPOW     , MVT::f64, Expand);
247  setOperationAction(ISD::FPOW     , MVT::f32, Expand);
248
249  // int <-> fp are custom expanded into bit_convert + ARMISD ops.
250  if (!UseSoftFloat && Subtarget->hasVFP2() && !Subtarget->isThumb()) {
251    setOperationAction(ISD::SINT_TO_FP, MVT::i32, Custom);
252    setOperationAction(ISD::UINT_TO_FP, MVT::i32, Custom);
253    setOperationAction(ISD::FP_TO_UINT, MVT::i32, Custom);
254    setOperationAction(ISD::FP_TO_SINT, MVT::i32, Custom);
255  }
256
257  // We have target-specific dag combine patterns for the following nodes:
258  // ARMISD::FMRRD  - No need to call setTargetDAGCombine
259
260  setStackPointerRegisterToSaveRestore(ARM::SP);
261  setSchedulingPreference(SchedulingForRegPressure);
262  setIfCvtBlockSizeLimit(Subtarget->isThumb() ? 0 : 10);
263  setIfCvtDupBlockSizeLimit(Subtarget->isThumb() ? 0 : 2);
264
265  maxStoresPerMemcpy = 1;   //// temporary - rewrite interface to use type
266}
267
268
269const char *ARMTargetLowering::getTargetNodeName(unsigned Opcode) const {
270  switch (Opcode) {
271  default: return 0;
272  case ARMISD::Wrapper:       return "ARMISD::Wrapper";
273  case ARMISD::WrapperJT:     return "ARMISD::WrapperJT";
274  case ARMISD::CALL:          return "ARMISD::CALL";
275  case ARMISD::CALL_PRED:     return "ARMISD::CALL_PRED";
276  case ARMISD::CALL_NOLINK:   return "ARMISD::CALL_NOLINK";
277  case ARMISD::tCALL:         return "ARMISD::tCALL";
278  case ARMISD::BRCOND:        return "ARMISD::BRCOND";
279  case ARMISD::BR_JT:         return "ARMISD::BR_JT";
280  case ARMISD::RET_FLAG:      return "ARMISD::RET_FLAG";
281  case ARMISD::PIC_ADD:       return "ARMISD::PIC_ADD";
282  case ARMISD::CMP:           return "ARMISD::CMP";
283  case ARMISD::CMPNZ:         return "ARMISD::CMPNZ";
284  case ARMISD::CMPFP:         return "ARMISD::CMPFP";
285  case ARMISD::CMPFPw0:       return "ARMISD::CMPFPw0";
286  case ARMISD::FMSTAT:        return "ARMISD::FMSTAT";
287  case ARMISD::CMOV:          return "ARMISD::CMOV";
288  case ARMISD::CNEG:          return "ARMISD::CNEG";
289
290  case ARMISD::FTOSI:         return "ARMISD::FTOSI";
291  case ARMISD::FTOUI:         return "ARMISD::FTOUI";
292  case ARMISD::SITOF:         return "ARMISD::SITOF";
293  case ARMISD::UITOF:         return "ARMISD::UITOF";
294
295  case ARMISD::SRL_FLAG:      return "ARMISD::SRL_FLAG";
296  case ARMISD::SRA_FLAG:      return "ARMISD::SRA_FLAG";
297  case ARMISD::RRX:           return "ARMISD::RRX";
298
299  case ARMISD::FMRRD:         return "ARMISD::FMRRD";
300  case ARMISD::FMDRR:         return "ARMISD::FMDRR";
301
302  case ARMISD::THREAD_POINTER:return "ARMISD::THREAD_POINTER";
303  }
304}
305
306//===----------------------------------------------------------------------===//
307// Lowering Code
308//===----------------------------------------------------------------------===//
309
310
311/// IntCCToARMCC - Convert a DAG integer condition code to an ARM CC
312static ARMCC::CondCodes IntCCToARMCC(ISD::CondCode CC) {
313  switch (CC) {
314  default: assert(0 && "Unknown condition code!");
315  case ISD::SETNE:  return ARMCC::NE;
316  case ISD::SETEQ:  return ARMCC::EQ;
317  case ISD::SETGT:  return ARMCC::GT;
318  case ISD::SETGE:  return ARMCC::GE;
319  case ISD::SETLT:  return ARMCC::LT;
320  case ISD::SETLE:  return ARMCC::LE;
321  case ISD::SETUGT: return ARMCC::HI;
322  case ISD::SETUGE: return ARMCC::HS;
323  case ISD::SETULT: return ARMCC::LO;
324  case ISD::SETULE: return ARMCC::LS;
325  }
326}
327
328/// FPCCToARMCC - Convert a DAG fp condition code to an ARM CC. It
329/// returns true if the operands should be inverted to form the proper
330/// comparison.
331static bool FPCCToARMCC(ISD::CondCode CC, ARMCC::CondCodes &CondCode,
332                        ARMCC::CondCodes &CondCode2) {
333  bool Invert = false;
334  CondCode2 = ARMCC::AL;
335  switch (CC) {
336  default: assert(0 && "Unknown FP condition!");
337  case ISD::SETEQ:
338  case ISD::SETOEQ: CondCode = ARMCC::EQ; break;
339  case ISD::SETGT:
340  case ISD::SETOGT: CondCode = ARMCC::GT; break;
341  case ISD::SETGE:
342  case ISD::SETOGE: CondCode = ARMCC::GE; break;
343  case ISD::SETOLT: CondCode = ARMCC::MI; break;
344  case ISD::SETOLE: CondCode = ARMCC::GT; Invert = true; break;
345  case ISD::SETONE: CondCode = ARMCC::MI; CondCode2 = ARMCC::GT; break;
346  case ISD::SETO:   CondCode = ARMCC::VC; break;
347  case ISD::SETUO:  CondCode = ARMCC::VS; break;
348  case ISD::SETUEQ: CondCode = ARMCC::EQ; CondCode2 = ARMCC::VS; break;
349  case ISD::SETUGT: CondCode = ARMCC::HI; break;
350  case ISD::SETUGE: CondCode = ARMCC::PL; break;
351  case ISD::SETLT:
352  case ISD::SETULT: CondCode = ARMCC::LT; break;
353  case ISD::SETLE:
354  case ISD::SETULE: CondCode = ARMCC::LE; break;
355  case ISD::SETNE:
356  case ISD::SETUNE: CondCode = ARMCC::NE; break;
357  }
358  return Invert;
359}
360
361static void
362HowToPassArgument(MVT ObjectVT, unsigned NumGPRs,
363                  unsigned StackOffset, unsigned &NeededGPRs,
364                  unsigned &NeededStackSize, unsigned &GPRPad,
365                  unsigned &StackPad, ISD::ArgFlagsTy Flags) {
366  NeededStackSize = 0;
367  NeededGPRs = 0;
368  StackPad = 0;
369  GPRPad = 0;
370  unsigned align = Flags.getOrigAlign();
371  GPRPad = NumGPRs % ((align + 3)/4);
372  StackPad = StackOffset % align;
373  unsigned firstGPR = NumGPRs + GPRPad;
374  switch (ObjectVT.getSimpleVT()) {
375  default: assert(0 && "Unhandled argument type!");
376  case MVT::i32:
377  case MVT::f32:
378    if (firstGPR < 4)
379      NeededGPRs = 1;
380    else
381      NeededStackSize = 4;
382    break;
383  case MVT::i64:
384  case MVT::f64:
385    if (firstGPR < 3)
386      NeededGPRs = 2;
387    else if (firstGPR == 3) {
388      NeededGPRs = 1;
389      NeededStackSize = 4;
390    } else
391      NeededStackSize = 8;
392  }
393}
394
395/// LowerCALL - Lowering a ISD::CALL node into a callseq_start <-
396/// ARMISD:CALL <- callseq_end chain. Also add input and output parameter
397/// nodes.
398SDValue ARMTargetLowering::LowerCALL(SDValue Op, SelectionDAG &DAG) {
399  CallSDNode *TheCall = cast<CallSDNode>(Op.getNode());
400  MVT RetVT = TheCall->getRetValType(0);
401  SDValue Chain    = TheCall->getChain();
402  unsigned CallConv  = TheCall->getCallingConv();
403  assert((CallConv == CallingConv::C ||
404          CallConv == CallingConv::Fast) && "unknown calling convention");
405  SDValue Callee   = TheCall->getCallee();
406  unsigned NumOps    = TheCall->getNumArgs();
407  unsigned ArgOffset = 0;   // Frame mechanisms handle retaddr slot
408  unsigned NumGPRs = 0;     // GPRs used for parameter passing.
409
410  // Count how many bytes are to be pushed on the stack.
411  unsigned NumBytes = 0;
412
413  // Add up all the space actually used.
414  for (unsigned i = 0; i < NumOps; ++i) {
415    unsigned ObjSize;
416    unsigned ObjGPRs;
417    unsigned StackPad;
418    unsigned GPRPad;
419    MVT ObjectVT = TheCall->getArg(i).getValueType();
420    ISD::ArgFlagsTy Flags = TheCall->getArgFlags(i);
421    HowToPassArgument(ObjectVT, NumGPRs, NumBytes, ObjGPRs, ObjSize,
422                      GPRPad, StackPad, Flags);
423    NumBytes += ObjSize + StackPad;
424    NumGPRs += ObjGPRs + GPRPad;
425  }
426
427  // Adjust the stack pointer for the new arguments...
428  // These operations are automatically eliminated by the prolog/epilog pass
429  Chain = DAG.getCALLSEQ_START(Chain, DAG.getIntPtrConstant(NumBytes, true));
430
431  SDValue StackPtr = DAG.getRegister(ARM::SP, MVT::i32);
432
433  static const unsigned GPRArgRegs[] = {
434    ARM::R0, ARM::R1, ARM::R2, ARM::R3
435  };
436
437  NumGPRs = 0;
438  std::vector<std::pair<unsigned, SDValue> > RegsToPass;
439  std::vector<SDValue> MemOpChains;
440  for (unsigned i = 0; i != NumOps; ++i) {
441    SDValue Arg = TheCall->getArg(i);
442    ISD::ArgFlagsTy Flags = TheCall->getArgFlags(i);
443    MVT ArgVT = Arg.getValueType();
444
445    unsigned ObjSize;
446    unsigned ObjGPRs;
447    unsigned GPRPad;
448    unsigned StackPad;
449    HowToPassArgument(ArgVT, NumGPRs, ArgOffset, ObjGPRs,
450                      ObjSize, GPRPad, StackPad, Flags);
451    NumGPRs += GPRPad;
452    ArgOffset += StackPad;
453    if (ObjGPRs > 0) {
454      switch (ArgVT.getSimpleVT()) {
455      default: assert(0 && "Unexpected ValueType for argument!");
456      case MVT::i32:
457        RegsToPass.push_back(std::make_pair(GPRArgRegs[NumGPRs], Arg));
458        break;
459      case MVT::f32:
460        RegsToPass.push_back(std::make_pair(GPRArgRegs[NumGPRs],
461                                 DAG.getNode(ISD::BIT_CONVERT, MVT::i32, Arg)));
462        break;
463      case MVT::i64: {
464        SDValue Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Arg,
465                                   DAG.getConstant(0, getPointerTy()));
466        SDValue Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Arg,
467                                   DAG.getConstant(1, getPointerTy()));
468        RegsToPass.push_back(std::make_pair(GPRArgRegs[NumGPRs], Lo));
469        if (ObjGPRs == 2)
470          RegsToPass.push_back(std::make_pair(GPRArgRegs[NumGPRs+1], Hi));
471        else {
472          SDValue PtrOff= DAG.getConstant(ArgOffset, StackPtr.getValueType());
473          PtrOff = DAG.getNode(ISD::ADD, MVT::i32, StackPtr, PtrOff);
474          MemOpChains.push_back(DAG.getStore(Chain, Hi, PtrOff, NULL, 0));
475        }
476        break;
477      }
478      case MVT::f64: {
479        SDValue Cvt = DAG.getNode(ARMISD::FMRRD,
480                                    DAG.getVTList(MVT::i32, MVT::i32),
481                                    &Arg, 1);
482        RegsToPass.push_back(std::make_pair(GPRArgRegs[NumGPRs], Cvt));
483        if (ObjGPRs == 2)
484          RegsToPass.push_back(std::make_pair(GPRArgRegs[NumGPRs+1],
485                                              Cvt.getValue(1)));
486        else {
487          SDValue PtrOff= DAG.getConstant(ArgOffset, StackPtr.getValueType());
488          PtrOff = DAG.getNode(ISD::ADD, MVT::i32, StackPtr, PtrOff);
489          MemOpChains.push_back(DAG.getStore(Chain, Cvt.getValue(1), PtrOff,
490                                             NULL, 0));
491        }
492        break;
493      }
494      }
495    } else {
496      assert(ObjSize != 0);
497      SDValue PtrOff = DAG.getConstant(ArgOffset, StackPtr.getValueType());
498      PtrOff = DAG.getNode(ISD::ADD, MVT::i32, StackPtr, PtrOff);
499      MemOpChains.push_back(DAG.getStore(Chain, Arg, PtrOff, NULL, 0));
500    }
501
502    NumGPRs += ObjGPRs;
503    ArgOffset += ObjSize;
504  }
505
506  if (!MemOpChains.empty())
507    Chain = DAG.getNode(ISD::TokenFactor, MVT::Other,
508                        &MemOpChains[0], MemOpChains.size());
509
510  // Build a sequence of copy-to-reg nodes chained together with token chain
511  // and flag operands which copy the outgoing args into the appropriate regs.
512  SDValue InFlag;
513  for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
514    Chain = DAG.getCopyToReg(Chain, RegsToPass[i].first, RegsToPass[i].second,
515                             InFlag);
516    InFlag = Chain.getValue(1);
517  }
518
519  // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
520  // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
521  // node so that legalize doesn't hack it.
522  bool isDirect = false;
523  bool isARMFunc = false;
524  bool isLocalARMFunc = false;
525  if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
526    GlobalValue *GV = G->getGlobal();
527    isDirect = true;
528    bool isExt = (GV->isDeclaration() || GV->hasWeakLinkage() ||
529                  GV->hasLinkOnceLinkage());
530    bool isStub = (isExt && Subtarget->isTargetDarwin()) &&
531                   getTargetMachine().getRelocationModel() != Reloc::Static;
532    isARMFunc = !Subtarget->isThumb() || isStub;
533    // ARM call to a local ARM function is predicable.
534    isLocalARMFunc = !Subtarget->isThumb() && !isExt;
535    // tBX takes a register source operand.
536    if (isARMFunc && Subtarget->isThumb() && !Subtarget->hasV5TOps()) {
537      ARMConstantPoolValue *CPV = new ARMConstantPoolValue(GV, ARMPCLabelIndex,
538                                                           ARMCP::CPStub, 4);
539      SDValue CPAddr = DAG.getTargetConstantPool(CPV, getPointerTy(), 2);
540      CPAddr = DAG.getNode(ARMISD::Wrapper, MVT::i32, CPAddr);
541      Callee = DAG.getLoad(getPointerTy(), DAG.getEntryNode(), CPAddr, NULL, 0);
542      SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex++, MVT::i32);
543      Callee = DAG.getNode(ARMISD::PIC_ADD, getPointerTy(), Callee, PICLabel);
544   } else
545      Callee = DAG.getTargetGlobalAddress(GV, getPointerTy());
546  } else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) {
547    isDirect = true;
548    bool isStub = Subtarget->isTargetDarwin() &&
549                  getTargetMachine().getRelocationModel() != Reloc::Static;
550    isARMFunc = !Subtarget->isThumb() || isStub;
551    // tBX takes a register source operand.
552    const char *Sym = S->getSymbol();
553    if (isARMFunc && Subtarget->isThumb() && !Subtarget->hasV5TOps()) {
554      ARMConstantPoolValue *CPV = new ARMConstantPoolValue(Sym, ARMPCLabelIndex,
555                                                           ARMCP::CPStub, 4);
556      SDValue CPAddr = DAG.getTargetConstantPool(CPV, getPointerTy(), 2);
557      CPAddr = DAG.getNode(ARMISD::Wrapper, MVT::i32, CPAddr);
558      Callee = DAG.getLoad(getPointerTy(), DAG.getEntryNode(), CPAddr, NULL, 0);
559      SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex++, MVT::i32);
560      Callee = DAG.getNode(ARMISD::PIC_ADD, getPointerTy(), Callee, PICLabel);
561    } else
562      Callee = DAG.getTargetExternalSymbol(Sym, getPointerTy());
563  }
564
565  // FIXME: handle tail calls differently.
566  unsigned CallOpc;
567  if (Subtarget->isThumb()) {
568    if (!Subtarget->hasV5TOps() && (!isDirect || isARMFunc))
569      CallOpc = ARMISD::CALL_NOLINK;
570    else
571      CallOpc = isARMFunc ? ARMISD::CALL : ARMISD::tCALL;
572  } else {
573    CallOpc = (isDirect || Subtarget->hasV5TOps())
574      ? (isLocalARMFunc ? ARMISD::CALL_PRED : ARMISD::CALL)
575      : ARMISD::CALL_NOLINK;
576  }
577  if (CallOpc == ARMISD::CALL_NOLINK && !Subtarget->isThumb()) {
578    // implicit def LR - LR mustn't be allocated as GRP:$dst of CALL_NOLINK
579    Chain = DAG.getCopyToReg(Chain, ARM::LR,
580                             DAG.getNode(ISD::UNDEF, MVT::i32), InFlag);
581    InFlag = Chain.getValue(1);
582  }
583
584  std::vector<SDValue> Ops;
585  Ops.push_back(Chain);
586  Ops.push_back(Callee);
587
588  // Add argument registers to the end of the list so that they are known live
589  // into the call.
590  for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i)
591    Ops.push_back(DAG.getRegister(RegsToPass[i].first,
592                                  RegsToPass[i].second.getValueType()));
593
594  if (InFlag.getNode())
595    Ops.push_back(InFlag);
596  // Returns a chain and a flag for retval copy to use.
597  Chain = DAG.getNode(CallOpc, DAG.getVTList(MVT::Other, MVT::Flag),
598                      &Ops[0], Ops.size());
599  InFlag = Chain.getValue(1);
600
601  Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(NumBytes, true),
602                             DAG.getIntPtrConstant(0, true), InFlag);
603  if (RetVT != MVT::Other)
604    InFlag = Chain.getValue(1);
605
606  std::vector<SDValue> ResultVals;
607
608  // If the call has results, copy the values out of the ret val registers.
609  switch (RetVT.getSimpleVT()) {
610  default: assert(0 && "Unexpected ret value!");
611  case MVT::Other:
612    break;
613  case MVT::i32:
614    Chain = DAG.getCopyFromReg(Chain, ARM::R0, MVT::i32, InFlag).getValue(1);
615    ResultVals.push_back(Chain.getValue(0));
616    if (TheCall->getNumRetVals() > 1 &&
617        TheCall->getRetValType(1) == MVT::i32) {
618      // Returns a i64 value.
619      Chain = DAG.getCopyFromReg(Chain, ARM::R1, MVT::i32,
620                                 Chain.getValue(2)).getValue(1);
621      ResultVals.push_back(Chain.getValue(0));
622    }
623    break;
624  case MVT::f32:
625    Chain = DAG.getCopyFromReg(Chain, ARM::R0, MVT::i32, InFlag).getValue(1);
626    ResultVals.push_back(DAG.getNode(ISD::BIT_CONVERT, MVT::f32,
627                                     Chain.getValue(0)));
628    break;
629  case MVT::f64: {
630    SDValue Lo = DAG.getCopyFromReg(Chain, ARM::R0, MVT::i32, InFlag);
631    SDValue Hi = DAG.getCopyFromReg(Lo, ARM::R1, MVT::i32, Lo.getValue(2));
632    ResultVals.push_back(DAG.getNode(ARMISD::FMDRR, MVT::f64, Lo, Hi));
633    break;
634  }
635  }
636
637  if (ResultVals.empty())
638    return Chain;
639
640  ResultVals.push_back(Chain);
641  SDValue Res = DAG.getMergeValues(&ResultVals[0], ResultVals.size());
642  return Res.getValue(Op.getResNo());
643}
644
645static SDValue LowerRET(SDValue Op, SelectionDAG &DAG) {
646  SDValue Copy;
647  SDValue Chain = Op.getOperand(0);
648  switch(Op.getNumOperands()) {
649  default:
650    assert(0 && "Do not know how to return this many arguments!");
651    abort();
652  case 1: {
653    SDValue LR = DAG.getRegister(ARM::LR, MVT::i32);
654    return DAG.getNode(ARMISD::RET_FLAG, MVT::Other, Chain);
655  }
656  case 3:
657    Op = Op.getOperand(1);
658    if (Op.getValueType() == MVT::f32) {
659      Op = DAG.getNode(ISD::BIT_CONVERT, MVT::i32, Op);
660    } else if (Op.getValueType() == MVT::f64) {
661      // Legalize ret f64 -> ret 2 x i32.  We always have fmrrd if f64 is
662      // available.
663      Op = DAG.getNode(ARMISD::FMRRD, DAG.getVTList(MVT::i32, MVT::i32), &Op,1);
664      SDValue Sign = DAG.getConstant(0, MVT::i32);
665      return DAG.getNode(ISD::RET, MVT::Other, Chain, Op, Sign,
666                         Op.getValue(1), Sign);
667    }
668    Copy = DAG.getCopyToReg(Chain, ARM::R0, Op, SDValue());
669    if (DAG.getMachineFunction().getRegInfo().liveout_empty())
670      DAG.getMachineFunction().getRegInfo().addLiveOut(ARM::R0);
671    break;
672  case 5:
673    Copy = DAG.getCopyToReg(Chain, ARM::R1, Op.getOperand(3), SDValue());
674    Copy = DAG.getCopyToReg(Copy, ARM::R0, Op.getOperand(1), Copy.getValue(1));
675    // If we haven't noted the R0+R1 are live out, do so now.
676    if (DAG.getMachineFunction().getRegInfo().liveout_empty()) {
677      DAG.getMachineFunction().getRegInfo().addLiveOut(ARM::R0);
678      DAG.getMachineFunction().getRegInfo().addLiveOut(ARM::R1);
679    }
680    break;
681  case 9:  // i128 -> 4 regs
682    Copy = DAG.getCopyToReg(Chain, ARM::R3, Op.getOperand(7), SDValue());
683    Copy = DAG.getCopyToReg(Copy , ARM::R2, Op.getOperand(5), Copy.getValue(1));
684    Copy = DAG.getCopyToReg(Copy , ARM::R1, Op.getOperand(3), Copy.getValue(1));
685    Copy = DAG.getCopyToReg(Copy , ARM::R0, Op.getOperand(1), Copy.getValue(1));
686    // If we haven't noted the R0+R1 are live out, do so now.
687    if (DAG.getMachineFunction().getRegInfo().liveout_empty()) {
688      DAG.getMachineFunction().getRegInfo().addLiveOut(ARM::R0);
689      DAG.getMachineFunction().getRegInfo().addLiveOut(ARM::R1);
690      DAG.getMachineFunction().getRegInfo().addLiveOut(ARM::R2);
691      DAG.getMachineFunction().getRegInfo().addLiveOut(ARM::R3);
692    }
693    break;
694
695  }
696
697  //We must use RET_FLAG instead of BRIND because BRIND doesn't have a flag
698  return DAG.getNode(ARMISD::RET_FLAG, MVT::Other, Copy, Copy.getValue(1));
699}
700
701// ConstantPool, JumpTable, GlobalAddress, and ExternalSymbol are lowered as
702// their target countpart wrapped in the ARMISD::Wrapper node. Suppose N is
703// one of the above mentioned nodes. It has to be wrapped because otherwise
704// Select(N) returns N. So the raw TargetGlobalAddress nodes, etc. can only
705// be used to form addressing mode. These wrapped nodes will be selected
706// into MOVi.
707static SDValue LowerConstantPool(SDValue Op, SelectionDAG &DAG) {
708  MVT PtrVT = Op.getValueType();
709  ConstantPoolSDNode *CP = cast<ConstantPoolSDNode>(Op);
710  SDValue Res;
711  if (CP->isMachineConstantPoolEntry())
712    Res = DAG.getTargetConstantPool(CP->getMachineCPVal(), PtrVT,
713                                    CP->getAlignment());
714  else
715    Res = DAG.getTargetConstantPool(CP->getConstVal(), PtrVT,
716                                    CP->getAlignment());
717  return DAG.getNode(ARMISD::Wrapper, MVT::i32, Res);
718}
719
720// Lower ISD::GlobalTLSAddress using the "general dynamic" model
721SDValue
722ARMTargetLowering::LowerToTLSGeneralDynamicModel(GlobalAddressSDNode *GA,
723                                                 SelectionDAG &DAG) {
724  MVT PtrVT = getPointerTy();
725  unsigned char PCAdj = Subtarget->isThumb() ? 4 : 8;
726  ARMConstantPoolValue *CPV =
727    new ARMConstantPoolValue(GA->getGlobal(), ARMPCLabelIndex, ARMCP::CPValue,
728                             PCAdj, "tlsgd", true);
729  SDValue Argument = DAG.getTargetConstantPool(CPV, PtrVT, 2);
730  Argument = DAG.getNode(ARMISD::Wrapper, MVT::i32, Argument);
731  Argument = DAG.getLoad(PtrVT, DAG.getEntryNode(), Argument, NULL, 0);
732  SDValue Chain = Argument.getValue(1);
733
734  SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex++, MVT::i32);
735  Argument = DAG.getNode(ARMISD::PIC_ADD, PtrVT, Argument, PICLabel);
736
737  // call __tls_get_addr.
738  ArgListTy Args;
739  ArgListEntry Entry;
740  Entry.Node = Argument;
741  Entry.Ty = (const Type *) Type::Int32Ty;
742  Args.push_back(Entry);
743  std::pair<SDValue, SDValue> CallResult =
744    LowerCallTo(Chain, (const Type *) Type::Int32Ty, false, false, false, false,
745                CallingConv::C, false,
746                DAG.getExternalSymbol("__tls_get_addr", PtrVT), Args, DAG);
747  return CallResult.first;
748}
749
750// Lower ISD::GlobalTLSAddress using the "initial exec" or
751// "local exec" model.
752SDValue
753ARMTargetLowering::LowerToTLSExecModels(GlobalAddressSDNode *GA,
754                                            SelectionDAG &DAG) {
755  GlobalValue *GV = GA->getGlobal();
756  SDValue Offset;
757  SDValue Chain = DAG.getEntryNode();
758  MVT PtrVT = getPointerTy();
759  // Get the Thread Pointer
760  SDValue ThreadPointer = DAG.getNode(ARMISD::THREAD_POINTER, PtrVT);
761
762  if (GV->isDeclaration()){
763    // initial exec model
764    unsigned char PCAdj = Subtarget->isThumb() ? 4 : 8;
765    ARMConstantPoolValue *CPV =
766      new ARMConstantPoolValue(GA->getGlobal(), ARMPCLabelIndex, ARMCP::CPValue,
767                               PCAdj, "gottpoff", true);
768    Offset = DAG.getTargetConstantPool(CPV, PtrVT, 2);
769    Offset = DAG.getNode(ARMISD::Wrapper, MVT::i32, Offset);
770    Offset = DAG.getLoad(PtrVT, Chain, Offset, NULL, 0);
771    Chain = Offset.getValue(1);
772
773    SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex++, MVT::i32);
774    Offset = DAG.getNode(ARMISD::PIC_ADD, PtrVT, Offset, PICLabel);
775
776    Offset = DAG.getLoad(PtrVT, Chain, Offset, NULL, 0);
777  } else {
778    // local exec model
779    ARMConstantPoolValue *CPV =
780      new ARMConstantPoolValue(GV, ARMCP::CPValue, "tpoff");
781    Offset = DAG.getTargetConstantPool(CPV, PtrVT, 2);
782    Offset = DAG.getNode(ARMISD::Wrapper, MVT::i32, Offset);
783    Offset = DAG.getLoad(PtrVT, Chain, Offset, NULL, 0);
784  }
785
786  // The address of the thread local variable is the add of the thread
787  // pointer with the offset of the variable.
788  return DAG.getNode(ISD::ADD, PtrVT, ThreadPointer, Offset);
789}
790
791SDValue
792ARMTargetLowering::LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) {
793  // TODO: implement the "local dynamic" model
794  assert(Subtarget->isTargetELF() &&
795         "TLS not implemented for non-ELF targets");
796  GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
797  // If the relocation model is PIC, use the "General Dynamic" TLS Model,
798  // otherwise use the "Local Exec" TLS Model
799  if (getTargetMachine().getRelocationModel() == Reloc::PIC_)
800    return LowerToTLSGeneralDynamicModel(GA, DAG);
801  else
802    return LowerToTLSExecModels(GA, DAG);
803}
804
805SDValue ARMTargetLowering::LowerGlobalAddressELF(SDValue Op,
806                                                   SelectionDAG &DAG) {
807  MVT PtrVT = getPointerTy();
808  GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
809  Reloc::Model RelocM = getTargetMachine().getRelocationModel();
810  if (RelocM == Reloc::PIC_) {
811    bool UseGOTOFF = GV->hasInternalLinkage() || GV->hasHiddenVisibility();
812    ARMConstantPoolValue *CPV =
813      new ARMConstantPoolValue(GV, ARMCP::CPValue, UseGOTOFF ? "GOTOFF":"GOT");
814    SDValue CPAddr = DAG.getTargetConstantPool(CPV, PtrVT, 2);
815    CPAddr = DAG.getNode(ARMISD::Wrapper, MVT::i32, CPAddr);
816    SDValue Result = DAG.getLoad(PtrVT, DAG.getEntryNode(), CPAddr, NULL, 0);
817    SDValue Chain = Result.getValue(1);
818    SDValue GOT = DAG.getNode(ISD::GLOBAL_OFFSET_TABLE, PtrVT);
819    Result = DAG.getNode(ISD::ADD, PtrVT, Result, GOT);
820    if (!UseGOTOFF)
821      Result = DAG.getLoad(PtrVT, Chain, Result, NULL, 0);
822    return Result;
823  } else {
824    SDValue CPAddr = DAG.getTargetConstantPool(GV, PtrVT, 2);
825    CPAddr = DAG.getNode(ARMISD::Wrapper, MVT::i32, CPAddr);
826    return DAG.getLoad(PtrVT, DAG.getEntryNode(), CPAddr, NULL, 0);
827  }
828}
829
830/// GVIsIndirectSymbol - true if the GV will be accessed via an indirect symbol
831/// even in non-static mode.
832static bool GVIsIndirectSymbol(GlobalValue *GV, Reloc::Model RelocM) {
833  return RelocM != Reloc::Static &&
834    (GV->hasWeakLinkage() || GV->hasLinkOnceLinkage() ||
835     (GV->isDeclaration() && !GV->hasNotBeenReadFromBitcode()));
836}
837
838SDValue ARMTargetLowering::LowerGlobalAddressDarwin(SDValue Op,
839                                                      SelectionDAG &DAG) {
840  MVT PtrVT = getPointerTy();
841  GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
842  Reloc::Model RelocM = getTargetMachine().getRelocationModel();
843  bool IsIndirect = GVIsIndirectSymbol(GV, RelocM);
844  SDValue CPAddr;
845  if (RelocM == Reloc::Static)
846    CPAddr = DAG.getTargetConstantPool(GV, PtrVT, 2);
847  else {
848    unsigned PCAdj = (RelocM != Reloc::PIC_)
849      ? 0 : (Subtarget->isThumb() ? 4 : 8);
850    ARMCP::ARMCPKind Kind = IsIndirect ? ARMCP::CPNonLazyPtr
851      : ARMCP::CPValue;
852    ARMConstantPoolValue *CPV = new ARMConstantPoolValue(GV, ARMPCLabelIndex,
853                                                         Kind, PCAdj);
854    CPAddr = DAG.getTargetConstantPool(CPV, PtrVT, 2);
855  }
856  CPAddr = DAG.getNode(ARMISD::Wrapper, MVT::i32, CPAddr);
857
858  SDValue Result = DAG.getLoad(PtrVT, DAG.getEntryNode(), CPAddr, NULL, 0);
859  SDValue Chain = Result.getValue(1);
860
861  if (RelocM == Reloc::PIC_) {
862    SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex++, MVT::i32);
863    Result = DAG.getNode(ARMISD::PIC_ADD, PtrVT, Result, PICLabel);
864  }
865  if (IsIndirect)
866    Result = DAG.getLoad(PtrVT, Chain, Result, NULL, 0);
867
868  return Result;
869}
870
871SDValue ARMTargetLowering::LowerGLOBAL_OFFSET_TABLE(SDValue Op,
872                                                      SelectionDAG &DAG){
873  assert(Subtarget->isTargetELF() &&
874         "GLOBAL OFFSET TABLE not implemented for non-ELF targets");
875  MVT PtrVT = getPointerTy();
876  unsigned PCAdj = Subtarget->isThumb() ? 4 : 8;
877  ARMConstantPoolValue *CPV = new ARMConstantPoolValue("_GLOBAL_OFFSET_TABLE_",
878                                                       ARMPCLabelIndex,
879                                                       ARMCP::CPValue, PCAdj);
880  SDValue CPAddr = DAG.getTargetConstantPool(CPV, PtrVT, 2);
881  CPAddr = DAG.getNode(ARMISD::Wrapper, MVT::i32, CPAddr);
882  SDValue Result = DAG.getLoad(PtrVT, DAG.getEntryNode(), CPAddr, NULL, 0);
883  SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex++, MVT::i32);
884  return DAG.getNode(ARMISD::PIC_ADD, PtrVT, Result, PICLabel);
885}
886
887static SDValue LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG) {
888  MVT PtrVT = DAG.getTargetLoweringInfo().getPointerTy();
889  unsigned IntNo = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
890  switch (IntNo) {
891  default: return SDValue();    // Don't custom lower most intrinsics.
892  case Intrinsic::arm_thread_pointer:
893      return DAG.getNode(ARMISD::THREAD_POINTER, PtrVT);
894  }
895}
896
897static SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG,
898                              unsigned VarArgsFrameIndex) {
899  // vastart just stores the address of the VarArgsFrameIndex slot into the
900  // memory location argument.
901  MVT PtrVT = DAG.getTargetLoweringInfo().getPointerTy();
902  SDValue FR = DAG.getFrameIndex(VarArgsFrameIndex, PtrVT);
903  const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
904  return DAG.getStore(Op.getOperand(0), FR, Op.getOperand(1), SV, 0);
905}
906
907static SDValue LowerFORMAL_ARGUMENT(SDValue Op, SelectionDAG &DAG,
908                                      unsigned ArgNo, unsigned &NumGPRs,
909                                      unsigned &ArgOffset) {
910  MachineFunction &MF = DAG.getMachineFunction();
911  MVT ObjectVT = Op.getValue(ArgNo).getValueType();
912  SDValue Root = Op.getOperand(0);
913  MachineRegisterInfo &RegInfo = MF.getRegInfo();
914
915  static const unsigned GPRArgRegs[] = {
916    ARM::R0, ARM::R1, ARM::R2, ARM::R3
917  };
918
919  unsigned ObjSize;
920  unsigned ObjGPRs;
921  unsigned GPRPad;
922  unsigned StackPad;
923  ISD::ArgFlagsTy Flags =
924    cast<ARG_FLAGSSDNode>(Op.getOperand(ArgNo + 3))->getArgFlags();
925  HowToPassArgument(ObjectVT, NumGPRs, ArgOffset, ObjGPRs,
926                    ObjSize, GPRPad, StackPad, Flags);
927  NumGPRs += GPRPad;
928  ArgOffset += StackPad;
929
930  SDValue ArgValue;
931  if (ObjGPRs == 1) {
932    unsigned VReg = RegInfo.createVirtualRegister(&ARM::GPRRegClass);
933    RegInfo.addLiveIn(GPRArgRegs[NumGPRs], VReg);
934    ArgValue = DAG.getCopyFromReg(Root, VReg, MVT::i32);
935    if (ObjectVT == MVT::f32)
936      ArgValue = DAG.getNode(ISD::BIT_CONVERT, MVT::f32, ArgValue);
937  } else if (ObjGPRs == 2) {
938    unsigned VReg = RegInfo.createVirtualRegister(&ARM::GPRRegClass);
939    RegInfo.addLiveIn(GPRArgRegs[NumGPRs], VReg);
940    ArgValue = DAG.getCopyFromReg(Root, VReg, MVT::i32);
941
942    VReg = RegInfo.createVirtualRegister(&ARM::GPRRegClass);
943    RegInfo.addLiveIn(GPRArgRegs[NumGPRs+1], VReg);
944    SDValue ArgValue2 = DAG.getCopyFromReg(Root, VReg, MVT::i32);
945
946    assert(ObjectVT != MVT::i64 && "i64 should already be lowered");
947    ArgValue = DAG.getNode(ARMISD::FMDRR, MVT::f64, ArgValue, ArgValue2);
948  }
949  NumGPRs += ObjGPRs;
950
951  if (ObjSize) {
952    MachineFrameInfo *MFI = MF.getFrameInfo();
953    int FI = MFI->CreateFixedObject(ObjSize, ArgOffset);
954    SDValue FIN = DAG.getFrameIndex(FI, MVT::i32);
955    if (ObjGPRs == 0)
956      ArgValue = DAG.getLoad(ObjectVT, Root, FIN, NULL, 0);
957    else {
958      SDValue ArgValue2 = DAG.getLoad(MVT::i32, Root, FIN, NULL, 0);
959      assert(ObjectVT != MVT::i64 && "i64 should already be lowered");
960      ArgValue = DAG.getNode(ARMISD::FMDRR, MVT::f64, ArgValue, ArgValue2);
961    }
962
963    ArgOffset += ObjSize;   // Move on to the next argument.
964  }
965
966  return ArgValue;
967}
968
969SDValue
970ARMTargetLowering::LowerFORMAL_ARGUMENTS(SDValue Op, SelectionDAG &DAG) {
971  std::vector<SDValue> ArgValues;
972  SDValue Root = Op.getOperand(0);
973  unsigned ArgOffset = 0;   // Frame mechanisms handle retaddr slot
974  unsigned NumGPRs = 0;     // GPRs used for parameter passing.
975
976  unsigned NumArgs = Op.getNode()->getNumValues()-1;
977  for (unsigned ArgNo = 0; ArgNo < NumArgs; ++ArgNo)
978    ArgValues.push_back(LowerFORMAL_ARGUMENT(Op, DAG, ArgNo,
979                                             NumGPRs, ArgOffset));
980
981  bool isVarArg = cast<ConstantSDNode>(Op.getOperand(2))->getZExtValue() != 0;
982  if (isVarArg) {
983    static const unsigned GPRArgRegs[] = {
984      ARM::R0, ARM::R1, ARM::R2, ARM::R3
985    };
986
987    MachineFunction &MF = DAG.getMachineFunction();
988    MachineRegisterInfo &RegInfo = MF.getRegInfo();
989    MachineFrameInfo *MFI = MF.getFrameInfo();
990    ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
991    unsigned Align = MF.getTarget().getFrameInfo()->getStackAlignment();
992    unsigned VARegSize = (4 - NumGPRs) * 4;
993    unsigned VARegSaveSize = (VARegSize + Align - 1) & ~(Align - 1);
994    if (VARegSaveSize) {
995      // If this function is vararg, store any remaining integer argument regs
996      // to their spots on the stack so that they may be loaded by deferencing
997      // the result of va_next.
998      AFI->setVarArgsRegSaveSize(VARegSaveSize);
999      VarArgsFrameIndex = MFI->CreateFixedObject(VARegSaveSize, ArgOffset +
1000                                                 VARegSaveSize - VARegSize);
1001      SDValue FIN = DAG.getFrameIndex(VarArgsFrameIndex, getPointerTy());
1002
1003      SmallVector<SDValue, 4> MemOps;
1004      for (; NumGPRs < 4; ++NumGPRs) {
1005        unsigned VReg = RegInfo.createVirtualRegister(&ARM::GPRRegClass);
1006        RegInfo.addLiveIn(GPRArgRegs[NumGPRs], VReg);
1007        SDValue Val = DAG.getCopyFromReg(Root, VReg, MVT::i32);
1008        SDValue Store = DAG.getStore(Val.getValue(1), Val, FIN, NULL, 0);
1009        MemOps.push_back(Store);
1010        FIN = DAG.getNode(ISD::ADD, getPointerTy(), FIN,
1011                          DAG.getConstant(4, getPointerTy()));
1012      }
1013      if (!MemOps.empty())
1014        Root = DAG.getNode(ISD::TokenFactor, MVT::Other,
1015                           &MemOps[0], MemOps.size());
1016    } else
1017      // This will point to the next argument passed via stack.
1018      VarArgsFrameIndex = MFI->CreateFixedObject(4, ArgOffset);
1019  }
1020
1021  ArgValues.push_back(Root);
1022
1023  // Return the new list of results.
1024  return DAG.getMergeValues(Op.getNode()->getVTList(), &ArgValues[0],
1025                            ArgValues.size());
1026}
1027
1028/// isFloatingPointZero - Return true if this is +0.0.
1029static bool isFloatingPointZero(SDValue Op) {
1030  if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(Op))
1031    return CFP->getValueAPF().isPosZero();
1032  else if (ISD::isEXTLoad(Op.getNode()) || ISD::isNON_EXTLoad(Op.getNode())) {
1033    // Maybe this has already been legalized into the constant pool?
1034    if (Op.getOperand(1).getOpcode() == ARMISD::Wrapper) {
1035      SDValue WrapperOp = Op.getOperand(1).getOperand(0);
1036      if (ConstantPoolSDNode *CP = dyn_cast<ConstantPoolSDNode>(WrapperOp))
1037        if (ConstantFP *CFP = dyn_cast<ConstantFP>(CP->getConstVal()))
1038          return CFP->getValueAPF().isPosZero();
1039    }
1040  }
1041  return false;
1042}
1043
1044static bool isLegalCmpImmediate(unsigned C, bool isThumb) {
1045  return ( isThumb && (C & ~255U) == 0) ||
1046         (!isThumb && ARM_AM::getSOImmVal(C) != -1);
1047}
1048
1049/// Returns appropriate ARM CMP (cmp) and corresponding condition code for
1050/// the given operands.
1051static SDValue getARMCmp(SDValue LHS, SDValue RHS, ISD::CondCode CC,
1052                           SDValue &ARMCC, SelectionDAG &DAG, bool isThumb) {
1053  if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(RHS.getNode())) {
1054    unsigned C = RHSC->getZExtValue();
1055    if (!isLegalCmpImmediate(C, isThumb)) {
1056      // Constant does not fit, try adjusting it by one?
1057      switch (CC) {
1058      default: break;
1059      case ISD::SETLT:
1060      case ISD::SETGE:
1061        if (isLegalCmpImmediate(C-1, isThumb)) {
1062          CC = (CC == ISD::SETLT) ? ISD::SETLE : ISD::SETGT;
1063          RHS = DAG.getConstant(C-1, MVT::i32);
1064        }
1065        break;
1066      case ISD::SETULT:
1067      case ISD::SETUGE:
1068        if (C > 0 && isLegalCmpImmediate(C-1, isThumb)) {
1069          CC = (CC == ISD::SETULT) ? ISD::SETULE : ISD::SETUGT;
1070          RHS = DAG.getConstant(C-1, MVT::i32);
1071        }
1072        break;
1073      case ISD::SETLE:
1074      case ISD::SETGT:
1075        if (isLegalCmpImmediate(C+1, isThumb)) {
1076          CC = (CC == ISD::SETLE) ? ISD::SETLT : ISD::SETGE;
1077          RHS = DAG.getConstant(C+1, MVT::i32);
1078        }
1079        break;
1080      case ISD::SETULE:
1081      case ISD::SETUGT:
1082        if (C < 0xffffffff && isLegalCmpImmediate(C+1, isThumb)) {
1083          CC = (CC == ISD::SETULE) ? ISD::SETULT : ISD::SETUGE;
1084          RHS = DAG.getConstant(C+1, MVT::i32);
1085        }
1086        break;
1087      }
1088    }
1089  }
1090
1091  ARMCC::CondCodes CondCode = IntCCToARMCC(CC);
1092  ARMISD::NodeType CompareType;
1093  switch (CondCode) {
1094  default:
1095    CompareType = ARMISD::CMP;
1096    break;
1097  case ARMCC::EQ:
1098  case ARMCC::NE:
1099  case ARMCC::MI:
1100  case ARMCC::PL:
1101    // Uses only N and Z Flags
1102    CompareType = ARMISD::CMPNZ;
1103    break;
1104  }
1105  ARMCC = DAG.getConstant(CondCode, MVT::i32);
1106  return DAG.getNode(CompareType, MVT::Flag, LHS, RHS);
1107}
1108
1109/// Returns a appropriate VFP CMP (fcmp{s|d}+fmstat) for the given operands.
1110static SDValue getVFPCmp(SDValue LHS, SDValue RHS, SelectionDAG &DAG) {
1111  SDValue Cmp;
1112  if (!isFloatingPointZero(RHS))
1113    Cmp = DAG.getNode(ARMISD::CMPFP, MVT::Flag, LHS, RHS);
1114  else
1115    Cmp = DAG.getNode(ARMISD::CMPFPw0, MVT::Flag, LHS);
1116  return DAG.getNode(ARMISD::FMSTAT, MVT::Flag, Cmp);
1117}
1118
1119static SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG,
1120                                const ARMSubtarget *ST) {
1121  MVT VT = Op.getValueType();
1122  SDValue LHS = Op.getOperand(0);
1123  SDValue RHS = Op.getOperand(1);
1124  ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(4))->get();
1125  SDValue TrueVal = Op.getOperand(2);
1126  SDValue FalseVal = Op.getOperand(3);
1127
1128  if (LHS.getValueType() == MVT::i32) {
1129    SDValue ARMCC;
1130    SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
1131    SDValue Cmp = getARMCmp(LHS, RHS, CC, ARMCC, DAG, ST->isThumb());
1132    return DAG.getNode(ARMISD::CMOV, VT, FalseVal, TrueVal, ARMCC, CCR, Cmp);
1133  }
1134
1135  ARMCC::CondCodes CondCode, CondCode2;
1136  if (FPCCToARMCC(CC, CondCode, CondCode2))
1137    std::swap(TrueVal, FalseVal);
1138
1139  SDValue ARMCC = DAG.getConstant(CondCode, MVT::i32);
1140  SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
1141  SDValue Cmp = getVFPCmp(LHS, RHS, DAG);
1142  SDValue Result = DAG.getNode(ARMISD::CMOV, VT, FalseVal, TrueVal,
1143                                 ARMCC, CCR, Cmp);
1144  if (CondCode2 != ARMCC::AL) {
1145    SDValue ARMCC2 = DAG.getConstant(CondCode2, MVT::i32);
1146    // FIXME: Needs another CMP because flag can have but one use.
1147    SDValue Cmp2 = getVFPCmp(LHS, RHS, DAG);
1148    Result = DAG.getNode(ARMISD::CMOV, VT, Result, TrueVal, ARMCC2, CCR, Cmp2);
1149  }
1150  return Result;
1151}
1152
1153static SDValue LowerBR_CC(SDValue Op, SelectionDAG &DAG,
1154                            const ARMSubtarget *ST) {
1155  SDValue  Chain = Op.getOperand(0);
1156  ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(1))->get();
1157  SDValue    LHS = Op.getOperand(2);
1158  SDValue    RHS = Op.getOperand(3);
1159  SDValue   Dest = Op.getOperand(4);
1160
1161  if (LHS.getValueType() == MVT::i32) {
1162    SDValue ARMCC;
1163    SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
1164    SDValue Cmp = getARMCmp(LHS, RHS, CC, ARMCC, DAG, ST->isThumb());
1165    return DAG.getNode(ARMISD::BRCOND, MVT::Other, Chain, Dest, ARMCC, CCR,Cmp);
1166  }
1167
1168  assert(LHS.getValueType() == MVT::f32 || LHS.getValueType() == MVT::f64);
1169  ARMCC::CondCodes CondCode, CondCode2;
1170  if (FPCCToARMCC(CC, CondCode, CondCode2))
1171    // Swap the LHS/RHS of the comparison if needed.
1172    std::swap(LHS, RHS);
1173
1174  SDValue Cmp = getVFPCmp(LHS, RHS, DAG);
1175  SDValue ARMCC = DAG.getConstant(CondCode, MVT::i32);
1176  SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
1177  SDVTList VTList = DAG.getVTList(MVT::Other, MVT::Flag);
1178  SDValue Ops[] = { Chain, Dest, ARMCC, CCR, Cmp };
1179  SDValue Res = DAG.getNode(ARMISD::BRCOND, VTList, Ops, 5);
1180  if (CondCode2 != ARMCC::AL) {
1181    ARMCC = DAG.getConstant(CondCode2, MVT::i32);
1182    SDValue Ops[] = { Res, Dest, ARMCC, CCR, Res.getValue(1) };
1183    Res = DAG.getNode(ARMISD::BRCOND, VTList, Ops, 5);
1184  }
1185  return Res;
1186}
1187
1188SDValue ARMTargetLowering::LowerBR_JT(SDValue Op, SelectionDAG &DAG) {
1189  SDValue Chain = Op.getOperand(0);
1190  SDValue Table = Op.getOperand(1);
1191  SDValue Index = Op.getOperand(2);
1192
1193  MVT PTy = getPointerTy();
1194  JumpTableSDNode *JT = cast<JumpTableSDNode>(Table);
1195  ARMFunctionInfo *AFI = DAG.getMachineFunction().getInfo<ARMFunctionInfo>();
1196  SDValue UId =  DAG.getConstant(AFI->createJumpTableUId(), PTy);
1197  SDValue JTI = DAG.getTargetJumpTable(JT->getIndex(), PTy);
1198  Table = DAG.getNode(ARMISD::WrapperJT, MVT::i32, JTI, UId);
1199  Index = DAG.getNode(ISD::MUL, PTy, Index, DAG.getConstant(4, PTy));
1200  SDValue Addr = DAG.getNode(ISD::ADD, PTy, Index, Table);
1201  bool isPIC = getTargetMachine().getRelocationModel() == Reloc::PIC_;
1202  Addr = DAG.getLoad(isPIC ? (MVT)MVT::i32 : PTy,
1203                     Chain, Addr, NULL, 0);
1204  Chain = Addr.getValue(1);
1205  if (isPIC)
1206    Addr = DAG.getNode(ISD::ADD, PTy, Addr, Table);
1207  return DAG.getNode(ARMISD::BR_JT, MVT::Other, Chain, Addr, JTI, UId);
1208}
1209
1210static SDValue LowerFP_TO_INT(SDValue Op, SelectionDAG &DAG) {
1211  unsigned Opc =
1212    Op.getOpcode() == ISD::FP_TO_SINT ? ARMISD::FTOSI : ARMISD::FTOUI;
1213  Op = DAG.getNode(Opc, MVT::f32, Op.getOperand(0));
1214  return DAG.getNode(ISD::BIT_CONVERT, MVT::i32, Op);
1215}
1216
1217static SDValue LowerINT_TO_FP(SDValue Op, SelectionDAG &DAG) {
1218  MVT VT = Op.getValueType();
1219  unsigned Opc =
1220    Op.getOpcode() == ISD::SINT_TO_FP ? ARMISD::SITOF : ARMISD::UITOF;
1221
1222  Op = DAG.getNode(ISD::BIT_CONVERT, MVT::f32, Op.getOperand(0));
1223  return DAG.getNode(Opc, VT, Op);
1224}
1225
1226static SDValue LowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) {
1227  // Implement fcopysign with a fabs and a conditional fneg.
1228  SDValue Tmp0 = Op.getOperand(0);
1229  SDValue Tmp1 = Op.getOperand(1);
1230  MVT VT = Op.getValueType();
1231  MVT SrcVT = Tmp1.getValueType();
1232  SDValue AbsVal = DAG.getNode(ISD::FABS, VT, Tmp0);
1233  SDValue Cmp = getVFPCmp(Tmp1, DAG.getConstantFP(0.0, SrcVT), DAG);
1234  SDValue ARMCC = DAG.getConstant(ARMCC::LT, MVT::i32);
1235  SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
1236  return DAG.getNode(ARMISD::CNEG, VT, AbsVal, AbsVal, ARMCC, CCR, Cmp);
1237}
1238
1239SDValue
1240ARMTargetLowering::EmitTargetCodeForMemcpy(SelectionDAG &DAG,
1241                                           SDValue Chain,
1242                                           SDValue Dst, SDValue Src,
1243                                           SDValue Size, unsigned Align,
1244                                           bool AlwaysInline,
1245                                         const Value *DstSV, uint64_t DstSVOff,
1246                                         const Value *SrcSV, uint64_t SrcSVOff){
1247  // Do repeated 4-byte loads and stores. To be improved.
1248  // This requires 4-byte alignment.
1249  if ((Align & 3) != 0)
1250    return SDValue();
1251  // This requires the copy size to be a constant, preferrably
1252  // within a subtarget-specific limit.
1253  ConstantSDNode *ConstantSize = dyn_cast<ConstantSDNode>(Size);
1254  if (!ConstantSize)
1255    return SDValue();
1256  uint64_t SizeVal = ConstantSize->getZExtValue();
1257  if (!AlwaysInline && SizeVal > getSubtarget()->getMaxInlineSizeThreshold())
1258    return SDValue();
1259
1260  unsigned BytesLeft = SizeVal & 3;
1261  unsigned NumMemOps = SizeVal >> 2;
1262  unsigned EmittedNumMemOps = 0;
1263  MVT VT = MVT::i32;
1264  unsigned VTSize = 4;
1265  unsigned i = 0;
1266  const unsigned MAX_LOADS_IN_LDM = 6;
1267  SDValue TFOps[MAX_LOADS_IN_LDM];
1268  SDValue Loads[MAX_LOADS_IN_LDM];
1269  uint64_t SrcOff = 0, DstOff = 0;
1270
1271  // Emit up to MAX_LOADS_IN_LDM loads, then a TokenFactor barrier, then the
1272  // same number of stores.  The loads and stores will get combined into
1273  // ldm/stm later on.
1274  while (EmittedNumMemOps < NumMemOps) {
1275    for (i = 0;
1276         i < MAX_LOADS_IN_LDM && EmittedNumMemOps + i < NumMemOps; ++i) {
1277      Loads[i] = DAG.getLoad(VT, Chain,
1278                             DAG.getNode(ISD::ADD, MVT::i32, Src,
1279                                         DAG.getConstant(SrcOff, MVT::i32)),
1280                             SrcSV, SrcSVOff + SrcOff);
1281      TFOps[i] = Loads[i].getValue(1);
1282      SrcOff += VTSize;
1283    }
1284    Chain = DAG.getNode(ISD::TokenFactor, MVT::Other, &TFOps[0], i);
1285
1286    for (i = 0;
1287         i < MAX_LOADS_IN_LDM && EmittedNumMemOps + i < NumMemOps; ++i) {
1288      TFOps[i] = DAG.getStore(Chain, Loads[i],
1289                           DAG.getNode(ISD::ADD, MVT::i32, Dst,
1290                                       DAG.getConstant(DstOff, MVT::i32)),
1291                           DstSV, DstSVOff + DstOff);
1292      DstOff += VTSize;
1293    }
1294    Chain = DAG.getNode(ISD::TokenFactor, MVT::Other, &TFOps[0], i);
1295
1296    EmittedNumMemOps += i;
1297  }
1298
1299  if (BytesLeft == 0)
1300    return Chain;
1301
1302  // Issue loads / stores for the trailing (1 - 3) bytes.
1303  unsigned BytesLeftSave = BytesLeft;
1304  i = 0;
1305  while (BytesLeft) {
1306    if (BytesLeft >= 2) {
1307      VT = MVT::i16;
1308      VTSize = 2;
1309    } else {
1310      VT = MVT::i8;
1311      VTSize = 1;
1312    }
1313
1314    Loads[i] = DAG.getLoad(VT, Chain,
1315                           DAG.getNode(ISD::ADD, MVT::i32, Src,
1316                                       DAG.getConstant(SrcOff, MVT::i32)),
1317                           SrcSV, SrcSVOff + SrcOff);
1318    TFOps[i] = Loads[i].getValue(1);
1319    ++i;
1320    SrcOff += VTSize;
1321    BytesLeft -= VTSize;
1322  }
1323  Chain = DAG.getNode(ISD::TokenFactor, MVT::Other, &TFOps[0], i);
1324
1325  i = 0;
1326  BytesLeft = BytesLeftSave;
1327  while (BytesLeft) {
1328    if (BytesLeft >= 2) {
1329      VT = MVT::i16;
1330      VTSize = 2;
1331    } else {
1332      VT = MVT::i8;
1333      VTSize = 1;
1334    }
1335
1336    TFOps[i] = DAG.getStore(Chain, Loads[i],
1337                            DAG.getNode(ISD::ADD, MVT::i32, Dst,
1338                                        DAG.getConstant(DstOff, MVT::i32)),
1339                            DstSV, DstSVOff + DstOff);
1340    ++i;
1341    DstOff += VTSize;
1342    BytesLeft -= VTSize;
1343  }
1344  return DAG.getNode(ISD::TokenFactor, MVT::Other, &TFOps[0], i);
1345}
1346
1347static SDValue ExpandBIT_CONVERT(SDNode *N, SelectionDAG &DAG) {
1348  SDValue Op = N->getOperand(0);
1349  if (N->getValueType(0) == MVT::f64) {
1350    // Turn i64->f64 into FMDRR.
1351    SDValue Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Op,
1352                             DAG.getConstant(0, MVT::i32));
1353    SDValue Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Op,
1354                             DAG.getConstant(1, MVT::i32));
1355    return DAG.getNode(ARMISD::FMDRR, MVT::f64, Lo, Hi);
1356  }
1357
1358  // Turn f64->i64 into FMRRD.
1359  SDValue Cvt = DAG.getNode(ARMISD::FMRRD, DAG.getVTList(MVT::i32, MVT::i32),
1360                            &Op, 1);
1361
1362  // Merge the pieces into a single i64 value.
1363  return DAG.getNode(ISD::BUILD_PAIR, MVT::i64, Cvt, Cvt.getValue(1));
1364}
1365
1366static SDValue ExpandSRx(SDNode *N, SelectionDAG &DAG, const ARMSubtarget *ST) {
1367  assert(N->getValueType(0) == MVT::i64 &&
1368         (N->getOpcode() == ISD::SRL || N->getOpcode() == ISD::SRA) &&
1369         "Unknown shift to lower!");
1370
1371  // We only lower SRA, SRL of 1 here, all others use generic lowering.
1372  if (!isa<ConstantSDNode>(N->getOperand(1)) ||
1373      cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() != 1)
1374    return SDValue();
1375
1376  // If we are in thumb mode, we don't have RRX.
1377  if (ST->isThumb()) return SDValue();
1378
1379  // Okay, we have a 64-bit SRA or SRL of 1.  Lower this to an RRX expr.
1380  SDValue Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, N->getOperand(0),
1381                             DAG.getConstant(0, MVT::i32));
1382  SDValue Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, N->getOperand(0),
1383                             DAG.getConstant(1, MVT::i32));
1384
1385  // First, build a SRA_FLAG/SRL_FLAG op, which shifts the top part by one and
1386  // captures the result into a carry flag.
1387  unsigned Opc = N->getOpcode() == ISD::SRL ? ARMISD::SRL_FLAG:ARMISD::SRA_FLAG;
1388  Hi = DAG.getNode(Opc, DAG.getVTList(MVT::i32, MVT::Flag), &Hi, 1);
1389
1390  // The low part is an ARMISD::RRX operand, which shifts the carry in.
1391  Lo = DAG.getNode(ARMISD::RRX, MVT::i32, Lo, Hi.getValue(1));
1392
1393  // Merge the pieces into a single i64 value.
1394 return DAG.getNode(ISD::BUILD_PAIR, MVT::i64, Lo, Hi);
1395}
1396
1397
1398SDValue ARMTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) {
1399  switch (Op.getOpcode()) {
1400  default: assert(0 && "Don't know how to custom lower this!"); abort();
1401  case ISD::ConstantPool:  return LowerConstantPool(Op, DAG);
1402  case ISD::GlobalAddress:
1403    return Subtarget->isTargetDarwin() ? LowerGlobalAddressDarwin(Op, DAG) :
1404      LowerGlobalAddressELF(Op, DAG);
1405  case ISD::GlobalTLSAddress:   return LowerGlobalTLSAddress(Op, DAG);
1406  case ISD::CALL:          return LowerCALL(Op, DAG);
1407  case ISD::RET:           return LowerRET(Op, DAG);
1408  case ISD::SELECT_CC:     return LowerSELECT_CC(Op, DAG, Subtarget);
1409  case ISD::BR_CC:         return LowerBR_CC(Op, DAG, Subtarget);
1410  case ISD::BR_JT:         return LowerBR_JT(Op, DAG);
1411  case ISD::VASTART:       return LowerVASTART(Op, DAG, VarArgsFrameIndex);
1412  case ISD::SINT_TO_FP:
1413  case ISD::UINT_TO_FP:    return LowerINT_TO_FP(Op, DAG);
1414  case ISD::FP_TO_SINT:
1415  case ISD::FP_TO_UINT:    return LowerFP_TO_INT(Op, DAG);
1416  case ISD::FCOPYSIGN:     return LowerFCOPYSIGN(Op, DAG);
1417  case ISD::FORMAL_ARGUMENTS: return LowerFORMAL_ARGUMENTS(Op, DAG);
1418  case ISD::RETURNADDR:    break;
1419  case ISD::FRAMEADDR:     break;
1420  case ISD::GLOBAL_OFFSET_TABLE: return LowerGLOBAL_OFFSET_TABLE(Op, DAG);
1421  case ISD::INTRINSIC_WO_CHAIN: return LowerINTRINSIC_WO_CHAIN(Op, DAG);
1422  case ISD::BIT_CONVERT:   return ExpandBIT_CONVERT(Op.getNode(), DAG);
1423  case ISD::SRL:
1424  case ISD::SRA:           return ExpandSRx(Op.getNode(), DAG,Subtarget);
1425  }
1426  return SDValue();
1427}
1428
1429
1430/// ReplaceNodeResults - Replace the results of node with an illegal result
1431/// type with new values built out of custom code.
1432///
1433void ARMTargetLowering::ReplaceNodeResults(SDNode *N,
1434                                           SmallVectorImpl<SDValue>&Results,
1435                                           SelectionDAG &DAG) {
1436  switch (N->getOpcode()) {
1437  default:
1438    assert(0 && "Don't know how to custom expand this!");
1439    return;
1440  case ISD::BIT_CONVERT:
1441    Results.push_back(ExpandBIT_CONVERT(N, DAG));
1442    return;
1443  case ISD::SRL:
1444  case ISD::SRA: {
1445    SDValue Res = ExpandSRx(N, DAG, Subtarget);
1446    if (Res.getNode())
1447      Results.push_back(Res);
1448    return;
1449  }
1450  }
1451}
1452
1453
1454//===----------------------------------------------------------------------===//
1455//                           ARM Scheduler Hooks
1456//===----------------------------------------------------------------------===//
1457
1458MachineBasicBlock *
1459ARMTargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
1460                                           MachineBasicBlock *BB) {
1461  const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
1462  switch (MI->getOpcode()) {
1463  default: assert(false && "Unexpected instr type to insert");
1464  case ARM::tMOVCCr: {
1465    // To "insert" a SELECT_CC instruction, we actually have to insert the
1466    // diamond control-flow pattern.  The incoming instruction knows the
1467    // destination vreg to set, the condition code register to branch on, the
1468    // true/false values to select between, and a branch opcode to use.
1469    const BasicBlock *LLVM_BB = BB->getBasicBlock();
1470    MachineFunction::iterator It = BB;
1471    ++It;
1472
1473    //  thisMBB:
1474    //  ...
1475    //   TrueVal = ...
1476    //   cmpTY ccX, r1, r2
1477    //   bCC copy1MBB
1478    //   fallthrough --> copy0MBB
1479    MachineBasicBlock *thisMBB  = BB;
1480    MachineFunction *F = BB->getParent();
1481    MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
1482    MachineBasicBlock *sinkMBB  = F->CreateMachineBasicBlock(LLVM_BB);
1483    BuildMI(BB, TII->get(ARM::tBcc)).addMBB(sinkMBB)
1484      .addImm(MI->getOperand(3).getImm()).addReg(MI->getOperand(4).getReg());
1485    F->insert(It, copy0MBB);
1486    F->insert(It, sinkMBB);
1487    // Update machine-CFG edges by first adding all successors of the current
1488    // block to the new block which will contain the Phi node for the select.
1489    for(MachineBasicBlock::succ_iterator i = BB->succ_begin(),
1490        e = BB->succ_end(); i != e; ++i)
1491      sinkMBB->addSuccessor(*i);
1492    // Next, remove all successors of the current block, and add the true
1493    // and fallthrough blocks as its successors.
1494    while(!BB->succ_empty())
1495      BB->removeSuccessor(BB->succ_begin());
1496    BB->addSuccessor(copy0MBB);
1497    BB->addSuccessor(sinkMBB);
1498
1499    //  copy0MBB:
1500    //   %FalseValue = ...
1501    //   # fallthrough to sinkMBB
1502    BB = copy0MBB;
1503
1504    // Update machine-CFG edges
1505    BB->addSuccessor(sinkMBB);
1506
1507    //  sinkMBB:
1508    //   %Result = phi [ %FalseValue, copy0MBB ], [ %TrueValue, thisMBB ]
1509    //  ...
1510    BB = sinkMBB;
1511    BuildMI(BB, TII->get(ARM::PHI), MI->getOperand(0).getReg())
1512      .addReg(MI->getOperand(1).getReg()).addMBB(copy0MBB)
1513      .addReg(MI->getOperand(2).getReg()).addMBB(thisMBB);
1514
1515    F->DeleteMachineInstr(MI);   // The pseudo instruction is gone now.
1516    return BB;
1517  }
1518  }
1519}
1520
1521//===----------------------------------------------------------------------===//
1522//                           ARM Optimization Hooks
1523//===----------------------------------------------------------------------===//
1524
1525/// PerformFMRRDCombine - Target-specific dag combine xforms for ARMISD::FMRRD.
1526static SDValue PerformFMRRDCombine(SDNode *N,
1527                                     TargetLowering::DAGCombinerInfo &DCI) {
1528  // fmrrd(fmdrr x, y) -> x,y
1529  SDValue InDouble = N->getOperand(0);
1530  if (InDouble.getOpcode() == ARMISD::FMDRR)
1531    return DCI.CombineTo(N, InDouble.getOperand(0), InDouble.getOperand(1));
1532  return SDValue();
1533}
1534
1535SDValue ARMTargetLowering::PerformDAGCombine(SDNode *N,
1536                                               DAGCombinerInfo &DCI) const {
1537  switch (N->getOpcode()) {
1538  default: break;
1539  case ARMISD::FMRRD: return PerformFMRRDCombine(N, DCI);
1540  }
1541
1542  return SDValue();
1543}
1544
1545
1546/// isLegalAddressImmediate - Return true if the integer value can be used
1547/// as the offset of the target addressing mode for load / store of the
1548/// given type.
1549static bool isLegalAddressImmediate(int64_t V, MVT VT,
1550                                    const ARMSubtarget *Subtarget) {
1551  if (V == 0)
1552    return true;
1553
1554  if (Subtarget->isThumb()) {
1555    if (V < 0)
1556      return false;
1557
1558    unsigned Scale = 1;
1559    switch (VT.getSimpleVT()) {
1560    default: return false;
1561    case MVT::i1:
1562    case MVT::i8:
1563      // Scale == 1;
1564      break;
1565    case MVT::i16:
1566      // Scale == 2;
1567      Scale = 2;
1568      break;
1569    case MVT::i32:
1570      // Scale == 4;
1571      Scale = 4;
1572      break;
1573    }
1574
1575    if ((V & (Scale - 1)) != 0)
1576      return false;
1577    V /= Scale;
1578    return V == (V & ((1LL << 5) - 1));
1579  }
1580
1581  if (V < 0)
1582    V = - V;
1583  switch (VT.getSimpleVT()) {
1584  default: return false;
1585  case MVT::i1:
1586  case MVT::i8:
1587  case MVT::i32:
1588    // +- imm12
1589    return V == (V & ((1LL << 12) - 1));
1590  case MVT::i16:
1591    // +- imm8
1592    return V == (V & ((1LL << 8) - 1));
1593  case MVT::f32:
1594  case MVT::f64:
1595    if (!Subtarget->hasVFP2())
1596      return false;
1597    if ((V & 3) != 0)
1598      return false;
1599    V >>= 2;
1600    return V == (V & ((1LL << 8) - 1));
1601  }
1602}
1603
1604/// isLegalAddressingMode - Return true if the addressing mode represented
1605/// by AM is legal for this target, for a load/store of the specified type.
1606bool ARMTargetLowering::isLegalAddressingMode(const AddrMode &AM,
1607                                              const Type *Ty) const {
1608  if (!isLegalAddressImmediate(AM.BaseOffs, getValueType(Ty, true), Subtarget))
1609    return false;
1610
1611  // Can never fold addr of global into load/store.
1612  if (AM.BaseGV)
1613    return false;
1614
1615  switch (AM.Scale) {
1616  case 0:  // no scale reg, must be "r+i" or "r", or "i".
1617    break;
1618  case 1:
1619    if (Subtarget->isThumb())
1620      return false;
1621    // FALL THROUGH.
1622  default:
1623    // ARM doesn't support any R+R*scale+imm addr modes.
1624    if (AM.BaseOffs)
1625      return false;
1626
1627    int Scale = AM.Scale;
1628    switch (getValueType(Ty).getSimpleVT()) {
1629    default: return false;
1630    case MVT::i1:
1631    case MVT::i8:
1632    case MVT::i32:
1633    case MVT::i64:
1634      // This assumes i64 is legalized to a pair of i32. If not (i.e.
1635      // ldrd / strd are used, then its address mode is same as i16.
1636      // r + r
1637      if (Scale < 0) Scale = -Scale;
1638      if (Scale == 1)
1639        return true;
1640      // r + r << imm
1641      return isPowerOf2_32(Scale & ~1);
1642    case MVT::i16:
1643      // r + r
1644      if (((unsigned)AM.HasBaseReg + Scale) <= 2)
1645        return true;
1646      return false;
1647
1648    case MVT::isVoid:
1649      // Note, we allow "void" uses (basically, uses that aren't loads or
1650      // stores), because arm allows folding a scale into many arithmetic
1651      // operations.  This should be made more precise and revisited later.
1652
1653      // Allow r << imm, but the imm has to be a multiple of two.
1654      if (AM.Scale & 1) return false;
1655      return isPowerOf2_32(AM.Scale);
1656    }
1657    break;
1658  }
1659  return true;
1660}
1661
1662
1663static bool getIndexedAddressParts(SDNode *Ptr, MVT VT,
1664                                   bool isSEXTLoad, SDValue &Base,
1665                                   SDValue &Offset, bool &isInc,
1666                                   SelectionDAG &DAG) {
1667  if (Ptr->getOpcode() != ISD::ADD && Ptr->getOpcode() != ISD::SUB)
1668    return false;
1669
1670  if (VT == MVT::i16 || ((VT == MVT::i8 || VT == MVT::i1) && isSEXTLoad)) {
1671    // AddressingMode 3
1672    Base = Ptr->getOperand(0);
1673    if (ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(Ptr->getOperand(1))) {
1674      int RHSC = (int)RHS->getZExtValue();
1675      if (RHSC < 0 && RHSC > -256) {
1676        isInc = false;
1677        Offset = DAG.getConstant(-RHSC, RHS->getValueType(0));
1678        return true;
1679      }
1680    }
1681    isInc = (Ptr->getOpcode() == ISD::ADD);
1682    Offset = Ptr->getOperand(1);
1683    return true;
1684  } else if (VT == MVT::i32 || VT == MVT::i8 || VT == MVT::i1) {
1685    // AddressingMode 2
1686    if (ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(Ptr->getOperand(1))) {
1687      int RHSC = (int)RHS->getZExtValue();
1688      if (RHSC < 0 && RHSC > -0x1000) {
1689        isInc = false;
1690        Offset = DAG.getConstant(-RHSC, RHS->getValueType(0));
1691        Base = Ptr->getOperand(0);
1692        return true;
1693      }
1694    }
1695
1696    if (Ptr->getOpcode() == ISD::ADD) {
1697      isInc = true;
1698      ARM_AM::ShiftOpc ShOpcVal= ARM_AM::getShiftOpcForNode(Ptr->getOperand(0));
1699      if (ShOpcVal != ARM_AM::no_shift) {
1700        Base = Ptr->getOperand(1);
1701        Offset = Ptr->getOperand(0);
1702      } else {
1703        Base = Ptr->getOperand(0);
1704        Offset = Ptr->getOperand(1);
1705      }
1706      return true;
1707    }
1708
1709    isInc = (Ptr->getOpcode() == ISD::ADD);
1710    Base = Ptr->getOperand(0);
1711    Offset = Ptr->getOperand(1);
1712    return true;
1713  }
1714
1715  // FIXME: Use FLDM / FSTM to emulate indexed FP load / store.
1716  return false;
1717}
1718
1719/// getPreIndexedAddressParts - returns true by value, base pointer and
1720/// offset pointer and addressing mode by reference if the node's address
1721/// can be legally represented as pre-indexed load / store address.
1722bool
1723ARMTargetLowering::getPreIndexedAddressParts(SDNode *N, SDValue &Base,
1724                                             SDValue &Offset,
1725                                             ISD::MemIndexedMode &AM,
1726                                             SelectionDAG &DAG) {
1727  if (Subtarget->isThumb())
1728    return false;
1729
1730  MVT VT;
1731  SDValue Ptr;
1732  bool isSEXTLoad = false;
1733  if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
1734    Ptr = LD->getBasePtr();
1735    VT  = LD->getMemoryVT();
1736    isSEXTLoad = LD->getExtensionType() == ISD::SEXTLOAD;
1737  } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
1738    Ptr = ST->getBasePtr();
1739    VT  = ST->getMemoryVT();
1740  } else
1741    return false;
1742
1743  bool isInc;
1744  bool isLegal = getIndexedAddressParts(Ptr.getNode(), VT, isSEXTLoad, Base, Offset,
1745                                        isInc, DAG);
1746  if (isLegal) {
1747    AM = isInc ? ISD::PRE_INC : ISD::PRE_DEC;
1748    return true;
1749  }
1750  return false;
1751}
1752
1753/// getPostIndexedAddressParts - returns true by value, base pointer and
1754/// offset pointer and addressing mode by reference if this node can be
1755/// combined with a load / store to form a post-indexed load / store.
1756bool ARMTargetLowering::getPostIndexedAddressParts(SDNode *N, SDNode *Op,
1757                                                   SDValue &Base,
1758                                                   SDValue &Offset,
1759                                                   ISD::MemIndexedMode &AM,
1760                                                   SelectionDAG &DAG) {
1761  if (Subtarget->isThumb())
1762    return false;
1763
1764  MVT VT;
1765  SDValue Ptr;
1766  bool isSEXTLoad = false;
1767  if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
1768    VT  = LD->getMemoryVT();
1769    isSEXTLoad = LD->getExtensionType() == ISD::SEXTLOAD;
1770  } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
1771    VT  = ST->getMemoryVT();
1772  } else
1773    return false;
1774
1775  bool isInc;
1776  bool isLegal = getIndexedAddressParts(Op, VT, isSEXTLoad, Base, Offset,
1777                                        isInc, DAG);
1778  if (isLegal) {
1779    AM = isInc ? ISD::POST_INC : ISD::POST_DEC;
1780    return true;
1781  }
1782  return false;
1783}
1784
1785void ARMTargetLowering::computeMaskedBitsForTargetNode(const SDValue Op,
1786                                                       const APInt &Mask,
1787                                                       APInt &KnownZero,
1788                                                       APInt &KnownOne,
1789                                                       const SelectionDAG &DAG,
1790                                                       unsigned Depth) const {
1791  KnownZero = KnownOne = APInt(Mask.getBitWidth(), 0);
1792  switch (Op.getOpcode()) {
1793  default: break;
1794  case ARMISD::CMOV: {
1795    // Bits are known zero/one if known on the LHS and RHS.
1796    DAG.ComputeMaskedBits(Op.getOperand(0), Mask, KnownZero, KnownOne, Depth+1);
1797    if (KnownZero == 0 && KnownOne == 0) return;
1798
1799    APInt KnownZeroRHS, KnownOneRHS;
1800    DAG.ComputeMaskedBits(Op.getOperand(1), Mask,
1801                          KnownZeroRHS, KnownOneRHS, Depth+1);
1802    KnownZero &= KnownZeroRHS;
1803    KnownOne  &= KnownOneRHS;
1804    return;
1805  }
1806  }
1807}
1808
1809//===----------------------------------------------------------------------===//
1810//                           ARM Inline Assembly Support
1811//===----------------------------------------------------------------------===//
1812
1813/// getConstraintType - Given a constraint letter, return the type of
1814/// constraint it is for this target.
1815ARMTargetLowering::ConstraintType
1816ARMTargetLowering::getConstraintType(const std::string &Constraint) const {
1817  if (Constraint.size() == 1) {
1818    switch (Constraint[0]) {
1819    default:  break;
1820    case 'l': return C_RegisterClass;
1821    case 'w': return C_RegisterClass;
1822    }
1823  }
1824  return TargetLowering::getConstraintType(Constraint);
1825}
1826
1827std::pair<unsigned, const TargetRegisterClass*>
1828ARMTargetLowering::getRegForInlineAsmConstraint(const std::string &Constraint,
1829                                                MVT VT) const {
1830  if (Constraint.size() == 1) {
1831    // GCC RS6000 Constraint Letters
1832    switch (Constraint[0]) {
1833    case 'l':
1834    // FIXME: in thumb mode, 'l' is only low-regs.
1835    // FALL THROUGH.
1836    case 'r':
1837      return std::make_pair(0U, ARM::GPRRegisterClass);
1838    case 'w':
1839      if (VT == MVT::f32)
1840        return std::make_pair(0U, ARM::SPRRegisterClass);
1841      if (VT == MVT::f64)
1842        return std::make_pair(0U, ARM::DPRRegisterClass);
1843      break;
1844    }
1845  }
1846  return TargetLowering::getRegForInlineAsmConstraint(Constraint, VT);
1847}
1848
1849std::vector<unsigned> ARMTargetLowering::
1850getRegClassForInlineAsmConstraint(const std::string &Constraint,
1851                                  MVT VT) const {
1852  if (Constraint.size() != 1)
1853    return std::vector<unsigned>();
1854
1855  switch (Constraint[0]) {      // GCC ARM Constraint Letters
1856  default: break;
1857  case 'l':
1858  case 'r':
1859    return make_vector<unsigned>(ARM::R0, ARM::R1, ARM::R2, ARM::R3,
1860                                 ARM::R4, ARM::R5, ARM::R6, ARM::R7,
1861                                 ARM::R8, ARM::R9, ARM::R10, ARM::R11,
1862                                 ARM::R12, ARM::LR, 0);
1863  case 'w':
1864    if (VT == MVT::f32)
1865      return make_vector<unsigned>(ARM::S0, ARM::S1, ARM::S2, ARM::S3,
1866                                   ARM::S4, ARM::S5, ARM::S6, ARM::S7,
1867                                   ARM::S8, ARM::S9, ARM::S10, ARM::S11,
1868                                   ARM::S12,ARM::S13,ARM::S14,ARM::S15,
1869                                   ARM::S16,ARM::S17,ARM::S18,ARM::S19,
1870                                   ARM::S20,ARM::S21,ARM::S22,ARM::S23,
1871                                   ARM::S24,ARM::S25,ARM::S26,ARM::S27,
1872                                   ARM::S28,ARM::S29,ARM::S30,ARM::S31, 0);
1873    if (VT == MVT::f64)
1874      return make_vector<unsigned>(ARM::D0, ARM::D1, ARM::D2, ARM::D3,
1875                                   ARM::D4, ARM::D5, ARM::D6, ARM::D7,
1876                                   ARM::D8, ARM::D9, ARM::D10,ARM::D11,
1877                                   ARM::D12,ARM::D13,ARM::D14,ARM::D15, 0);
1878      break;
1879  }
1880
1881  return std::vector<unsigned>();
1882}
1883