SparcISelDAGToDAG.cpp revision 62819f31440fe1b1415473a89b8683b5b690d5fa 
1//===-- SparcISelDAGToDAG.cpp - A dag to dag inst selector for Sparc ------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by Chris Lattner and is distributed under
6// the University of Illinois Open Source License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines an instruction selector for the SPARC target.
11//
12//===----------------------------------------------------------------------===//
13
14#include "Sparc.h"
15#include "SparcTargetMachine.h"
16#include "llvm/DerivedTypes.h"
17#include "llvm/Function.h"
18#include "llvm/Intrinsics.h"
19#include "llvm/CodeGen/MachineFrameInfo.h"
20#include "llvm/CodeGen/MachineFunction.h"
21#include "llvm/CodeGen/MachineInstrBuilder.h"
22#include "llvm/CodeGen/SelectionDAG.h"
23#include "llvm/CodeGen/SelectionDAGISel.h"
24#include "llvm/CodeGen/SSARegMap.h"
25#include "llvm/Target/TargetLowering.h"
26#include "llvm/Support/Debug.h"
27#include <queue>
28#include <set>
29using namespace llvm;
30
31//===----------------------------------------------------------------------===//
32// TargetLowering Implementation
33//===----------------------------------------------------------------------===//
34
35namespace SPISD {
36  enum {
37    FIRST_NUMBER = ISD::BUILTIN_OP_END+SP::INSTRUCTION_LIST_END,
38    CMPICC,      // Compare two GPR operands, set icc.
39    CMPFCC,      // Compare two FP operands, set fcc.
40    BRICC,       // Branch to dest on icc condition
41    BRFCC,       // Branch to dest on fcc condition
42    SELECT_ICC,  // Select between two values using the current ICC flags.
43    SELECT_FCC,  // Select between two values using the current FCC flags.
44
45    Hi, Lo,      // Hi/Lo operations, typically on a global address.
46
47    FTOI,        // FP to Int within a FP register.
48    ITOF,        // Int to FP within a FP register.
49
50    CALL,        // A call instruction.
51    RET_FLAG     // Return with a flag operand.
52  };
53}
54
55/// IntCondCCodeToICC - Convert a DAG integer condition code to a SPARC ICC
56/// condition.
57static SPCC::CondCodes IntCondCCodeToICC(ISD::CondCode CC) {
58  switch (CC) {
59  default: assert(0 && "Unknown integer condition code!");
60  case ISD::SETEQ:  return SPCC::ICC_E;
61  case ISD::SETNE:  return SPCC::ICC_NE;
62  case ISD::SETLT:  return SPCC::ICC_L;
63  case ISD::SETGT:  return SPCC::ICC_G;
64  case ISD::SETLE:  return SPCC::ICC_LE;
65  case ISD::SETGE:  return SPCC::ICC_GE;
66  case ISD::SETULT: return SPCC::ICC_CS;
67  case ISD::SETULE: return SPCC::ICC_LEU;
68  case ISD::SETUGT: return SPCC::ICC_GU;
69  case ISD::SETUGE: return SPCC::ICC_CC;
70  }
71}
72
73/// FPCondCCodeToFCC - Convert a DAG floatingp oint condition code to a SPARC
74/// FCC condition.
75static SPCC::CondCodes FPCondCCodeToFCC(ISD::CondCode CC) {
76  switch (CC) {
77  default: assert(0 && "Unknown fp condition code!");
78  case ISD::SETEQ:
79  case ISD::SETOEQ: return SPCC::FCC_E;
80  case ISD::SETNE:
81  case ISD::SETUNE: return SPCC::FCC_NE;
82  case ISD::SETLT:
83  case ISD::SETOLT: return SPCC::FCC_L;
84  case ISD::SETGT:
85  case ISD::SETOGT: return SPCC::FCC_G;
86  case ISD::SETLE:
87  case ISD::SETOLE: return SPCC::FCC_LE;
88  case ISD::SETGE:
89  case ISD::SETOGE: return SPCC::FCC_GE;
90  case ISD::SETULT: return SPCC::FCC_UL;
91  case ISD::SETULE: return SPCC::FCC_ULE;
92  case ISD::SETUGT: return SPCC::FCC_UG;
93  case ISD::SETUGE: return SPCC::FCC_UGE;
94  case ISD::SETUO:  return SPCC::FCC_U;
95  case ISD::SETO:   return SPCC::FCC_O;
96  case ISD::SETONE: return SPCC::FCC_LG;
97  case ISD::SETUEQ: return SPCC::FCC_UE;
98  }
99}
100
101namespace {
102  class SparcTargetLowering : public TargetLowering {
103    int VarArgsFrameOffset;   // Frame offset to start of varargs area.
104  public:
105    SparcTargetLowering(TargetMachine &TM);
106    virtual SDOperand LowerOperation(SDOperand Op, SelectionDAG &DAG);
107
108    /// computeMaskedBitsForTargetNode - Determine which of the bits specified
109    /// in Mask are known to be either zero or one and return them in the
110    /// KnownZero/KnownOne bitsets.
111    virtual void computeMaskedBitsForTargetNode(const SDOperand Op,
112                                                uint64_t Mask,
113                                                uint64_t &KnownZero,
114                                                uint64_t &KnownOne,
115                                                unsigned Depth = 0) const;
116
117    virtual std::vector<SDOperand>
118      LowerArguments(Function &F, SelectionDAG &DAG);
119    virtual std::pair<SDOperand, SDOperand>
120      LowerCallTo(SDOperand Chain, const Type *RetTy, bool RetTyIsSigned,
121                  bool isVarArg, unsigned CC, bool isTailCall, SDOperand Callee,
122                  ArgListTy &Args, SelectionDAG &DAG);
123    virtual MachineBasicBlock *InsertAtEndOfBasicBlock(MachineInstr *MI,
124                                                       MachineBasicBlock *MBB);
125
126    virtual const char *getTargetNodeName(unsigned Opcode) const;
127  };
128}
129
130SparcTargetLowering::SparcTargetLowering(TargetMachine &TM)
131  : TargetLowering(TM) {
132
133  // Set up the register classes.
134  addRegisterClass(MVT::i32, SP::IntRegsRegisterClass);
135  addRegisterClass(MVT::f32, SP::FPRegsRegisterClass);
136  addRegisterClass(MVT::f64, SP::DFPRegsRegisterClass);
137
138  // Turn FP extload into load/fextend
139  setLoadXAction(ISD::EXTLOAD, MVT::f32, Expand);
140
141  // Custom legalize GlobalAddress nodes into LO/HI parts.
142  setOperationAction(ISD::GlobalAddress, MVT::i32, Custom);
143  setOperationAction(ISD::ConstantPool , MVT::i32, Custom);
144
145  // Sparc doesn't have sext_inreg, replace them with shl/sra
146  setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16, Expand);
147  setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i8 , Expand);
148  setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1 , Expand);
149
150  // Sparc has no REM operation.
151  setOperationAction(ISD::UREM, MVT::i32, Expand);
152  setOperationAction(ISD::SREM, MVT::i32, Expand);
153
154  // Custom expand fp<->sint
155  setOperationAction(ISD::FP_TO_SINT, MVT::i32, Custom);
156  setOperationAction(ISD::SINT_TO_FP, MVT::i32, Custom);
157
158  // Expand fp<->uint
159  setOperationAction(ISD::FP_TO_UINT, MVT::i32, Expand);
160  setOperationAction(ISD::UINT_TO_FP, MVT::i32, Expand);
161
162  setOperationAction(ISD::BIT_CONVERT, MVT::f32, Expand);
163  setOperationAction(ISD::BIT_CONVERT, MVT::i32, Expand);
164
165  // Sparc has no select or setcc: expand to SELECT_CC.
166  setOperationAction(ISD::SELECT, MVT::i32, Expand);
167  setOperationAction(ISD::SELECT, MVT::f32, Expand);
168  setOperationAction(ISD::SELECT, MVT::f64, Expand);
169  setOperationAction(ISD::SETCC, MVT::i32, Expand);
170  setOperationAction(ISD::SETCC, MVT::f32, Expand);
171  setOperationAction(ISD::SETCC, MVT::f64, Expand);
172
173  // Sparc doesn't have BRCOND either, it has BR_CC.
174  setOperationAction(ISD::BRCOND, MVT::Other, Expand);
175  setOperationAction(ISD::BRIND, MVT::Other, Expand);
176  setOperationAction(ISD::BR_JT, MVT::Other, Expand);
177  setOperationAction(ISD::BR_CC, MVT::i32, Custom);
178  setOperationAction(ISD::BR_CC, MVT::f32, Custom);
179  setOperationAction(ISD::BR_CC, MVT::f64, Custom);
180
181  setOperationAction(ISD::SELECT_CC, MVT::i32, Custom);
182  setOperationAction(ISD::SELECT_CC, MVT::f32, Custom);
183  setOperationAction(ISD::SELECT_CC, MVT::f64, Custom);
184
185  // SPARC has no intrinsics for these particular operations.
186  setOperationAction(ISD::MEMMOVE, MVT::Other, Expand);
187  setOperationAction(ISD::MEMSET, MVT::Other, Expand);
188  setOperationAction(ISD::MEMCPY, MVT::Other, Expand);
189
190  setOperationAction(ISD::FSIN , MVT::f64, Expand);
191  setOperationAction(ISD::FCOS , MVT::f64, Expand);
192  setOperationAction(ISD::FSIN , MVT::f32, Expand);
193  setOperationAction(ISD::FCOS , MVT::f32, Expand);
194  setOperationAction(ISD::CTPOP, MVT::i32, Expand);
195  setOperationAction(ISD::CTTZ , MVT::i32, Expand);
196  setOperationAction(ISD::CTLZ , MVT::i32, Expand);
197  setOperationAction(ISD::ROTL , MVT::i32, Expand);
198  setOperationAction(ISD::ROTR , MVT::i32, Expand);
199  setOperationAction(ISD::BSWAP, MVT::i32, Expand);
200  setOperationAction(ISD::FCOPYSIGN, MVT::f64, Expand);
201  setOperationAction(ISD::FCOPYSIGN, MVT::f32, Expand);
202
203  setOperationAction(ISD::SHL_PARTS, MVT::i32, Expand);
204  setOperationAction(ISD::SRA_PARTS, MVT::i32, Expand);
205  setOperationAction(ISD::SRL_PARTS, MVT::i32, Expand);
206
207  // We don't have line number support yet.
208  setOperationAction(ISD::LOCATION, MVT::Other, Expand);
209  setOperationAction(ISD::DEBUG_LOC, MVT::Other, Expand);
210  setOperationAction(ISD::LABEL, MVT::Other, Expand);
211
212  // RET must be custom lowered, to meet ABI requirements
213  setOperationAction(ISD::RET               , MVT::Other, Custom);
214
215  // VASTART needs to be custom lowered to use the VarArgsFrameIndex.
216  setOperationAction(ISD::VASTART           , MVT::Other, Custom);
217  // VAARG needs to be lowered to not do unaligned accesses for doubles.
218  setOperationAction(ISD::VAARG             , MVT::Other, Custom);
219
220  // Use the default implementation.
221  setOperationAction(ISD::VACOPY            , MVT::Other, Expand);
222  setOperationAction(ISD::VAEND             , MVT::Other, Expand);
223  setOperationAction(ISD::STACKSAVE         , MVT::Other, Expand);
224  setOperationAction(ISD::STACKRESTORE      , MVT::Other, Expand);
225  setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32  , Custom);
226
227  setOperationAction(ISD::ConstantFP, MVT::f64, Expand);
228  setOperationAction(ISD::ConstantFP, MVT::f32, Expand);
229
230  setStackPointerRegisterToSaveRestore(SP::O6);
231
232  if (TM.getSubtarget<SparcSubtarget>().isV9()) {
233    setOperationAction(ISD::CTPOP, MVT::i32, Legal);
234  }
235
236  computeRegisterProperties();
237}
238
239const char *SparcTargetLowering::getTargetNodeName(unsigned Opcode) const {
240  switch (Opcode) {
241  default: return 0;
242  case SPISD::CMPICC:     return "SPISD::CMPICC";
243  case SPISD::CMPFCC:     return "SPISD::CMPFCC";
244  case SPISD::BRICC:      return "SPISD::BRICC";
245  case SPISD::BRFCC:      return "SPISD::BRFCC";
246  case SPISD::SELECT_ICC: return "SPISD::SELECT_ICC";
247  case SPISD::SELECT_FCC: return "SPISD::SELECT_FCC";
248  case SPISD::Hi:         return "SPISD::Hi";
249  case SPISD::Lo:         return "SPISD::Lo";
250  case SPISD::FTOI:       return "SPISD::FTOI";
251  case SPISD::ITOF:       return "SPISD::ITOF";
252  case SPISD::CALL:       return "SPISD::CALL";
253  case SPISD::RET_FLAG:   return "SPISD::RET_FLAG";
254  }
255}
256
257/// isMaskedValueZeroForTargetNode - Return true if 'Op & Mask' is known to
258/// be zero. Op is expected to be a target specific node. Used by DAG
259/// combiner.
260void SparcTargetLowering::computeMaskedBitsForTargetNode(const SDOperand Op,
261                                                         uint64_t Mask,
262                                                         uint64_t &KnownZero,
263                                                         uint64_t &KnownOne,
264                                                         unsigned Depth) const {
265  uint64_t KnownZero2, KnownOne2;
266  KnownZero = KnownOne = 0;   // Don't know anything.
267
268  switch (Op.getOpcode()) {
269  default: break;
270  case SPISD::SELECT_ICC:
271  case SPISD::SELECT_FCC:
272    ComputeMaskedBits(Op.getOperand(1), Mask, KnownZero, KnownOne, Depth+1);
273    ComputeMaskedBits(Op.getOperand(0), Mask, KnownZero2, KnownOne2, Depth+1);
274    assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
275    assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
276
277    // Only known if known in both the LHS and RHS.
278    KnownOne &= KnownOne2;
279    KnownZero &= KnownZero2;
280    break;
281  }
282}
283
284/// LowerArguments - V8 uses a very simple ABI, where all values are passed in
285/// either one or two GPRs, including FP values.  TODO: we should pass FP values
286/// in FP registers for fastcc functions.
287std::vector<SDOperand>
288SparcTargetLowering::LowerArguments(Function &F, SelectionDAG &DAG) {
289  MachineFunction &MF = DAG.getMachineFunction();
290  SSARegMap *RegMap = MF.getSSARegMap();
291  std::vector<SDOperand> ArgValues;
292
293  static const unsigned ArgRegs[] = {
294    SP::I0, SP::I1, SP::I2, SP::I3, SP::I4, SP::I5
295  };
296
297  const unsigned *CurArgReg = ArgRegs, *ArgRegEnd = ArgRegs+6;
298  unsigned ArgOffset = 68;
299
300  SDOperand Root = DAG.getRoot();
301  std::vector<SDOperand> OutChains;
302
303  for (Function::arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E; ++I) {
304    MVT::ValueType ObjectVT = getValueType(I->getType());
305
306    switch (ObjectVT) {
307    default: assert(0 && "Unhandled argument type!");
308    case MVT::i1:
309    case MVT::i8:
310    case MVT::i16:
311    case MVT::i32:
312      if (I->use_empty()) {                // Argument is dead.
313        if (CurArgReg < ArgRegEnd) ++CurArgReg;
314        ArgValues.push_back(DAG.getNode(ISD::UNDEF, ObjectVT));
315      } else if (CurArgReg < ArgRegEnd) {  // Lives in an incoming GPR
316        unsigned VReg = RegMap->createVirtualRegister(&SP::IntRegsRegClass);
317        MF.addLiveIn(*CurArgReg++, VReg);
318        SDOperand Arg = DAG.getCopyFromReg(Root, VReg, MVT::i32);
319        if (ObjectVT != MVT::i32) {
320          unsigned AssertOp = ISD::AssertSext;
321          Arg = DAG.getNode(AssertOp, MVT::i32, Arg,
322                            DAG.getValueType(ObjectVT));
323          Arg = DAG.getNode(ISD::TRUNCATE, ObjectVT, Arg);
324        }
325        ArgValues.push_back(Arg);
326      } else {
327        int FrameIdx = MF.getFrameInfo()->CreateFixedObject(4, ArgOffset);
328        SDOperand FIPtr = DAG.getFrameIndex(FrameIdx, MVT::i32);
329        SDOperand Load;
330        if (ObjectVT == MVT::i32) {
331          Load = DAG.getLoad(MVT::i32, Root, FIPtr, NULL, 0);
332        } else {
333          ISD::LoadExtType LoadOp = ISD::SEXTLOAD;
334
335          // Sparc is big endian, so add an offset based on the ObjectVT.
336          unsigned Offset = 4-std::max(1U, MVT::getSizeInBits(ObjectVT)/8);
337          FIPtr = DAG.getNode(ISD::ADD, MVT::i32, FIPtr,
338                              DAG.getConstant(Offset, MVT::i32));
339          Load = DAG.getExtLoad(LoadOp, MVT::i32, Root, FIPtr,
340                                NULL, 0, ObjectVT);
341          Load = DAG.getNode(ISD::TRUNCATE, ObjectVT, Load);
342        }
343        ArgValues.push_back(Load);
344      }
345
346      ArgOffset += 4;
347      break;
348    case MVT::f32:
349      if (I->use_empty()) {                // Argument is dead.
350        if (CurArgReg < ArgRegEnd) ++CurArgReg;
351        ArgValues.push_back(DAG.getNode(ISD::UNDEF, ObjectVT));
352      } else if (CurArgReg < ArgRegEnd) {  // Lives in an incoming GPR
353        // FP value is passed in an integer register.
354        unsigned VReg = RegMap->createVirtualRegister(&SP::IntRegsRegClass);
355        MF.addLiveIn(*CurArgReg++, VReg);
356        SDOperand Arg = DAG.getCopyFromReg(Root, VReg, MVT::i32);
357
358        Arg = DAG.getNode(ISD::BIT_CONVERT, MVT::f32, Arg);
359        ArgValues.push_back(Arg);
360      } else {
361        int FrameIdx = MF.getFrameInfo()->CreateFixedObject(4, ArgOffset);
362        SDOperand FIPtr = DAG.getFrameIndex(FrameIdx, MVT::i32);
363        SDOperand Load = DAG.getLoad(MVT::f32, Root, FIPtr, NULL, 0);
364        ArgValues.push_back(Load);
365      }
366      ArgOffset += 4;
367      break;
368
369    case MVT::i64:
370    case MVT::f64:
371      if (I->use_empty()) {                // Argument is dead.
372        if (CurArgReg < ArgRegEnd) ++CurArgReg;
373        if (CurArgReg < ArgRegEnd) ++CurArgReg;
374        ArgValues.push_back(DAG.getNode(ISD::UNDEF, ObjectVT));
375      } else if (/* FIXME: Apparently this isn't safe?? */
376                 0 && CurArgReg == ArgRegEnd && ObjectVT == MVT::f64 &&
377                 ((CurArgReg-ArgRegs) & 1) == 0) {
378        // If this is a double argument and the whole thing lives on the stack,
379        // and the argument is aligned, load the double straight from the stack.
380        // We can't do a load in cases like void foo([6ints], int,double),
381        // because the double wouldn't be aligned!
382        int FrameIdx = MF.getFrameInfo()->CreateFixedObject(8, ArgOffset);
383        SDOperand FIPtr = DAG.getFrameIndex(FrameIdx, MVT::i32);
384        ArgValues.push_back(DAG.getLoad(MVT::f64, Root, FIPtr, NULL, 0));
385      } else {
386        SDOperand HiVal;
387        if (CurArgReg < ArgRegEnd) {  // Lives in an incoming GPR
388          unsigned VRegHi = RegMap->createVirtualRegister(&SP::IntRegsRegClass);
389          MF.addLiveIn(*CurArgReg++, VRegHi);
390          HiVal = DAG.getCopyFromReg(Root, VRegHi, MVT::i32);
391        } else {
392          int FrameIdx = MF.getFrameInfo()->CreateFixedObject(4, ArgOffset);
393          SDOperand FIPtr = DAG.getFrameIndex(FrameIdx, MVT::i32);
394          HiVal = DAG.getLoad(MVT::i32, Root, FIPtr, NULL, 0);
395        }
396
397        SDOperand LoVal;
398        if (CurArgReg < ArgRegEnd) {  // Lives in an incoming GPR
399          unsigned VRegLo = RegMap->createVirtualRegister(&SP::IntRegsRegClass);
400          MF.addLiveIn(*CurArgReg++, VRegLo);
401          LoVal = DAG.getCopyFromReg(Root, VRegLo, MVT::i32);
402        } else {
403          int FrameIdx = MF.getFrameInfo()->CreateFixedObject(4, ArgOffset+4);
404          SDOperand FIPtr = DAG.getFrameIndex(FrameIdx, MVT::i32);
405          LoVal = DAG.getLoad(MVT::i32, Root, FIPtr, NULL, 0);
406        }
407
408        // Compose the two halves together into an i64 unit.
409        SDOperand WholeValue =
410          DAG.getNode(ISD::BUILD_PAIR, MVT::i64, LoVal, HiVal);
411
412        // If we want a double, do a bit convert.
413        if (ObjectVT == MVT::f64)
414          WholeValue = DAG.getNode(ISD::BIT_CONVERT, MVT::f64, WholeValue);
415
416        ArgValues.push_back(WholeValue);
417      }
418      ArgOffset += 8;
419      break;
420    }
421  }
422
423  // Store remaining ArgRegs to the stack if this is a varargs function.
424  if (F.getFunctionType()->isVarArg()) {
425    // Remember the vararg offset for the va_start implementation.
426    VarArgsFrameOffset = ArgOffset;
427
428    for (; CurArgReg != ArgRegEnd; ++CurArgReg) {
429      unsigned VReg = RegMap->createVirtualRegister(&SP::IntRegsRegClass);
430      MF.addLiveIn(*CurArgReg, VReg);
431      SDOperand Arg = DAG.getCopyFromReg(DAG.getRoot(), VReg, MVT::i32);
432
433      int FrameIdx = MF.getFrameInfo()->CreateFixedObject(4, ArgOffset);
434      SDOperand FIPtr = DAG.getFrameIndex(FrameIdx, MVT::i32);
435
436      OutChains.push_back(DAG.getStore(DAG.getRoot(), Arg, FIPtr, NULL, 0));
437      ArgOffset += 4;
438    }
439  }
440
441  if (!OutChains.empty())
442    DAG.setRoot(DAG.getNode(ISD::TokenFactor, MVT::Other,
443                            &OutChains[0], OutChains.size()));
444
445  // Finally, inform the code generator which regs we return values in.
446  switch (getValueType(F.getReturnType())) {
447  default: assert(0 && "Unknown type!");
448  case MVT::isVoid: break;
449  case MVT::i1:
450  case MVT::i8:
451  case MVT::i16:
452  case MVT::i32:
453    MF.addLiveOut(SP::I0);
454    break;
455  case MVT::i64:
456    MF.addLiveOut(SP::I0);
457    MF.addLiveOut(SP::I1);
458    break;
459  case MVT::f32:
460    MF.addLiveOut(SP::F0);
461    break;
462  case MVT::f64:
463    MF.addLiveOut(SP::D0);
464    break;
465  }
466
467  return ArgValues;
468}
469
470std::pair<SDOperand, SDOperand>
471SparcTargetLowering::LowerCallTo(SDOperand Chain, const Type *RetTy,
472                                 bool RetTyIsSigned, bool isVarArg, unsigned CC,
473                                 bool isTailCall, SDOperand Callee,
474                                 ArgListTy &Args, SelectionDAG &DAG) {
475  // Count the size of the outgoing arguments.
476  unsigned ArgsSize = 0;
477  for (unsigned i = 0, e = Args.size(); i != e; ++i) {
478    switch (getValueType(Args[i].Ty)) {
479    default: assert(0 && "Unknown value type!");
480    case MVT::i1:
481    case MVT::i8:
482    case MVT::i16:
483    case MVT::i32:
484    case MVT::f32:
485      ArgsSize += 4;
486      break;
487    case MVT::i64:
488    case MVT::f64:
489      ArgsSize += 8;
490      break;
491    }
492  }
493  if (ArgsSize > 4*6)
494    ArgsSize -= 4*6;    // Space for first 6 arguments is prereserved.
495  else
496    ArgsSize = 0;
497
498  // Keep stack frames 8-byte aligned.
499  ArgsSize = (ArgsSize+7) & ~7;
500
501  Chain = DAG.getCALLSEQ_START(Chain,DAG.getConstant(ArgsSize, getPointerTy()));
502
503  SDOperand StackPtr;
504  std::vector<SDOperand> Stores;
505  std::vector<SDOperand> RegValuesToPass;
506  unsigned ArgOffset = 68;
507  for (unsigned i = 0, e = Args.size(); i != e; ++i) {
508    SDOperand Val = Args[i].Node;
509    MVT::ValueType ObjectVT = Val.getValueType();
510    SDOperand ValToStore(0, 0);
511    unsigned ObjSize;
512    switch (ObjectVT) {
513    default: assert(0 && "Unhandled argument type!");
514    case MVT::i1:
515    case MVT::i8:
516    case MVT::i16: {
517      // Promote the integer to 32-bits.  If the input type is signed, use a
518      // sign extend, otherwise use a zero extend.
519      ISD::NodeType ExtendKind = ISD::ZERO_EXTEND;
520      if (Args[i].isSigned)
521        ExtendKind = ISD::SIGN_EXTEND;
522      Val = DAG.getNode(ExtendKind, MVT::i32, Val);
523      // FALL THROUGH
524    }
525    case MVT::i32:
526      ObjSize = 4;
527
528      if (RegValuesToPass.size() >= 6) {
529        ValToStore = Val;
530      } else {
531        RegValuesToPass.push_back(Val);
532      }
533      break;
534    case MVT::f32:
535      ObjSize = 4;
536      if (RegValuesToPass.size() >= 6) {
537        ValToStore = Val;
538      } else {
539        // Convert this to a FP value in an int reg.
540        Val = DAG.getNode(ISD::BIT_CONVERT, MVT::i32, Val);
541        RegValuesToPass.push_back(Val);
542      }
543      break;
544    case MVT::f64:
545      ObjSize = 8;
546      // If we can store this directly into the outgoing slot, do so.  We can
547      // do this when all ArgRegs are used and if the outgoing slot is aligned.
548      // FIXME: McGill/misr fails with this.
549      if (0 && RegValuesToPass.size() >= 6 && ((ArgOffset-68) & 7) == 0) {
550        ValToStore = Val;
551        break;
552      }
553
554      // Otherwise, convert this to a FP value in int regs.
555      Val = DAG.getNode(ISD::BIT_CONVERT, MVT::i64, Val);
556      // FALL THROUGH
557    case MVT::i64:
558      ObjSize = 8;
559      if (RegValuesToPass.size() >= 6) {
560        ValToStore = Val;    // Whole thing is passed in memory.
561        break;
562      }
563
564      // Split the value into top and bottom part.  Top part goes in a reg.
565      SDOperand Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, getPointerTy(), Val,
566                                 DAG.getConstant(1, MVT::i32));
567      SDOperand Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, getPointerTy(), Val,
568                                 DAG.getConstant(0, MVT::i32));
569      RegValuesToPass.push_back(Hi);
570
571      if (RegValuesToPass.size() >= 6) {
572        ValToStore = Lo;
573        ArgOffset += 4;
574        ObjSize = 4;
575      } else {
576        RegValuesToPass.push_back(Lo);
577      }
578      break;
579    }
580
581    if (ValToStore.Val) {
582      if (!StackPtr.Val) {
583        StackPtr = DAG.getRegister(SP::O6, MVT::i32);
584      }
585      SDOperand PtrOff = DAG.getConstant(ArgOffset, getPointerTy());
586      PtrOff = DAG.getNode(ISD::ADD, MVT::i32, StackPtr, PtrOff);
587      Stores.push_back(DAG.getStore(Chain, ValToStore, PtrOff, NULL, 0));
588    }
589    ArgOffset += ObjSize;
590  }
591
592  // Emit all stores, make sure the occur before any copies into physregs.
593  if (!Stores.empty())
594    Chain = DAG.getNode(ISD::TokenFactor, MVT::Other, &Stores[0],Stores.size());
595
596  static const unsigned ArgRegs[] = {
597    SP::O0, SP::O1, SP::O2, SP::O3, SP::O4, SP::O5
598  };
599
600  // Build a sequence of copy-to-reg nodes chained together with token chain
601  // and flag operands which copy the outgoing args into O[0-5].
602  SDOperand InFlag;
603  for (unsigned i = 0, e = RegValuesToPass.size(); i != e; ++i) {
604    Chain = DAG.getCopyToReg(Chain, ArgRegs[i], RegValuesToPass[i], InFlag);
605    InFlag = Chain.getValue(1);
606  }
607
608  // If the callee is a GlobalAddress node (quite common, every direct call is)
609  // turn it into a TargetGlobalAddress node so that legalize doesn't hack it.
610  // Likewise ExternalSymbol -> TargetExternalSymbol.
611  if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
612    Callee = DAG.getTargetGlobalAddress(G->getGlobal(), MVT::i32);
613  else if (ExternalSymbolSDNode *E = dyn_cast<ExternalSymbolSDNode>(Callee))
614    Callee = DAG.getTargetExternalSymbol(E->getSymbol(), MVT::i32);
615
616  std::vector<MVT::ValueType> NodeTys;
617  NodeTys.push_back(MVT::Other);   // Returns a chain
618  NodeTys.push_back(MVT::Flag);    // Returns a flag for retval copy to use.
619  SDOperand Ops[] = { Chain, Callee, InFlag };
620  Chain = DAG.getNode(SPISD::CALL, NodeTys, Ops, InFlag.Val ? 3 : 2);
621  InFlag = Chain.getValue(1);
622
623  MVT::ValueType RetTyVT = getValueType(RetTy);
624  SDOperand RetVal;
625  if (RetTyVT != MVT::isVoid) {
626    switch (RetTyVT) {
627    default: assert(0 && "Unknown value type to return!");
628    case MVT::i1:
629    case MVT::i8:
630    case MVT::i16: {
631      RetVal = DAG.getCopyFromReg(Chain, SP::O0, MVT::i32, InFlag);
632      Chain = RetVal.getValue(1);
633
634      // Add a note to keep track of whether it is sign or zero extended.
635      ISD::NodeType AssertKind = ISD::AssertZext;
636      if (RetTyIsSigned)
637        AssertKind = ISD::AssertSext;
638      RetVal = DAG.getNode(AssertKind, MVT::i32, RetVal,
639                           DAG.getValueType(RetTyVT));
640      RetVal = DAG.getNode(ISD::TRUNCATE, RetTyVT, RetVal);
641      break;
642    }
643    case MVT::i32:
644      RetVal = DAG.getCopyFromReg(Chain, SP::O0, MVT::i32, InFlag);
645      Chain = RetVal.getValue(1);
646      break;
647    case MVT::f32:
648      RetVal = DAG.getCopyFromReg(Chain, SP::F0, MVT::f32, InFlag);
649      Chain = RetVal.getValue(1);
650      break;
651    case MVT::f64:
652      RetVal = DAG.getCopyFromReg(Chain, SP::D0, MVT::f64, InFlag);
653      Chain = RetVal.getValue(1);
654      break;
655    case MVT::i64:
656      SDOperand Lo = DAG.getCopyFromReg(Chain, SP::O1, MVT::i32, InFlag);
657      SDOperand Hi = DAG.getCopyFromReg(Lo.getValue(1), SP::O0, MVT::i32,
658                                        Lo.getValue(2));
659      RetVal = DAG.getNode(ISD::BUILD_PAIR, MVT::i64, Lo, Hi);
660      Chain = Hi.getValue(1);
661      break;
662    }
663  }
664
665  Chain = DAG.getNode(ISD::CALLSEQ_END, MVT::Other, Chain,
666                      DAG.getConstant(ArgsSize, getPointerTy()));
667
668  return std::make_pair(RetVal, Chain);
669}
670
671// Look at LHS/RHS/CC and see if they are a lowered setcc instruction.  If so
672// set LHS/RHS and SPCC to the LHS/RHS of the setcc and SPCC to the condition.
673static void LookThroughSetCC(SDOperand &LHS, SDOperand &RHS,
674                             ISD::CondCode CC, unsigned &SPCC) {
675  if (isa<ConstantSDNode>(RHS) && cast<ConstantSDNode>(RHS)->getValue() == 0 &&
676      CC == ISD::SETNE &&
677      ((LHS.getOpcode() == SPISD::SELECT_ICC &&
678        LHS.getOperand(3).getOpcode() == SPISD::CMPICC) ||
679       (LHS.getOpcode() == SPISD::SELECT_FCC &&
680        LHS.getOperand(3).getOpcode() == SPISD::CMPFCC)) &&
681      isa<ConstantSDNode>(LHS.getOperand(0)) &&
682      isa<ConstantSDNode>(LHS.getOperand(1)) &&
683      cast<ConstantSDNode>(LHS.getOperand(0))->getValue() == 1 &&
684      cast<ConstantSDNode>(LHS.getOperand(1))->getValue() == 0) {
685    SDOperand CMPCC = LHS.getOperand(3);
686    SPCC = cast<ConstantSDNode>(LHS.getOperand(2))->getValue();
687    LHS = CMPCC.getOperand(0);
688    RHS = CMPCC.getOperand(1);
689  }
690}
691
692
693SDOperand SparcTargetLowering::
694LowerOperation(SDOperand Op, SelectionDAG &DAG) {
695  switch (Op.getOpcode()) {
696  default: assert(0 && "Should not custom lower this!");
697  case ISD::GlobalAddress: {
698    GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
699    SDOperand GA = DAG.getTargetGlobalAddress(GV, MVT::i32);
700    SDOperand Hi = DAG.getNode(SPISD::Hi, MVT::i32, GA);
701    SDOperand Lo = DAG.getNode(SPISD::Lo, MVT::i32, GA);
702    return DAG.getNode(ISD::ADD, MVT::i32, Lo, Hi);
703  }
704  case ISD::ConstantPool: {
705    Constant *C = cast<ConstantPoolSDNode>(Op)->getConstVal();
706    SDOperand CP = DAG.getTargetConstantPool(C, MVT::i32,
707                                  cast<ConstantPoolSDNode>(Op)->getAlignment());
708    SDOperand Hi = DAG.getNode(SPISD::Hi, MVT::i32, CP);
709    SDOperand Lo = DAG.getNode(SPISD::Lo, MVT::i32, CP);
710    return DAG.getNode(ISD::ADD, MVT::i32, Lo, Hi);
711  }
712  case ISD::FP_TO_SINT:
713    // Convert the fp value to integer in an FP register.
714    assert(Op.getValueType() == MVT::i32);
715    Op = DAG.getNode(SPISD::FTOI, MVT::f32, Op.getOperand(0));
716    return DAG.getNode(ISD::BIT_CONVERT, MVT::i32, Op);
717  case ISD::SINT_TO_FP: {
718    assert(Op.getOperand(0).getValueType() == MVT::i32);
719    SDOperand Tmp = DAG.getNode(ISD::BIT_CONVERT, MVT::f32, Op.getOperand(0));
720    // Convert the int value to FP in an FP register.
721    return DAG.getNode(SPISD::ITOF, Op.getValueType(), Tmp);
722  }
723  case ISD::BR_CC: {
724    SDOperand Chain = Op.getOperand(0);
725    ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(1))->get();
726    SDOperand LHS = Op.getOperand(2);
727    SDOperand RHS = Op.getOperand(3);
728    SDOperand Dest = Op.getOperand(4);
729    unsigned Opc, SPCC = ~0U;
730
731    // If this is a br_cc of a "setcc", and if the setcc got lowered into
732    // an CMP[IF]CC/SELECT_[IF]CC pair, find the original compared values.
733    LookThroughSetCC(LHS, RHS, CC, SPCC);
734
735    // Get the condition flag.
736    SDOperand CompareFlag;
737    if (LHS.getValueType() == MVT::i32) {
738      std::vector<MVT::ValueType> VTs;
739      VTs.push_back(MVT::i32);
740      VTs.push_back(MVT::Flag);
741      SDOperand Ops[2] = { LHS, RHS };
742      CompareFlag = DAG.getNode(SPISD::CMPICC, VTs, Ops, 2).getValue(1);
743      if (SPCC == ~0U) SPCC = IntCondCCodeToICC(CC);
744      Opc = SPISD::BRICC;
745    } else {
746      CompareFlag = DAG.getNode(SPISD::CMPFCC, MVT::Flag, LHS, RHS);
747      if (SPCC == ~0U) SPCC = FPCondCCodeToFCC(CC);
748      Opc = SPISD::BRFCC;
749    }
750    return DAG.getNode(Opc, MVT::Other, Chain, Dest,
751                       DAG.getConstant(SPCC, MVT::i32), CompareFlag);
752  }
753  case ISD::SELECT_CC: {
754    SDOperand LHS = Op.getOperand(0);
755    SDOperand RHS = Op.getOperand(1);
756    ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(4))->get();
757    SDOperand TrueVal = Op.getOperand(2);
758    SDOperand FalseVal = Op.getOperand(3);
759    unsigned Opc, SPCC = ~0U;
760
761    // If this is a select_cc of a "setcc", and if the setcc got lowered into
762    // an CMP[IF]CC/SELECT_[IF]CC pair, find the original compared values.
763    LookThroughSetCC(LHS, RHS, CC, SPCC);
764
765    SDOperand CompareFlag;
766    if (LHS.getValueType() == MVT::i32) {
767      std::vector<MVT::ValueType> VTs;
768      VTs.push_back(LHS.getValueType());   // subcc returns a value
769      VTs.push_back(MVT::Flag);
770      SDOperand Ops[2] = { LHS, RHS };
771      CompareFlag = DAG.getNode(SPISD::CMPICC, VTs, Ops, 2).getValue(1);
772      Opc = SPISD::SELECT_ICC;
773      if (SPCC == ~0U) SPCC = IntCondCCodeToICC(CC);
774    } else {
775      CompareFlag = DAG.getNode(SPISD::CMPFCC, MVT::Flag, LHS, RHS);
776      Opc = SPISD::SELECT_FCC;
777      if (SPCC == ~0U) SPCC = FPCondCCodeToFCC(CC);
778    }
779    return DAG.getNode(Opc, TrueVal.getValueType(), TrueVal, FalseVal,
780                       DAG.getConstant(SPCC, MVT::i32), CompareFlag);
781  }
782  case ISD::VASTART: {
783    // vastart just stores the address of the VarArgsFrameIndex slot into the
784    // memory location argument.
785    SDOperand Offset = DAG.getNode(ISD::ADD, MVT::i32,
786                                   DAG.getRegister(SP::I6, MVT::i32),
787                                DAG.getConstant(VarArgsFrameOffset, MVT::i32));
788    SrcValueSDNode *SV = cast<SrcValueSDNode>(Op.getOperand(2));
789    return DAG.getStore(Op.getOperand(0), Offset,
790                        Op.getOperand(1), SV->getValue(), SV->getOffset());
791  }
792  case ISD::VAARG: {
793    SDNode *Node = Op.Val;
794    MVT::ValueType VT = Node->getValueType(0);
795    SDOperand InChain = Node->getOperand(0);
796    SDOperand VAListPtr = Node->getOperand(1);
797    SrcValueSDNode *SV = cast<SrcValueSDNode>(Node->getOperand(2));
798    SDOperand VAList = DAG.getLoad(getPointerTy(), InChain, VAListPtr,
799                                   SV->getValue(), SV->getOffset());
800    // Increment the pointer, VAList, to the next vaarg
801    SDOperand NextPtr = DAG.getNode(ISD::ADD, getPointerTy(), VAList,
802                                    DAG.getConstant(MVT::getSizeInBits(VT)/8,
803                                                    getPointerTy()));
804    // Store the incremented VAList to the legalized pointer
805    InChain = DAG.getStore(VAList.getValue(1), NextPtr,
806                           VAListPtr, SV->getValue(), SV->getOffset());
807    // Load the actual argument out of the pointer VAList, unless this is an
808    // f64 load.
809    if (VT != MVT::f64) {
810      return DAG.getLoad(VT, InChain, VAList, NULL, 0);
811    } else {
812      // Otherwise, load it as i64, then do a bitconvert.
813      SDOperand V = DAG.getLoad(MVT::i64, InChain, VAList, NULL, 0);
814      std::vector<MVT::ValueType> Tys;
815      Tys.push_back(MVT::f64);
816      Tys.push_back(MVT::Other);
817      // Bit-Convert the value to f64.
818      SDOperand Ops[2] = { DAG.getNode(ISD::BIT_CONVERT, MVT::f64, V),
819                           V.getValue(1) };
820      return DAG.getNode(ISD::MERGE_VALUES, Tys, Ops, 2);
821    }
822  }
823  case ISD::DYNAMIC_STACKALLOC: {
824    SDOperand Chain = Op.getOperand(0);  // Legalize the chain.
825    SDOperand Size  = Op.getOperand(1);  // Legalize the size.
826
827    unsigned SPReg = SP::O6;
828    SDOperand SP = DAG.getCopyFromReg(Chain, SPReg, MVT::i32);
829    SDOperand NewSP = DAG.getNode(ISD::SUB, MVT::i32, SP, Size);    // Value
830    Chain = DAG.getCopyToReg(SP.getValue(1), SPReg, NewSP);      // Output chain
831
832    // The resultant pointer is actually 16 words from the bottom of the stack,
833    // to provide a register spill area.
834    SDOperand NewVal = DAG.getNode(ISD::ADD, MVT::i32, NewSP,
835                                   DAG.getConstant(96, MVT::i32));
836    std::vector<MVT::ValueType> Tys;
837    Tys.push_back(MVT::i32);
838    Tys.push_back(MVT::Other);
839    SDOperand Ops[2] = { NewVal, Chain };
840    return DAG.getNode(ISD::MERGE_VALUES, Tys, Ops, 2);
841  }
842  case ISD::RET: {
843    SDOperand Copy;
844
845    switch(Op.getNumOperands()) {
846    default:
847      assert(0 && "Do not know how to return this many arguments!");
848      abort();
849    case 1:
850      return SDOperand(); // ret void is legal
851    case 3: {
852      unsigned ArgReg;
853      switch(Op.getOperand(1).getValueType()) {
854      default: assert(0 && "Unknown type to return!");
855      case MVT::i32: ArgReg = SP::I0; break;
856      case MVT::f32: ArgReg = SP::F0; break;
857      case MVT::f64: ArgReg = SP::D0; break;
858      }
859      Copy = DAG.getCopyToReg(Op.getOperand(0), ArgReg, Op.getOperand(1),
860                              SDOperand());
861      break;
862    }
863    case 5:
864      Copy = DAG.getCopyToReg(Op.getOperand(0), SP::I0, Op.getOperand(3),
865                              SDOperand());
866      Copy = DAG.getCopyToReg(Copy, SP::I1, Op.getOperand(1), Copy.getValue(1));
867      break;
868    }
869    return DAG.getNode(SPISD::RET_FLAG, MVT::Other, Copy, Copy.getValue(1));
870  }
871  // Frame & Return address.  Currently unimplemented
872  case ISD::RETURNADDR:         break;
873  case ISD::FRAMEADDR:          break;
874  // Exception address and exception selector.  Currently unimplemented.
875  case ISD::EXCEPTIONADDR: break;
876  case ISD::EHSELECTION:   break;
877  }
878  return SDOperand();
879}
880
881MachineBasicBlock *
882SparcTargetLowering::InsertAtEndOfBasicBlock(MachineInstr *MI,
883                                             MachineBasicBlock *BB) {
884  const TargetInstrInfo &TII = *getTargetMachine().getInstrInfo();
885  unsigned BROpcode;
886  unsigned CC;
887  // Figure out the conditional branch opcode to use for this select_cc.
888  switch (MI->getOpcode()) {
889  default: assert(0 && "Unknown SELECT_CC!");
890  case SP::SELECT_CC_Int_ICC:
891  case SP::SELECT_CC_FP_ICC:
892  case SP::SELECT_CC_DFP_ICC:
893    BROpcode = SP::BCOND;
894    break;
895  case SP::SELECT_CC_Int_FCC:
896  case SP::SELECT_CC_FP_FCC:
897  case SP::SELECT_CC_DFP_FCC:
898    BROpcode = SP::FBCOND;
899    break;
900  }
901
902  CC = (SPCC::CondCodes)MI->getOperand(3).getImmedValue();
903
904  // To "insert" a SELECT_CC instruction, we actually have to insert the diamond
905  // control-flow pattern.  The incoming instruction knows the destination vreg
906  // to set, the condition code register to branch on, the true/false values to
907  // select between, and a branch opcode to use.
908  const BasicBlock *LLVM_BB = BB->getBasicBlock();
909  ilist<MachineBasicBlock>::iterator It = BB;
910  ++It;
911
912  //  thisMBB:
913  //  ...
914  //   TrueVal = ...
915  //   [f]bCC copy1MBB
916  //   fallthrough --> copy0MBB
917  MachineBasicBlock *thisMBB = BB;
918  MachineBasicBlock *copy0MBB = new MachineBasicBlock(LLVM_BB);
919  MachineBasicBlock *sinkMBB = new MachineBasicBlock(LLVM_BB);
920  BuildMI(BB, TII.get(BROpcode)).addMBB(sinkMBB).addImm(CC);
921  MachineFunction *F = BB->getParent();
922  F->getBasicBlockList().insert(It, copy0MBB);
923  F->getBasicBlockList().insert(It, sinkMBB);
924  // Update machine-CFG edges by first adding all successors of the current
925  // block to the new block which will contain the Phi node for the select.
926  for(MachineBasicBlock::succ_iterator i = BB->succ_begin(),
927      e = BB->succ_end(); i != e; ++i)
928    sinkMBB->addSuccessor(*i);
929  // Next, remove all successors of the current block, and add the true
930  // and fallthrough blocks as its successors.
931  while(!BB->succ_empty())
932    BB->removeSuccessor(BB->succ_begin());
933  BB->addSuccessor(copy0MBB);
934  BB->addSuccessor(sinkMBB);
935
936  //  copy0MBB:
937  //   %FalseValue = ...
938  //   # fallthrough to sinkMBB
939  BB = copy0MBB;
940
941  // Update machine-CFG edges
942  BB->addSuccessor(sinkMBB);
943
944  //  sinkMBB:
945  //   %Result = phi [ %FalseValue, copy0MBB ], [ %TrueValue, thisMBB ]
946  //  ...
947  BB = sinkMBB;
948  BuildMI(BB, TII.get(SP::PHI), MI->getOperand(0).getReg())
949    .addReg(MI->getOperand(2).getReg()).addMBB(copy0MBB)
950    .addReg(MI->getOperand(1).getReg()).addMBB(thisMBB);
951
952  delete MI;   // The pseudo instruction is gone now.
953  return BB;
954}
955
956//===----------------------------------------------------------------------===//
957// Instruction Selector Implementation
958//===----------------------------------------------------------------------===//
959
960//===--------------------------------------------------------------------===//
961/// SparcDAGToDAGISel - SPARC specific code to select SPARC machine
962/// instructions for SelectionDAG operations.
963///
964namespace {
965class SparcDAGToDAGISel : public SelectionDAGISel {
966  SparcTargetLowering Lowering;
967
968  /// Subtarget - Keep a pointer to the Sparc Subtarget around so that we can
969  /// make the right decision when generating code for different targets.
970  const SparcSubtarget &Subtarget;
971public:
972  SparcDAGToDAGISel(TargetMachine &TM)
973    : SelectionDAGISel(Lowering), Lowering(TM),
974      Subtarget(TM.getSubtarget<SparcSubtarget>()) {
975  }
976
977  SDNode *Select(SDOperand Op);
978
979  // Complex Pattern Selectors.
980  bool SelectADDRrr(SDOperand Op, SDOperand N, SDOperand &R1, SDOperand &R2);
981  bool SelectADDRri(SDOperand Op, SDOperand N, SDOperand &Base,
982                    SDOperand &Offset);
983
984  /// InstructionSelectBasicBlock - This callback is invoked by
985  /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
986  virtual void InstructionSelectBasicBlock(SelectionDAG &DAG);
987
988  virtual const char *getPassName() const {
989    return "SPARC DAG->DAG Pattern Instruction Selection";
990  }
991
992  // Include the pieces autogenerated from the target description.
993#include "SparcGenDAGISel.inc"
994};
995}  // end anonymous namespace
996
997/// InstructionSelectBasicBlock - This callback is invoked by
998/// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
999void SparcDAGToDAGISel::InstructionSelectBasicBlock(SelectionDAG &DAG) {
1000  DEBUG(BB->dump());
1001
1002  // Select target instructions for the DAG.
1003  DAG.setRoot(SelectRoot(DAG.getRoot()));
1004  DAG.RemoveDeadNodes();
1005
1006  // Emit machine code to BB.
1007  ScheduleAndEmitDAG(DAG);
1008}
1009
1010bool SparcDAGToDAGISel::SelectADDRri(SDOperand Op, SDOperand Addr,
1011                                     SDOperand &Base, SDOperand &Offset) {
1012  if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>(Addr)) {
1013    Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i32);
1014    Offset = CurDAG->getTargetConstant(0, MVT::i32);
1015    return true;
1016  }
1017  if (Addr.getOpcode() == ISD::TargetExternalSymbol ||
1018      Addr.getOpcode() == ISD::TargetGlobalAddress)
1019    return false;  // direct calls.
1020
1021  if (Addr.getOpcode() == ISD::ADD) {
1022    if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Addr.getOperand(1))) {
1023      if (Predicate_simm13(CN)) {
1024        if (FrameIndexSDNode *FIN =
1025                dyn_cast<FrameIndexSDNode>(Addr.getOperand(0))) {
1026          // Constant offset from frame ref.
1027          Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i32);
1028        } else {
1029          Base = Addr.getOperand(0);
1030        }
1031        Offset = CurDAG->getTargetConstant(CN->getValue(), MVT::i32);
1032        return true;
1033      }
1034    }
1035    if (Addr.getOperand(0).getOpcode() == SPISD::Lo) {
1036      Base = Addr.getOperand(1);
1037      Offset = Addr.getOperand(0).getOperand(0);
1038      return true;
1039    }
1040    if (Addr.getOperand(1).getOpcode() == SPISD::Lo) {
1041      Base = Addr.getOperand(0);
1042      Offset = Addr.getOperand(1).getOperand(0);
1043      return true;
1044    }
1045  }
1046  Base = Addr;
1047  Offset = CurDAG->getTargetConstant(0, MVT::i32);
1048  return true;
1049}
1050
1051bool SparcDAGToDAGISel::SelectADDRrr(SDOperand Op, SDOperand Addr,
1052                                     SDOperand &R1,  SDOperand &R2) {
1053  if (Addr.getOpcode() == ISD::FrameIndex) return false;
1054  if (Addr.getOpcode() == ISD::TargetExternalSymbol ||
1055      Addr.getOpcode() == ISD::TargetGlobalAddress)
1056    return false;  // direct calls.
1057
1058  if (Addr.getOpcode() == ISD::ADD) {
1059    if (isa<ConstantSDNode>(Addr.getOperand(1)) &&
1060        Predicate_simm13(Addr.getOperand(1).Val))
1061      return false;  // Let the reg+imm pattern catch this!
1062    if (Addr.getOperand(0).getOpcode() == SPISD::Lo ||
1063        Addr.getOperand(1).getOpcode() == SPISD::Lo)
1064      return false;  // Let the reg+imm pattern catch this!
1065    R1 = Addr.getOperand(0);
1066    R2 = Addr.getOperand(1);
1067    return true;
1068  }
1069
1070  R1 = Addr;
1071  R2 = CurDAG->getRegister(SP::G0, MVT::i32);
1072  return true;
1073}
1074
1075SDNode *SparcDAGToDAGISel::Select(SDOperand Op) {
1076  SDNode *N = Op.Val;
1077  if (N->getOpcode() >= ISD::BUILTIN_OP_END &&
1078      N->getOpcode() < SPISD::FIRST_NUMBER)
1079    return NULL;   // Already selected.
1080
1081  switch (N->getOpcode()) {
1082  default: break;
1083  case ISD::SDIV:
1084  case ISD::UDIV: {
1085    // FIXME: should use a custom expander to expose the SRA to the dag.
1086    SDOperand DivLHS = N->getOperand(0);
1087    SDOperand DivRHS = N->getOperand(1);
1088    AddToISelQueue(DivLHS);
1089    AddToISelQueue(DivRHS);
1090
1091    // Set the Y register to the high-part.
1092    SDOperand TopPart;
1093    if (N->getOpcode() == ISD::SDIV) {
1094      TopPart = SDOperand(CurDAG->getTargetNode(SP::SRAri, MVT::i32, DivLHS,
1095                                   CurDAG->getTargetConstant(31, MVT::i32)), 0);
1096    } else {
1097      TopPart = CurDAG->getRegister(SP::G0, MVT::i32);
1098    }
1099    TopPart = SDOperand(CurDAG->getTargetNode(SP::WRYrr, MVT::Flag, TopPart,
1100                                     CurDAG->getRegister(SP::G0, MVT::i32)), 0);
1101
1102    // FIXME: Handle div by immediate.
1103    unsigned Opcode = N->getOpcode() == ISD::SDIV ? SP::SDIVrr : SP::UDIVrr;
1104    return CurDAG->SelectNodeTo(N, Opcode, MVT::i32, DivLHS, DivRHS,
1105                                TopPart);
1106  }
1107  case ISD::MULHU:
1108  case ISD::MULHS: {
1109    // FIXME: Handle mul by immediate.
1110    SDOperand MulLHS = N->getOperand(0);
1111    SDOperand MulRHS = N->getOperand(1);
1112    AddToISelQueue(MulLHS);
1113    AddToISelQueue(MulRHS);
1114    unsigned Opcode = N->getOpcode() == ISD::MULHU ? SP::UMULrr : SP::SMULrr;
1115    SDNode *Mul = CurDAG->getTargetNode(Opcode, MVT::i32, MVT::Flag,
1116                                        MulLHS, MulRHS);
1117    // The high part is in the Y register.
1118    return CurDAG->SelectNodeTo(N, SP::RDY, MVT::i32, SDOperand(Mul, 1));
1119    return NULL;
1120  }
1121  }
1122
1123  return SelectCode(Op);
1124}
1125
1126
1127/// createSparcISelDag - This pass converts a legalized DAG into a
1128/// SPARC-specific DAG, ready for instruction scheduling.
1129///
1130FunctionPass *llvm::createSparcISelDag(TargetMachine &TM) {
1131  return new SparcDAGToDAGISel(TM);
1132}
1133