1//===-- AlphaISelLowering.cpp - Alpha 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 implements the AlphaISelLowering class.
11//
12//===----------------------------------------------------------------------===//
13
14#include "AlphaISelLowering.h"
15#include "AlphaTargetMachine.h"
16#include "AlphaMachineFunctionInfo.h"
17#include "llvm/CodeGen/CallingConvLower.h"
18#include "llvm/CodeGen/MachineFrameInfo.h"
19#include "llvm/CodeGen/MachineFunction.h"
20#include "llvm/CodeGen/MachineInstrBuilder.h"
21#include "llvm/CodeGen/MachineRegisterInfo.h"
22#include "llvm/CodeGen/SelectionDAG.h"
23#include "llvm/CodeGen/MachineRegisterInfo.h"
24#include "llvm/CodeGen/PseudoSourceValue.h"
25#include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
26#include "llvm/Constants.h"
27#include "llvm/Function.h"
28#include "llvm/Module.h"
29#include "llvm/Intrinsics.h"
30#include "llvm/Type.h"
31#include "llvm/Support/CommandLine.h"
32#include "llvm/Support/ErrorHandling.h"
33#include "llvm/Support/raw_ostream.h"
34using namespace llvm;
35
36/// AddLiveIn - This helper function adds the specified physical register to the
37/// MachineFunction as a live in value.  It also creates a corresponding virtual
38/// register for it.
39static unsigned AddLiveIn(MachineFunction &MF, unsigned PReg,
40                          TargetRegisterClass *RC) {
41  assert(RC->contains(PReg) && "Not the correct regclass!");
42  unsigned VReg = MF.getRegInfo().createVirtualRegister(RC);
43  MF.getRegInfo().addLiveIn(PReg, VReg);
44  return VReg;
45}
46
47AlphaTargetLowering::AlphaTargetLowering(TargetMachine &TM)
48  : TargetLowering(TM, new TargetLoweringObjectFileELF()) {
49  // Set up the TargetLowering object.
50  //I am having problems with shr n i8 1
51  setBooleanContents(ZeroOrOneBooleanContent);
52  setBooleanVectorContents(ZeroOrOneBooleanContent); // FIXME: Is this correct?
53
54  addRegisterClass(MVT::i64, Alpha::GPRCRegisterClass);
55  addRegisterClass(MVT::f64, Alpha::F8RCRegisterClass);
56  addRegisterClass(MVT::f32, Alpha::F4RCRegisterClass);
57
58  // We want to custom lower some of our intrinsics.
59  setOperationAction(ISD::INTRINSIC_WO_CHAIN, MVT::Other, Custom);
60
61  setLoadExtAction(ISD::EXTLOAD, MVT::i1,  Promote);
62  setLoadExtAction(ISD::EXTLOAD, MVT::f32, Expand);
63
64  setLoadExtAction(ISD::ZEXTLOAD, MVT::i1,  Promote);
65  setLoadExtAction(ISD::ZEXTLOAD, MVT::i32, Expand);
66
67  setLoadExtAction(ISD::SEXTLOAD, MVT::i1,  Promote);
68  setLoadExtAction(ISD::SEXTLOAD, MVT::i8,  Expand);
69  setLoadExtAction(ISD::SEXTLOAD, MVT::i16, Expand);
70
71  setTruncStoreAction(MVT::f64, MVT::f32, Expand);
72
73  //  setOperationAction(ISD::BRIND,        MVT::Other,   Expand);
74  setOperationAction(ISD::BR_JT,        MVT::Other, Expand);
75  setOperationAction(ISD::BR_CC,        MVT::Other, Expand);
76  setOperationAction(ISD::SELECT_CC,    MVT::Other, Expand);
77
78  setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1, Expand);
79
80  setOperationAction(ISD::FREM, MVT::f32, Expand);
81  setOperationAction(ISD::FREM, MVT::f64, Expand);
82
83  setOperationAction(ISD::UINT_TO_FP, MVT::i64, Expand);
84  setOperationAction(ISD::SINT_TO_FP, MVT::i64, Custom);
85  setOperationAction(ISD::FP_TO_UINT, MVT::i64, Expand);
86  setOperationAction(ISD::FP_TO_SINT, MVT::i64, Custom);
87
88  if (!TM.getSubtarget<AlphaSubtarget>().hasCT()) {
89    setOperationAction(ISD::CTPOP    , MVT::i64  , Expand);
90    setOperationAction(ISD::CTTZ     , MVT::i64  , Expand);
91    setOperationAction(ISD::CTLZ     , MVT::i64  , Expand);
92  }
93  setOperationAction(ISD::BSWAP    , MVT::i64, Expand);
94  setOperationAction(ISD::ROTL     , MVT::i64, Expand);
95  setOperationAction(ISD::ROTR     , MVT::i64, Expand);
96
97  setOperationAction(ISD::SREM     , MVT::i64, Custom);
98  setOperationAction(ISD::UREM     , MVT::i64, Custom);
99  setOperationAction(ISD::SDIV     , MVT::i64, Custom);
100  setOperationAction(ISD::UDIV     , MVT::i64, Custom);
101
102  setOperationAction(ISD::ADDC     , MVT::i64, Expand);
103  setOperationAction(ISD::ADDE     , MVT::i64, Expand);
104  setOperationAction(ISD::SUBC     , MVT::i64, Expand);
105  setOperationAction(ISD::SUBE     , MVT::i64, Expand);
106
107  setOperationAction(ISD::UMUL_LOHI, MVT::i64, Expand);
108  setOperationAction(ISD::SMUL_LOHI, MVT::i64, Expand);
109
110  setOperationAction(ISD::SRL_PARTS, MVT::i64, Custom);
111  setOperationAction(ISD::SRA_PARTS, MVT::i64, Expand);
112  setOperationAction(ISD::SHL_PARTS, MVT::i64, Expand);
113
114  // We don't support sin/cos/sqrt/pow
115  setOperationAction(ISD::FSIN , MVT::f64, Expand);
116  setOperationAction(ISD::FCOS , MVT::f64, Expand);
117  setOperationAction(ISD::FSIN , MVT::f32, Expand);
118  setOperationAction(ISD::FCOS , MVT::f32, Expand);
119
120  setOperationAction(ISD::FSQRT, MVT::f64, Expand);
121  setOperationAction(ISD::FSQRT, MVT::f32, Expand);
122
123  setOperationAction(ISD::FPOW , MVT::f32, Expand);
124  setOperationAction(ISD::FPOW , MVT::f64, Expand);
125
126  setOperationAction(ISD::FMA, MVT::f64, Expand);
127  setOperationAction(ISD::FMA, MVT::f32, Expand);
128
129  setOperationAction(ISD::SETCC, MVT::f32, Promote);
130
131  setOperationAction(ISD::BITCAST, MVT::f32, Promote);
132
133  setOperationAction(ISD::EH_LABEL, MVT::Other, Expand);
134
135  // Not implemented yet.
136  setOperationAction(ISD::STACKSAVE, MVT::Other, Expand);
137  setOperationAction(ISD::STACKRESTORE, MVT::Other, Expand);
138  setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i64, Expand);
139
140  // We want to legalize GlobalAddress and ConstantPool and
141  // ExternalSymbols nodes into the appropriate instructions to
142  // materialize the address.
143  setOperationAction(ISD::GlobalAddress,  MVT::i64, Custom);
144  setOperationAction(ISD::ConstantPool,   MVT::i64, Custom);
145  setOperationAction(ISD::ExternalSymbol, MVT::i64, Custom);
146  setOperationAction(ISD::GlobalTLSAddress, MVT::i64, Custom);
147
148  setOperationAction(ISD::VASTART, MVT::Other, Custom);
149  setOperationAction(ISD::VAEND,   MVT::Other, Expand);
150  setOperationAction(ISD::VACOPY,  MVT::Other, Custom);
151  setOperationAction(ISD::VAARG,   MVT::Other, Custom);
152  setOperationAction(ISD::VAARG,   MVT::i32,   Custom);
153
154  setOperationAction(ISD::JumpTable, MVT::i64, Custom);
155  setOperationAction(ISD::JumpTable, MVT::i32, Custom);
156
157  setOperationAction(ISD::ATOMIC_LOAD,  MVT::i32, Expand);
158  setOperationAction(ISD::ATOMIC_STORE, MVT::i32, Expand);
159
160  setStackPointerRegisterToSaveRestore(Alpha::R30);
161
162  setJumpBufSize(272);
163  setJumpBufAlignment(16);
164
165  setMinFunctionAlignment(4);
166
167  setInsertFencesForAtomic(true);
168
169  computeRegisterProperties();
170}
171
172EVT AlphaTargetLowering::getSetCCResultType(EVT VT) const {
173  return MVT::i64;
174}
175
176const char *AlphaTargetLowering::getTargetNodeName(unsigned Opcode) const {
177  switch (Opcode) {
178  default: return 0;
179  case AlphaISD::CVTQT_: return "Alpha::CVTQT_";
180  case AlphaISD::CVTQS_: return "Alpha::CVTQS_";
181  case AlphaISD::CVTTQ_: return "Alpha::CVTTQ_";
182  case AlphaISD::GPRelHi: return "Alpha::GPRelHi";
183  case AlphaISD::GPRelLo: return "Alpha::GPRelLo";
184  case AlphaISD::RelLit: return "Alpha::RelLit";
185  case AlphaISD::GlobalRetAddr: return "Alpha::GlobalRetAddr";
186  case AlphaISD::CALL:   return "Alpha::CALL";
187  case AlphaISD::DivCall: return "Alpha::DivCall";
188  case AlphaISD::RET_FLAG: return "Alpha::RET_FLAG";
189  case AlphaISD::COND_BRANCH_I: return "Alpha::COND_BRANCH_I";
190  case AlphaISD::COND_BRANCH_F: return "Alpha::COND_BRANCH_F";
191  }
192}
193
194static SDValue LowerJumpTable(SDValue Op, SelectionDAG &DAG) {
195  EVT PtrVT = Op.getValueType();
196  JumpTableSDNode *JT = cast<JumpTableSDNode>(Op);
197  SDValue JTI = DAG.getTargetJumpTable(JT->getIndex(), PtrVT);
198  // FIXME there isn't really any debug info here
199  DebugLoc dl = Op.getDebugLoc();
200
201  SDValue Hi = DAG.getNode(AlphaISD::GPRelHi,  dl, MVT::i64, JTI,
202                             DAG.getGLOBAL_OFFSET_TABLE(MVT::i64));
203  SDValue Lo = DAG.getNode(AlphaISD::GPRelLo, dl, MVT::i64, JTI, Hi);
204  return Lo;
205}
206
207//http://www.cs.arizona.edu/computer.help/policy/DIGITAL_unix/
208//AA-PY8AC-TET1_html/callCH3.html#BLOCK21
209
210//For now, just use variable size stack frame format
211
212//In a standard call, the first six items are passed in registers $16
213//- $21 and/or registers $f16 - $f21. (See Section 4.1.2 for details
214//of argument-to-register correspondence.) The remaining items are
215//collected in a memory argument list that is a naturally aligned
216//array of quadwords. In a standard call, this list, if present, must
217//be passed at 0(SP).
218//7 ... n         0(SP) ... (n-7)*8(SP)
219
220// //#define FP    $15
221// //#define RA    $26
222// //#define PV    $27
223// //#define GP    $29
224// //#define SP    $30
225
226#include "AlphaGenCallingConv.inc"
227
228SDValue
229AlphaTargetLowering::LowerCall(SDValue Chain, SDValue Callee,
230                               CallingConv::ID CallConv, bool isVarArg,
231                               bool &isTailCall,
232                               const SmallVectorImpl<ISD::OutputArg> &Outs,
233                               const SmallVectorImpl<SDValue> &OutVals,
234                               const SmallVectorImpl<ISD::InputArg> &Ins,
235                               DebugLoc dl, SelectionDAG &DAG,
236                               SmallVectorImpl<SDValue> &InVals) const {
237  // Alpha target does not yet support tail call optimization.
238  isTailCall = false;
239
240  // Analyze operands of the call, assigning locations to each operand.
241  SmallVector<CCValAssign, 16> ArgLocs;
242  CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
243		 getTargetMachine(), ArgLocs, *DAG.getContext());
244
245  CCInfo.AnalyzeCallOperands(Outs, CC_Alpha);
246
247    // Get a count of how many bytes are to be pushed on the stack.
248  unsigned NumBytes = CCInfo.getNextStackOffset();
249
250  Chain = DAG.getCALLSEQ_START(Chain, DAG.getConstant(NumBytes,
251                                                      getPointerTy(), true));
252
253  SmallVector<std::pair<unsigned, SDValue>, 4> RegsToPass;
254  SmallVector<SDValue, 12> MemOpChains;
255  SDValue StackPtr;
256
257  // Walk the register/memloc assignments, inserting copies/loads.
258  for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
259    CCValAssign &VA = ArgLocs[i];
260
261    SDValue Arg = OutVals[i];
262
263    // Promote the value if needed.
264    switch (VA.getLocInfo()) {
265      default: assert(0 && "Unknown loc info!");
266      case CCValAssign::Full: break;
267      case CCValAssign::SExt:
268        Arg = DAG.getNode(ISD::SIGN_EXTEND, dl, VA.getLocVT(), Arg);
269        break;
270      case CCValAssign::ZExt:
271        Arg = DAG.getNode(ISD::ZERO_EXTEND, dl, VA.getLocVT(), Arg);
272        break;
273      case CCValAssign::AExt:
274        Arg = DAG.getNode(ISD::ANY_EXTEND, dl, VA.getLocVT(), Arg);
275        break;
276    }
277
278    // Arguments that can be passed on register must be kept at RegsToPass
279    // vector
280    if (VA.isRegLoc()) {
281      RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
282    } else {
283      assert(VA.isMemLoc());
284
285      if (StackPtr.getNode() == 0)
286        StackPtr = DAG.getCopyFromReg(Chain, dl, Alpha::R30, MVT::i64);
287
288      SDValue PtrOff = DAG.getNode(ISD::ADD, dl, getPointerTy(),
289                                   StackPtr,
290                                   DAG.getIntPtrConstant(VA.getLocMemOffset()));
291
292      MemOpChains.push_back(DAG.getStore(Chain, dl, Arg, PtrOff,
293                                         MachinePointerInfo(),false, false, 0));
294    }
295  }
296
297  // Transform all store nodes into one single node because all store nodes are
298  // independent of each other.
299  if (!MemOpChains.empty())
300    Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
301                        &MemOpChains[0], MemOpChains.size());
302
303  // Build a sequence of copy-to-reg nodes chained together with token chain and
304  // flag operands which copy the outgoing args into registers.  The InFlag in
305  // necessary since all emitted instructions must be stuck together.
306  SDValue InFlag;
307  for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
308    Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first,
309                             RegsToPass[i].second, InFlag);
310    InFlag = Chain.getValue(1);
311  }
312
313  // Returns a chain & a flag for retval copy to use.
314  SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
315  SmallVector<SDValue, 8> Ops;
316  Ops.push_back(Chain);
317  Ops.push_back(Callee);
318
319  // Add argument registers to the end of the list so that they are
320  // known live into the call.
321  for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i)
322    Ops.push_back(DAG.getRegister(RegsToPass[i].first,
323                                  RegsToPass[i].second.getValueType()));
324
325  if (InFlag.getNode())
326    Ops.push_back(InFlag);
327
328  Chain = DAG.getNode(AlphaISD::CALL, dl, NodeTys, &Ops[0], Ops.size());
329  InFlag = Chain.getValue(1);
330
331  // Create the CALLSEQ_END node.
332  Chain = DAG.getCALLSEQ_END(Chain,
333                             DAG.getConstant(NumBytes, getPointerTy(), true),
334                             DAG.getConstant(0, getPointerTy(), true),
335                             InFlag);
336  InFlag = Chain.getValue(1);
337
338  // Handle result values, copying them out of physregs into vregs that we
339  // return.
340  return LowerCallResult(Chain, InFlag, CallConv, isVarArg,
341                         Ins, dl, DAG, InVals);
342}
343
344/// LowerCallResult - Lower the result values of a call into the
345/// appropriate copies out of appropriate physical registers.
346///
347SDValue
348AlphaTargetLowering::LowerCallResult(SDValue Chain, SDValue InFlag,
349                                     CallingConv::ID CallConv, bool isVarArg,
350                                     const SmallVectorImpl<ISD::InputArg> &Ins,
351                                     DebugLoc dl, SelectionDAG &DAG,
352                                     SmallVectorImpl<SDValue> &InVals) const {
353
354  // Assign locations to each value returned by this call.
355  SmallVector<CCValAssign, 16> RVLocs;
356  CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
357		 getTargetMachine(), RVLocs, *DAG.getContext());
358
359  CCInfo.AnalyzeCallResult(Ins, RetCC_Alpha);
360
361  // Copy all of the result registers out of their specified physreg.
362  for (unsigned i = 0; i != RVLocs.size(); ++i) {
363    CCValAssign &VA = RVLocs[i];
364
365    Chain = DAG.getCopyFromReg(Chain, dl, VA.getLocReg(),
366                               VA.getLocVT(), InFlag).getValue(1);
367    SDValue RetValue = Chain.getValue(0);
368    InFlag = Chain.getValue(2);
369
370    // If this is an 8/16/32-bit value, it is really passed promoted to 64
371    // bits. Insert an assert[sz]ext to capture this, then truncate to the
372    // right size.
373    if (VA.getLocInfo() == CCValAssign::SExt)
374      RetValue = DAG.getNode(ISD::AssertSext, dl, VA.getLocVT(), RetValue,
375                             DAG.getValueType(VA.getValVT()));
376    else if (VA.getLocInfo() == CCValAssign::ZExt)
377      RetValue = DAG.getNode(ISD::AssertZext, dl, VA.getLocVT(), RetValue,
378                             DAG.getValueType(VA.getValVT()));
379
380    if (VA.getLocInfo() != CCValAssign::Full)
381      RetValue = DAG.getNode(ISD::TRUNCATE, dl, VA.getValVT(), RetValue);
382
383    InVals.push_back(RetValue);
384  }
385
386  return Chain;
387}
388
389SDValue
390AlphaTargetLowering::LowerFormalArguments(SDValue Chain,
391                                          CallingConv::ID CallConv, bool isVarArg,
392                                          const SmallVectorImpl<ISD::InputArg>
393                                            &Ins,
394                                          DebugLoc dl, SelectionDAG &DAG,
395                                          SmallVectorImpl<SDValue> &InVals)
396                                            const {
397
398  MachineFunction &MF = DAG.getMachineFunction();
399  MachineFrameInfo *MFI = MF.getFrameInfo();
400  AlphaMachineFunctionInfo *FuncInfo = MF.getInfo<AlphaMachineFunctionInfo>();
401
402  unsigned args_int[] = {
403    Alpha::R16, Alpha::R17, Alpha::R18, Alpha::R19, Alpha::R20, Alpha::R21};
404  unsigned args_float[] = {
405    Alpha::F16, Alpha::F17, Alpha::F18, Alpha::F19, Alpha::F20, Alpha::F21};
406
407  for (unsigned ArgNo = 0, e = Ins.size(); ArgNo != e; ++ArgNo) {
408    SDValue argt;
409    EVT ObjectVT = Ins[ArgNo].VT;
410    SDValue ArgVal;
411
412    if (ArgNo  < 6) {
413      switch (ObjectVT.getSimpleVT().SimpleTy) {
414      default:
415        assert(false && "Invalid value type!");
416      case MVT::f64:
417        args_float[ArgNo] = AddLiveIn(MF, args_float[ArgNo],
418                                      &Alpha::F8RCRegClass);
419        ArgVal = DAG.getCopyFromReg(Chain, dl, args_float[ArgNo], ObjectVT);
420        break;
421      case MVT::f32:
422        args_float[ArgNo] = AddLiveIn(MF, args_float[ArgNo],
423                                      &Alpha::F4RCRegClass);
424        ArgVal = DAG.getCopyFromReg(Chain, dl, args_float[ArgNo], ObjectVT);
425        break;
426      case MVT::i64:
427        args_int[ArgNo] = AddLiveIn(MF, args_int[ArgNo],
428                                    &Alpha::GPRCRegClass);
429        ArgVal = DAG.getCopyFromReg(Chain, dl, args_int[ArgNo], MVT::i64);
430        break;
431      }
432    } else { //more args
433      // Create the frame index object for this incoming parameter...
434      int FI = MFI->CreateFixedObject(8, 8 * (ArgNo - 6), true);
435
436      // Create the SelectionDAG nodes corresponding to a load
437      //from this parameter
438      SDValue FIN = DAG.getFrameIndex(FI, MVT::i64);
439      ArgVal = DAG.getLoad(ObjectVT, dl, Chain, FIN, MachinePointerInfo(),
440                           false, false, 0);
441    }
442    InVals.push_back(ArgVal);
443  }
444
445  // If the functions takes variable number of arguments, copy all regs to stack
446  if (isVarArg) {
447    FuncInfo->setVarArgsOffset(Ins.size() * 8);
448    std::vector<SDValue> LS;
449    for (int i = 0; i < 6; ++i) {
450      if (TargetRegisterInfo::isPhysicalRegister(args_int[i]))
451        args_int[i] = AddLiveIn(MF, args_int[i], &Alpha::GPRCRegClass);
452      SDValue argt = DAG.getCopyFromReg(Chain, dl, args_int[i], MVT::i64);
453      int FI = MFI->CreateFixedObject(8, -8 * (6 - i), true);
454      if (i == 0) FuncInfo->setVarArgsBase(FI);
455      SDValue SDFI = DAG.getFrameIndex(FI, MVT::i64);
456      LS.push_back(DAG.getStore(Chain, dl, argt, SDFI, MachinePointerInfo(),
457                                false, false, 0));
458
459      if (TargetRegisterInfo::isPhysicalRegister(args_float[i]))
460        args_float[i] = AddLiveIn(MF, args_float[i], &Alpha::F8RCRegClass);
461      argt = DAG.getCopyFromReg(Chain, dl, args_float[i], MVT::f64);
462      FI = MFI->CreateFixedObject(8, - 8 * (12 - i), true);
463      SDFI = DAG.getFrameIndex(FI, MVT::i64);
464      LS.push_back(DAG.getStore(Chain, dl, argt, SDFI, MachinePointerInfo(),
465                                false, false, 0));
466    }
467
468    //Set up a token factor with all the stack traffic
469    Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, &LS[0], LS.size());
470  }
471
472  return Chain;
473}
474
475SDValue
476AlphaTargetLowering::LowerReturn(SDValue Chain,
477                                 CallingConv::ID CallConv, bool isVarArg,
478                                 const SmallVectorImpl<ISD::OutputArg> &Outs,
479                                 const SmallVectorImpl<SDValue> &OutVals,
480                                 DebugLoc dl, SelectionDAG &DAG) const {
481
482  SDValue Copy = DAG.getCopyToReg(Chain, dl, Alpha::R26,
483                                  DAG.getNode(AlphaISD::GlobalRetAddr,
484                                              DebugLoc(), MVT::i64),
485                                  SDValue());
486  switch (Outs.size()) {
487  default:
488    llvm_unreachable("Do not know how to return this many arguments!");
489  case 0:
490    break;
491    //return SDValue(); // ret void is legal
492  case 1: {
493    EVT ArgVT = Outs[0].VT;
494    unsigned ArgReg;
495    if (ArgVT.isInteger())
496      ArgReg = Alpha::R0;
497    else {
498      assert(ArgVT.isFloatingPoint());
499      ArgReg = Alpha::F0;
500    }
501    Copy = DAG.getCopyToReg(Copy, dl, ArgReg,
502                            OutVals[0], Copy.getValue(1));
503    if (DAG.getMachineFunction().getRegInfo().liveout_empty())
504      DAG.getMachineFunction().getRegInfo().addLiveOut(ArgReg);
505    break;
506  }
507  case 2: {
508    EVT ArgVT = Outs[0].VT;
509    unsigned ArgReg1, ArgReg2;
510    if (ArgVT.isInteger()) {
511      ArgReg1 = Alpha::R0;
512      ArgReg2 = Alpha::R1;
513    } else {
514      assert(ArgVT.isFloatingPoint());
515      ArgReg1 = Alpha::F0;
516      ArgReg2 = Alpha::F1;
517    }
518    Copy = DAG.getCopyToReg(Copy, dl, ArgReg1,
519                            OutVals[0], Copy.getValue(1));
520    if (std::find(DAG.getMachineFunction().getRegInfo().liveout_begin(),
521                  DAG.getMachineFunction().getRegInfo().liveout_end(), ArgReg1)
522        == DAG.getMachineFunction().getRegInfo().liveout_end())
523      DAG.getMachineFunction().getRegInfo().addLiveOut(ArgReg1);
524    Copy = DAG.getCopyToReg(Copy, dl, ArgReg2,
525                            OutVals[1], Copy.getValue(1));
526    if (std::find(DAG.getMachineFunction().getRegInfo().liveout_begin(),
527                   DAG.getMachineFunction().getRegInfo().liveout_end(), ArgReg2)
528        == DAG.getMachineFunction().getRegInfo().liveout_end())
529      DAG.getMachineFunction().getRegInfo().addLiveOut(ArgReg2);
530    break;
531  }
532  }
533  return DAG.getNode(AlphaISD::RET_FLAG, dl,
534                     MVT::Other, Copy, Copy.getValue(1));
535}
536
537void AlphaTargetLowering::LowerVAARG(SDNode *N, SDValue &Chain,
538                                     SDValue &DataPtr,
539                                     SelectionDAG &DAG) const {
540  Chain = N->getOperand(0);
541  SDValue VAListP = N->getOperand(1);
542  const Value *VAListS = cast<SrcValueSDNode>(N->getOperand(2))->getValue();
543  DebugLoc dl = N->getDebugLoc();
544
545  SDValue Base = DAG.getLoad(MVT::i64, dl, Chain, VAListP,
546                             MachinePointerInfo(VAListS),
547                             false, false, 0);
548  SDValue Tmp = DAG.getNode(ISD::ADD, dl, MVT::i64, VAListP,
549                              DAG.getConstant(8, MVT::i64));
550  SDValue Offset = DAG.getExtLoad(ISD::SEXTLOAD, dl, MVT::i64, Base.getValue(1),
551                                  Tmp, MachinePointerInfo(),
552                                  MVT::i32, false, false, 0);
553  DataPtr = DAG.getNode(ISD::ADD, dl, MVT::i64, Base, Offset);
554  if (N->getValueType(0).isFloatingPoint())
555  {
556    //if fp && Offset < 6*8, then subtract 6*8 from DataPtr
557    SDValue FPDataPtr = DAG.getNode(ISD::SUB, dl, MVT::i64, DataPtr,
558                                      DAG.getConstant(8*6, MVT::i64));
559    SDValue CC = DAG.getSetCC(dl, MVT::i64, Offset,
560                                DAG.getConstant(8*6, MVT::i64), ISD::SETLT);
561    DataPtr = DAG.getNode(ISD::SELECT, dl, MVT::i64, CC, FPDataPtr, DataPtr);
562  }
563
564  SDValue NewOffset = DAG.getNode(ISD::ADD, dl, MVT::i64, Offset,
565                                    DAG.getConstant(8, MVT::i64));
566  Chain = DAG.getTruncStore(Offset.getValue(1), dl, NewOffset, Tmp,
567                            MachinePointerInfo(),
568                            MVT::i32, false, false, 0);
569}
570
571/// LowerOperation - Provide custom lowering hooks for some operations.
572///
573SDValue AlphaTargetLowering::LowerOperation(SDValue Op,
574                                            SelectionDAG &DAG) const {
575  DebugLoc dl = Op.getDebugLoc();
576  switch (Op.getOpcode()) {
577  default: llvm_unreachable("Wasn't expecting to be able to lower this!");
578  case ISD::JumpTable: return LowerJumpTable(Op, DAG);
579
580  case ISD::INTRINSIC_WO_CHAIN: {
581    unsigned IntNo = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
582    switch (IntNo) {
583    default: break;    // Don't custom lower most intrinsics.
584    case Intrinsic::alpha_umulh:
585      return DAG.getNode(ISD::MULHU, dl, MVT::i64,
586                         Op.getOperand(1), Op.getOperand(2));
587    }
588  }
589
590  case ISD::SRL_PARTS: {
591    SDValue ShOpLo = Op.getOperand(0);
592    SDValue ShOpHi = Op.getOperand(1);
593    SDValue ShAmt  = Op.getOperand(2);
594    SDValue bm = DAG.getNode(ISD::SUB, dl, MVT::i64,
595                             DAG.getConstant(64, MVT::i64), ShAmt);
596    SDValue BMCC = DAG.getSetCC(dl, MVT::i64, bm,
597                                DAG.getConstant(0, MVT::i64), ISD::SETLE);
598    // if 64 - shAmt <= 0
599    SDValue Hi_Neg = DAG.getConstant(0, MVT::i64);
600    SDValue ShAmt_Neg = DAG.getNode(ISD::SUB, dl, MVT::i64,
601                                    DAG.getConstant(0, MVT::i64), bm);
602    SDValue Lo_Neg = DAG.getNode(ISD::SRL, dl, MVT::i64, ShOpHi, ShAmt_Neg);
603    // else
604    SDValue carries = DAG.getNode(ISD::SHL, dl, MVT::i64, ShOpHi, bm);
605    SDValue Hi_Pos =  DAG.getNode(ISD::SRL, dl, MVT::i64, ShOpHi, ShAmt);
606    SDValue Lo_Pos = DAG.getNode(ISD::SRL, dl, MVT::i64, ShOpLo, ShAmt);
607    Lo_Pos = DAG.getNode(ISD::OR, dl, MVT::i64, Lo_Pos, carries);
608    // Merge
609    SDValue Hi = DAG.getNode(ISD::SELECT, dl, MVT::i64, BMCC, Hi_Neg, Hi_Pos);
610    SDValue Lo = DAG.getNode(ISD::SELECT, dl, MVT::i64, BMCC, Lo_Neg, Lo_Pos);
611    SDValue Ops[2] = { Lo, Hi };
612    return DAG.getMergeValues(Ops, 2, dl);
613  }
614    //  case ISD::SRA_PARTS:
615
616    //  case ISD::SHL_PARTS:
617
618
619  case ISD::SINT_TO_FP: {
620    assert(Op.getOperand(0).getValueType() == MVT::i64 &&
621           "Unhandled SINT_TO_FP type in custom expander!");
622    SDValue LD;
623    bool isDouble = Op.getValueType() == MVT::f64;
624    LD = DAG.getNode(ISD::BITCAST, dl, MVT::f64, Op.getOperand(0));
625    SDValue FP = DAG.getNode(isDouble?AlphaISD::CVTQT_:AlphaISD::CVTQS_, dl,
626                               isDouble?MVT::f64:MVT::f32, LD);
627    return FP;
628  }
629  case ISD::FP_TO_SINT: {
630    bool isDouble = Op.getOperand(0).getValueType() == MVT::f64;
631    SDValue src = Op.getOperand(0);
632
633    if (!isDouble) //Promote
634      src = DAG.getNode(ISD::FP_EXTEND, dl, MVT::f64, src);
635
636    src = DAG.getNode(AlphaISD::CVTTQ_, dl, MVT::f64, src);
637
638    return DAG.getNode(ISD::BITCAST, dl, MVT::i64, src);
639  }
640  case ISD::ConstantPool: {
641    ConstantPoolSDNode *CP = cast<ConstantPoolSDNode>(Op);
642    const Constant *C = CP->getConstVal();
643    SDValue CPI = DAG.getTargetConstantPool(C, MVT::i64, CP->getAlignment());
644    // FIXME there isn't really any debug info here
645
646    SDValue Hi = DAG.getNode(AlphaISD::GPRelHi,  dl, MVT::i64, CPI,
647                               DAG.getGLOBAL_OFFSET_TABLE(MVT::i64));
648    SDValue Lo = DAG.getNode(AlphaISD::GPRelLo, dl, MVT::i64, CPI, Hi);
649    return Lo;
650  }
651  case ISD::GlobalTLSAddress:
652    llvm_unreachable("TLS not implemented for Alpha.");
653  case ISD::GlobalAddress: {
654    GlobalAddressSDNode *GSDN = cast<GlobalAddressSDNode>(Op);
655    const GlobalValue *GV = GSDN->getGlobal();
656    SDValue GA = DAG.getTargetGlobalAddress(GV, dl, MVT::i64,
657                                            GSDN->getOffset());
658    // FIXME there isn't really any debug info here
659
660    //    if (!GV->hasWeakLinkage() && !GV->isDeclaration()
661    //        && !GV->hasLinkOnceLinkage()) {
662    if (GV->hasLocalLinkage()) {
663      SDValue Hi = DAG.getNode(AlphaISD::GPRelHi,  dl, MVT::i64, GA,
664                                DAG.getGLOBAL_OFFSET_TABLE(MVT::i64));
665      SDValue Lo = DAG.getNode(AlphaISD::GPRelLo, dl, MVT::i64, GA, Hi);
666      return Lo;
667    } else
668      return DAG.getNode(AlphaISD::RelLit, dl, MVT::i64, GA,
669                         DAG.getGLOBAL_OFFSET_TABLE(MVT::i64));
670  }
671  case ISD::ExternalSymbol: {
672    return DAG.getNode(AlphaISD::RelLit, dl, MVT::i64,
673                       DAG.getTargetExternalSymbol(cast<ExternalSymbolSDNode>(Op)
674                                                   ->getSymbol(), MVT::i64),
675                       DAG.getGLOBAL_OFFSET_TABLE(MVT::i64));
676  }
677
678  case ISD::UREM:
679  case ISD::SREM:
680    //Expand only on constant case
681    if (Op.getOperand(1).getOpcode() == ISD::Constant) {
682      EVT VT = Op.getNode()->getValueType(0);
683      SDValue Tmp1 = Op.getNode()->getOpcode() == ISD::UREM ?
684        BuildUDIV(Op.getNode(), DAG, NULL) :
685        BuildSDIV(Op.getNode(), DAG, NULL);
686      Tmp1 = DAG.getNode(ISD::MUL, dl, VT, Tmp1, Op.getOperand(1));
687      Tmp1 = DAG.getNode(ISD::SUB, dl, VT, Op.getOperand(0), Tmp1);
688      return Tmp1;
689    }
690    //fall through
691  case ISD::SDIV:
692  case ISD::UDIV:
693    if (Op.getValueType().isInteger()) {
694      if (Op.getOperand(1).getOpcode() == ISD::Constant)
695        return Op.getOpcode() == ISD::SDIV ? BuildSDIV(Op.getNode(), DAG, NULL)
696          : BuildUDIV(Op.getNode(), DAG, NULL);
697      const char* opstr = 0;
698      switch (Op.getOpcode()) {
699      case ISD::UREM: opstr = "__remqu"; break;
700      case ISD::SREM: opstr = "__remq";  break;
701      case ISD::UDIV: opstr = "__divqu"; break;
702      case ISD::SDIV: opstr = "__divq";  break;
703      }
704      SDValue Tmp1 = Op.getOperand(0),
705        Tmp2 = Op.getOperand(1),
706        Addr = DAG.getExternalSymbol(opstr, MVT::i64);
707      return DAG.getNode(AlphaISD::DivCall, dl, MVT::i64, Addr, Tmp1, Tmp2);
708    }
709    break;
710
711  case ISD::VAARG: {
712    SDValue Chain, DataPtr;
713    LowerVAARG(Op.getNode(), Chain, DataPtr, DAG);
714
715    SDValue Result;
716    if (Op.getValueType() == MVT::i32)
717      Result = DAG.getExtLoad(ISD::SEXTLOAD, dl, MVT::i64, Chain, DataPtr,
718                              MachinePointerInfo(), MVT::i32, false, false, 0);
719    else
720      Result = DAG.getLoad(Op.getValueType(), dl, Chain, DataPtr,
721                           MachinePointerInfo(),
722                           false, false, 0);
723    return Result;
724  }
725  case ISD::VACOPY: {
726    SDValue Chain = Op.getOperand(0);
727    SDValue DestP = Op.getOperand(1);
728    SDValue SrcP = Op.getOperand(2);
729    const Value *DestS = cast<SrcValueSDNode>(Op.getOperand(3))->getValue();
730    const Value *SrcS = cast<SrcValueSDNode>(Op.getOperand(4))->getValue();
731
732    SDValue Val = DAG.getLoad(getPointerTy(), dl, Chain, SrcP,
733                              MachinePointerInfo(SrcS),
734                              false, false, 0);
735    SDValue Result = DAG.getStore(Val.getValue(1), dl, Val, DestP,
736                                  MachinePointerInfo(DestS),
737                                  false, false, 0);
738    SDValue NP = DAG.getNode(ISD::ADD, dl, MVT::i64, SrcP,
739                               DAG.getConstant(8, MVT::i64));
740    Val = DAG.getExtLoad(ISD::SEXTLOAD, dl, MVT::i64, Result,
741                         NP, MachinePointerInfo(), MVT::i32, false, false, 0);
742    SDValue NPD = DAG.getNode(ISD::ADD, dl, MVT::i64, DestP,
743                                DAG.getConstant(8, MVT::i64));
744    return DAG.getTruncStore(Val.getValue(1), dl, Val, NPD,
745                             MachinePointerInfo(), MVT::i32,
746                             false, false, 0);
747  }
748  case ISD::VASTART: {
749    MachineFunction &MF = DAG.getMachineFunction();
750    AlphaMachineFunctionInfo *FuncInfo = MF.getInfo<AlphaMachineFunctionInfo>();
751
752    SDValue Chain = Op.getOperand(0);
753    SDValue VAListP = Op.getOperand(1);
754    const Value *VAListS = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
755
756    // vastart stores the address of the VarArgsBase and VarArgsOffset
757    SDValue FR  = DAG.getFrameIndex(FuncInfo->getVarArgsBase(), MVT::i64);
758    SDValue S1  = DAG.getStore(Chain, dl, FR, VAListP,
759                               MachinePointerInfo(VAListS), false, false, 0);
760    SDValue SA2 = DAG.getNode(ISD::ADD, dl, MVT::i64, VAListP,
761                                DAG.getConstant(8, MVT::i64));
762    return DAG.getTruncStore(S1, dl,
763                             DAG.getConstant(FuncInfo->getVarArgsOffset(),
764                                             MVT::i64),
765                             SA2, MachinePointerInfo(),
766                             MVT::i32, false, false, 0);
767  }
768  case ISD::RETURNADDR:
769    return DAG.getNode(AlphaISD::GlobalRetAddr, DebugLoc(), MVT::i64);
770      //FIXME: implement
771  case ISD::FRAMEADDR:          break;
772  }
773
774  return SDValue();
775}
776
777void AlphaTargetLowering::ReplaceNodeResults(SDNode *N,
778                                             SmallVectorImpl<SDValue>&Results,
779                                             SelectionDAG &DAG) const {
780  DebugLoc dl = N->getDebugLoc();
781  assert(N->getValueType(0) == MVT::i32 &&
782         N->getOpcode() == ISD::VAARG &&
783         "Unknown node to custom promote!");
784
785  SDValue Chain, DataPtr;
786  LowerVAARG(N, Chain, DataPtr, DAG);
787  SDValue Res = DAG.getLoad(N->getValueType(0), dl, Chain, DataPtr,
788                            MachinePointerInfo(),
789                            false, false, 0);
790  Results.push_back(Res);
791  Results.push_back(SDValue(Res.getNode(), 1));
792}
793
794
795//Inline Asm
796
797/// getConstraintType - Given a constraint letter, return the type of
798/// constraint it is for this target.
799AlphaTargetLowering::ConstraintType
800AlphaTargetLowering::getConstraintType(const std::string &Constraint) const {
801  if (Constraint.size() == 1) {
802    switch (Constraint[0]) {
803    default: break;
804    case 'f':
805    case 'r':
806      return C_RegisterClass;
807    }
808  }
809  return TargetLowering::getConstraintType(Constraint);
810}
811
812/// Examine constraint type and operand type and determine a weight value.
813/// This object must already have been set up with the operand type
814/// and the current alternative constraint selected.
815TargetLowering::ConstraintWeight
816AlphaTargetLowering::getSingleConstraintMatchWeight(
817    AsmOperandInfo &info, const char *constraint) const {
818  ConstraintWeight weight = CW_Invalid;
819  Value *CallOperandVal = info.CallOperandVal;
820    // If we don't have a value, we can't do a match,
821    // but allow it at the lowest weight.
822  if (CallOperandVal == NULL)
823    return CW_Default;
824  // Look at the constraint type.
825  switch (*constraint) {
826  default:
827    weight = TargetLowering::getSingleConstraintMatchWeight(info, constraint);
828    break;
829  case 'f':
830    weight = CW_Register;
831    break;
832  }
833  return weight;
834}
835
836/// Given a register class constraint, like 'r', if this corresponds directly
837/// to an LLVM register class, return a register of 0 and the register class
838/// pointer.
839std::pair<unsigned, const TargetRegisterClass*> AlphaTargetLowering::
840getRegForInlineAsmConstraint(const std::string &Constraint, EVT VT) const
841{
842  if (Constraint.size() == 1) {
843    switch (Constraint[0]) {
844    case 'r':
845      return std::make_pair(0U, Alpha::GPRCRegisterClass);
846    case 'f':
847      return VT == MVT::f64 ? std::make_pair(0U, Alpha::F8RCRegisterClass) :
848	std::make_pair(0U, Alpha::F4RCRegisterClass);
849    }
850  }
851  return TargetLowering::getRegForInlineAsmConstraint(Constraint, VT);
852}
853
854//===----------------------------------------------------------------------===//
855//  Other Lowering Code
856//===----------------------------------------------------------------------===//
857
858MachineBasicBlock *
859AlphaTargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
860                                                 MachineBasicBlock *BB) const {
861  const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
862  assert((MI->getOpcode() == Alpha::CAS32 ||
863          MI->getOpcode() == Alpha::CAS64 ||
864          MI->getOpcode() == Alpha::LAS32 ||
865          MI->getOpcode() == Alpha::LAS64 ||
866          MI->getOpcode() == Alpha::SWAP32 ||
867          MI->getOpcode() == Alpha::SWAP64) &&
868         "Unexpected instr type to insert");
869
870  bool is32 = MI->getOpcode() == Alpha::CAS32 ||
871    MI->getOpcode() == Alpha::LAS32 ||
872    MI->getOpcode() == Alpha::SWAP32;
873
874  //Load locked store conditional for atomic ops take on the same form
875  //start:
876  //ll
877  //do stuff (maybe branch to exit)
878  //sc
879  //test sc and maybe branck to start
880  //exit:
881  const BasicBlock *LLVM_BB = BB->getBasicBlock();
882  DebugLoc dl = MI->getDebugLoc();
883  MachineFunction::iterator It = BB;
884  ++It;
885
886  MachineBasicBlock *thisMBB = BB;
887  MachineFunction *F = BB->getParent();
888  MachineBasicBlock *llscMBB = F->CreateMachineBasicBlock(LLVM_BB);
889  MachineBasicBlock *sinkMBB = F->CreateMachineBasicBlock(LLVM_BB);
890
891  sinkMBB->splice(sinkMBB->begin(), thisMBB,
892                  llvm::next(MachineBasicBlock::iterator(MI)),
893                  thisMBB->end());
894  sinkMBB->transferSuccessorsAndUpdatePHIs(thisMBB);
895
896  F->insert(It, llscMBB);
897  F->insert(It, sinkMBB);
898
899  BuildMI(thisMBB, dl, TII->get(Alpha::BR)).addMBB(llscMBB);
900
901  unsigned reg_res = MI->getOperand(0).getReg(),
902    reg_ptr = MI->getOperand(1).getReg(),
903    reg_v2 = MI->getOperand(2).getReg(),
904    reg_store = F->getRegInfo().createVirtualRegister(&Alpha::GPRCRegClass);
905
906  BuildMI(llscMBB, dl, TII->get(is32 ? Alpha::LDL_L : Alpha::LDQ_L),
907          reg_res).addImm(0).addReg(reg_ptr);
908  switch (MI->getOpcode()) {
909  case Alpha::CAS32:
910  case Alpha::CAS64: {
911    unsigned reg_cmp
912      = F->getRegInfo().createVirtualRegister(&Alpha::GPRCRegClass);
913    BuildMI(llscMBB, dl, TII->get(Alpha::CMPEQ), reg_cmp)
914      .addReg(reg_v2).addReg(reg_res);
915    BuildMI(llscMBB, dl, TII->get(Alpha::BEQ))
916      .addImm(0).addReg(reg_cmp).addMBB(sinkMBB);
917    BuildMI(llscMBB, dl, TII->get(Alpha::BISr), reg_store)
918      .addReg(Alpha::R31).addReg(MI->getOperand(3).getReg());
919    break;
920  }
921  case Alpha::LAS32:
922  case Alpha::LAS64: {
923    BuildMI(llscMBB, dl,TII->get(is32 ? Alpha::ADDLr : Alpha::ADDQr), reg_store)
924      .addReg(reg_res).addReg(reg_v2);
925    break;
926  }
927  case Alpha::SWAP32:
928  case Alpha::SWAP64: {
929    BuildMI(llscMBB, dl, TII->get(Alpha::BISr), reg_store)
930      .addReg(reg_v2).addReg(reg_v2);
931    break;
932  }
933  }
934  BuildMI(llscMBB, dl, TII->get(is32 ? Alpha::STL_C : Alpha::STQ_C), reg_store)
935    .addReg(reg_store).addImm(0).addReg(reg_ptr);
936  BuildMI(llscMBB, dl, TII->get(Alpha::BEQ))
937    .addImm(0).addReg(reg_store).addMBB(llscMBB);
938  BuildMI(llscMBB, dl, TII->get(Alpha::BR)).addMBB(sinkMBB);
939
940  thisMBB->addSuccessor(llscMBB);
941  llscMBB->addSuccessor(llscMBB);
942  llscMBB->addSuccessor(sinkMBB);
943  MI->eraseFromParent();   // The pseudo instruction is gone now.
944
945  return sinkMBB;
946}
947
948bool
949AlphaTargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
950  // The Alpha target isn't yet aware of offsets.
951  return false;
952}
953
954bool AlphaTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT) const {
955  if (VT != MVT::f32 && VT != MVT::f64)
956    return false;
957  // +0.0   F31
958  // +0.0f  F31
959  // -0.0  -F31
960  // -0.0f -F31
961  return Imm.isZero() || Imm.isNegZero();
962}
963