AutoUpgrade.cpp revision 51fce2c886e4ca33272975cc80bc1cc5abfcdffd 
1//===-- AutoUpgrade.cpp - Implement auto-upgrade helper functions ---------===//
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 auto-upgrade helper functions
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/AutoUpgrade.h"
15#include "llvm/DebugInfo.h"
16#include "llvm/IR/Constants.h"
17#include "llvm/IR/Function.h"
18#include "llvm/IR/IRBuilder.h"
19#include "llvm/IR/Instruction.h"
20#include "llvm/IR/IntrinsicInst.h"
21#include "llvm/IR/LLVMContext.h"
22#include "llvm/IR/Module.h"
23#include "llvm/Support/CFG.h"
24#include "llvm/Support/CallSite.h"
25#include "llvm/Support/ErrorHandling.h"
26#include <cstring>
27using namespace llvm;
28
29// Upgrade the declarations of the SSE4.1 functions whose arguments have
30// changed their type from v4f32 to v2i64.
31static bool UpgradeSSE41Function(Function* F, Intrinsic::ID IID,
32                                 Function *&NewFn) {
33  // Check whether this is an old version of the function, which received
34  // v4f32 arguments.
35  Type *Arg0Type = F->getFunctionType()->getParamType(0);
36  if (Arg0Type != VectorType::get(Type::getFloatTy(F->getContext()), 4))
37    return false;
38
39  // Yes, it's old, replace it with new version.
40  F->setName(F->getName() + ".old");
41  NewFn = Intrinsic::getDeclaration(F->getParent(), IID);
42  return true;
43}
44
45static bool UpgradeIntrinsicFunction1(Function *F, Function *&NewFn) {
46  assert(F && "Illegal to upgrade a non-existent Function.");
47
48  // Quickly eliminate it, if it's not a candidate.
49  StringRef Name = F->getName();
50  if (Name.size() <= 8 || !Name.startswith("llvm."))
51    return false;
52  Name = Name.substr(5); // Strip off "llvm."
53
54  switch (Name[0]) {
55  default: break;
56  case 'a': {
57    if (Name.startswith("arm.neon.vclz")) {
58      Type* args[2] = {
59        F->arg_begin()->getType(),
60        Type::getInt1Ty(F->getContext())
61      };
62      // Can't use Intrinsic::getDeclaration here as it adds a ".i1" to
63      // the end of the name. Change name from llvm.arm.neon.vclz.* to
64      //  llvm.ctlz.*
65      FunctionType* fType = FunctionType::get(F->getReturnType(), args, false);
66      NewFn = Function::Create(fType, F->getLinkage(),
67                               "llvm.ctlz." + Name.substr(14), F->getParent());
68      return true;
69    }
70    if (Name.startswith("arm.neon.vcnt")) {
71      NewFn = Intrinsic::getDeclaration(F->getParent(), Intrinsic::ctpop,
72                                        F->arg_begin()->getType());
73      return true;
74    }
75    break;
76  }
77  case 'c': {
78    if (Name.startswith("ctlz.") && F->arg_size() == 1) {
79      F->setName(Name + ".old");
80      NewFn = Intrinsic::getDeclaration(F->getParent(), Intrinsic::ctlz,
81                                        F->arg_begin()->getType());
82      return true;
83    }
84    if (Name.startswith("cttz.") && F->arg_size() == 1) {
85      F->setName(Name + ".old");
86      NewFn = Intrinsic::getDeclaration(F->getParent(), Intrinsic::cttz,
87                                        F->arg_begin()->getType());
88      return true;
89    }
90    break;
91  }
92  case 'o':
93    // We only need to change the name to match the mangling including the
94    // address space.
95    if (F->arg_size() == 2 && Name.startswith("objectsize.")) {
96      Type *Tys[2] = { F->getReturnType(), F->arg_begin()->getType() };
97      if (F->getName() != Intrinsic::getName(Intrinsic::objectsize, Tys)) {
98        F->setName(Name + ".old");
99        NewFn = Intrinsic::getDeclaration(F->getParent(),
100                                          Intrinsic::objectsize, Tys);
101        return true;
102      }
103    }
104    break;
105
106  case 'x': {
107    if (Name.startswith("x86.sse2.pcmpeq.") ||
108        Name.startswith("x86.sse2.pcmpgt.") ||
109        Name.startswith("x86.avx2.pcmpeq.") ||
110        Name.startswith("x86.avx2.pcmpgt.") ||
111        Name.startswith("x86.avx.vpermil.") ||
112        Name == "x86.avx.movnt.dq.256" ||
113        Name == "x86.avx.movnt.pd.256" ||
114        Name == "x86.avx.movnt.ps.256" ||
115        Name == "x86.sse42.crc32.64.8" ||
116        (Name.startswith("x86.xop.vpcom") && F->arg_size() == 2)) {
117      NewFn = 0;
118      return true;
119    }
120    // SSE4.1 ptest functions may have an old signature.
121    if (Name.startswith("x86.sse41.ptest")) {
122      if (Name == "x86.sse41.ptestc")
123        return UpgradeSSE41Function(F, Intrinsic::x86_sse41_ptestc, NewFn);
124      if (Name == "x86.sse41.ptestz")
125        return UpgradeSSE41Function(F, Intrinsic::x86_sse41_ptestz, NewFn);
126      if (Name == "x86.sse41.ptestnzc")
127        return UpgradeSSE41Function(F, Intrinsic::x86_sse41_ptestnzc, NewFn);
128    }
129    // frcz.ss/sd may need to have an argument dropped
130    if (Name.startswith("x86.xop.vfrcz.ss") && F->arg_size() == 2) {
131      F->setName(Name + ".old");
132      NewFn = Intrinsic::getDeclaration(F->getParent(),
133                                        Intrinsic::x86_xop_vfrcz_ss);
134      return true;
135    }
136    if (Name.startswith("x86.xop.vfrcz.sd") && F->arg_size() == 2) {
137      F->setName(Name + ".old");
138      NewFn = Intrinsic::getDeclaration(F->getParent(),
139                                        Intrinsic::x86_xop_vfrcz_sd);
140      return true;
141    }
142    // Fix the FMA4 intrinsics to remove the 4
143    if (Name.startswith("x86.fma4.")) {
144      F->setName("llvm.x86.fma" + Name.substr(8));
145      NewFn = F;
146      return true;
147    }
148    break;
149  }
150  }
151
152  //  This may not belong here. This function is effectively being overloaded
153  //  to both detect an intrinsic which needs upgrading, and to provide the
154  //  upgraded form of the intrinsic. We should perhaps have two separate
155  //  functions for this.
156  return false;
157}
158
159bool llvm::UpgradeIntrinsicFunction(Function *F, Function *&NewFn) {
160  NewFn = 0;
161  bool Upgraded = UpgradeIntrinsicFunction1(F, NewFn);
162
163  // Upgrade intrinsic attributes.  This does not change the function.
164  if (NewFn)
165    F = NewFn;
166  if (unsigned id = F->getIntrinsicID())
167    F->setAttributes(Intrinsic::getAttributes(F->getContext(),
168                                              (Intrinsic::ID)id));
169  return Upgraded;
170}
171
172bool llvm::UpgradeGlobalVariable(GlobalVariable *GV) {
173  // Nothing to do yet.
174  return false;
175}
176
177// UpgradeIntrinsicCall - Upgrade a call to an old intrinsic to be a call the
178// upgraded intrinsic. All argument and return casting must be provided in
179// order to seamlessly integrate with existing context.
180void llvm::UpgradeIntrinsicCall(CallInst *CI, Function *NewFn) {
181  Function *F = CI->getCalledFunction();
182  LLVMContext &C = CI->getContext();
183  IRBuilder<> Builder(C);
184  Builder.SetInsertPoint(CI->getParent(), CI);
185
186  assert(F && "Intrinsic call is not direct?");
187
188  if (!NewFn) {
189    // Get the Function's name.
190    StringRef Name = F->getName();
191
192    Value *Rep;
193    // Upgrade packed integer vector compares intrinsics to compare instructions
194    if (Name.startswith("llvm.x86.sse2.pcmpeq.") ||
195        Name.startswith("llvm.x86.avx2.pcmpeq.")) {
196      Rep = Builder.CreateICmpEQ(CI->getArgOperand(0), CI->getArgOperand(1),
197                                 "pcmpeq");
198      // need to sign extend since icmp returns vector of i1
199      Rep = Builder.CreateSExt(Rep, CI->getType(), "");
200    } else if (Name.startswith("llvm.x86.sse2.pcmpgt.") ||
201               Name.startswith("llvm.x86.avx2.pcmpgt.")) {
202      Rep = Builder.CreateICmpSGT(CI->getArgOperand(0), CI->getArgOperand(1),
203                                  "pcmpgt");
204      // need to sign extend since icmp returns vector of i1
205      Rep = Builder.CreateSExt(Rep, CI->getType(), "");
206    } else if (Name == "llvm.x86.avx.movnt.dq.256" ||
207               Name == "llvm.x86.avx.movnt.ps.256" ||
208               Name == "llvm.x86.avx.movnt.pd.256") {
209      IRBuilder<> Builder(C);
210      Builder.SetInsertPoint(CI->getParent(), CI);
211
212      Module *M = F->getParent();
213      SmallVector<Value *, 1> Elts;
214      Elts.push_back(ConstantInt::get(Type::getInt32Ty(C), 1));
215      MDNode *Node = MDNode::get(C, Elts);
216
217      Value *Arg0 = CI->getArgOperand(0);
218      Value *Arg1 = CI->getArgOperand(1);
219
220      // Convert the type of the pointer to a pointer to the stored type.
221      Value *BC = Builder.CreateBitCast(Arg0,
222                                        PointerType::getUnqual(Arg1->getType()),
223                                        "cast");
224      StoreInst *SI = Builder.CreateStore(Arg1, BC);
225      SI->setMetadata(M->getMDKindID("nontemporal"), Node);
226      SI->setAlignment(16);
227
228      // Remove intrinsic.
229      CI->eraseFromParent();
230      return;
231    } else if (Name.startswith("llvm.x86.xop.vpcom")) {
232      Intrinsic::ID intID;
233      if (Name.endswith("ub"))
234        intID = Intrinsic::x86_xop_vpcomub;
235      else if (Name.endswith("uw"))
236        intID = Intrinsic::x86_xop_vpcomuw;
237      else if (Name.endswith("ud"))
238        intID = Intrinsic::x86_xop_vpcomud;
239      else if (Name.endswith("uq"))
240        intID = Intrinsic::x86_xop_vpcomuq;
241      else if (Name.endswith("b"))
242        intID = Intrinsic::x86_xop_vpcomb;
243      else if (Name.endswith("w"))
244        intID = Intrinsic::x86_xop_vpcomw;
245      else if (Name.endswith("d"))
246        intID = Intrinsic::x86_xop_vpcomd;
247      else if (Name.endswith("q"))
248        intID = Intrinsic::x86_xop_vpcomq;
249      else
250        llvm_unreachable("Unknown suffix");
251
252      Name = Name.substr(18); // strip off "llvm.x86.xop.vpcom"
253      unsigned Imm;
254      if (Name.startswith("lt"))
255        Imm = 0;
256      else if (Name.startswith("le"))
257        Imm = 1;
258      else if (Name.startswith("gt"))
259        Imm = 2;
260      else if (Name.startswith("ge"))
261        Imm = 3;
262      else if (Name.startswith("eq"))
263        Imm = 4;
264      else if (Name.startswith("ne"))
265        Imm = 5;
266      else if (Name.startswith("true"))
267        Imm = 6;
268      else if (Name.startswith("false"))
269        Imm = 7;
270      else
271        llvm_unreachable("Unknown condition");
272
273      Function *VPCOM = Intrinsic::getDeclaration(F->getParent(), intID);
274      Rep = Builder.CreateCall3(VPCOM, CI->getArgOperand(0),
275                                CI->getArgOperand(1), Builder.getInt8(Imm));
276    } else if (Name == "llvm.x86.sse42.crc32.64.8") {
277      Function *CRC32 = Intrinsic::getDeclaration(F->getParent(),
278                                               Intrinsic::x86_sse42_crc32_32_8);
279      Value *Trunc0 = Builder.CreateTrunc(CI->getArgOperand(0), Type::getInt32Ty(C));
280      Rep = Builder.CreateCall2(CRC32, Trunc0, CI->getArgOperand(1));
281      Rep = Builder.CreateZExt(Rep, CI->getType(), "");
282    } else {
283      bool PD128 = false, PD256 = false, PS128 = false, PS256 = false;
284      if (Name == "llvm.x86.avx.vpermil.pd.256")
285        PD256 = true;
286      else if (Name == "llvm.x86.avx.vpermil.pd")
287        PD128 = true;
288      else if (Name == "llvm.x86.avx.vpermil.ps.256")
289        PS256 = true;
290      else if (Name == "llvm.x86.avx.vpermil.ps")
291        PS128 = true;
292
293      if (PD256 || PD128 || PS256 || PS128) {
294        Value *Op0 = CI->getArgOperand(0);
295        unsigned Imm = cast<ConstantInt>(CI->getArgOperand(1))->getZExtValue();
296        SmallVector<Constant*, 8> Idxs;
297
298        if (PD128)
299          for (unsigned i = 0; i != 2; ++i)
300            Idxs.push_back(Builder.getInt32((Imm >> i) & 0x1));
301        else if (PD256)
302          for (unsigned l = 0; l != 4; l+=2)
303            for (unsigned i = 0; i != 2; ++i)
304              Idxs.push_back(Builder.getInt32(((Imm >> (l+i)) & 0x1) + l));
305        else if (PS128)
306          for (unsigned i = 0; i != 4; ++i)
307            Idxs.push_back(Builder.getInt32((Imm >> (2 * i)) & 0x3));
308        else if (PS256)
309          for (unsigned l = 0; l != 8; l+=4)
310            for (unsigned i = 0; i != 4; ++i)
311              Idxs.push_back(Builder.getInt32(((Imm >> (2 * i)) & 0x3) + l));
312        else
313          llvm_unreachable("Unexpected function");
314
315        Rep = Builder.CreateShuffleVector(Op0, Op0, ConstantVector::get(Idxs));
316      } else {
317        llvm_unreachable("Unknown function for CallInst upgrade.");
318      }
319    }
320
321    CI->replaceAllUsesWith(Rep);
322    CI->eraseFromParent();
323    return;
324  }
325
326  std::string Name = CI->getName().str();
327  CI->setName(Name + ".old");
328
329  switch (NewFn->getIntrinsicID()) {
330  default:
331    llvm_unreachable("Unknown function for CallInst upgrade.");
332
333  case Intrinsic::ctlz:
334  case Intrinsic::cttz:
335    assert(CI->getNumArgOperands() == 1 &&
336           "Mismatch between function args and call args");
337    CI->replaceAllUsesWith(Builder.CreateCall2(NewFn, CI->getArgOperand(0),
338                                               Builder.getFalse(), Name));
339    CI->eraseFromParent();
340    return;
341
342  case Intrinsic::objectsize:
343    CI->replaceAllUsesWith(Builder.CreateCall2(NewFn,
344                                               CI->getArgOperand(0),
345                                               CI->getArgOperand(1),
346                                               Name));
347    CI->eraseFromParent();
348    return;
349
350  case Intrinsic::arm_neon_vclz: {
351    // Change name from llvm.arm.neon.vclz.* to llvm.ctlz.*
352    CI->replaceAllUsesWith(Builder.CreateCall2(NewFn, CI->getArgOperand(0),
353                                               Builder.getFalse(),
354                                               "llvm.ctlz." + Name.substr(14)));
355    CI->eraseFromParent();
356    return;
357  }
358  case Intrinsic::ctpop: {
359    CI->replaceAllUsesWith(Builder.CreateCall(NewFn, CI->getArgOperand(0)));
360    CI->eraseFromParent();
361    return;
362  }
363
364  case Intrinsic::x86_xop_vfrcz_ss:
365  case Intrinsic::x86_xop_vfrcz_sd:
366    CI->replaceAllUsesWith(Builder.CreateCall(NewFn, CI->getArgOperand(1),
367                                              Name));
368    CI->eraseFromParent();
369    return;
370
371  case Intrinsic::x86_sse41_ptestc:
372  case Intrinsic::x86_sse41_ptestz:
373  case Intrinsic::x86_sse41_ptestnzc: {
374    // The arguments for these intrinsics used to be v4f32, and changed
375    // to v2i64. This is purely a nop, since those are bitwise intrinsics.
376    // So, the only thing required is a bitcast for both arguments.
377    // First, check the arguments have the old type.
378    Value *Arg0 = CI->getArgOperand(0);
379    if (Arg0->getType() != VectorType::get(Type::getFloatTy(C), 4))
380      return;
381
382    // Old intrinsic, add bitcasts
383    Value *Arg1 = CI->getArgOperand(1);
384
385    Value *BC0 =
386      Builder.CreateBitCast(Arg0,
387                            VectorType::get(Type::getInt64Ty(C), 2),
388                            "cast");
389    Value *BC1 =
390      Builder.CreateBitCast(Arg1,
391                            VectorType::get(Type::getInt64Ty(C), 2),
392                            "cast");
393
394    CallInst* NewCall = Builder.CreateCall2(NewFn, BC0, BC1, Name);
395    CI->replaceAllUsesWith(NewCall);
396    CI->eraseFromParent();
397    return;
398  }
399  }
400}
401
402// This tests each Function to determine if it needs upgrading. When we find
403// one we are interested in, we then upgrade all calls to reflect the new
404// function.
405void llvm::UpgradeCallsToIntrinsic(Function* F) {
406  assert(F && "Illegal attempt to upgrade a non-existent intrinsic.");
407
408  // Upgrade the function and check if it is a totaly new function.
409  Function *NewFn;
410  if (UpgradeIntrinsicFunction(F, NewFn)) {
411    if (NewFn != F) {
412      // Replace all uses to the old function with the new one if necessary.
413      for (Value::use_iterator UI = F->use_begin(), UE = F->use_end();
414           UI != UE; ) {
415        if (CallInst *CI = dyn_cast<CallInst>(*UI++))
416          UpgradeIntrinsicCall(CI, NewFn);
417      }
418      // Remove old function, no longer used, from the module.
419      F->eraseFromParent();
420    }
421  }
422}
423
424void llvm::UpgradeInstWithTBAATag(Instruction *I) {
425  MDNode *MD = I->getMetadata(LLVMContext::MD_tbaa);
426  assert(MD && "UpgradeInstWithTBAATag should have a TBAA tag");
427  // Check if the tag uses struct-path aware TBAA format.
428  if (isa<MDNode>(MD->getOperand(0)) && MD->getNumOperands() >= 3)
429    return;
430
431  if (MD->getNumOperands() == 3) {
432    Value *Elts[] = {
433      MD->getOperand(0),
434      MD->getOperand(1)
435    };
436    MDNode *ScalarType = MDNode::get(I->getContext(), Elts);
437    // Create a MDNode <ScalarType, ScalarType, offset 0, const>
438    Value *Elts2[] = {
439      ScalarType, ScalarType,
440      Constant::getNullValue(Type::getInt64Ty(I->getContext())),
441      MD->getOperand(2)
442    };
443    I->setMetadata(LLVMContext::MD_tbaa, MDNode::get(I->getContext(), Elts2));
444  } else {
445    // Create a MDNode <MD, MD, offset 0>
446    Value *Elts[] = {MD, MD,
447      Constant::getNullValue(Type::getInt64Ty(I->getContext()))};
448    I->setMetadata(LLVMContext::MD_tbaa, MDNode::get(I->getContext(), Elts));
449  }
450}
451
452Instruction *llvm::UpgradeBitCastInst(unsigned Opc, Value *V, Type *DestTy,
453                                      Instruction *&Temp) {
454  if (Opc != Instruction::BitCast)
455    return 0;
456
457  Temp = 0;
458  Type *SrcTy = V->getType();
459  if (SrcTy->isPtrOrPtrVectorTy() && DestTy->isPtrOrPtrVectorTy() &&
460      SrcTy->getPointerAddressSpace() != DestTy->getPointerAddressSpace()) {
461    LLVMContext &Context = V->getContext();
462
463    // We have no information about target data layout, so we assume that
464    // the maximum pointer size is 64bit.
465    Type *MidTy = Type::getInt64Ty(Context);
466    Temp = CastInst::Create(Instruction::PtrToInt, V, MidTy);
467
468    return CastInst::Create(Instruction::IntToPtr, Temp, DestTy);
469  }
470
471  return 0;
472}
473
474Value *llvm::UpgradeBitCastExpr(unsigned Opc, Constant *C, Type *DestTy) {
475  if (Opc != Instruction::BitCast)
476    return 0;
477
478  Type *SrcTy = C->getType();
479  if (SrcTy->isPtrOrPtrVectorTy() && DestTy->isPtrOrPtrVectorTy() &&
480      SrcTy->getPointerAddressSpace() != DestTy->getPointerAddressSpace()) {
481    LLVMContext &Context = C->getContext();
482
483    // We have no information about target data layout, so we assume that
484    // the maximum pointer size is 64bit.
485    Type *MidTy = Type::getInt64Ty(Context);
486
487    return ConstantExpr::getIntToPtr(ConstantExpr::getPtrToInt(C, MidTy),
488                                     DestTy);
489  }
490
491  return 0;
492}
493
494/// Check the debug info version number, if it is out-dated, drop the debug
495/// info. Return true if module is modified.
496bool llvm::UpgradeDebugInfo(Module &M) {
497  if (getDebugMetadataVersionFromModule(M) == DEBUG_METADATA_VERSION)
498    return false;
499
500  return StripDebugInfo(M);
501}
502