lib/IR/AutoUpgrade.cpp

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