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/Constants.h"
  16 #include "llvm/Function.h"
  17 #include "llvm/IRBuilder.h"
  18 #include "llvm/Instruction.h"
  19 #include "llvm/IntrinsicInst.h"
  20 #include "llvm/LLVMContext.h"
  21 #include "llvm/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 'x': {
  92     if (Name.startswith("x86.sse2.pcmpeq.") ||
  93         Name.startswith("x86.sse2.pcmpgt.") ||
  94         Name.startswith("x86.avx2.pcmpeq.") ||
  95         Name.startswith("x86.avx2.pcmpgt.") ||
  96         Name.startswith("x86.avx.vpermil.") ||
  97         Name == "x86.avx.movnt.dq.256" ||
  98         Name == "x86.avx.movnt.pd.256" ||
  99         Name == "x86.avx.movnt.ps.256" ||
 100         (Name.startswith("x86.xop.vpcom") && F->arg_size() == 2)) {
 101       NewFn = 0;
 102       return true;
 103     }
 104     // SSE4.1 ptest functions may have an old signature.
 105     if (Name.startswith("x86.sse41.ptest")) {
 106       if (Name == "x86.sse41.ptestc")
 107         return UpgradeSSE41Function(F, Intrinsic::x86_sse41_ptestc, NewFn);
 108       if (Name == "x86.sse41.ptestz")
 109         return UpgradeSSE41Function(F, Intrinsic::x86_sse41_ptestz, NewFn);
 110       if (Name == "x86.sse41.ptestnzc")
 111         return UpgradeSSE41Function(F, Intrinsic::x86_sse41_ptestnzc, NewFn);
 112     }
 113     // frcz.ss/sd may need to have an argument dropped
 114     if (Name.startswith("x86.xop.vfrcz.ss") && F->arg_size() == 2) {
 115       F->setName(Name + ".old");
 116       NewFn = Intrinsic::getDeclaration(F->getParent(),
 117                                         Intrinsic::x86_xop_vfrcz_ss);
 118       return true;
 119     }
 120     if (Name.startswith("x86.xop.vfrcz.sd") && F->arg_size() == 2) {
 121       F->setName(Name + ".old");
 122       NewFn = Intrinsic::getDeclaration(F->getParent(),
 123                                         Intrinsic::x86_xop_vfrcz_sd);
 124       return true;
 125     }
 126     // Fix the FMA4 intrinsics to remove the 4
 127     if (Name.startswith("x86.fma4.")) {
 128       F->setName("llvm.x86.fma" + Name.substr(8));
 129       NewFn = F;
 130       return true;
 131     }
 132     break;
 133   }
 134   }
 135
 136   //  This may not belong here. This function is effectively being overloaded
 137   //  to both detect an intrinsic which needs upgrading, and to provide the
 138   //  upgraded form of the intrinsic. We should perhaps have two separate
 139   //  functions for this.
 140   return false;
 141 }
 142
 143 bool llvm::UpgradeIntrinsicFunction(Function *F, Function *&NewFn) {
 144   NewFn = 0;
 145   bool Upgraded = UpgradeIntrinsicFunction1(F, NewFn);
 146
 147   // Upgrade intrinsic attributes.  This does not change the function.
 148   if (NewFn)
 149     F = NewFn;
 150   if (unsigned id = F->getIntrinsicID())
 151     F->setAttributes(Intrinsic::getAttributes(F->getContext(),
 152                                               (Intrinsic::ID)id));
 153   return Upgraded;
 154 }
 155
 156 bool llvm::UpgradeGlobalVariable(GlobalVariable *GV) {
 157   // Nothing to do yet.
 158   return false;
 159 }
 160
 161 // UpgradeIntrinsicCall - Upgrade a call to an old intrinsic to be a call the
 162 // upgraded intrinsic. All argument and return casting must be provided in
 163 // order to seamlessly integrate with existing context.
 164 void llvm::UpgradeIntrinsicCall(CallInst *CI, Function *NewFn) {
 165   Function *F = CI->getCalledFunction();
 166   LLVMContext &C = CI->getContext();
 167   IRBuilder<> Builder(C);
 168   Builder.SetInsertPoint(CI->getParent(), CI);
 169
 170   assert(F && "Intrinsic call is not direct?");
 171
 172   if (!NewFn) {
 173     // Get the Function's name.
 174     StringRef Name = F->getName();
 175
 176     Value *Rep;
 177     // Upgrade packed integer vector compares intrinsics to compare instructions
 178     if (Name.startswith("llvm.x86.sse2.pcmpeq.") ||
 179         Name.startswith("llvm.x86.avx2.pcmpeq.")) {
 180       Rep = Builder.CreateICmpEQ(CI->getArgOperand(0), CI->getArgOperand(1),
 181                                  "pcmpeq");
 182       // need to sign extend since icmp returns vector of i1
 183       Rep = Builder.CreateSExt(Rep, CI->getType(), "");
 184     } else if (Name.startswith("llvm.x86.sse2.pcmpgt.") ||
 185                Name.startswith("llvm.x86.avx2.pcmpgt.")) {
 186       Rep = Builder.CreateICmpSGT(CI->getArgOperand(0), CI->getArgOperand(1),
 187                                   "pcmpgt");
 188       // need to sign extend since icmp returns vector of i1
 189       Rep = Builder.CreateSExt(Rep, CI->getType(), "");
 190     } else if (Name == "llvm.x86.avx.movnt.dq.256" ||
 191                Name == "llvm.x86.avx.movnt.ps.256" ||
 192                Name == "llvm.x86.avx.movnt.pd.256") {
 193       IRBuilder<> Builder(C);
 194       Builder.SetInsertPoint(CI->getParent(), CI);
 195
 196       Module *M = F->getParent();
 197       SmallVector<Value *, 1> Elts;
 198       Elts.push_back(ConstantInt::get(Type::getInt32Ty(C), 1));
 199       MDNode *Node = MDNode::get(C, Elts);
 200
 201       Value *Arg0 = CI->getArgOperand(0);
 202       Value *Arg1 = CI->getArgOperand(1);
 203
 204       // Convert the type of the pointer to a pointer to the stored type.
 205       Value *BC = Builder.CreateBitCast(Arg0,
 206                                         PointerType::getUnqual(Arg1->getType()),
 207                                         "cast");
 208       StoreInst *SI = Builder.CreateStore(Arg1, BC);
 209       SI->setMetadata(M->getMDKindID("nontemporal"), Node);
 210       SI->setAlignment(16);
 211
 212       // Remove intrinsic.
 213       CI->eraseFromParent();
 214       return;
 215     } else if (Name.startswith("llvm.x86.xop.vpcom")) {
 216       Intrinsic::ID intID;
 217       if (Name.endswith("ub"))
 218         intID = Intrinsic::x86_xop_vpcomub;
 219       else if (Name.endswith("uw"))
 220         intID = Intrinsic::x86_xop_vpcomuw;
 221       else if (Name.endswith("ud"))
 222         intID = Intrinsic::x86_xop_vpcomud;
 223       else if (Name.endswith("uq"))
 224         intID = Intrinsic::x86_xop_vpcomuq;
 225       else if (Name.endswith("b"))
 226         intID = Intrinsic::x86_xop_vpcomb;
 227       else if (Name.endswith("w"))
 228         intID = Intrinsic::x86_xop_vpcomw;
 229       else if (Name.endswith("d"))
 230         intID = Intrinsic::x86_xop_vpcomd;
 231       else if (Name.endswith("q"))
 232         intID = Intrinsic::x86_xop_vpcomq;
 233       else
 234         llvm_unreachable("Unknown suffix");
 235
 236       Name = Name.substr(18); // strip off "llvm.x86.xop.vpcom"
 237       unsigned Imm;
 238       if (Name.startswith("lt"))
 239         Imm = 0;
 240       else if (Name.startswith("le"))
 241         Imm = 1;
 242       else if (Name.startswith("gt"))
 243         Imm = 2;
 244       else if (Name.startswith("ge"))
 245         Imm = 3;
 246       else if (Name.startswith("eq"))
 247         Imm = 4;
 248       else if (Name.startswith("ne"))
 249         Imm = 5;
 250       else if (Name.startswith("true"))
 251         Imm = 6;
 252       else if (Name.startswith("false"))
 253         Imm = 7;
 254       else
 255         llvm_unreachable("Unknown condition");
 256
 257       Function *VPCOM = Intrinsic::getDeclaration(F->getParent(), intID);
 258       Rep = Builder.CreateCall3(VPCOM, CI->getArgOperand(0),
 259                                 CI->getArgOperand(1), Builder.getInt8(Imm));
 260     } else {
 261       bool PD128 = false, PD256 = false, PS128 = false, PS256 = false;
 262       if (Name == "llvm.x86.avx.vpermil.pd.256")
 263         PD256 = true;
 264       else if (Name == "llvm.x86.avx.vpermil.pd")
 265         PD128 = true;
 266       else if (Name == "llvm.x86.avx.vpermil.ps.256")
 267         PS256 = true;
 268       else if (Name == "llvm.x86.avx.vpermil.ps")
 269         PS128 = true;
 270
 271       if (PD256 || PD128 || PS256 || PS128) {
 272         Value *Op0 = CI->getArgOperand(0);
 273         unsigned Imm = cast<ConstantInt>(CI->getArgOperand(1))->getZExtValue();
 274         SmallVector<Constant*, 8> Idxs;
 275
 276         if (PD128)
 277           for (unsigned i = 0; i != 2; ++i)
 278             Idxs.push_back(Builder.getInt32((Imm >> i) & 0x1));
 279         else if (PD256)
 280           for (unsigned l = 0; l != 4; l+=2)
 281             for (unsigned i = 0; i != 2; ++i)
 282               Idxs.push_back(Builder.getInt32(((Imm >> (l+i)) & 0x1) + l));
 283         else if (PS128)
 284           for (unsigned i = 0; i != 4; ++i)
 285             Idxs.push_back(Builder.getInt32((Imm >> (2 * i)) & 0x3));
 286         else if (PS256)
 287           for (unsigned l = 0; l != 8; l+=4)
 288             for (unsigned i = 0; i != 4; ++i)
 289               Idxs.push_back(Builder.getInt32(((Imm >> (2 * i)) & 0x3) + l));
 290         else
 291           llvm_unreachable("Unexpected function");
 292
 293         Rep = Builder.CreateShuffleVector(Op0, Op0, ConstantVector::get(Idxs));
 294       } else {
 295         llvm_unreachable("Unknown function for CallInst upgrade.");
 296       }
 297     }
 298
 299     CI->replaceAllUsesWith(Rep);
 300     CI->eraseFromParent();
 301     return;
 302   }
 303
 304   std::string Name = CI->getName().str();
 305   CI->setName(Name + ".old");
 306
 307   switch (NewFn->getIntrinsicID()) {
 308   default:
 309     llvm_unreachable("Unknown function for CallInst upgrade.");
 310
 311   case Intrinsic::ctlz:
 312   case Intrinsic::cttz:
 313     assert(CI->getNumArgOperands() == 1 &&
 314            "Mismatch between function args and call args");
 315     CI->replaceAllUsesWith(Builder.CreateCall2(NewFn, CI->getArgOperand(0),
 316                                                Builder.getFalse(), Name));
 317     CI->eraseFromParent();
 318     return;
 319
 320   case Intrinsic::arm_neon_vclz: {
 321     // Change name from llvm.arm.neon.vclz.* to llvm.ctlz.*
 322     CI->replaceAllUsesWith(Builder.CreateCall2(NewFn, CI->getArgOperand(0),
 323                                                Builder.getFalse(),
 324                                                "llvm.ctlz." + Name.substr(14)));
 325     CI->eraseFromParent();
 326     return;
 327   }
 328   case Intrinsic::ctpop: {
 329     CI->replaceAllUsesWith(Builder.CreateCall(NewFn, CI->getArgOperand(0)));
 330     CI->eraseFromParent();
 331     return;
 332   }
 333
 334   case Intrinsic::x86_xop_vfrcz_ss:
 335   case Intrinsic::x86_xop_vfrcz_sd:
 336     CI->replaceAllUsesWith(Builder.CreateCall(NewFn, CI->getArgOperand(1),
 337                                               Name));
 338     CI->eraseFromParent();
 339     return;
 340
 341   case Intrinsic::x86_sse41_ptestc:
 342   case Intrinsic::x86_sse41_ptestz:
 343   case Intrinsic::x86_sse41_ptestnzc: {
 344     // The arguments for these intrinsics used to be v4f32, and changed
 345     // to v2i64. This is purely a nop, since those are bitwise intrinsics.
 346     // So, the only thing required is a bitcast for both arguments.
 347     // First, check the arguments have the old type.
 348     Value *Arg0 = CI->getArgOperand(0);
 349     if (Arg0->getType() != VectorType::get(Type::getFloatTy(C), 4))
 350       return;
 351
 352     // Old intrinsic, add bitcasts
 353     Value *Arg1 = CI->getArgOperand(1);
 354
 355     Value *BC0 =
 356       Builder.CreateBitCast(Arg0,
 357                             VectorType::get(Type::getInt64Ty(C), 2),
 358                             "cast");
 359     Value *BC1 =
 360       Builder.CreateBitCast(Arg1,
 361                             VectorType::get(Type::getInt64Ty(C), 2),
 362                             "cast");
 363
 364     CallInst* NewCall = Builder.CreateCall2(NewFn, BC0, BC1, Name);
 365     CI->replaceAllUsesWith(NewCall);
 366     CI->eraseFromParent();
 367     return;
 368   }
 369   }
 370 }
 371
 372 // This tests each Function to determine if it needs upgrading. When we find
 373 // one we are interested in, we then upgrade all calls to reflect the new
 374 // function.
 375 void llvm::UpgradeCallsToIntrinsic(Function* F) {
 376   assert(F && "Illegal attempt to upgrade a non-existent intrinsic.");
 377
 378   // Upgrade the function and check if it is a totaly new function.
 379   Function *NewFn;
 380   if (UpgradeIntrinsicFunction(F, NewFn)) {
 381     if (NewFn != F) {
 382       // Replace all uses to the old function with the new one if necessary.
 383       for (Value::use_iterator UI = F->use_begin(), UE = F->use_end();
 384            UI != UE; ) {
 385         if (CallInst *CI = dyn_cast<CallInst>(*UI++))
 386           UpgradeIntrinsicCall(CI, NewFn);
 387       }
 388       // Remove old function, no longer used, from the module.
 389       F->eraseFromParent();
 390     }
 391   }
 392 }
 393