IntrinsicLowering.cpp revision b86413602e2d1d0d510016044092949168ac4d3f
1//===-- IntrinsicLowering.cpp - Intrinsic Lowering default 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 IntrinsicLowering class. 11// 12//===----------------------------------------------------------------------===// 13 14#include "llvm/Constants.h" 15#include "llvm/DerivedTypes.h" 16#include "llvm/Module.h" 17#include "llvm/Type.h" 18#include "llvm/CodeGen/IntrinsicLowering.h" 19#include "llvm/Support/ErrorHandling.h" 20#include "llvm/Support/IRBuilder.h" 21#include "llvm/Support/raw_ostream.h" 22#include "llvm/Target/TargetData.h" 23#include "llvm/ADT/SmallVector.h" 24using namespace llvm; 25 26template <class ArgIt> 27static void EnsureFunctionExists(Module &M, const char *Name, 28 ArgIt ArgBegin, ArgIt ArgEnd, 29 const Type *RetTy) { 30 // Insert a correctly-typed definition now. 31 std::vector<const Type *> ParamTys; 32 for (ArgIt I = ArgBegin; I != ArgEnd; ++I) 33 ParamTys.push_back(I->getType()); 34 M.getOrInsertFunction(Name, FunctionType::get(RetTy, ParamTys, false)); 35} 36 37static void EnsureFPIntrinsicsExist(Module &M, Function *Fn, 38 const char *FName, 39 const char *DName, const char *LDName) { 40 // Insert definitions for all the floating point types. 41 switch((int)Fn->arg_begin()->getType()->getTypeID()) { 42 case Type::FloatTyID: 43 EnsureFunctionExists(M, FName, Fn->arg_begin(), Fn->arg_end(), 44 Type::getFloatTy(M.getContext())); 45 break; 46 case Type::DoubleTyID: 47 EnsureFunctionExists(M, DName, Fn->arg_begin(), Fn->arg_end(), 48 Type::getDoubleTy(M.getContext())); 49 break; 50 case Type::X86_FP80TyID: 51 case Type::FP128TyID: 52 case Type::PPC_FP128TyID: 53 EnsureFunctionExists(M, LDName, Fn->arg_begin(), Fn->arg_end(), 54 Fn->arg_begin()->getType()); 55 break; 56 } 57} 58 59/// ReplaceCallWith - This function is used when we want to lower an intrinsic 60/// call to a call of an external function. This handles hard cases such as 61/// when there was already a prototype for the external function, and if that 62/// prototype doesn't match the arguments we expect to pass in. 63template <class ArgIt> 64static CallInst *ReplaceCallWith(const char *NewFn, CallInst *CI, 65 ArgIt ArgBegin, ArgIt ArgEnd, 66 const Type *RetTy) { 67 // If we haven't already looked up this function, check to see if the 68 // program already contains a function with this name. 69 Module *M = CI->getParent()->getParent()->getParent(); 70 // Get or insert the definition now. 71 std::vector<const Type *> ParamTys; 72 for (ArgIt I = ArgBegin; I != ArgEnd; ++I) 73 ParamTys.push_back((*I)->getType()); 74 Constant* FCache = M->getOrInsertFunction(NewFn, 75 FunctionType::get(RetTy, ParamTys, false)); 76 77 IRBuilder<> Builder(CI->getParent(), CI); 78 SmallVector<Value *, 8> Args(ArgBegin, ArgEnd); 79 CallInst *NewCI = Builder.CreateCall(FCache, Args.begin(), Args.end()); 80 NewCI->setName(CI->getName()); 81 if (!CI->use_empty()) 82 CI->replaceAllUsesWith(NewCI); 83 return NewCI; 84} 85 86void IntrinsicLowering::AddPrototypes(Module &M) { 87 LLVMContext &Context = M.getContext(); 88 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) 89 if (I->isDeclaration() && !I->use_empty()) 90 switch (I->getIntrinsicID()) { 91 default: break; 92 case Intrinsic::setjmp: 93 EnsureFunctionExists(M, "setjmp", I->arg_begin(), I->arg_end(), 94 Type::getInt32Ty(M.getContext())); 95 break; 96 case Intrinsic::longjmp: 97 EnsureFunctionExists(M, "longjmp", I->arg_begin(), I->arg_end(), 98 Type::getVoidTy(M.getContext())); 99 break; 100 case Intrinsic::siglongjmp: 101 EnsureFunctionExists(M, "abort", I->arg_end(), I->arg_end(), 102 Type::getVoidTy(M.getContext())); 103 break; 104 case Intrinsic::memcpy: 105 M.getOrInsertFunction("memcpy", 106 Type::getInt8PtrTy(Context), 107 Type::getInt8PtrTy(Context), 108 Type::getInt8PtrTy(Context), 109 TD.getIntPtrType(Context), (Type *)0); 110 break; 111 case Intrinsic::memmove: 112 M.getOrInsertFunction("memmove", 113 Type::getInt8PtrTy(Context), 114 Type::getInt8PtrTy(Context), 115 Type::getInt8PtrTy(Context), 116 TD.getIntPtrType(Context), (Type *)0); 117 break; 118 case Intrinsic::memset: 119 M.getOrInsertFunction("memset", 120 Type::getInt8PtrTy(Context), 121 Type::getInt8PtrTy(Context), 122 Type::getInt32Ty(M.getContext()), 123 TD.getIntPtrType(Context), (Type *)0); 124 break; 125 case Intrinsic::sqrt: 126 EnsureFPIntrinsicsExist(M, I, "sqrtf", "sqrt", "sqrtl"); 127 break; 128 case Intrinsic::sin: 129 EnsureFPIntrinsicsExist(M, I, "sinf", "sin", "sinl"); 130 break; 131 case Intrinsic::cos: 132 EnsureFPIntrinsicsExist(M, I, "cosf", "cos", "cosl"); 133 break; 134 case Intrinsic::pow: 135 EnsureFPIntrinsicsExist(M, I, "powf", "pow", "powl"); 136 break; 137 case Intrinsic::log: 138 EnsureFPIntrinsicsExist(M, I, "logf", "log", "logl"); 139 break; 140 case Intrinsic::log2: 141 EnsureFPIntrinsicsExist(M, I, "log2f", "log2", "log2l"); 142 break; 143 case Intrinsic::log10: 144 EnsureFPIntrinsicsExist(M, I, "log10f", "log10", "log10l"); 145 break; 146 case Intrinsic::exp: 147 EnsureFPIntrinsicsExist(M, I, "expf", "exp", "expl"); 148 break; 149 case Intrinsic::exp2: 150 EnsureFPIntrinsicsExist(M, I, "exp2f", "exp2", "exp2l"); 151 break; 152 } 153} 154 155/// LowerBSWAP - Emit the code to lower bswap of V before the specified 156/// instruction IP. 157static Value *LowerBSWAP(LLVMContext &Context, Value *V, Instruction *IP) { 158 assert(V->getType()->isIntegerTy() && "Can't bswap a non-integer type!"); 159 160 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 161 162 IRBuilder<> Builder(IP->getParent(), IP); 163 164 switch(BitSize) { 165 default: llvm_unreachable("Unhandled type size of value to byteswap!"); 166 case 16: { 167 Value *Tmp1 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 8), 168 "bswap.2"); 169 Value *Tmp2 = Builder.CreateLShr(V, ConstantInt::get(V->getType(), 8), 170 "bswap.1"); 171 V = Builder.CreateOr(Tmp1, Tmp2, "bswap.i16"); 172 break; 173 } 174 case 32: { 175 Value *Tmp4 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 24), 176 "bswap.4"); 177 Value *Tmp3 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 8), 178 "bswap.3"); 179 Value *Tmp2 = Builder.CreateLShr(V, ConstantInt::get(V->getType(), 8), 180 "bswap.2"); 181 Value *Tmp1 = Builder.CreateLShr(V,ConstantInt::get(V->getType(), 24), 182 "bswap.1"); 183 Tmp3 = Builder.CreateAnd(Tmp3, 184 ConstantInt::get(Type::getInt32Ty(Context), 0xFF0000), 185 "bswap.and3"); 186 Tmp2 = Builder.CreateAnd(Tmp2, 187 ConstantInt::get(Type::getInt32Ty(Context), 0xFF00), 188 "bswap.and2"); 189 Tmp4 = Builder.CreateOr(Tmp4, Tmp3, "bswap.or1"); 190 Tmp2 = Builder.CreateOr(Tmp2, Tmp1, "bswap.or2"); 191 V = Builder.CreateOr(Tmp4, Tmp2, "bswap.i32"); 192 break; 193 } 194 case 64: { 195 Value *Tmp8 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 56), 196 "bswap.8"); 197 Value *Tmp7 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 40), 198 "bswap.7"); 199 Value *Tmp6 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 24), 200 "bswap.6"); 201 Value *Tmp5 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 8), 202 "bswap.5"); 203 Value* Tmp4 = Builder.CreateLShr(V, ConstantInt::get(V->getType(), 8), 204 "bswap.4"); 205 Value* Tmp3 = Builder.CreateLShr(V, 206 ConstantInt::get(V->getType(), 24), 207 "bswap.3"); 208 Value* Tmp2 = Builder.CreateLShr(V, 209 ConstantInt::get(V->getType(), 40), 210 "bswap.2"); 211 Value* Tmp1 = Builder.CreateLShr(V, 212 ConstantInt::get(V->getType(), 56), 213 "bswap.1"); 214 Tmp7 = Builder.CreateAnd(Tmp7, 215 ConstantInt::get(Type::getInt64Ty(Context), 216 0xFF000000000000ULL), 217 "bswap.and7"); 218 Tmp6 = Builder.CreateAnd(Tmp6, 219 ConstantInt::get(Type::getInt64Ty(Context), 220 0xFF0000000000ULL), 221 "bswap.and6"); 222 Tmp5 = Builder.CreateAnd(Tmp5, 223 ConstantInt::get(Type::getInt64Ty(Context), 224 0xFF00000000ULL), 225 "bswap.and5"); 226 Tmp4 = Builder.CreateAnd(Tmp4, 227 ConstantInt::get(Type::getInt64Ty(Context), 228 0xFF000000ULL), 229 "bswap.and4"); 230 Tmp3 = Builder.CreateAnd(Tmp3, 231 ConstantInt::get(Type::getInt64Ty(Context), 232 0xFF0000ULL), 233 "bswap.and3"); 234 Tmp2 = Builder.CreateAnd(Tmp2, 235 ConstantInt::get(Type::getInt64Ty(Context), 236 0xFF00ULL), 237 "bswap.and2"); 238 Tmp8 = Builder.CreateOr(Tmp8, Tmp7, "bswap.or1"); 239 Tmp6 = Builder.CreateOr(Tmp6, Tmp5, "bswap.or2"); 240 Tmp4 = Builder.CreateOr(Tmp4, Tmp3, "bswap.or3"); 241 Tmp2 = Builder.CreateOr(Tmp2, Tmp1, "bswap.or4"); 242 Tmp8 = Builder.CreateOr(Tmp8, Tmp6, "bswap.or5"); 243 Tmp4 = Builder.CreateOr(Tmp4, Tmp2, "bswap.or6"); 244 V = Builder.CreateOr(Tmp8, Tmp4, "bswap.i64"); 245 break; 246 } 247 } 248 return V; 249} 250 251/// LowerCTPOP - Emit the code to lower ctpop of V before the specified 252/// instruction IP. 253static Value *LowerCTPOP(LLVMContext &Context, Value *V, Instruction *IP) { 254 assert(V->getType()->isIntegerTy() && "Can't ctpop a non-integer type!"); 255 256 static const uint64_t MaskValues[6] = { 257 0x5555555555555555ULL, 0x3333333333333333ULL, 258 0x0F0F0F0F0F0F0F0FULL, 0x00FF00FF00FF00FFULL, 259 0x0000FFFF0000FFFFULL, 0x00000000FFFFFFFFULL 260 }; 261 262 IRBuilder<> Builder(IP->getParent(), IP); 263 264 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 265 unsigned WordSize = (BitSize + 63) / 64; 266 Value *Count = ConstantInt::get(V->getType(), 0); 267 268 for (unsigned n = 0; n < WordSize; ++n) { 269 Value *PartValue = V; 270 for (unsigned i = 1, ct = 0; i < (BitSize>64 ? 64 : BitSize); 271 i <<= 1, ++ct) { 272 Value *MaskCst = ConstantInt::get(V->getType(), MaskValues[ct]); 273 Value *LHS = Builder.CreateAnd(PartValue, MaskCst, "cppop.and1"); 274 Value *VShift = Builder.CreateLShr(PartValue, 275 ConstantInt::get(V->getType(), i), 276 "ctpop.sh"); 277 Value *RHS = Builder.CreateAnd(VShift, MaskCst, "cppop.and2"); 278 PartValue = Builder.CreateAdd(LHS, RHS, "ctpop.step"); 279 } 280 Count = Builder.CreateAdd(PartValue, Count, "ctpop.part"); 281 if (BitSize > 64) { 282 V = Builder.CreateLShr(V, ConstantInt::get(V->getType(), 64), 283 "ctpop.part.sh"); 284 BitSize -= 64; 285 } 286 } 287 288 return Count; 289} 290 291/// LowerCTLZ - Emit the code to lower ctlz of V before the specified 292/// instruction IP. 293static Value *LowerCTLZ(LLVMContext &Context, Value *V, Instruction *IP) { 294 295 IRBuilder<> Builder(IP->getParent(), IP); 296 297 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 298 for (unsigned i = 1; i < BitSize; i <<= 1) { 299 Value *ShVal = ConstantInt::get(V->getType(), i); 300 ShVal = Builder.CreateLShr(V, ShVal, "ctlz.sh"); 301 V = Builder.CreateOr(V, ShVal, "ctlz.step"); 302 } 303 304 V = Builder.CreateNot(V); 305 return LowerCTPOP(Context, V, IP); 306} 307 308static void ReplaceFPIntrinsicWithCall(CallInst *CI, const char *Fname, 309 const char *Dname, 310 const char *LDname) { 311 switch (CI->getOperand(0)->getType()->getTypeID()) { 312 default: llvm_unreachable("Invalid type in intrinsic"); 313 case Type::FloatTyID: 314 ReplaceCallWith(Fname, CI, CI->op_begin(), CI->op_end() - 1, 315 Type::getFloatTy(CI->getContext())); 316 break; 317 case Type::DoubleTyID: 318 ReplaceCallWith(Dname, CI, CI->op_begin(), CI->op_end() - 1, 319 Type::getDoubleTy(CI->getContext())); 320 break; 321 case Type::X86_FP80TyID: 322 case Type::FP128TyID: 323 case Type::PPC_FP128TyID: 324 ReplaceCallWith(LDname, CI, CI->op_begin(), CI->op_end() - 1, 325 CI->getOperand(0)->getType()); 326 break; 327 } 328} 329 330void IntrinsicLowering::LowerIntrinsicCall(CallInst *CI) { 331 IRBuilder<> Builder(CI->getParent(), CI); 332 LLVMContext &Context = CI->getContext(); 333 334 const Function *Callee = CI->getCalledFunction(); 335 assert(Callee && "Cannot lower an indirect call!"); 336 337 switch (Callee->getIntrinsicID()) { 338 case Intrinsic::not_intrinsic: 339 report_fatal_error("Cannot lower a call to a non-intrinsic function '"+ 340 Callee->getName() + "'!"); 341 default: 342 report_fatal_error("Code generator does not support intrinsic function '"+ 343 Callee->getName()+"'!"); 344 345 // The setjmp/longjmp intrinsics should only exist in the code if it was 346 // never optimized (ie, right out of the CFE), or if it has been hacked on 347 // by the lowerinvoke pass. In both cases, the right thing to do is to 348 // convert the call to an explicit setjmp or longjmp call. 349 case Intrinsic::setjmp: { 350 Value *V = ReplaceCallWith("setjmp", CI, CI->op_begin(), CI->op_end() - 1, 351 Type::getInt32Ty(Context)); 352 if (!CI->getType()->isVoidTy()) 353 CI->replaceAllUsesWith(V); 354 break; 355 } 356 case Intrinsic::sigsetjmp: 357 if (!CI->getType()->isVoidTy()) 358 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 359 break; 360 361 case Intrinsic::longjmp: { 362 ReplaceCallWith("longjmp", CI, CI->op_begin(), CI->op_end() - 1, 363 Type::getVoidTy(Context)); 364 break; 365 } 366 367 case Intrinsic::siglongjmp: { 368 // Insert the call to abort 369 ReplaceCallWith("abort", CI, CI->op_end(), CI->op_end(), 370 Type::getVoidTy(Context)); 371 break; 372 } 373 case Intrinsic::ctpop: 374 CI->replaceAllUsesWith(LowerCTPOP(Context, CI->getOperand(0), CI)); 375 break; 376 377 case Intrinsic::bswap: 378 CI->replaceAllUsesWith(LowerBSWAP(Context, CI->getOperand(0), CI)); 379 break; 380 381 case Intrinsic::ctlz: 382 CI->replaceAllUsesWith(LowerCTLZ(Context, CI->getOperand(0), CI)); 383 break; 384 385 case Intrinsic::cttz: { 386 // cttz(x) -> ctpop(~X & (X-1)) 387 Value *Src = CI->getOperand(0); 388 Value *NotSrc = Builder.CreateNot(Src); 389 NotSrc->setName(Src->getName() + ".not"); 390 Value *SrcM1 = ConstantInt::get(Src->getType(), 1); 391 SrcM1 = Builder.CreateSub(Src, SrcM1); 392 Src = LowerCTPOP(Context, Builder.CreateAnd(NotSrc, SrcM1), CI); 393 CI->replaceAllUsesWith(Src); 394 break; 395 } 396 397 case Intrinsic::stacksave: 398 case Intrinsic::stackrestore: { 399 if (!Warned) 400 errs() << "WARNING: this target does not support the llvm.stack" 401 << (Callee->getIntrinsicID() == Intrinsic::stacksave ? 402 "save" : "restore") << " intrinsic.\n"; 403 Warned = true; 404 if (Callee->getIntrinsicID() == Intrinsic::stacksave) 405 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 406 break; 407 } 408 409 case Intrinsic::returnaddress: 410 case Intrinsic::frameaddress: 411 errs() << "WARNING: this target does not support the llvm." 412 << (Callee->getIntrinsicID() == Intrinsic::returnaddress ? 413 "return" : "frame") << "address intrinsic.\n"; 414 CI->replaceAllUsesWith(ConstantPointerNull::get( 415 cast<PointerType>(CI->getType()))); 416 break; 417 418 case Intrinsic::prefetch: 419 break; // Simply strip out prefetches on unsupported architectures 420 421 case Intrinsic::pcmarker: 422 break; // Simply strip out pcmarker on unsupported architectures 423 case Intrinsic::readcyclecounter: { 424 errs() << "WARNING: this target does not support the llvm.readcyclecoun" 425 << "ter intrinsic. It is being lowered to a constant 0\n"; 426 CI->replaceAllUsesWith(ConstantInt::get(Type::getInt64Ty(Context), 0)); 427 break; 428 } 429 430 case Intrinsic::dbg_declare: 431 break; // Simply strip out debugging intrinsics 432 433 case Intrinsic::eh_exception: 434 case Intrinsic::eh_selector: 435 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 436 break; 437 438 case Intrinsic::eh_typeid_for: 439 // Return something different to eh_selector. 440 CI->replaceAllUsesWith(ConstantInt::get(CI->getType(), 1)); 441 break; 442 443 case Intrinsic::var_annotation: 444 break; // Strip out annotate intrinsic 445 446 case Intrinsic::memcpy: { 447 const IntegerType *IntPtr = TD.getIntPtrType(Context); 448 Value *Size = Builder.CreateIntCast(CI->getOperand(2), IntPtr, 449 /* isSigned */ false); 450 Value *Ops[3]; 451 Ops[0] = CI->getOperand(0); 452 Ops[1] = CI->getOperand(1); 453 Ops[2] = Size; 454 ReplaceCallWith("memcpy", CI, Ops, Ops+3, CI->getOperand(0)->getType()); 455 break; 456 } 457 case Intrinsic::memmove: { 458 const IntegerType *IntPtr = TD.getIntPtrType(Context); 459 Value *Size = Builder.CreateIntCast(CI->getOperand(2), IntPtr, 460 /* isSigned */ false); 461 Value *Ops[3]; 462 Ops[0] = CI->getOperand(0); 463 Ops[1] = CI->getOperand(1); 464 Ops[2] = Size; 465 ReplaceCallWith("memmove", CI, Ops, Ops+3, CI->getOperand(0)->getType()); 466 break; 467 } 468 case Intrinsic::memset: { 469 const IntegerType *IntPtr = TD.getIntPtrType(Context); 470 Value *Size = Builder.CreateIntCast(CI->getOperand(2), IntPtr, 471 /* isSigned */ false); 472 Value *Ops[3]; 473 Ops[0] = CI->getOperand(0); 474 // Extend the amount to i32. 475 Ops[1] = Builder.CreateIntCast(CI->getOperand(1), Type::getInt32Ty(Context), 476 /* isSigned */ false); 477 Ops[2] = Size; 478 ReplaceCallWith("memset", CI, Ops, Ops+3, CI->getOperand(0)->getType()); 479 break; 480 } 481 case Intrinsic::sqrt: { 482 ReplaceFPIntrinsicWithCall(CI, "sqrtf", "sqrt", "sqrtl"); 483 break; 484 } 485 case Intrinsic::log: { 486 ReplaceFPIntrinsicWithCall(CI, "logf", "log", "logl"); 487 break; 488 } 489 case Intrinsic::log2: { 490 ReplaceFPIntrinsicWithCall(CI, "log2f", "log2", "log2l"); 491 break; 492 } 493 case Intrinsic::log10: { 494 ReplaceFPIntrinsicWithCall(CI, "log10f", "log10", "log10l"); 495 break; 496 } 497 case Intrinsic::exp: { 498 ReplaceFPIntrinsicWithCall(CI, "expf", "exp", "expl"); 499 break; 500 } 501 case Intrinsic::exp2: { 502 ReplaceFPIntrinsicWithCall(CI, "exp2f", "exp2", "exp2l"); 503 break; 504 } 505 case Intrinsic::pow: { 506 ReplaceFPIntrinsicWithCall(CI, "powf", "pow", "powl"); 507 break; 508 } 509 case Intrinsic::flt_rounds: 510 // Lower to "round to the nearest" 511 if (!CI->getType()->isVoidTy()) 512 CI->replaceAllUsesWith(ConstantInt::get(CI->getType(), 1)); 513 break; 514 case Intrinsic::invariant_start: 515 case Intrinsic::lifetime_start: 516 // Discard region information. 517 CI->replaceAllUsesWith(UndefValue::get(CI->getType())); 518 break; 519 case Intrinsic::invariant_end: 520 case Intrinsic::lifetime_end: 521 // Discard region information. 522 break; 523 } 524 525 assert(CI->use_empty() && 526 "Lowering should have eliminated any uses of the intrinsic call!"); 527 CI->eraseFromParent(); 528} 529