1 //===- AMDGPULibCalls.cpp -------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 /// \file 10 /// This file does AMD library function optimizations. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "AMDGPU.h" 15 #include "AMDGPULibFunc.h" 16 #include "GCNSubtarget.h" 17 #include "llvm/Analysis/AssumptionCache.h" 18 #include "llvm/Analysis/TargetLibraryInfo.h" 19 #include "llvm/Analysis/ValueTracking.h" 20 #include "llvm/IR/Dominators.h" 21 #include "llvm/IR/IRBuilder.h" 22 #include "llvm/IR/IntrinsicInst.h" 23 #include "llvm/IR/IntrinsicsAMDGPU.h" 24 #include "llvm/IR/PatternMatch.h" 25 #include "llvm/InitializePasses.h" 26 #include <cmath> 27 28 #define DEBUG_TYPE "amdgpu-simplifylib" 29 30 using namespace llvm; 31 using namespace llvm::PatternMatch; 32 33 static cl::opt<bool> EnablePreLink("amdgpu-prelink", 34 cl::desc("Enable pre-link mode optimizations"), 35 cl::init(false), 36 cl::Hidden); 37 38 static cl::list<std::string> UseNative("amdgpu-use-native", 39 cl::desc("Comma separated list of functions to replace with native, or all"), 40 cl::CommaSeparated, cl::ValueOptional, 41 cl::Hidden); 42 43 #define MATH_PI numbers::pi 44 #define MATH_E numbers::e 45 #define MATH_SQRT2 numbers::sqrt2 46 #define MATH_SQRT1_2 numbers::inv_sqrt2 47 48 namespace llvm { 49 50 class AMDGPULibCalls { 51 private: 52 const TargetLibraryInfo *TLInfo = nullptr; 53 AssumptionCache *AC = nullptr; 54 DominatorTree *DT = nullptr; 55 56 typedef llvm::AMDGPULibFunc FuncInfo; 57 58 bool UnsafeFPMath = false; 59 60 // -fuse-native. 61 bool AllNative = false; 62 63 bool useNativeFunc(const StringRef F) const; 64 65 // Return a pointer (pointer expr) to the function if function definition with 66 // "FuncName" exists. It may create a new function prototype in pre-link mode. 67 FunctionCallee getFunction(Module *M, const FuncInfo &fInfo); 68 69 bool parseFunctionName(const StringRef &FMangledName, FuncInfo &FInfo); 70 71 bool TDOFold(CallInst *CI, const FuncInfo &FInfo); 72 73 /* Specialized optimizations */ 74 75 // pow/powr/pown 76 bool fold_pow(FPMathOperator *FPOp, IRBuilder<> &B, const FuncInfo &FInfo); 77 78 // rootn 79 bool fold_rootn(FPMathOperator *FPOp, IRBuilder<> &B, const FuncInfo &FInfo); 80 81 // -fuse-native for sincos 82 bool sincosUseNative(CallInst *aCI, const FuncInfo &FInfo); 83 84 // evaluate calls if calls' arguments are constants. 85 bool evaluateScalarMathFunc(const FuncInfo &FInfo, double &Res0, double &Res1, 86 Constant *copr0, Constant *copr1); 87 bool evaluateCall(CallInst *aCI, const FuncInfo &FInfo); 88 89 // sqrt 90 bool fold_sqrt(FPMathOperator *FPOp, IRBuilder<> &B, const FuncInfo &FInfo); 91 92 /// Insert a value to sincos function \p Fsincos. Returns (value of sin, value 93 /// of cos, sincos call). 94 std::tuple<Value *, Value *, Value *> insertSinCos(Value *Arg, 95 FastMathFlags FMF, 96 IRBuilder<> &B, 97 FunctionCallee Fsincos); 98 99 // sin/cos 100 bool fold_sincos(FPMathOperator *FPOp, IRBuilder<> &B, const FuncInfo &FInfo); 101 102 // __read_pipe/__write_pipe 103 bool fold_read_write_pipe(CallInst *CI, IRBuilder<> &B, 104 const FuncInfo &FInfo); 105 106 // Get a scalar native builtin single argument FP function 107 FunctionCallee getNativeFunction(Module *M, const FuncInfo &FInfo); 108 109 /// Substitute a call to a known libcall with an intrinsic call. If \p 110 /// AllowMinSize is true, allow the replacement in a minsize function. 111 bool shouldReplaceLibcallWithIntrinsic(const CallInst *CI, 112 bool AllowMinSizeF32 = false, 113 bool AllowF64 = false, 114 bool AllowStrictFP = false); 115 void replaceLibCallWithSimpleIntrinsic(IRBuilder<> &B, CallInst *CI, 116 Intrinsic::ID IntrID); 117 118 bool tryReplaceLibcallWithSimpleIntrinsic(IRBuilder<> &B, CallInst *CI, 119 Intrinsic::ID IntrID, 120 bool AllowMinSizeF32 = false, 121 bool AllowF64 = false, 122 bool AllowStrictFP = false); 123 124 protected: 125 bool isUnsafeMath(const FPMathOperator *FPOp) const; 126 bool isUnsafeFiniteOnlyMath(const FPMathOperator *FPOp) const; 127 128 bool canIncreasePrecisionOfConstantFold(const FPMathOperator *FPOp) const; 129 130 static void replaceCall(Instruction *I, Value *With) { 131 I->replaceAllUsesWith(With); 132 I->eraseFromParent(); 133 } 134 135 static void replaceCall(FPMathOperator *I, Value *With) { 136 replaceCall(cast<Instruction>(I), With); 137 } 138 139 public: 140 AMDGPULibCalls() {} 141 142 bool fold(CallInst *CI); 143 144 void initFunction(Function &F, FunctionAnalysisManager &FAM); 145 void initNativeFuncs(); 146 147 // Replace a normal math function call with that native version 148 bool useNative(CallInst *CI); 149 }; 150 151 } // end llvm namespace 152 153 template <typename IRB> 154 static CallInst *CreateCallEx(IRB &B, FunctionCallee Callee, Value *Arg, 155 const Twine &Name = "") { 156 CallInst *R = B.CreateCall(Callee, Arg, Name); 157 if (Function *F = dyn_cast<Function>(Callee.getCallee())) 158 R->setCallingConv(F->getCallingConv()); 159 return R; 160 } 161 162 template <typename IRB> 163 static CallInst *CreateCallEx2(IRB &B, FunctionCallee Callee, Value *Arg1, 164 Value *Arg2, const Twine &Name = "") { 165 CallInst *R = B.CreateCall(Callee, {Arg1, Arg2}, Name); 166 if (Function *F = dyn_cast<Function>(Callee.getCallee())) 167 R->setCallingConv(F->getCallingConv()); 168 return R; 169 } 170 171 // Data structures for table-driven optimizations. 172 // FuncTbl works for both f32 and f64 functions with 1 input argument 173 174 struct TableEntry { 175 double result; 176 double input; 177 }; 178 179 /* a list of {result, input} */ 180 static const TableEntry tbl_acos[] = { 181 {MATH_PI / 2.0, 0.0}, 182 {MATH_PI / 2.0, -0.0}, 183 {0.0, 1.0}, 184 {MATH_PI, -1.0} 185 }; 186 static const TableEntry tbl_acosh[] = { 187 {0.0, 1.0} 188 }; 189 static const TableEntry tbl_acospi[] = { 190 {0.5, 0.0}, 191 {0.5, -0.0}, 192 {0.0, 1.0}, 193 {1.0, -1.0} 194 }; 195 static const TableEntry tbl_asin[] = { 196 {0.0, 0.0}, 197 {-0.0, -0.0}, 198 {MATH_PI / 2.0, 1.0}, 199 {-MATH_PI / 2.0, -1.0} 200 }; 201 static const TableEntry tbl_asinh[] = { 202 {0.0, 0.0}, 203 {-0.0, -0.0} 204 }; 205 static const TableEntry tbl_asinpi[] = { 206 {0.0, 0.0}, 207 {-0.0, -0.0}, 208 {0.5, 1.0}, 209 {-0.5, -1.0} 210 }; 211 static const TableEntry tbl_atan[] = { 212 {0.0, 0.0}, 213 {-0.0, -0.0}, 214 {MATH_PI / 4.0, 1.0}, 215 {-MATH_PI / 4.0, -1.0} 216 }; 217 static const TableEntry tbl_atanh[] = { 218 {0.0, 0.0}, 219 {-0.0, -0.0} 220 }; 221 static const TableEntry tbl_atanpi[] = { 222 {0.0, 0.0}, 223 {-0.0, -0.0}, 224 {0.25, 1.0}, 225 {-0.25, -1.0} 226 }; 227 static const TableEntry tbl_cbrt[] = { 228 {0.0, 0.0}, 229 {-0.0, -0.0}, 230 {1.0, 1.0}, 231 {-1.0, -1.0}, 232 }; 233 static const TableEntry tbl_cos[] = { 234 {1.0, 0.0}, 235 {1.0, -0.0} 236 }; 237 static const TableEntry tbl_cosh[] = { 238 {1.0, 0.0}, 239 {1.0, -0.0} 240 }; 241 static const TableEntry tbl_cospi[] = { 242 {1.0, 0.0}, 243 {1.0, -0.0} 244 }; 245 static const TableEntry tbl_erfc[] = { 246 {1.0, 0.0}, 247 {1.0, -0.0} 248 }; 249 static const TableEntry tbl_erf[] = { 250 {0.0, 0.0}, 251 {-0.0, -0.0} 252 }; 253 static const TableEntry tbl_exp[] = { 254 {1.0, 0.0}, 255 {1.0, -0.0}, 256 {MATH_E, 1.0} 257 }; 258 static const TableEntry tbl_exp2[] = { 259 {1.0, 0.0}, 260 {1.0, -0.0}, 261 {2.0, 1.0} 262 }; 263 static const TableEntry tbl_exp10[] = { 264 {1.0, 0.0}, 265 {1.0, -0.0}, 266 {10.0, 1.0} 267 }; 268 static const TableEntry tbl_expm1[] = { 269 {0.0, 0.0}, 270 {-0.0, -0.0} 271 }; 272 static const TableEntry tbl_log[] = { 273 {0.0, 1.0}, 274 {1.0, MATH_E} 275 }; 276 static const TableEntry tbl_log2[] = { 277 {0.0, 1.0}, 278 {1.0, 2.0} 279 }; 280 static const TableEntry tbl_log10[] = { 281 {0.0, 1.0}, 282 {1.0, 10.0} 283 }; 284 static const TableEntry tbl_rsqrt[] = { 285 {1.0, 1.0}, 286 {MATH_SQRT1_2, 2.0} 287 }; 288 static const TableEntry tbl_sin[] = { 289 {0.0, 0.0}, 290 {-0.0, -0.0} 291 }; 292 static const TableEntry tbl_sinh[] = { 293 {0.0, 0.0}, 294 {-0.0, -0.0} 295 }; 296 static const TableEntry tbl_sinpi[] = { 297 {0.0, 0.0}, 298 {-0.0, -0.0} 299 }; 300 static const TableEntry tbl_sqrt[] = { 301 {0.0, 0.0}, 302 {1.0, 1.0}, 303 {MATH_SQRT2, 2.0} 304 }; 305 static const TableEntry tbl_tan[] = { 306 {0.0, 0.0}, 307 {-0.0, -0.0} 308 }; 309 static const TableEntry tbl_tanh[] = { 310 {0.0, 0.0}, 311 {-0.0, -0.0} 312 }; 313 static const TableEntry tbl_tanpi[] = { 314 {0.0, 0.0}, 315 {-0.0, -0.0} 316 }; 317 static const TableEntry tbl_tgamma[] = { 318 {1.0, 1.0}, 319 {1.0, 2.0}, 320 {2.0, 3.0}, 321 {6.0, 4.0} 322 }; 323 324 static bool HasNative(AMDGPULibFunc::EFuncId id) { 325 switch(id) { 326 case AMDGPULibFunc::EI_DIVIDE: 327 case AMDGPULibFunc::EI_COS: 328 case AMDGPULibFunc::EI_EXP: 329 case AMDGPULibFunc::EI_EXP2: 330 case AMDGPULibFunc::EI_EXP10: 331 case AMDGPULibFunc::EI_LOG: 332 case AMDGPULibFunc::EI_LOG2: 333 case AMDGPULibFunc::EI_LOG10: 334 case AMDGPULibFunc::EI_POWR: 335 case AMDGPULibFunc::EI_RECIP: 336 case AMDGPULibFunc::EI_RSQRT: 337 case AMDGPULibFunc::EI_SIN: 338 case AMDGPULibFunc::EI_SINCOS: 339 case AMDGPULibFunc::EI_SQRT: 340 case AMDGPULibFunc::EI_TAN: 341 return true; 342 default:; 343 } 344 return false; 345 } 346 347 using TableRef = ArrayRef<TableEntry>; 348 349 static TableRef getOptTable(AMDGPULibFunc::EFuncId id) { 350 switch(id) { 351 case AMDGPULibFunc::EI_ACOS: return TableRef(tbl_acos); 352 case AMDGPULibFunc::EI_ACOSH: return TableRef(tbl_acosh); 353 case AMDGPULibFunc::EI_ACOSPI: return TableRef(tbl_acospi); 354 case AMDGPULibFunc::EI_ASIN: return TableRef(tbl_asin); 355 case AMDGPULibFunc::EI_ASINH: return TableRef(tbl_asinh); 356 case AMDGPULibFunc::EI_ASINPI: return TableRef(tbl_asinpi); 357 case AMDGPULibFunc::EI_ATAN: return TableRef(tbl_atan); 358 case AMDGPULibFunc::EI_ATANH: return TableRef(tbl_atanh); 359 case AMDGPULibFunc::EI_ATANPI: return TableRef(tbl_atanpi); 360 case AMDGPULibFunc::EI_CBRT: return TableRef(tbl_cbrt); 361 case AMDGPULibFunc::EI_NCOS: 362 case AMDGPULibFunc::EI_COS: return TableRef(tbl_cos); 363 case AMDGPULibFunc::EI_COSH: return TableRef(tbl_cosh); 364 case AMDGPULibFunc::EI_COSPI: return TableRef(tbl_cospi); 365 case AMDGPULibFunc::EI_ERFC: return TableRef(tbl_erfc); 366 case AMDGPULibFunc::EI_ERF: return TableRef(tbl_erf); 367 case AMDGPULibFunc::EI_EXP: return TableRef(tbl_exp); 368 case AMDGPULibFunc::EI_NEXP2: 369 case AMDGPULibFunc::EI_EXP2: return TableRef(tbl_exp2); 370 case AMDGPULibFunc::EI_EXP10: return TableRef(tbl_exp10); 371 case AMDGPULibFunc::EI_EXPM1: return TableRef(tbl_expm1); 372 case AMDGPULibFunc::EI_LOG: return TableRef(tbl_log); 373 case AMDGPULibFunc::EI_NLOG2: 374 case AMDGPULibFunc::EI_LOG2: return TableRef(tbl_log2); 375 case AMDGPULibFunc::EI_LOG10: return TableRef(tbl_log10); 376 case AMDGPULibFunc::EI_NRSQRT: 377 case AMDGPULibFunc::EI_RSQRT: return TableRef(tbl_rsqrt); 378 case AMDGPULibFunc::EI_NSIN: 379 case AMDGPULibFunc::EI_SIN: return TableRef(tbl_sin); 380 case AMDGPULibFunc::EI_SINH: return TableRef(tbl_sinh); 381 case AMDGPULibFunc::EI_SINPI: return TableRef(tbl_sinpi); 382 case AMDGPULibFunc::EI_NSQRT: 383 case AMDGPULibFunc::EI_SQRT: return TableRef(tbl_sqrt); 384 case AMDGPULibFunc::EI_TAN: return TableRef(tbl_tan); 385 case AMDGPULibFunc::EI_TANH: return TableRef(tbl_tanh); 386 case AMDGPULibFunc::EI_TANPI: return TableRef(tbl_tanpi); 387 case AMDGPULibFunc::EI_TGAMMA: return TableRef(tbl_tgamma); 388 default:; 389 } 390 return TableRef(); 391 } 392 393 static inline int getVecSize(const AMDGPULibFunc& FInfo) { 394 return FInfo.getLeads()[0].VectorSize; 395 } 396 397 static inline AMDGPULibFunc::EType getArgType(const AMDGPULibFunc& FInfo) { 398 return (AMDGPULibFunc::EType)FInfo.getLeads()[0].ArgType; 399 } 400 401 FunctionCallee AMDGPULibCalls::getFunction(Module *M, const FuncInfo &fInfo) { 402 // If we are doing PreLinkOpt, the function is external. So it is safe to 403 // use getOrInsertFunction() at this stage. 404 405 return EnablePreLink ? AMDGPULibFunc::getOrInsertFunction(M, fInfo) 406 : AMDGPULibFunc::getFunction(M, fInfo); 407 } 408 409 bool AMDGPULibCalls::parseFunctionName(const StringRef &FMangledName, 410 FuncInfo &FInfo) { 411 return AMDGPULibFunc::parse(FMangledName, FInfo); 412 } 413 414 bool AMDGPULibCalls::isUnsafeMath(const FPMathOperator *FPOp) const { 415 return UnsafeFPMath || FPOp->isFast(); 416 } 417 418 bool AMDGPULibCalls::isUnsafeFiniteOnlyMath(const FPMathOperator *FPOp) const { 419 return UnsafeFPMath || 420 (FPOp->hasApproxFunc() && FPOp->hasNoNaNs() && FPOp->hasNoInfs()); 421 } 422 423 bool AMDGPULibCalls::canIncreasePrecisionOfConstantFold( 424 const FPMathOperator *FPOp) const { 425 // TODO: Refine to approxFunc or contract 426 return isUnsafeMath(FPOp); 427 } 428 429 void AMDGPULibCalls::initFunction(Function &F, FunctionAnalysisManager &FAM) { 430 UnsafeFPMath = F.getFnAttribute("unsafe-fp-math").getValueAsBool(); 431 AC = &FAM.getResult<AssumptionAnalysis>(F); 432 TLInfo = &FAM.getResult<TargetLibraryAnalysis>(F); 433 DT = FAM.getCachedResult<DominatorTreeAnalysis>(F); 434 } 435 436 bool AMDGPULibCalls::useNativeFunc(const StringRef F) const { 437 return AllNative || llvm::is_contained(UseNative, F); 438 } 439 440 void AMDGPULibCalls::initNativeFuncs() { 441 AllNative = useNativeFunc("all") || 442 (UseNative.getNumOccurrences() && UseNative.size() == 1 && 443 UseNative.begin()->empty()); 444 } 445 446 bool AMDGPULibCalls::sincosUseNative(CallInst *aCI, const FuncInfo &FInfo) { 447 bool native_sin = useNativeFunc("sin"); 448 bool native_cos = useNativeFunc("cos"); 449 450 if (native_sin && native_cos) { 451 Module *M = aCI->getModule(); 452 Value *opr0 = aCI->getArgOperand(0); 453 454 AMDGPULibFunc nf; 455 nf.getLeads()[0].ArgType = FInfo.getLeads()[0].ArgType; 456 nf.getLeads()[0].VectorSize = FInfo.getLeads()[0].VectorSize; 457 458 nf.setPrefix(AMDGPULibFunc::NATIVE); 459 nf.setId(AMDGPULibFunc::EI_SIN); 460 FunctionCallee sinExpr = getFunction(M, nf); 461 462 nf.setPrefix(AMDGPULibFunc::NATIVE); 463 nf.setId(AMDGPULibFunc::EI_COS); 464 FunctionCallee cosExpr = getFunction(M, nf); 465 if (sinExpr && cosExpr) { 466 Value *sinval = CallInst::Create(sinExpr, opr0, "splitsin", aCI); 467 Value *cosval = CallInst::Create(cosExpr, opr0, "splitcos", aCI); 468 new StoreInst(cosval, aCI->getArgOperand(1), aCI); 469 470 DEBUG_WITH_TYPE("usenative", dbgs() << "<useNative> replace " << *aCI 471 << " with native version of sin/cos"); 472 473 replaceCall(aCI, sinval); 474 return true; 475 } 476 } 477 return false; 478 } 479 480 bool AMDGPULibCalls::useNative(CallInst *aCI) { 481 Function *Callee = aCI->getCalledFunction(); 482 if (!Callee || aCI->isNoBuiltin()) 483 return false; 484 485 FuncInfo FInfo; 486 if (!parseFunctionName(Callee->getName(), FInfo) || !FInfo.isMangled() || 487 FInfo.getPrefix() != AMDGPULibFunc::NOPFX || 488 getArgType(FInfo) == AMDGPULibFunc::F64 || !HasNative(FInfo.getId()) || 489 !(AllNative || useNativeFunc(FInfo.getName()))) { 490 return false; 491 } 492 493 if (FInfo.getId() == AMDGPULibFunc::EI_SINCOS) 494 return sincosUseNative(aCI, FInfo); 495 496 FInfo.setPrefix(AMDGPULibFunc::NATIVE); 497 FunctionCallee F = getFunction(aCI->getModule(), FInfo); 498 if (!F) 499 return false; 500 501 aCI->setCalledFunction(F); 502 DEBUG_WITH_TYPE("usenative", dbgs() << "<useNative> replace " << *aCI 503 << " with native version"); 504 return true; 505 } 506 507 // Clang emits call of __read_pipe_2 or __read_pipe_4 for OpenCL read_pipe 508 // builtin, with appended type size and alignment arguments, where 2 or 4 509 // indicates the original number of arguments. The library has optimized version 510 // of __read_pipe_2/__read_pipe_4 when the type size and alignment has the same 511 // power of 2 value. This function transforms __read_pipe_2 to __read_pipe_2_N 512 // for such cases where N is the size in bytes of the type (N = 1, 2, 4, 8, ..., 513 // 128). The same for __read_pipe_4, write_pipe_2, and write_pipe_4. 514 bool AMDGPULibCalls::fold_read_write_pipe(CallInst *CI, IRBuilder<> &B, 515 const FuncInfo &FInfo) { 516 auto *Callee = CI->getCalledFunction(); 517 if (!Callee->isDeclaration()) 518 return false; 519 520 assert(Callee->hasName() && "Invalid read_pipe/write_pipe function"); 521 auto *M = Callee->getParent(); 522 std::string Name = std::string(Callee->getName()); 523 auto NumArg = CI->arg_size(); 524 if (NumArg != 4 && NumArg != 6) 525 return false; 526 ConstantInt *PacketSize = 527 dyn_cast<ConstantInt>(CI->getArgOperand(NumArg - 2)); 528 ConstantInt *PacketAlign = 529 dyn_cast<ConstantInt>(CI->getArgOperand(NumArg - 1)); 530 if (!PacketSize || !PacketAlign) 531 return false; 532 533 unsigned Size = PacketSize->getZExtValue(); 534 Align Alignment = PacketAlign->getAlignValue(); 535 if (Alignment != Size) 536 return false; 537 538 unsigned PtrArgLoc = CI->arg_size() - 3; 539 Value *PtrArg = CI->getArgOperand(PtrArgLoc); 540 Type *PtrTy = PtrArg->getType(); 541 542 SmallVector<llvm::Type *, 6> ArgTys; 543 for (unsigned I = 0; I != PtrArgLoc; ++I) 544 ArgTys.push_back(CI->getArgOperand(I)->getType()); 545 ArgTys.push_back(PtrTy); 546 547 Name = Name + "_" + std::to_string(Size); 548 auto *FTy = FunctionType::get(Callee->getReturnType(), 549 ArrayRef<Type *>(ArgTys), false); 550 AMDGPULibFunc NewLibFunc(Name, FTy); 551 FunctionCallee F = AMDGPULibFunc::getOrInsertFunction(M, NewLibFunc); 552 if (!F) 553 return false; 554 555 auto *BCast = B.CreatePointerCast(PtrArg, PtrTy); 556 SmallVector<Value *, 6> Args; 557 for (unsigned I = 0; I != PtrArgLoc; ++I) 558 Args.push_back(CI->getArgOperand(I)); 559 Args.push_back(BCast); 560 561 auto *NCI = B.CreateCall(F, Args); 562 NCI->setAttributes(CI->getAttributes()); 563 CI->replaceAllUsesWith(NCI); 564 CI->dropAllReferences(); 565 CI->eraseFromParent(); 566 567 return true; 568 } 569 570 static bool isKnownIntegral(const Value *V) { 571 if (isa<UndefValue>(V)) 572 return true; 573 574 if (const ConstantFP *CF = dyn_cast<ConstantFP>(V)) 575 return CF->getValueAPF().isInteger(); 576 577 if (const ConstantDataVector *CDV = dyn_cast<ConstantDataVector>(V)) { 578 for (unsigned i = 0, e = CDV->getNumElements(); i != e; ++i) { 579 Constant *ConstElt = CDV->getElementAsConstant(i); 580 if (isa<UndefValue>(ConstElt)) 581 continue; 582 const ConstantFP *CFP = dyn_cast<ConstantFP>(ConstElt); 583 if (!CFP || !CFP->getValue().isInteger()) 584 return false; 585 } 586 587 return true; 588 } 589 590 return false; 591 } 592 593 // This function returns false if no change; return true otherwise. 594 bool AMDGPULibCalls::fold(CallInst *CI) { 595 Function *Callee = CI->getCalledFunction(); 596 // Ignore indirect calls. 597 if (!Callee || Callee->isIntrinsic() || CI->isNoBuiltin()) 598 return false; 599 600 FuncInfo FInfo; 601 if (!parseFunctionName(Callee->getName(), FInfo)) 602 return false; 603 604 // Further check the number of arguments to see if they match. 605 // TODO: Check calling convention matches too 606 if (!FInfo.isCompatibleSignature(CI->getFunctionType())) 607 return false; 608 609 LLVM_DEBUG(dbgs() << "AMDIC: try folding " << *CI << '\n'); 610 611 if (TDOFold(CI, FInfo)) 612 return true; 613 614 IRBuilder<> B(CI); 615 616 if (FPMathOperator *FPOp = dyn_cast<FPMathOperator>(CI)) { 617 // Under unsafe-math, evaluate calls if possible. 618 // According to Brian Sumner, we can do this for all f32 function calls 619 // using host's double function calls. 620 if (canIncreasePrecisionOfConstantFold(FPOp) && evaluateCall(CI, FInfo)) 621 return true; 622 623 // Copy fast flags from the original call. 624 FastMathFlags FMF = FPOp->getFastMathFlags(); 625 B.setFastMathFlags(FMF); 626 627 // Specialized optimizations for each function call. 628 // 629 // TODO: Handle other simple intrinsic wrappers. Sqrt. 630 // 631 // TODO: Handle native functions 632 switch (FInfo.getId()) { 633 case AMDGPULibFunc::EI_EXP: 634 if (FMF.none()) 635 return false; 636 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::exp, 637 FMF.approxFunc()); 638 case AMDGPULibFunc::EI_EXP2: 639 if (FMF.none()) 640 return false; 641 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::exp2, 642 FMF.approxFunc()); 643 case AMDGPULibFunc::EI_LOG: 644 if (FMF.none()) 645 return false; 646 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::log, 647 FMF.approxFunc()); 648 case AMDGPULibFunc::EI_LOG2: 649 if (FMF.none()) 650 return false; 651 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::log2, 652 FMF.approxFunc()); 653 case AMDGPULibFunc::EI_LOG10: 654 if (FMF.none()) 655 return false; 656 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::log10, 657 FMF.approxFunc()); 658 case AMDGPULibFunc::EI_FMIN: 659 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::minnum, 660 true, true); 661 case AMDGPULibFunc::EI_FMAX: 662 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::maxnum, 663 true, true); 664 case AMDGPULibFunc::EI_FMA: 665 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::fma, true, 666 true); 667 case AMDGPULibFunc::EI_MAD: 668 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::fmuladd, 669 true, true); 670 case AMDGPULibFunc::EI_FABS: 671 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::fabs, true, 672 true, true); 673 case AMDGPULibFunc::EI_COPYSIGN: 674 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::copysign, 675 true, true, true); 676 case AMDGPULibFunc::EI_FLOOR: 677 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::floor, true, 678 true); 679 case AMDGPULibFunc::EI_CEIL: 680 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::ceil, true, 681 true); 682 case AMDGPULibFunc::EI_TRUNC: 683 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::trunc, true, 684 true); 685 case AMDGPULibFunc::EI_RINT: 686 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::rint, true, 687 true); 688 case AMDGPULibFunc::EI_ROUND: 689 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::round, true, 690 true); 691 case AMDGPULibFunc::EI_LDEXP: { 692 if (!shouldReplaceLibcallWithIntrinsic(CI, true, true)) 693 return false; 694 695 Value *Arg1 = CI->getArgOperand(1); 696 if (VectorType *VecTy = dyn_cast<VectorType>(CI->getType()); 697 VecTy && !isa<VectorType>(Arg1->getType())) { 698 Value *SplatArg1 = B.CreateVectorSplat(VecTy->getElementCount(), Arg1); 699 CI->setArgOperand(1, SplatArg1); 700 } 701 702 CI->setCalledFunction(Intrinsic::getDeclaration( 703 CI->getModule(), Intrinsic::ldexp, 704 {CI->getType(), CI->getArgOperand(1)->getType()})); 705 return true; 706 } 707 case AMDGPULibFunc::EI_POW: { 708 Module *M = Callee->getParent(); 709 AMDGPULibFunc PowrInfo(AMDGPULibFunc::EI_POWR, FInfo); 710 FunctionCallee PowrFunc = getFunction(M, PowrInfo); 711 CallInst *Call = cast<CallInst>(FPOp); 712 713 // pow(x, y) -> powr(x, y) for x >= -0.0 714 // TODO: Account for flags on current call 715 if (PowrFunc && 716 cannotBeOrderedLessThanZero(FPOp->getOperand(0), M->getDataLayout(), 717 TLInfo, 0, AC, Call, DT)) { 718 Call->setCalledFunction(PowrFunc); 719 return fold_pow(FPOp, B, PowrInfo) || true; 720 } 721 722 return fold_pow(FPOp, B, FInfo); 723 } 724 case AMDGPULibFunc::EI_POWR: 725 case AMDGPULibFunc::EI_POWN: 726 return fold_pow(FPOp, B, FInfo); 727 case AMDGPULibFunc::EI_ROOTN: 728 return fold_rootn(FPOp, B, FInfo); 729 case AMDGPULibFunc::EI_SQRT: 730 return fold_sqrt(FPOp, B, FInfo); 731 case AMDGPULibFunc::EI_COS: 732 case AMDGPULibFunc::EI_SIN: 733 return fold_sincos(FPOp, B, FInfo); 734 default: 735 break; 736 } 737 } else { 738 // Specialized optimizations for each function call 739 switch (FInfo.getId()) { 740 case AMDGPULibFunc::EI_READ_PIPE_2: 741 case AMDGPULibFunc::EI_READ_PIPE_4: 742 case AMDGPULibFunc::EI_WRITE_PIPE_2: 743 case AMDGPULibFunc::EI_WRITE_PIPE_4: 744 return fold_read_write_pipe(CI, B, FInfo); 745 default: 746 break; 747 } 748 } 749 750 return false; 751 } 752 753 bool AMDGPULibCalls::TDOFold(CallInst *CI, const FuncInfo &FInfo) { 754 // Table-Driven optimization 755 const TableRef tr = getOptTable(FInfo.getId()); 756 if (tr.empty()) 757 return false; 758 759 int const sz = (int)tr.size(); 760 Value *opr0 = CI->getArgOperand(0); 761 762 if (getVecSize(FInfo) > 1) { 763 if (ConstantDataVector *CV = dyn_cast<ConstantDataVector>(opr0)) { 764 SmallVector<double, 0> DVal; 765 for (int eltNo = 0; eltNo < getVecSize(FInfo); ++eltNo) { 766 ConstantFP *eltval = dyn_cast<ConstantFP>( 767 CV->getElementAsConstant((unsigned)eltNo)); 768 assert(eltval && "Non-FP arguments in math function!"); 769 bool found = false; 770 for (int i=0; i < sz; ++i) { 771 if (eltval->isExactlyValue(tr[i].input)) { 772 DVal.push_back(tr[i].result); 773 found = true; 774 break; 775 } 776 } 777 if (!found) { 778 // This vector constants not handled yet. 779 return false; 780 } 781 } 782 LLVMContext &context = CI->getParent()->getParent()->getContext(); 783 Constant *nval; 784 if (getArgType(FInfo) == AMDGPULibFunc::F32) { 785 SmallVector<float, 0> FVal; 786 for (unsigned i = 0; i < DVal.size(); ++i) { 787 FVal.push_back((float)DVal[i]); 788 } 789 ArrayRef<float> tmp(FVal); 790 nval = ConstantDataVector::get(context, tmp); 791 } else { // F64 792 ArrayRef<double> tmp(DVal); 793 nval = ConstantDataVector::get(context, tmp); 794 } 795 LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> " << *nval << "\n"); 796 replaceCall(CI, nval); 797 return true; 798 } 799 } else { 800 // Scalar version 801 if (ConstantFP *CF = dyn_cast<ConstantFP>(opr0)) { 802 for (int i = 0; i < sz; ++i) { 803 if (CF->isExactlyValue(tr[i].input)) { 804 Value *nval = ConstantFP::get(CF->getType(), tr[i].result); 805 LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> " << *nval << "\n"); 806 replaceCall(CI, nval); 807 return true; 808 } 809 } 810 } 811 } 812 813 return false; 814 } 815 816 namespace llvm { 817 static double log2(double V) { 818 #if _XOPEN_SOURCE >= 600 || defined(_ISOC99_SOURCE) || _POSIX_C_SOURCE >= 200112L 819 return ::log2(V); 820 #else 821 return log(V) / numbers::ln2; 822 #endif 823 } 824 } 825 826 bool AMDGPULibCalls::fold_pow(FPMathOperator *FPOp, IRBuilder<> &B, 827 const FuncInfo &FInfo) { 828 assert((FInfo.getId() == AMDGPULibFunc::EI_POW || 829 FInfo.getId() == AMDGPULibFunc::EI_POWR || 830 FInfo.getId() == AMDGPULibFunc::EI_POWN) && 831 "fold_pow: encounter a wrong function call"); 832 833 Module *M = B.GetInsertBlock()->getModule(); 834 Type *eltType = FPOp->getType()->getScalarType(); 835 Value *opr0 = FPOp->getOperand(0); 836 Value *opr1 = FPOp->getOperand(1); 837 838 const APFloat *CF = nullptr; 839 const APInt *CINT = nullptr; 840 if (!match(opr1, m_APFloatAllowUndef(CF))) 841 match(opr1, m_APIntAllowUndef(CINT)); 842 843 // 0x1111111 means that we don't do anything for this call. 844 int ci_opr1 = (CINT ? (int)CINT->getSExtValue() : 0x1111111); 845 846 if ((CF && CF->isZero()) || (CINT && ci_opr1 == 0)) { 847 // pow/powr/pown(x, 0) == 1 848 LLVM_DEBUG(errs() << "AMDIC: " << *FPOp << " ---> 1\n"); 849 Constant *cnval = ConstantFP::get(eltType, 1.0); 850 if (getVecSize(FInfo) > 1) { 851 cnval = ConstantDataVector::getSplat(getVecSize(FInfo), cnval); 852 } 853 replaceCall(FPOp, cnval); 854 return true; 855 } 856 if ((CF && CF->isExactlyValue(1.0)) || (CINT && ci_opr1 == 1)) { 857 // pow/powr/pown(x, 1.0) = x 858 LLVM_DEBUG(errs() << "AMDIC: " << *FPOp << " ---> " << *opr0 << "\n"); 859 replaceCall(FPOp, opr0); 860 return true; 861 } 862 if ((CF && CF->isExactlyValue(2.0)) || (CINT && ci_opr1 == 2)) { 863 // pow/powr/pown(x, 2.0) = x*x 864 LLVM_DEBUG(errs() << "AMDIC: " << *FPOp << " ---> " << *opr0 << " * " 865 << *opr0 << "\n"); 866 Value *nval = B.CreateFMul(opr0, opr0, "__pow2"); 867 replaceCall(FPOp, nval); 868 return true; 869 } 870 if ((CF && CF->isExactlyValue(-1.0)) || (CINT && ci_opr1 == -1)) { 871 // pow/powr/pown(x, -1.0) = 1.0/x 872 LLVM_DEBUG(errs() << "AMDIC: " << *FPOp << " ---> 1 / " << *opr0 << "\n"); 873 Constant *cnval = ConstantFP::get(eltType, 1.0); 874 if (getVecSize(FInfo) > 1) { 875 cnval = ConstantDataVector::getSplat(getVecSize(FInfo), cnval); 876 } 877 Value *nval = B.CreateFDiv(cnval, opr0, "__powrecip"); 878 replaceCall(FPOp, nval); 879 return true; 880 } 881 882 if (CF && (CF->isExactlyValue(0.5) || CF->isExactlyValue(-0.5))) { 883 // pow[r](x, [-]0.5) = sqrt(x) 884 bool issqrt = CF->isExactlyValue(0.5); 885 if (FunctionCallee FPExpr = 886 getFunction(M, AMDGPULibFunc(issqrt ? AMDGPULibFunc::EI_SQRT 887 : AMDGPULibFunc::EI_RSQRT, 888 FInfo))) { 889 LLVM_DEBUG(errs() << "AMDIC: " << *FPOp << " ---> " << FInfo.getName() 890 << '(' << *opr0 << ")\n"); 891 Value *nval = CreateCallEx(B,FPExpr, opr0, issqrt ? "__pow2sqrt" 892 : "__pow2rsqrt"); 893 replaceCall(FPOp, nval); 894 return true; 895 } 896 } 897 898 if (!isUnsafeFiniteOnlyMath(FPOp)) 899 return false; 900 901 // Unsafe Math optimization 902 903 // Remember that ci_opr1 is set if opr1 is integral 904 if (CF) { 905 double dval = (getArgType(FInfo) == AMDGPULibFunc::F32) 906 ? (double)CF->convertToFloat() 907 : CF->convertToDouble(); 908 int ival = (int)dval; 909 if ((double)ival == dval) { 910 ci_opr1 = ival; 911 } else 912 ci_opr1 = 0x11111111; 913 } 914 915 // pow/powr/pown(x, c) = [1/](x*x*..x); where 916 // trunc(c) == c && the number of x == c && |c| <= 12 917 unsigned abs_opr1 = (ci_opr1 < 0) ? -ci_opr1 : ci_opr1; 918 if (abs_opr1 <= 12) { 919 Constant *cnval; 920 Value *nval; 921 if (abs_opr1 == 0) { 922 cnval = ConstantFP::get(eltType, 1.0); 923 if (getVecSize(FInfo) > 1) { 924 cnval = ConstantDataVector::getSplat(getVecSize(FInfo), cnval); 925 } 926 nval = cnval; 927 } else { 928 Value *valx2 = nullptr; 929 nval = nullptr; 930 while (abs_opr1 > 0) { 931 valx2 = valx2 ? B.CreateFMul(valx2, valx2, "__powx2") : opr0; 932 if (abs_opr1 & 1) { 933 nval = nval ? B.CreateFMul(nval, valx2, "__powprod") : valx2; 934 } 935 abs_opr1 >>= 1; 936 } 937 } 938 939 if (ci_opr1 < 0) { 940 cnval = ConstantFP::get(eltType, 1.0); 941 if (getVecSize(FInfo) > 1) { 942 cnval = ConstantDataVector::getSplat(getVecSize(FInfo), cnval); 943 } 944 nval = B.CreateFDiv(cnval, nval, "__1powprod"); 945 } 946 LLVM_DEBUG(errs() << "AMDIC: " << *FPOp << " ---> " 947 << ((ci_opr1 < 0) ? "1/prod(" : "prod(") << *opr0 948 << ")\n"); 949 replaceCall(FPOp, nval); 950 return true; 951 } 952 953 // powr ---> exp2(y * log2(x)) 954 // pown/pow ---> powr(fabs(x), y) | (x & ((int)y << 31)) 955 FunctionCallee ExpExpr = 956 getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_EXP2, FInfo)); 957 if (!ExpExpr) 958 return false; 959 960 bool needlog = false; 961 bool needabs = false; 962 bool needcopysign = false; 963 Constant *cnval = nullptr; 964 if (getVecSize(FInfo) == 1) { 965 CF = nullptr; 966 match(opr0, m_APFloatAllowUndef(CF)); 967 968 if (CF) { 969 double V = (getArgType(FInfo) == AMDGPULibFunc::F32) 970 ? (double)CF->convertToFloat() 971 : CF->convertToDouble(); 972 973 V = log2(std::abs(V)); 974 cnval = ConstantFP::get(eltType, V); 975 needcopysign = (FInfo.getId() != AMDGPULibFunc::EI_POWR) && 976 CF->isNegative(); 977 } else { 978 needlog = true; 979 needcopysign = needabs = FInfo.getId() != AMDGPULibFunc::EI_POWR && 980 (!CF || CF->isNegative()); 981 } 982 } else { 983 ConstantDataVector *CDV = dyn_cast<ConstantDataVector>(opr0); 984 985 if (!CDV) { 986 needlog = true; 987 needcopysign = needabs = FInfo.getId() != AMDGPULibFunc::EI_POWR; 988 } else { 989 assert ((int)CDV->getNumElements() == getVecSize(FInfo) && 990 "Wrong vector size detected"); 991 992 SmallVector<double, 0> DVal; 993 for (int i=0; i < getVecSize(FInfo); ++i) { 994 double V = CDV->getElementAsAPFloat(i).convertToDouble(); 995 if (V < 0.0) needcopysign = true; 996 V = log2(std::abs(V)); 997 DVal.push_back(V); 998 } 999 if (getArgType(FInfo) == AMDGPULibFunc::F32) { 1000 SmallVector<float, 0> FVal; 1001 for (unsigned i=0; i < DVal.size(); ++i) { 1002 FVal.push_back((float)DVal[i]); 1003 } 1004 ArrayRef<float> tmp(FVal); 1005 cnval = ConstantDataVector::get(M->getContext(), tmp); 1006 } else { 1007 ArrayRef<double> tmp(DVal); 1008 cnval = ConstantDataVector::get(M->getContext(), tmp); 1009 } 1010 } 1011 } 1012 1013 if (needcopysign && (FInfo.getId() == AMDGPULibFunc::EI_POW)) { 1014 // We cannot handle corner cases for a general pow() function, give up 1015 // unless y is a constant integral value. Then proceed as if it were pown. 1016 if (!isKnownIntegral(opr1)) 1017 return false; 1018 } 1019 1020 Value *nval; 1021 if (needabs) { 1022 nval = B.CreateUnaryIntrinsic(Intrinsic::fabs, opr0, nullptr, "__fabs"); 1023 } else { 1024 nval = cnval ? cnval : opr0; 1025 } 1026 if (needlog) { 1027 FunctionCallee LogExpr = 1028 getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_LOG2, FInfo)); 1029 if (!LogExpr) 1030 return false; 1031 nval = CreateCallEx(B,LogExpr, nval, "__log2"); 1032 } 1033 1034 if (FInfo.getId() == AMDGPULibFunc::EI_POWN) { 1035 // convert int(32) to fp(f32 or f64) 1036 opr1 = B.CreateSIToFP(opr1, nval->getType(), "pownI2F"); 1037 } 1038 nval = B.CreateFMul(opr1, nval, "__ylogx"); 1039 nval = CreateCallEx(B,ExpExpr, nval, "__exp2"); 1040 1041 if (needcopysign) { 1042 Value *opr_n; 1043 Type* rTy = opr0->getType(); 1044 Type* nTyS = B.getIntNTy(eltType->getPrimitiveSizeInBits()); 1045 Type *nTy = nTyS; 1046 if (const auto *vTy = dyn_cast<FixedVectorType>(rTy)) 1047 nTy = FixedVectorType::get(nTyS, vTy); 1048 unsigned size = nTy->getScalarSizeInBits(); 1049 opr_n = FPOp->getOperand(1); 1050 if (opr_n->getType()->isIntegerTy()) 1051 opr_n = B.CreateZExtOrTrunc(opr_n, nTy, "__ytou"); 1052 else 1053 opr_n = B.CreateFPToSI(opr1, nTy, "__ytou"); 1054 1055 Value *sign = B.CreateShl(opr_n, size-1, "__yeven"); 1056 sign = B.CreateAnd(B.CreateBitCast(opr0, nTy), sign, "__pow_sign"); 1057 nval = B.CreateOr(B.CreateBitCast(nval, nTy), sign); 1058 nval = B.CreateBitCast(nval, opr0->getType()); 1059 } 1060 1061 LLVM_DEBUG(errs() << "AMDIC: " << *FPOp << " ---> " 1062 << "exp2(" << *opr1 << " * log2(" << *opr0 << "))\n"); 1063 replaceCall(FPOp, nval); 1064 1065 return true; 1066 } 1067 1068 bool AMDGPULibCalls::fold_rootn(FPMathOperator *FPOp, IRBuilder<> &B, 1069 const FuncInfo &FInfo) { 1070 // skip vector function 1071 if (getVecSize(FInfo) != 1) 1072 return false; 1073 1074 Value *opr0 = FPOp->getOperand(0); 1075 Value *opr1 = FPOp->getOperand(1); 1076 1077 ConstantInt *CINT = dyn_cast<ConstantInt>(opr1); 1078 if (!CINT) { 1079 return false; 1080 } 1081 int ci_opr1 = (int)CINT->getSExtValue(); 1082 if (ci_opr1 == 1) { // rootn(x, 1) = x 1083 LLVM_DEBUG(errs() << "AMDIC: " << *FPOp << " ---> " << *opr0 << "\n"); 1084 replaceCall(FPOp, opr0); 1085 return true; 1086 } 1087 1088 Module *M = B.GetInsertBlock()->getModule(); 1089 if (ci_opr1 == 2) { // rootn(x, 2) = sqrt(x) 1090 if (FunctionCallee FPExpr = 1091 getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_SQRT, FInfo))) { 1092 LLVM_DEBUG(errs() << "AMDIC: " << *FPOp << " ---> sqrt(" << *opr0 1093 << ")\n"); 1094 Value *nval = CreateCallEx(B,FPExpr, opr0, "__rootn2sqrt"); 1095 replaceCall(FPOp, nval); 1096 return true; 1097 } 1098 } else if (ci_opr1 == 3) { // rootn(x, 3) = cbrt(x) 1099 if (FunctionCallee FPExpr = 1100 getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_CBRT, FInfo))) { 1101 LLVM_DEBUG(errs() << "AMDIC: " << *FPOp << " ---> cbrt(" << *opr0 1102 << ")\n"); 1103 Value *nval = CreateCallEx(B,FPExpr, opr0, "__rootn2cbrt"); 1104 replaceCall(FPOp, nval); 1105 return true; 1106 } 1107 } else if (ci_opr1 == -1) { // rootn(x, -1) = 1.0/x 1108 LLVM_DEBUG(errs() << "AMDIC: " << *FPOp << " ---> 1.0 / " << *opr0 << "\n"); 1109 Value *nval = B.CreateFDiv(ConstantFP::get(opr0->getType(), 1.0), 1110 opr0, 1111 "__rootn2div"); 1112 replaceCall(FPOp, nval); 1113 return true; 1114 } else if (ci_opr1 == -2) { // rootn(x, -2) = rsqrt(x) 1115 if (FunctionCallee FPExpr = 1116 getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_RSQRT, FInfo))) { 1117 LLVM_DEBUG(errs() << "AMDIC: " << *FPOp << " ---> rsqrt(" << *opr0 1118 << ")\n"); 1119 Value *nval = CreateCallEx(B,FPExpr, opr0, "__rootn2rsqrt"); 1120 replaceCall(FPOp, nval); 1121 return true; 1122 } 1123 } 1124 return false; 1125 } 1126 1127 // Get a scalar native builtin single argument FP function 1128 FunctionCallee AMDGPULibCalls::getNativeFunction(Module *M, 1129 const FuncInfo &FInfo) { 1130 if (getArgType(FInfo) == AMDGPULibFunc::F64 || !HasNative(FInfo.getId())) 1131 return nullptr; 1132 FuncInfo nf = FInfo; 1133 nf.setPrefix(AMDGPULibFunc::NATIVE); 1134 return getFunction(M, nf); 1135 } 1136 1137 // Some library calls are just wrappers around llvm intrinsics, but compiled 1138 // conservatively. Preserve the flags from the original call site by 1139 // substituting them with direct calls with all the flags. 1140 bool AMDGPULibCalls::shouldReplaceLibcallWithIntrinsic(const CallInst *CI, 1141 bool AllowMinSizeF32, 1142 bool AllowF64, 1143 bool AllowStrictFP) { 1144 Type *FltTy = CI->getType()->getScalarType(); 1145 const bool IsF32 = FltTy->isFloatTy(); 1146 1147 // f64 intrinsics aren't implemented for most operations. 1148 if (!IsF32 && !FltTy->isHalfTy() && (!AllowF64 || !FltTy->isDoubleTy())) 1149 return false; 1150 1151 // We're implicitly inlining by replacing the libcall with the intrinsic, so 1152 // don't do it for noinline call sites. 1153 if (CI->isNoInline()) 1154 return false; 1155 1156 const Function *ParentF = CI->getFunction(); 1157 // TODO: Handle strictfp 1158 if (!AllowStrictFP && ParentF->hasFnAttribute(Attribute::StrictFP)) 1159 return false; 1160 1161 if (IsF32 && !AllowMinSizeF32 && ParentF->hasMinSize()) 1162 return false; 1163 return true; 1164 } 1165 1166 void AMDGPULibCalls::replaceLibCallWithSimpleIntrinsic(IRBuilder<> &B, 1167 CallInst *CI, 1168 Intrinsic::ID IntrID) { 1169 if (CI->arg_size() == 2) { 1170 Value *Arg0 = CI->getArgOperand(0); 1171 Value *Arg1 = CI->getArgOperand(1); 1172 VectorType *Arg0VecTy = dyn_cast<VectorType>(Arg0->getType()); 1173 VectorType *Arg1VecTy = dyn_cast<VectorType>(Arg1->getType()); 1174 if (Arg0VecTy && !Arg1VecTy) { 1175 Value *SplatRHS = B.CreateVectorSplat(Arg0VecTy->getElementCount(), Arg1); 1176 CI->setArgOperand(1, SplatRHS); 1177 } else if (!Arg0VecTy && Arg1VecTy) { 1178 Value *SplatLHS = B.CreateVectorSplat(Arg1VecTy->getElementCount(), Arg0); 1179 CI->setArgOperand(0, SplatLHS); 1180 } 1181 } 1182 1183 CI->setCalledFunction( 1184 Intrinsic::getDeclaration(CI->getModule(), IntrID, {CI->getType()})); 1185 } 1186 1187 bool AMDGPULibCalls::tryReplaceLibcallWithSimpleIntrinsic( 1188 IRBuilder<> &B, CallInst *CI, Intrinsic::ID IntrID, bool AllowMinSizeF32, 1189 bool AllowF64, bool AllowStrictFP) { 1190 if (!shouldReplaceLibcallWithIntrinsic(CI, AllowMinSizeF32, AllowF64, 1191 AllowStrictFP)) 1192 return false; 1193 replaceLibCallWithSimpleIntrinsic(B, CI, IntrID); 1194 return true; 1195 } 1196 1197 // fold sqrt -> native_sqrt (x) 1198 bool AMDGPULibCalls::fold_sqrt(FPMathOperator *FPOp, IRBuilder<> &B, 1199 const FuncInfo &FInfo) { 1200 if (!isUnsafeMath(FPOp)) 1201 return false; 1202 1203 if (getArgType(FInfo) == AMDGPULibFunc::F32 && (getVecSize(FInfo) == 1) && 1204 (FInfo.getPrefix() != AMDGPULibFunc::NATIVE)) { 1205 Module *M = B.GetInsertBlock()->getModule(); 1206 1207 if (FunctionCallee FPExpr = getNativeFunction( 1208 M, AMDGPULibFunc(AMDGPULibFunc::EI_SQRT, FInfo))) { 1209 Value *opr0 = FPOp->getOperand(0); 1210 LLVM_DEBUG(errs() << "AMDIC: " << *FPOp << " ---> " 1211 << "sqrt(" << *opr0 << ")\n"); 1212 Value *nval = CreateCallEx(B,FPExpr, opr0, "__sqrt"); 1213 replaceCall(FPOp, nval); 1214 return true; 1215 } 1216 } 1217 return false; 1218 } 1219 1220 std::tuple<Value *, Value *, Value *> 1221 AMDGPULibCalls::insertSinCos(Value *Arg, FastMathFlags FMF, IRBuilder<> &B, 1222 FunctionCallee Fsincos) { 1223 DebugLoc DL = B.getCurrentDebugLocation(); 1224 Function *F = B.GetInsertBlock()->getParent(); 1225 B.SetInsertPointPastAllocas(F); 1226 1227 AllocaInst *Alloc = B.CreateAlloca(Arg->getType(), nullptr, "__sincos_"); 1228 1229 if (Instruction *ArgInst = dyn_cast<Instruction>(Arg)) { 1230 // If the argument is an instruction, it must dominate all uses so put our 1231 // sincos call there. Otherwise, right after the allocas works well enough 1232 // if it's an argument or constant. 1233 1234 B.SetInsertPoint(ArgInst->getParent(), ++ArgInst->getIterator()); 1235 1236 // SetInsertPoint unwelcomely always tries to set the debug loc. 1237 B.SetCurrentDebugLocation(DL); 1238 } 1239 1240 Type *CosPtrTy = Fsincos.getFunctionType()->getParamType(1); 1241 1242 // The allocaInst allocates the memory in private address space. This need 1243 // to be addrspacecasted to point to the address space of cos pointer type. 1244 // In OpenCL 2.0 this is generic, while in 1.2 that is private. 1245 Value *CastAlloc = B.CreateAddrSpaceCast(Alloc, CosPtrTy); 1246 1247 CallInst *SinCos = CreateCallEx2(B, Fsincos, Arg, CastAlloc); 1248 1249 // TODO: Is it worth trying to preserve the location for the cos calls for the 1250 // load? 1251 1252 LoadInst *LoadCos = B.CreateLoad(Alloc->getAllocatedType(), Alloc); 1253 return {SinCos, LoadCos, SinCos}; 1254 } 1255 1256 // fold sin, cos -> sincos. 1257 bool AMDGPULibCalls::fold_sincos(FPMathOperator *FPOp, IRBuilder<> &B, 1258 const FuncInfo &fInfo) { 1259 assert(fInfo.getId() == AMDGPULibFunc::EI_SIN || 1260 fInfo.getId() == AMDGPULibFunc::EI_COS); 1261 1262 if ((getArgType(fInfo) != AMDGPULibFunc::F32 && 1263 getArgType(fInfo) != AMDGPULibFunc::F64) || 1264 fInfo.getPrefix() != AMDGPULibFunc::NOPFX) 1265 return false; 1266 1267 bool const isSin = fInfo.getId() == AMDGPULibFunc::EI_SIN; 1268 1269 Value *CArgVal = FPOp->getOperand(0); 1270 CallInst *CI = cast<CallInst>(FPOp); 1271 1272 Function *F = B.GetInsertBlock()->getParent(); 1273 Module *M = F->getParent(); 1274 1275 // Merge the sin and cos. For OpenCL 2.0, there may only be a generic pointer 1276 // implementation. Prefer the private form if available. 1277 AMDGPULibFunc SinCosLibFuncPrivate(AMDGPULibFunc::EI_SINCOS, fInfo); 1278 SinCosLibFuncPrivate.getLeads()[0].PtrKind = 1279 AMDGPULibFunc::getEPtrKindFromAddrSpace(AMDGPUAS::PRIVATE_ADDRESS); 1280 1281 AMDGPULibFunc SinCosLibFuncGeneric(AMDGPULibFunc::EI_SINCOS, fInfo); 1282 SinCosLibFuncGeneric.getLeads()[0].PtrKind = 1283 AMDGPULibFunc::getEPtrKindFromAddrSpace(AMDGPUAS::FLAT_ADDRESS); 1284 1285 FunctionCallee FSinCosPrivate = getFunction(M, SinCosLibFuncPrivate); 1286 FunctionCallee FSinCosGeneric = getFunction(M, SinCosLibFuncGeneric); 1287 FunctionCallee FSinCos = FSinCosPrivate ? FSinCosPrivate : FSinCosGeneric; 1288 if (!FSinCos) 1289 return false; 1290 1291 SmallVector<CallInst *> SinCalls; 1292 SmallVector<CallInst *> CosCalls; 1293 SmallVector<CallInst *> SinCosCalls; 1294 FuncInfo PartnerInfo(isSin ? AMDGPULibFunc::EI_COS : AMDGPULibFunc::EI_SIN, 1295 fInfo); 1296 const std::string PairName = PartnerInfo.mangle(); 1297 1298 StringRef SinName = isSin ? CI->getCalledFunction()->getName() : PairName; 1299 StringRef CosName = isSin ? PairName : CI->getCalledFunction()->getName(); 1300 const std::string SinCosPrivateName = SinCosLibFuncPrivate.mangle(); 1301 const std::string SinCosGenericName = SinCosLibFuncGeneric.mangle(); 1302 1303 // Intersect the two sets of flags. 1304 FastMathFlags FMF = FPOp->getFastMathFlags(); 1305 MDNode *FPMath = CI->getMetadata(LLVMContext::MD_fpmath); 1306 1307 SmallVector<DILocation *> MergeDbgLocs = {CI->getDebugLoc()}; 1308 1309 for (User* U : CArgVal->users()) { 1310 CallInst *XI = dyn_cast<CallInst>(U); 1311 if (!XI || XI->getFunction() != F || XI->isNoBuiltin()) 1312 continue; 1313 1314 Function *UCallee = XI->getCalledFunction(); 1315 if (!UCallee) 1316 continue; 1317 1318 bool Handled = true; 1319 1320 if (UCallee->getName() == SinName) 1321 SinCalls.push_back(XI); 1322 else if (UCallee->getName() == CosName) 1323 CosCalls.push_back(XI); 1324 else if (UCallee->getName() == SinCosPrivateName || 1325 UCallee->getName() == SinCosGenericName) 1326 SinCosCalls.push_back(XI); 1327 else 1328 Handled = false; 1329 1330 if (Handled) { 1331 MergeDbgLocs.push_back(XI->getDebugLoc()); 1332 auto *OtherOp = cast<FPMathOperator>(XI); 1333 FMF &= OtherOp->getFastMathFlags(); 1334 FPMath = MDNode::getMostGenericFPMath( 1335 FPMath, XI->getMetadata(LLVMContext::MD_fpmath)); 1336 } 1337 } 1338 1339 if (SinCalls.empty() || CosCalls.empty()) 1340 return false; 1341 1342 B.setFastMathFlags(FMF); 1343 B.setDefaultFPMathTag(FPMath); 1344 DILocation *DbgLoc = DILocation::getMergedLocations(MergeDbgLocs); 1345 B.SetCurrentDebugLocation(DbgLoc); 1346 1347 auto [Sin, Cos, SinCos] = insertSinCos(CArgVal, FMF, B, FSinCos); 1348 1349 auto replaceTrigInsts = [](ArrayRef<CallInst *> Calls, Value *Res) { 1350 for (CallInst *C : Calls) 1351 C->replaceAllUsesWith(Res); 1352 1353 // Leave the other dead instructions to avoid clobbering iterators. 1354 }; 1355 1356 replaceTrigInsts(SinCalls, Sin); 1357 replaceTrigInsts(CosCalls, Cos); 1358 replaceTrigInsts(SinCosCalls, SinCos); 1359 1360 // It's safe to delete the original now. 1361 CI->eraseFromParent(); 1362 return true; 1363 } 1364 1365 bool AMDGPULibCalls::evaluateScalarMathFunc(const FuncInfo &FInfo, double &Res0, 1366 double &Res1, Constant *copr0, 1367 Constant *copr1) { 1368 // By default, opr0/opr1/opr3 holds values of float/double type. 1369 // If they are not float/double, each function has to its 1370 // operand separately. 1371 double opr0 = 0.0, opr1 = 0.0; 1372 ConstantFP *fpopr0 = dyn_cast_or_null<ConstantFP>(copr0); 1373 ConstantFP *fpopr1 = dyn_cast_or_null<ConstantFP>(copr1); 1374 if (fpopr0) { 1375 opr0 = (getArgType(FInfo) == AMDGPULibFunc::F64) 1376 ? fpopr0->getValueAPF().convertToDouble() 1377 : (double)fpopr0->getValueAPF().convertToFloat(); 1378 } 1379 1380 if (fpopr1) { 1381 opr1 = (getArgType(FInfo) == AMDGPULibFunc::F64) 1382 ? fpopr1->getValueAPF().convertToDouble() 1383 : (double)fpopr1->getValueAPF().convertToFloat(); 1384 } 1385 1386 switch (FInfo.getId()) { 1387 default : return false; 1388 1389 case AMDGPULibFunc::EI_ACOS: 1390 Res0 = acos(opr0); 1391 return true; 1392 1393 case AMDGPULibFunc::EI_ACOSH: 1394 // acosh(x) == log(x + sqrt(x*x - 1)) 1395 Res0 = log(opr0 + sqrt(opr0*opr0 - 1.0)); 1396 return true; 1397 1398 case AMDGPULibFunc::EI_ACOSPI: 1399 Res0 = acos(opr0) / MATH_PI; 1400 return true; 1401 1402 case AMDGPULibFunc::EI_ASIN: 1403 Res0 = asin(opr0); 1404 return true; 1405 1406 case AMDGPULibFunc::EI_ASINH: 1407 // asinh(x) == log(x + sqrt(x*x + 1)) 1408 Res0 = log(opr0 + sqrt(opr0*opr0 + 1.0)); 1409 return true; 1410 1411 case AMDGPULibFunc::EI_ASINPI: 1412 Res0 = asin(opr0) / MATH_PI; 1413 return true; 1414 1415 case AMDGPULibFunc::EI_ATAN: 1416 Res0 = atan(opr0); 1417 return true; 1418 1419 case AMDGPULibFunc::EI_ATANH: 1420 // atanh(x) == (log(x+1) - log(x-1))/2; 1421 Res0 = (log(opr0 + 1.0) - log(opr0 - 1.0))/2.0; 1422 return true; 1423 1424 case AMDGPULibFunc::EI_ATANPI: 1425 Res0 = atan(opr0) / MATH_PI; 1426 return true; 1427 1428 case AMDGPULibFunc::EI_CBRT: 1429 Res0 = (opr0 < 0.0) ? -pow(-opr0, 1.0/3.0) : pow(opr0, 1.0/3.0); 1430 return true; 1431 1432 case AMDGPULibFunc::EI_COS: 1433 Res0 = cos(opr0); 1434 return true; 1435 1436 case AMDGPULibFunc::EI_COSH: 1437 Res0 = cosh(opr0); 1438 return true; 1439 1440 case AMDGPULibFunc::EI_COSPI: 1441 Res0 = cos(MATH_PI * opr0); 1442 return true; 1443 1444 case AMDGPULibFunc::EI_EXP: 1445 Res0 = exp(opr0); 1446 return true; 1447 1448 case AMDGPULibFunc::EI_EXP2: 1449 Res0 = pow(2.0, opr0); 1450 return true; 1451 1452 case AMDGPULibFunc::EI_EXP10: 1453 Res0 = pow(10.0, opr0); 1454 return true; 1455 1456 case AMDGPULibFunc::EI_LOG: 1457 Res0 = log(opr0); 1458 return true; 1459 1460 case AMDGPULibFunc::EI_LOG2: 1461 Res0 = log(opr0) / log(2.0); 1462 return true; 1463 1464 case AMDGPULibFunc::EI_LOG10: 1465 Res0 = log(opr0) / log(10.0); 1466 return true; 1467 1468 case AMDGPULibFunc::EI_RSQRT: 1469 Res0 = 1.0 / sqrt(opr0); 1470 return true; 1471 1472 case AMDGPULibFunc::EI_SIN: 1473 Res0 = sin(opr0); 1474 return true; 1475 1476 case AMDGPULibFunc::EI_SINH: 1477 Res0 = sinh(opr0); 1478 return true; 1479 1480 case AMDGPULibFunc::EI_SINPI: 1481 Res0 = sin(MATH_PI * opr0); 1482 return true; 1483 1484 case AMDGPULibFunc::EI_TAN: 1485 Res0 = tan(opr0); 1486 return true; 1487 1488 case AMDGPULibFunc::EI_TANH: 1489 Res0 = tanh(opr0); 1490 return true; 1491 1492 case AMDGPULibFunc::EI_TANPI: 1493 Res0 = tan(MATH_PI * opr0); 1494 return true; 1495 1496 // two-arg functions 1497 case AMDGPULibFunc::EI_POW: 1498 case AMDGPULibFunc::EI_POWR: 1499 Res0 = pow(opr0, opr1); 1500 return true; 1501 1502 case AMDGPULibFunc::EI_POWN: { 1503 if (ConstantInt *iopr1 = dyn_cast_or_null<ConstantInt>(copr1)) { 1504 double val = (double)iopr1->getSExtValue(); 1505 Res0 = pow(opr0, val); 1506 return true; 1507 } 1508 return false; 1509 } 1510 1511 case AMDGPULibFunc::EI_ROOTN: { 1512 if (ConstantInt *iopr1 = dyn_cast_or_null<ConstantInt>(copr1)) { 1513 double val = (double)iopr1->getSExtValue(); 1514 Res0 = pow(opr0, 1.0 / val); 1515 return true; 1516 } 1517 return false; 1518 } 1519 1520 // with ptr arg 1521 case AMDGPULibFunc::EI_SINCOS: 1522 Res0 = sin(opr0); 1523 Res1 = cos(opr0); 1524 return true; 1525 } 1526 1527 return false; 1528 } 1529 1530 bool AMDGPULibCalls::evaluateCall(CallInst *aCI, const FuncInfo &FInfo) { 1531 int numArgs = (int)aCI->arg_size(); 1532 if (numArgs > 3) 1533 return false; 1534 1535 Constant *copr0 = nullptr; 1536 Constant *copr1 = nullptr; 1537 if (numArgs > 0) { 1538 if ((copr0 = dyn_cast<Constant>(aCI->getArgOperand(0))) == nullptr) 1539 return false; 1540 } 1541 1542 if (numArgs > 1) { 1543 if ((copr1 = dyn_cast<Constant>(aCI->getArgOperand(1))) == nullptr) { 1544 if (FInfo.getId() != AMDGPULibFunc::EI_SINCOS) 1545 return false; 1546 } 1547 } 1548 1549 // At this point, all arguments to aCI are constants. 1550 1551 // max vector size is 16, and sincos will generate two results. 1552 double DVal0[16], DVal1[16]; 1553 int FuncVecSize = getVecSize(FInfo); 1554 bool hasTwoResults = (FInfo.getId() == AMDGPULibFunc::EI_SINCOS); 1555 if (FuncVecSize == 1) { 1556 if (!evaluateScalarMathFunc(FInfo, DVal0[0], DVal1[0], copr0, copr1)) { 1557 return false; 1558 } 1559 } else { 1560 ConstantDataVector *CDV0 = dyn_cast_or_null<ConstantDataVector>(copr0); 1561 ConstantDataVector *CDV1 = dyn_cast_or_null<ConstantDataVector>(copr1); 1562 for (int i = 0; i < FuncVecSize; ++i) { 1563 Constant *celt0 = CDV0 ? CDV0->getElementAsConstant(i) : nullptr; 1564 Constant *celt1 = CDV1 ? CDV1->getElementAsConstant(i) : nullptr; 1565 if (!evaluateScalarMathFunc(FInfo, DVal0[i], DVal1[i], celt0, celt1)) { 1566 return false; 1567 } 1568 } 1569 } 1570 1571 LLVMContext &context = aCI->getContext(); 1572 Constant *nval0, *nval1; 1573 if (FuncVecSize == 1) { 1574 nval0 = ConstantFP::get(aCI->getType(), DVal0[0]); 1575 if (hasTwoResults) 1576 nval1 = ConstantFP::get(aCI->getType(), DVal1[0]); 1577 } else { 1578 if (getArgType(FInfo) == AMDGPULibFunc::F32) { 1579 SmallVector <float, 0> FVal0, FVal1; 1580 for (int i = 0; i < FuncVecSize; ++i) 1581 FVal0.push_back((float)DVal0[i]); 1582 ArrayRef<float> tmp0(FVal0); 1583 nval0 = ConstantDataVector::get(context, tmp0); 1584 if (hasTwoResults) { 1585 for (int i = 0; i < FuncVecSize; ++i) 1586 FVal1.push_back((float)DVal1[i]); 1587 ArrayRef<float> tmp1(FVal1); 1588 nval1 = ConstantDataVector::get(context, tmp1); 1589 } 1590 } else { 1591 ArrayRef<double> tmp0(DVal0); 1592 nval0 = ConstantDataVector::get(context, tmp0); 1593 if (hasTwoResults) { 1594 ArrayRef<double> tmp1(DVal1); 1595 nval1 = ConstantDataVector::get(context, tmp1); 1596 } 1597 } 1598 } 1599 1600 if (hasTwoResults) { 1601 // sincos 1602 assert(FInfo.getId() == AMDGPULibFunc::EI_SINCOS && 1603 "math function with ptr arg not supported yet"); 1604 new StoreInst(nval1, aCI->getArgOperand(1), aCI); 1605 } 1606 1607 replaceCall(aCI, nval0); 1608 return true; 1609 } 1610 1611 PreservedAnalyses AMDGPUSimplifyLibCallsPass::run(Function &F, 1612 FunctionAnalysisManager &AM) { 1613 AMDGPULibCalls Simplifier; 1614 Simplifier.initNativeFuncs(); 1615 Simplifier.initFunction(F, AM); 1616 1617 bool Changed = false; 1618 1619 LLVM_DEBUG(dbgs() << "AMDIC: process function "; 1620 F.printAsOperand(dbgs(), false, F.getParent()); dbgs() << '\n';); 1621 1622 for (auto &BB : F) { 1623 for (BasicBlock::iterator I = BB.begin(), E = BB.end(); I != E;) { 1624 // Ignore non-calls. 1625 CallInst *CI = dyn_cast<CallInst>(I); 1626 ++I; 1627 1628 if (CI) { 1629 if (Simplifier.fold(CI)) 1630 Changed = true; 1631 } 1632 } 1633 } 1634 return Changed ? PreservedAnalyses::none() : PreservedAnalyses::all(); 1635 } 1636 1637 PreservedAnalyses AMDGPUUseNativeCallsPass::run(Function &F, 1638 FunctionAnalysisManager &AM) { 1639 if (UseNative.empty()) 1640 return PreservedAnalyses::all(); 1641 1642 AMDGPULibCalls Simplifier; 1643 Simplifier.initNativeFuncs(); 1644 Simplifier.initFunction(F, AM); 1645 1646 bool Changed = false; 1647 for (auto &BB : F) { 1648 for (BasicBlock::iterator I = BB.begin(), E = BB.end(); I != E;) { 1649 // Ignore non-calls. 1650 CallInst *CI = dyn_cast<CallInst>(I); 1651 ++I; 1652 if (CI && Simplifier.useNative(CI)) 1653 Changed = true; 1654 } 1655 } 1656 return Changed ? PreservedAnalyses::none() : PreservedAnalyses::all(); 1657 } 1658