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/AliasAnalysis.h" 18 #include "llvm/Analysis/Loads.h" 19 #include "llvm/IR/IRBuilder.h" 20 #include "llvm/IR/IntrinsicInst.h" 21 #include "llvm/IR/IntrinsicsAMDGPU.h" 22 #include "llvm/InitializePasses.h" 23 #include <cmath> 24 25 #define DEBUG_TYPE "amdgpu-simplifylib" 26 27 using namespace llvm; 28 29 static cl::opt<bool> EnablePreLink("amdgpu-prelink", 30 cl::desc("Enable pre-link mode optimizations"), 31 cl::init(false), 32 cl::Hidden); 33 34 static cl::list<std::string> UseNative("amdgpu-use-native", 35 cl::desc("Comma separated list of functions to replace with native, or all"), 36 cl::CommaSeparated, cl::ValueOptional, 37 cl::Hidden); 38 39 #define MATH_PI numbers::pi 40 #define MATH_E numbers::e 41 #define MATH_SQRT2 numbers::sqrt2 42 #define MATH_SQRT1_2 numbers::inv_sqrt2 43 44 namespace llvm { 45 46 class AMDGPULibCalls { 47 private: 48 49 typedef llvm::AMDGPULibFunc FuncInfo; 50 51 bool UnsafeFPMath = false; 52 53 // -fuse-native. 54 bool AllNative = false; 55 56 bool useNativeFunc(const StringRef F) const; 57 58 // Return a pointer (pointer expr) to the function if function definition with 59 // "FuncName" exists. It may create a new function prototype in pre-link mode. 60 FunctionCallee getFunction(Module *M, const FuncInfo &fInfo); 61 62 bool parseFunctionName(const StringRef &FMangledName, FuncInfo &FInfo); 63 64 bool TDOFold(CallInst *CI, const FuncInfo &FInfo); 65 66 /* Specialized optimizations */ 67 68 // pow/powr/pown 69 bool fold_pow(FPMathOperator *FPOp, IRBuilder<> &B, const FuncInfo &FInfo); 70 71 // rootn 72 bool fold_rootn(FPMathOperator *FPOp, IRBuilder<> &B, const FuncInfo &FInfo); 73 74 // -fuse-native for sincos 75 bool sincosUseNative(CallInst *aCI, const FuncInfo &FInfo); 76 77 // evaluate calls if calls' arguments are constants. 78 bool evaluateScalarMathFunc(const FuncInfo &FInfo, double &Res0, double &Res1, 79 Constant *copr0, Constant *copr1); 80 bool evaluateCall(CallInst *aCI, const FuncInfo &FInfo); 81 82 // sqrt 83 bool fold_sqrt(FPMathOperator *FPOp, IRBuilder<> &B, const FuncInfo &FInfo); 84 85 /// Insert a value to sincos function \p Fsincos. Returns (value of sin, value 86 /// of cos, sincos call). 87 std::tuple<Value *, Value *, Value *> insertSinCos(Value *Arg, 88 FastMathFlags FMF, 89 IRBuilder<> &B, 90 FunctionCallee Fsincos); 91 92 // sin/cos 93 bool fold_sincos(FPMathOperator *FPOp, IRBuilder<> &B, const FuncInfo &FInfo); 94 95 // __read_pipe/__write_pipe 96 bool fold_read_write_pipe(CallInst *CI, IRBuilder<> &B, 97 const FuncInfo &FInfo); 98 99 // Get a scalar native builtin single argument FP function 100 FunctionCallee getNativeFunction(Module *M, const FuncInfo &FInfo); 101 102 /// Substitute a call to a known libcall with an intrinsic call. If \p 103 /// AllowMinSize is true, allow the replacement in a minsize function. 104 bool shouldReplaceLibcallWithIntrinsic(const CallInst *CI, 105 bool AllowMinSizeF32 = false, 106 bool AllowF64 = false, 107 bool AllowStrictFP = false); 108 void replaceLibCallWithSimpleIntrinsic(IRBuilder<> &B, CallInst *CI, 109 Intrinsic::ID IntrID); 110 111 bool tryReplaceLibcallWithSimpleIntrinsic(IRBuilder<> &B, CallInst *CI, 112 Intrinsic::ID IntrID, 113 bool AllowMinSizeF32 = false, 114 bool AllowF64 = false, 115 bool AllowStrictFP = false); 116 117 protected: 118 bool isUnsafeMath(const FPMathOperator *FPOp) const; 119 120 bool canIncreasePrecisionOfConstantFold(const FPMathOperator *FPOp) const; 121 122 static void replaceCall(Instruction *I, Value *With) { 123 I->replaceAllUsesWith(With); 124 I->eraseFromParent(); 125 } 126 127 static void replaceCall(FPMathOperator *I, Value *With) { 128 replaceCall(cast<Instruction>(I), With); 129 } 130 131 public: 132 AMDGPULibCalls() {} 133 134 bool fold(CallInst *CI); 135 136 void initFunction(const Function &F); 137 void initNativeFuncs(); 138 139 // Replace a normal math function call with that native version 140 bool useNative(CallInst *CI); 141 }; 142 143 } // end llvm namespace 144 145 template <typename IRB> 146 static CallInst *CreateCallEx(IRB &B, FunctionCallee Callee, Value *Arg, 147 const Twine &Name = "") { 148 CallInst *R = B.CreateCall(Callee, Arg, Name); 149 if (Function *F = dyn_cast<Function>(Callee.getCallee())) 150 R->setCallingConv(F->getCallingConv()); 151 return R; 152 } 153 154 template <typename IRB> 155 static CallInst *CreateCallEx2(IRB &B, FunctionCallee Callee, Value *Arg1, 156 Value *Arg2, const Twine &Name = "") { 157 CallInst *R = B.CreateCall(Callee, {Arg1, Arg2}, Name); 158 if (Function *F = dyn_cast<Function>(Callee.getCallee())) 159 R->setCallingConv(F->getCallingConv()); 160 return R; 161 } 162 163 // Data structures for table-driven optimizations. 164 // FuncTbl works for both f32 and f64 functions with 1 input argument 165 166 struct TableEntry { 167 double result; 168 double input; 169 }; 170 171 /* a list of {result, input} */ 172 static const TableEntry tbl_acos[] = { 173 {MATH_PI / 2.0, 0.0}, 174 {MATH_PI / 2.0, -0.0}, 175 {0.0, 1.0}, 176 {MATH_PI, -1.0} 177 }; 178 static const TableEntry tbl_acosh[] = { 179 {0.0, 1.0} 180 }; 181 static const TableEntry tbl_acospi[] = { 182 {0.5, 0.0}, 183 {0.5, -0.0}, 184 {0.0, 1.0}, 185 {1.0, -1.0} 186 }; 187 static const TableEntry tbl_asin[] = { 188 {0.0, 0.0}, 189 {-0.0, -0.0}, 190 {MATH_PI / 2.0, 1.0}, 191 {-MATH_PI / 2.0, -1.0} 192 }; 193 static const TableEntry tbl_asinh[] = { 194 {0.0, 0.0}, 195 {-0.0, -0.0} 196 }; 197 static const TableEntry tbl_asinpi[] = { 198 {0.0, 0.0}, 199 {-0.0, -0.0}, 200 {0.5, 1.0}, 201 {-0.5, -1.0} 202 }; 203 static const TableEntry tbl_atan[] = { 204 {0.0, 0.0}, 205 {-0.0, -0.0}, 206 {MATH_PI / 4.0, 1.0}, 207 {-MATH_PI / 4.0, -1.0} 208 }; 209 static const TableEntry tbl_atanh[] = { 210 {0.0, 0.0}, 211 {-0.0, -0.0} 212 }; 213 static const TableEntry tbl_atanpi[] = { 214 {0.0, 0.0}, 215 {-0.0, -0.0}, 216 {0.25, 1.0}, 217 {-0.25, -1.0} 218 }; 219 static const TableEntry tbl_cbrt[] = { 220 {0.0, 0.0}, 221 {-0.0, -0.0}, 222 {1.0, 1.0}, 223 {-1.0, -1.0}, 224 }; 225 static const TableEntry tbl_cos[] = { 226 {1.0, 0.0}, 227 {1.0, -0.0} 228 }; 229 static const TableEntry tbl_cosh[] = { 230 {1.0, 0.0}, 231 {1.0, -0.0} 232 }; 233 static const TableEntry tbl_cospi[] = { 234 {1.0, 0.0}, 235 {1.0, -0.0} 236 }; 237 static const TableEntry tbl_erfc[] = { 238 {1.0, 0.0}, 239 {1.0, -0.0} 240 }; 241 static const TableEntry tbl_erf[] = { 242 {0.0, 0.0}, 243 {-0.0, -0.0} 244 }; 245 static const TableEntry tbl_exp[] = { 246 {1.0, 0.0}, 247 {1.0, -0.0}, 248 {MATH_E, 1.0} 249 }; 250 static const TableEntry tbl_exp2[] = { 251 {1.0, 0.0}, 252 {1.0, -0.0}, 253 {2.0, 1.0} 254 }; 255 static const TableEntry tbl_exp10[] = { 256 {1.0, 0.0}, 257 {1.0, -0.0}, 258 {10.0, 1.0} 259 }; 260 static const TableEntry tbl_expm1[] = { 261 {0.0, 0.0}, 262 {-0.0, -0.0} 263 }; 264 static const TableEntry tbl_log[] = { 265 {0.0, 1.0}, 266 {1.0, MATH_E} 267 }; 268 static const TableEntry tbl_log2[] = { 269 {0.0, 1.0}, 270 {1.0, 2.0} 271 }; 272 static const TableEntry tbl_log10[] = { 273 {0.0, 1.0}, 274 {1.0, 10.0} 275 }; 276 static const TableEntry tbl_rsqrt[] = { 277 {1.0, 1.0}, 278 {MATH_SQRT1_2, 2.0} 279 }; 280 static const TableEntry tbl_sin[] = { 281 {0.0, 0.0}, 282 {-0.0, -0.0} 283 }; 284 static const TableEntry tbl_sinh[] = { 285 {0.0, 0.0}, 286 {-0.0, -0.0} 287 }; 288 static const TableEntry tbl_sinpi[] = { 289 {0.0, 0.0}, 290 {-0.0, -0.0} 291 }; 292 static const TableEntry tbl_sqrt[] = { 293 {0.0, 0.0}, 294 {1.0, 1.0}, 295 {MATH_SQRT2, 2.0} 296 }; 297 static const TableEntry tbl_tan[] = { 298 {0.0, 0.0}, 299 {-0.0, -0.0} 300 }; 301 static const TableEntry tbl_tanh[] = { 302 {0.0, 0.0}, 303 {-0.0, -0.0} 304 }; 305 static const TableEntry tbl_tanpi[] = { 306 {0.0, 0.0}, 307 {-0.0, -0.0} 308 }; 309 static const TableEntry tbl_tgamma[] = { 310 {1.0, 1.0}, 311 {1.0, 2.0}, 312 {2.0, 3.0}, 313 {6.0, 4.0} 314 }; 315 316 static bool HasNative(AMDGPULibFunc::EFuncId id) { 317 switch(id) { 318 case AMDGPULibFunc::EI_DIVIDE: 319 case AMDGPULibFunc::EI_COS: 320 case AMDGPULibFunc::EI_EXP: 321 case AMDGPULibFunc::EI_EXP2: 322 case AMDGPULibFunc::EI_EXP10: 323 case AMDGPULibFunc::EI_LOG: 324 case AMDGPULibFunc::EI_LOG2: 325 case AMDGPULibFunc::EI_LOG10: 326 case AMDGPULibFunc::EI_POWR: 327 case AMDGPULibFunc::EI_RECIP: 328 case AMDGPULibFunc::EI_RSQRT: 329 case AMDGPULibFunc::EI_SIN: 330 case AMDGPULibFunc::EI_SINCOS: 331 case AMDGPULibFunc::EI_SQRT: 332 case AMDGPULibFunc::EI_TAN: 333 return true; 334 default:; 335 } 336 return false; 337 } 338 339 using TableRef = ArrayRef<TableEntry>; 340 341 static TableRef getOptTable(AMDGPULibFunc::EFuncId id) { 342 switch(id) { 343 case AMDGPULibFunc::EI_ACOS: return TableRef(tbl_acos); 344 case AMDGPULibFunc::EI_ACOSH: return TableRef(tbl_acosh); 345 case AMDGPULibFunc::EI_ACOSPI: return TableRef(tbl_acospi); 346 case AMDGPULibFunc::EI_ASIN: return TableRef(tbl_asin); 347 case AMDGPULibFunc::EI_ASINH: return TableRef(tbl_asinh); 348 case AMDGPULibFunc::EI_ASINPI: return TableRef(tbl_asinpi); 349 case AMDGPULibFunc::EI_ATAN: return TableRef(tbl_atan); 350 case AMDGPULibFunc::EI_ATANH: return TableRef(tbl_atanh); 351 case AMDGPULibFunc::EI_ATANPI: return TableRef(tbl_atanpi); 352 case AMDGPULibFunc::EI_CBRT: return TableRef(tbl_cbrt); 353 case AMDGPULibFunc::EI_NCOS: 354 case AMDGPULibFunc::EI_COS: return TableRef(tbl_cos); 355 case AMDGPULibFunc::EI_COSH: return TableRef(tbl_cosh); 356 case AMDGPULibFunc::EI_COSPI: return TableRef(tbl_cospi); 357 case AMDGPULibFunc::EI_ERFC: return TableRef(tbl_erfc); 358 case AMDGPULibFunc::EI_ERF: return TableRef(tbl_erf); 359 case AMDGPULibFunc::EI_EXP: return TableRef(tbl_exp); 360 case AMDGPULibFunc::EI_NEXP2: 361 case AMDGPULibFunc::EI_EXP2: return TableRef(tbl_exp2); 362 case AMDGPULibFunc::EI_EXP10: return TableRef(tbl_exp10); 363 case AMDGPULibFunc::EI_EXPM1: return TableRef(tbl_expm1); 364 case AMDGPULibFunc::EI_LOG: return TableRef(tbl_log); 365 case AMDGPULibFunc::EI_NLOG2: 366 case AMDGPULibFunc::EI_LOG2: return TableRef(tbl_log2); 367 case AMDGPULibFunc::EI_LOG10: return TableRef(tbl_log10); 368 case AMDGPULibFunc::EI_NRSQRT: 369 case AMDGPULibFunc::EI_RSQRT: return TableRef(tbl_rsqrt); 370 case AMDGPULibFunc::EI_NSIN: 371 case AMDGPULibFunc::EI_SIN: return TableRef(tbl_sin); 372 case AMDGPULibFunc::EI_SINH: return TableRef(tbl_sinh); 373 case AMDGPULibFunc::EI_SINPI: return TableRef(tbl_sinpi); 374 case AMDGPULibFunc::EI_NSQRT: 375 case AMDGPULibFunc::EI_SQRT: return TableRef(tbl_sqrt); 376 case AMDGPULibFunc::EI_TAN: return TableRef(tbl_tan); 377 case AMDGPULibFunc::EI_TANH: return TableRef(tbl_tanh); 378 case AMDGPULibFunc::EI_TANPI: return TableRef(tbl_tanpi); 379 case AMDGPULibFunc::EI_TGAMMA: return TableRef(tbl_tgamma); 380 default:; 381 } 382 return TableRef(); 383 } 384 385 static inline int getVecSize(const AMDGPULibFunc& FInfo) { 386 return FInfo.getLeads()[0].VectorSize; 387 } 388 389 static inline AMDGPULibFunc::EType getArgType(const AMDGPULibFunc& FInfo) { 390 return (AMDGPULibFunc::EType)FInfo.getLeads()[0].ArgType; 391 } 392 393 FunctionCallee AMDGPULibCalls::getFunction(Module *M, const FuncInfo &fInfo) { 394 // If we are doing PreLinkOpt, the function is external. So it is safe to 395 // use getOrInsertFunction() at this stage. 396 397 return EnablePreLink ? AMDGPULibFunc::getOrInsertFunction(M, fInfo) 398 : AMDGPULibFunc::getFunction(M, fInfo); 399 } 400 401 bool AMDGPULibCalls::parseFunctionName(const StringRef &FMangledName, 402 FuncInfo &FInfo) { 403 return AMDGPULibFunc::parse(FMangledName, FInfo); 404 } 405 406 bool AMDGPULibCalls::isUnsafeMath(const FPMathOperator *FPOp) const { 407 return UnsafeFPMath || FPOp->isFast(); 408 } 409 410 bool AMDGPULibCalls::canIncreasePrecisionOfConstantFold( 411 const FPMathOperator *FPOp) const { 412 // TODO: Refine to approxFunc or contract 413 return isUnsafeMath(FPOp); 414 } 415 416 void AMDGPULibCalls::initFunction(const Function &F) { 417 UnsafeFPMath = F.getFnAttribute("unsafe-fp-math").getValueAsBool(); 418 } 419 420 bool AMDGPULibCalls::useNativeFunc(const StringRef F) const { 421 return AllNative || llvm::is_contained(UseNative, F); 422 } 423 424 void AMDGPULibCalls::initNativeFuncs() { 425 AllNative = useNativeFunc("all") || 426 (UseNative.getNumOccurrences() && UseNative.size() == 1 && 427 UseNative.begin()->empty()); 428 } 429 430 bool AMDGPULibCalls::sincosUseNative(CallInst *aCI, const FuncInfo &FInfo) { 431 bool native_sin = useNativeFunc("sin"); 432 bool native_cos = useNativeFunc("cos"); 433 434 if (native_sin && native_cos) { 435 Module *M = aCI->getModule(); 436 Value *opr0 = aCI->getArgOperand(0); 437 438 AMDGPULibFunc nf; 439 nf.getLeads()[0].ArgType = FInfo.getLeads()[0].ArgType; 440 nf.getLeads()[0].VectorSize = FInfo.getLeads()[0].VectorSize; 441 442 nf.setPrefix(AMDGPULibFunc::NATIVE); 443 nf.setId(AMDGPULibFunc::EI_SIN); 444 FunctionCallee sinExpr = getFunction(M, nf); 445 446 nf.setPrefix(AMDGPULibFunc::NATIVE); 447 nf.setId(AMDGPULibFunc::EI_COS); 448 FunctionCallee cosExpr = getFunction(M, nf); 449 if (sinExpr && cosExpr) { 450 Value *sinval = CallInst::Create(sinExpr, opr0, "splitsin", aCI); 451 Value *cosval = CallInst::Create(cosExpr, opr0, "splitcos", aCI); 452 new StoreInst(cosval, aCI->getArgOperand(1), aCI); 453 454 DEBUG_WITH_TYPE("usenative", dbgs() << "<useNative> replace " << *aCI 455 << " with native version of sin/cos"); 456 457 replaceCall(aCI, sinval); 458 return true; 459 } 460 } 461 return false; 462 } 463 464 bool AMDGPULibCalls::useNative(CallInst *aCI) { 465 Function *Callee = aCI->getCalledFunction(); 466 if (!Callee || aCI->isNoBuiltin()) 467 return false; 468 469 FuncInfo FInfo; 470 if (!parseFunctionName(Callee->getName(), FInfo) || !FInfo.isMangled() || 471 FInfo.getPrefix() != AMDGPULibFunc::NOPFX || 472 getArgType(FInfo) == AMDGPULibFunc::F64 || !HasNative(FInfo.getId()) || 473 !(AllNative || useNativeFunc(FInfo.getName()))) { 474 return false; 475 } 476 477 if (FInfo.getId() == AMDGPULibFunc::EI_SINCOS) 478 return sincosUseNative(aCI, FInfo); 479 480 FInfo.setPrefix(AMDGPULibFunc::NATIVE); 481 FunctionCallee F = getFunction(aCI->getModule(), FInfo); 482 if (!F) 483 return false; 484 485 aCI->setCalledFunction(F); 486 DEBUG_WITH_TYPE("usenative", dbgs() << "<useNative> replace " << *aCI 487 << " with native version"); 488 return true; 489 } 490 491 // Clang emits call of __read_pipe_2 or __read_pipe_4 for OpenCL read_pipe 492 // builtin, with appended type size and alignment arguments, where 2 or 4 493 // indicates the original number of arguments. The library has optimized version 494 // of __read_pipe_2/__read_pipe_4 when the type size and alignment has the same 495 // power of 2 value. This function transforms __read_pipe_2 to __read_pipe_2_N 496 // for such cases where N is the size in bytes of the type (N = 1, 2, 4, 8, ..., 497 // 128). The same for __read_pipe_4, write_pipe_2, and write_pipe_4. 498 bool AMDGPULibCalls::fold_read_write_pipe(CallInst *CI, IRBuilder<> &B, 499 const FuncInfo &FInfo) { 500 auto *Callee = CI->getCalledFunction(); 501 if (!Callee->isDeclaration()) 502 return false; 503 504 assert(Callee->hasName() && "Invalid read_pipe/write_pipe function"); 505 auto *M = Callee->getParent(); 506 std::string Name = std::string(Callee->getName()); 507 auto NumArg = CI->arg_size(); 508 if (NumArg != 4 && NumArg != 6) 509 return false; 510 ConstantInt *PacketSize = 511 dyn_cast<ConstantInt>(CI->getArgOperand(NumArg - 2)); 512 ConstantInt *PacketAlign = 513 dyn_cast<ConstantInt>(CI->getArgOperand(NumArg - 1)); 514 if (!PacketSize || !PacketAlign) 515 return false; 516 517 unsigned Size = PacketSize->getZExtValue(); 518 Align Alignment = PacketAlign->getAlignValue(); 519 if (Alignment != Size) 520 return false; 521 522 unsigned PtrArgLoc = CI->arg_size() - 3; 523 Value *PtrArg = CI->getArgOperand(PtrArgLoc); 524 Type *PtrTy = PtrArg->getType(); 525 526 SmallVector<llvm::Type *, 6> ArgTys; 527 for (unsigned I = 0; I != PtrArgLoc; ++I) 528 ArgTys.push_back(CI->getArgOperand(I)->getType()); 529 ArgTys.push_back(PtrTy); 530 531 Name = Name + "_" + std::to_string(Size); 532 auto *FTy = FunctionType::get(Callee->getReturnType(), 533 ArrayRef<Type *>(ArgTys), false); 534 AMDGPULibFunc NewLibFunc(Name, FTy); 535 FunctionCallee F = AMDGPULibFunc::getOrInsertFunction(M, NewLibFunc); 536 if (!F) 537 return false; 538 539 auto *BCast = B.CreatePointerCast(PtrArg, PtrTy); 540 SmallVector<Value *, 6> Args; 541 for (unsigned I = 0; I != PtrArgLoc; ++I) 542 Args.push_back(CI->getArgOperand(I)); 543 Args.push_back(BCast); 544 545 auto *NCI = B.CreateCall(F, Args); 546 NCI->setAttributes(CI->getAttributes()); 547 CI->replaceAllUsesWith(NCI); 548 CI->dropAllReferences(); 549 CI->eraseFromParent(); 550 551 return true; 552 } 553 554 // This function returns false if no change; return true otherwise. 555 bool AMDGPULibCalls::fold(CallInst *CI) { 556 Function *Callee = CI->getCalledFunction(); 557 // Ignore indirect calls. 558 if (!Callee || Callee->isIntrinsic() || CI->isNoBuiltin()) 559 return false; 560 561 FuncInfo FInfo; 562 if (!parseFunctionName(Callee->getName(), FInfo)) 563 return false; 564 565 // Further check the number of arguments to see if they match. 566 // TODO: Check calling convention matches too 567 if (!FInfo.isCompatibleSignature(CI->getFunctionType())) 568 return false; 569 570 LLVM_DEBUG(dbgs() << "AMDIC: try folding " << *CI << '\n'); 571 572 if (TDOFold(CI, FInfo)) 573 return true; 574 575 IRBuilder<> B(CI); 576 577 if (FPMathOperator *FPOp = dyn_cast<FPMathOperator>(CI)) { 578 // Under unsafe-math, evaluate calls if possible. 579 // According to Brian Sumner, we can do this for all f32 function calls 580 // using host's double function calls. 581 if (canIncreasePrecisionOfConstantFold(FPOp) && evaluateCall(CI, FInfo)) 582 return true; 583 584 // Copy fast flags from the original call. 585 FastMathFlags FMF = FPOp->getFastMathFlags(); 586 B.setFastMathFlags(FMF); 587 588 // Specialized optimizations for each function call. 589 // 590 // TODO: Handle other simple intrinsic wrappers. Sqrt. 591 // 592 // TODO: Handle native functions 593 switch (FInfo.getId()) { 594 case AMDGPULibFunc::EI_EXP: 595 if (FMF.none()) 596 return false; 597 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::exp, 598 FMF.approxFunc()); 599 case AMDGPULibFunc::EI_EXP2: 600 if (FMF.none()) 601 return false; 602 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::exp2, 603 FMF.approxFunc()); 604 case AMDGPULibFunc::EI_LOG: 605 if (FMF.none()) 606 return false; 607 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::log, 608 FMF.approxFunc()); 609 case AMDGPULibFunc::EI_LOG2: 610 if (FMF.none()) 611 return false; 612 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::log2, 613 FMF.approxFunc()); 614 case AMDGPULibFunc::EI_LOG10: 615 if (FMF.none()) 616 return false; 617 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::log10, 618 FMF.approxFunc()); 619 case AMDGPULibFunc::EI_FMIN: 620 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::minnum, 621 true, true); 622 case AMDGPULibFunc::EI_FMAX: 623 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::maxnum, 624 true, true); 625 case AMDGPULibFunc::EI_FMA: 626 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::fma, true, 627 true); 628 case AMDGPULibFunc::EI_MAD: 629 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::fmuladd, 630 true, true); 631 case AMDGPULibFunc::EI_FABS: 632 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::fabs, true, 633 true, true); 634 case AMDGPULibFunc::EI_COPYSIGN: 635 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::copysign, 636 true, true, true); 637 case AMDGPULibFunc::EI_FLOOR: 638 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::floor, true, 639 true); 640 case AMDGPULibFunc::EI_CEIL: 641 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::ceil, true, 642 true); 643 case AMDGPULibFunc::EI_TRUNC: 644 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::trunc, true, 645 true); 646 case AMDGPULibFunc::EI_RINT: 647 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::rint, true, 648 true); 649 case AMDGPULibFunc::EI_ROUND: 650 return tryReplaceLibcallWithSimpleIntrinsic(B, CI, Intrinsic::round, true, 651 true); 652 case AMDGPULibFunc::EI_LDEXP: { 653 if (!shouldReplaceLibcallWithIntrinsic(CI, true, true)) 654 return false; 655 656 Value *Arg1 = CI->getArgOperand(1); 657 if (VectorType *VecTy = dyn_cast<VectorType>(CI->getType()); 658 VecTy && !isa<VectorType>(Arg1->getType())) { 659 Value *SplatArg1 = B.CreateVectorSplat(VecTy->getElementCount(), Arg1); 660 CI->setArgOperand(1, SplatArg1); 661 } 662 663 CI->setCalledFunction(Intrinsic::getDeclaration( 664 CI->getModule(), Intrinsic::ldexp, 665 {CI->getType(), CI->getArgOperand(1)->getType()})); 666 return true; 667 } 668 case AMDGPULibFunc::EI_POW: 669 case AMDGPULibFunc::EI_POWR: 670 case AMDGPULibFunc::EI_POWN: 671 return fold_pow(FPOp, B, FInfo); 672 case AMDGPULibFunc::EI_ROOTN: 673 return fold_rootn(FPOp, B, FInfo); 674 case AMDGPULibFunc::EI_SQRT: 675 return fold_sqrt(FPOp, B, FInfo); 676 case AMDGPULibFunc::EI_COS: 677 case AMDGPULibFunc::EI_SIN: 678 return fold_sincos(FPOp, B, FInfo); 679 default: 680 break; 681 } 682 } else { 683 // Specialized optimizations for each function call 684 switch (FInfo.getId()) { 685 case AMDGPULibFunc::EI_READ_PIPE_2: 686 case AMDGPULibFunc::EI_READ_PIPE_4: 687 case AMDGPULibFunc::EI_WRITE_PIPE_2: 688 case AMDGPULibFunc::EI_WRITE_PIPE_4: 689 return fold_read_write_pipe(CI, B, FInfo); 690 default: 691 break; 692 } 693 } 694 695 return false; 696 } 697 698 bool AMDGPULibCalls::TDOFold(CallInst *CI, const FuncInfo &FInfo) { 699 // Table-Driven optimization 700 const TableRef tr = getOptTable(FInfo.getId()); 701 if (tr.empty()) 702 return false; 703 704 int const sz = (int)tr.size(); 705 Value *opr0 = CI->getArgOperand(0); 706 707 if (getVecSize(FInfo) > 1) { 708 if (ConstantDataVector *CV = dyn_cast<ConstantDataVector>(opr0)) { 709 SmallVector<double, 0> DVal; 710 for (int eltNo = 0; eltNo < getVecSize(FInfo); ++eltNo) { 711 ConstantFP *eltval = dyn_cast<ConstantFP>( 712 CV->getElementAsConstant((unsigned)eltNo)); 713 assert(eltval && "Non-FP arguments in math function!"); 714 bool found = false; 715 for (int i=0; i < sz; ++i) { 716 if (eltval->isExactlyValue(tr[i].input)) { 717 DVal.push_back(tr[i].result); 718 found = true; 719 break; 720 } 721 } 722 if (!found) { 723 // This vector constants not handled yet. 724 return false; 725 } 726 } 727 LLVMContext &context = CI->getParent()->getParent()->getContext(); 728 Constant *nval; 729 if (getArgType(FInfo) == AMDGPULibFunc::F32) { 730 SmallVector<float, 0> FVal; 731 for (unsigned i = 0; i < DVal.size(); ++i) { 732 FVal.push_back((float)DVal[i]); 733 } 734 ArrayRef<float> tmp(FVal); 735 nval = ConstantDataVector::get(context, tmp); 736 } else { // F64 737 ArrayRef<double> tmp(DVal); 738 nval = ConstantDataVector::get(context, tmp); 739 } 740 LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> " << *nval << "\n"); 741 replaceCall(CI, nval); 742 return true; 743 } 744 } else { 745 // Scalar version 746 if (ConstantFP *CF = dyn_cast<ConstantFP>(opr0)) { 747 for (int i = 0; i < sz; ++i) { 748 if (CF->isExactlyValue(tr[i].input)) { 749 Value *nval = ConstantFP::get(CF->getType(), tr[i].result); 750 LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> " << *nval << "\n"); 751 replaceCall(CI, nval); 752 return true; 753 } 754 } 755 } 756 } 757 758 return false; 759 } 760 761 namespace llvm { 762 static double log2(double V) { 763 #if _XOPEN_SOURCE >= 600 || defined(_ISOC99_SOURCE) || _POSIX_C_SOURCE >= 200112L 764 return ::log2(V); 765 #else 766 return log(V) / numbers::ln2; 767 #endif 768 } 769 } 770 771 bool AMDGPULibCalls::fold_pow(FPMathOperator *FPOp, IRBuilder<> &B, 772 const FuncInfo &FInfo) { 773 assert((FInfo.getId() == AMDGPULibFunc::EI_POW || 774 FInfo.getId() == AMDGPULibFunc::EI_POWR || 775 FInfo.getId() == AMDGPULibFunc::EI_POWN) && 776 "fold_pow: encounter a wrong function call"); 777 778 Module *M = B.GetInsertBlock()->getModule(); 779 ConstantFP *CF; 780 ConstantInt *CINT; 781 Type *eltType; 782 Value *opr0 = FPOp->getOperand(0); 783 Value *opr1 = FPOp->getOperand(1); 784 ConstantAggregateZero *CZero = dyn_cast<ConstantAggregateZero>(opr1); 785 786 if (getVecSize(FInfo) == 1) { 787 eltType = opr0->getType(); 788 CF = dyn_cast<ConstantFP>(opr1); 789 CINT = dyn_cast<ConstantInt>(opr1); 790 } else { 791 VectorType *VTy = dyn_cast<VectorType>(opr0->getType()); 792 assert(VTy && "Oprand of vector function should be of vectortype"); 793 eltType = VTy->getElementType(); 794 ConstantDataVector *CDV = dyn_cast<ConstantDataVector>(opr1); 795 796 // Now, only Handle vector const whose elements have the same value. 797 CF = CDV ? dyn_cast_or_null<ConstantFP>(CDV->getSplatValue()) : nullptr; 798 CINT = CDV ? dyn_cast_or_null<ConstantInt>(CDV->getSplatValue()) : nullptr; 799 } 800 801 // No unsafe math , no constant argument, do nothing 802 if (!isUnsafeMath(FPOp) && !CF && !CINT && !CZero) 803 return false; 804 805 // 0x1111111 means that we don't do anything for this call. 806 int ci_opr1 = (CINT ? (int)CINT->getSExtValue() : 0x1111111); 807 808 if ((CF && CF->isZero()) || (CINT && ci_opr1 == 0) || CZero) { 809 // pow/powr/pown(x, 0) == 1 810 LLVM_DEBUG(errs() << "AMDIC: " << *FPOp << " ---> 1\n"); 811 Constant *cnval = ConstantFP::get(eltType, 1.0); 812 if (getVecSize(FInfo) > 1) { 813 cnval = ConstantDataVector::getSplat(getVecSize(FInfo), cnval); 814 } 815 replaceCall(FPOp, cnval); 816 return true; 817 } 818 if ((CF && CF->isExactlyValue(1.0)) || (CINT && ci_opr1 == 1)) { 819 // pow/powr/pown(x, 1.0) = x 820 LLVM_DEBUG(errs() << "AMDIC: " << *FPOp << " ---> " << *opr0 << "\n"); 821 replaceCall(FPOp, opr0); 822 return true; 823 } 824 if ((CF && CF->isExactlyValue(2.0)) || (CINT && ci_opr1 == 2)) { 825 // pow/powr/pown(x, 2.0) = x*x 826 LLVM_DEBUG(errs() << "AMDIC: " << *FPOp << " ---> " << *opr0 << " * " 827 << *opr0 << "\n"); 828 Value *nval = B.CreateFMul(opr0, opr0, "__pow2"); 829 replaceCall(FPOp, nval); 830 return true; 831 } 832 if ((CF && CF->isExactlyValue(-1.0)) || (CINT && ci_opr1 == -1)) { 833 // pow/powr/pown(x, -1.0) = 1.0/x 834 LLVM_DEBUG(errs() << "AMDIC: " << *FPOp << " ---> 1 / " << *opr0 << "\n"); 835 Constant *cnval = ConstantFP::get(eltType, 1.0); 836 if (getVecSize(FInfo) > 1) { 837 cnval = ConstantDataVector::getSplat(getVecSize(FInfo), cnval); 838 } 839 Value *nval = B.CreateFDiv(cnval, opr0, "__powrecip"); 840 replaceCall(FPOp, nval); 841 return true; 842 } 843 844 if (CF && (CF->isExactlyValue(0.5) || CF->isExactlyValue(-0.5))) { 845 // pow[r](x, [-]0.5) = sqrt(x) 846 bool issqrt = CF->isExactlyValue(0.5); 847 if (FunctionCallee FPExpr = 848 getFunction(M, AMDGPULibFunc(issqrt ? AMDGPULibFunc::EI_SQRT 849 : AMDGPULibFunc::EI_RSQRT, 850 FInfo))) { 851 LLVM_DEBUG(errs() << "AMDIC: " << *FPOp << " ---> " << FInfo.getName() 852 << '(' << *opr0 << ")\n"); 853 Value *nval = CreateCallEx(B,FPExpr, opr0, issqrt ? "__pow2sqrt" 854 : "__pow2rsqrt"); 855 replaceCall(FPOp, nval); 856 return true; 857 } 858 } 859 860 if (!isUnsafeMath(FPOp)) 861 return false; 862 863 // Unsafe Math optimization 864 865 // Remember that ci_opr1 is set if opr1 is integral 866 if (CF) { 867 double dval = (getArgType(FInfo) == AMDGPULibFunc::F32) 868 ? (double)CF->getValueAPF().convertToFloat() 869 : CF->getValueAPF().convertToDouble(); 870 int ival = (int)dval; 871 if ((double)ival == dval) { 872 ci_opr1 = ival; 873 } else 874 ci_opr1 = 0x11111111; 875 } 876 877 // pow/powr/pown(x, c) = [1/](x*x*..x); where 878 // trunc(c) == c && the number of x == c && |c| <= 12 879 unsigned abs_opr1 = (ci_opr1 < 0) ? -ci_opr1 : ci_opr1; 880 if (abs_opr1 <= 12) { 881 Constant *cnval; 882 Value *nval; 883 if (abs_opr1 == 0) { 884 cnval = ConstantFP::get(eltType, 1.0); 885 if (getVecSize(FInfo) > 1) { 886 cnval = ConstantDataVector::getSplat(getVecSize(FInfo), cnval); 887 } 888 nval = cnval; 889 } else { 890 Value *valx2 = nullptr; 891 nval = nullptr; 892 while (abs_opr1 > 0) { 893 valx2 = valx2 ? B.CreateFMul(valx2, valx2, "__powx2") : opr0; 894 if (abs_opr1 & 1) { 895 nval = nval ? B.CreateFMul(nval, valx2, "__powprod") : valx2; 896 } 897 abs_opr1 >>= 1; 898 } 899 } 900 901 if (ci_opr1 < 0) { 902 cnval = ConstantFP::get(eltType, 1.0); 903 if (getVecSize(FInfo) > 1) { 904 cnval = ConstantDataVector::getSplat(getVecSize(FInfo), cnval); 905 } 906 nval = B.CreateFDiv(cnval, nval, "__1powprod"); 907 } 908 LLVM_DEBUG(errs() << "AMDIC: " << *FPOp << " ---> " 909 << ((ci_opr1 < 0) ? "1/prod(" : "prod(") << *opr0 910 << ")\n"); 911 replaceCall(FPOp, nval); 912 return true; 913 } 914 915 // powr ---> exp2(y * log2(x)) 916 // pown/pow ---> powr(fabs(x), y) | (x & ((int)y << 31)) 917 FunctionCallee ExpExpr = 918 getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_EXP2, FInfo)); 919 if (!ExpExpr) 920 return false; 921 922 bool needlog = false; 923 bool needabs = false; 924 bool needcopysign = false; 925 Constant *cnval = nullptr; 926 if (getVecSize(FInfo) == 1) { 927 CF = dyn_cast<ConstantFP>(opr0); 928 929 if (CF) { 930 double V = (getArgType(FInfo) == AMDGPULibFunc::F32) 931 ? (double)CF->getValueAPF().convertToFloat() 932 : CF->getValueAPF().convertToDouble(); 933 934 V = log2(std::abs(V)); 935 cnval = ConstantFP::get(eltType, V); 936 needcopysign = (FInfo.getId() != AMDGPULibFunc::EI_POWR) && 937 CF->isNegative(); 938 } else { 939 needlog = true; 940 needcopysign = needabs = FInfo.getId() != AMDGPULibFunc::EI_POWR && 941 (!CF || CF->isNegative()); 942 } 943 } else { 944 ConstantDataVector *CDV = dyn_cast<ConstantDataVector>(opr0); 945 946 if (!CDV) { 947 needlog = true; 948 needcopysign = needabs = FInfo.getId() != AMDGPULibFunc::EI_POWR; 949 } else { 950 assert ((int)CDV->getNumElements() == getVecSize(FInfo) && 951 "Wrong vector size detected"); 952 953 SmallVector<double, 0> DVal; 954 for (int i=0; i < getVecSize(FInfo); ++i) { 955 double V = (getArgType(FInfo) == AMDGPULibFunc::F32) 956 ? (double)CDV->getElementAsFloat(i) 957 : CDV->getElementAsDouble(i); 958 if (V < 0.0) needcopysign = true; 959 V = log2(std::abs(V)); 960 DVal.push_back(V); 961 } 962 if (getArgType(FInfo) == AMDGPULibFunc::F32) { 963 SmallVector<float, 0> FVal; 964 for (unsigned i=0; i < DVal.size(); ++i) { 965 FVal.push_back((float)DVal[i]); 966 } 967 ArrayRef<float> tmp(FVal); 968 cnval = ConstantDataVector::get(M->getContext(), tmp); 969 } else { 970 ArrayRef<double> tmp(DVal); 971 cnval = ConstantDataVector::get(M->getContext(), tmp); 972 } 973 } 974 } 975 976 if (needcopysign && (FInfo.getId() == AMDGPULibFunc::EI_POW)) { 977 // We cannot handle corner cases for a general pow() function, give up 978 // unless y is a constant integral value. Then proceed as if it were pown. 979 if (getVecSize(FInfo) == 1) { 980 if (const ConstantFP *CF = dyn_cast<ConstantFP>(opr1)) { 981 double y = (getArgType(FInfo) == AMDGPULibFunc::F32) 982 ? (double)CF->getValueAPF().convertToFloat() 983 : CF->getValueAPF().convertToDouble(); 984 if (y != (double)(int64_t)y) 985 return false; 986 } else 987 return false; 988 } else { 989 if (const ConstantDataVector *CDV = dyn_cast<ConstantDataVector>(opr1)) { 990 for (int i=0; i < getVecSize(FInfo); ++i) { 991 double y = (getArgType(FInfo) == AMDGPULibFunc::F32) 992 ? (double)CDV->getElementAsFloat(i) 993 : CDV->getElementAsDouble(i); 994 if (y != (double)(int64_t)y) 995 return false; 996 } 997 } else 998 return false; 999 } 1000 } 1001 1002 Value *nval; 1003 if (needabs) { 1004 nval = B.CreateUnaryIntrinsic(Intrinsic::fabs, opr0, nullptr, "__fabs"); 1005 } else { 1006 nval = cnval ? cnval : opr0; 1007 } 1008 if (needlog) { 1009 FunctionCallee LogExpr = 1010 getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_LOG2, FInfo)); 1011 if (!LogExpr) 1012 return false; 1013 nval = CreateCallEx(B,LogExpr, nval, "__log2"); 1014 } 1015 1016 if (FInfo.getId() == AMDGPULibFunc::EI_POWN) { 1017 // convert int(32) to fp(f32 or f64) 1018 opr1 = B.CreateSIToFP(opr1, nval->getType(), "pownI2F"); 1019 } 1020 nval = B.CreateFMul(opr1, nval, "__ylogx"); 1021 nval = CreateCallEx(B,ExpExpr, nval, "__exp2"); 1022 1023 if (needcopysign) { 1024 Value *opr_n; 1025 Type* rTy = opr0->getType(); 1026 Type* nTyS = eltType->isDoubleTy() ? B.getInt64Ty() : B.getInt32Ty(); 1027 Type *nTy = nTyS; 1028 if (const auto *vTy = dyn_cast<FixedVectorType>(rTy)) 1029 nTy = FixedVectorType::get(nTyS, vTy); 1030 unsigned size = nTy->getScalarSizeInBits(); 1031 opr_n = FPOp->getOperand(1); 1032 if (opr_n->getType()->isIntegerTy()) 1033 opr_n = B.CreateZExtOrBitCast(opr_n, nTy, "__ytou"); 1034 else 1035 opr_n = B.CreateFPToSI(opr1, nTy, "__ytou"); 1036 1037 Value *sign = B.CreateShl(opr_n, size-1, "__yeven"); 1038 sign = B.CreateAnd(B.CreateBitCast(opr0, nTy), sign, "__pow_sign"); 1039 nval = B.CreateOr(B.CreateBitCast(nval, nTy), sign); 1040 nval = B.CreateBitCast(nval, opr0->getType()); 1041 } 1042 1043 LLVM_DEBUG(errs() << "AMDIC: " << *FPOp << " ---> " 1044 << "exp2(" << *opr1 << " * log2(" << *opr0 << "))\n"); 1045 replaceCall(FPOp, nval); 1046 1047 return true; 1048 } 1049 1050 bool AMDGPULibCalls::fold_rootn(FPMathOperator *FPOp, IRBuilder<> &B, 1051 const FuncInfo &FInfo) { 1052 // skip vector function 1053 if (getVecSize(FInfo) != 1) 1054 return false; 1055 1056 Value *opr0 = FPOp->getOperand(0); 1057 Value *opr1 = FPOp->getOperand(1); 1058 1059 ConstantInt *CINT = dyn_cast<ConstantInt>(opr1); 1060 if (!CINT) { 1061 return false; 1062 } 1063 int ci_opr1 = (int)CINT->getSExtValue(); 1064 if (ci_opr1 == 1) { // rootn(x, 1) = x 1065 LLVM_DEBUG(errs() << "AMDIC: " << *FPOp << " ---> " << *opr0 << "\n"); 1066 replaceCall(FPOp, opr0); 1067 return true; 1068 } 1069 1070 Module *M = B.GetInsertBlock()->getModule(); 1071 if (ci_opr1 == 2) { // rootn(x, 2) = sqrt(x) 1072 if (FunctionCallee FPExpr = 1073 getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_SQRT, FInfo))) { 1074 LLVM_DEBUG(errs() << "AMDIC: " << *FPOp << " ---> sqrt(" << *opr0 1075 << ")\n"); 1076 Value *nval = CreateCallEx(B,FPExpr, opr0, "__rootn2sqrt"); 1077 replaceCall(FPOp, nval); 1078 return true; 1079 } 1080 } else if (ci_opr1 == 3) { // rootn(x, 3) = cbrt(x) 1081 if (FunctionCallee FPExpr = 1082 getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_CBRT, FInfo))) { 1083 LLVM_DEBUG(errs() << "AMDIC: " << *FPOp << " ---> cbrt(" << *opr0 1084 << ")\n"); 1085 Value *nval = CreateCallEx(B,FPExpr, opr0, "__rootn2cbrt"); 1086 replaceCall(FPOp, nval); 1087 return true; 1088 } 1089 } else if (ci_opr1 == -1) { // rootn(x, -1) = 1.0/x 1090 LLVM_DEBUG(errs() << "AMDIC: " << *FPOp << " ---> 1.0 / " << *opr0 << "\n"); 1091 Value *nval = B.CreateFDiv(ConstantFP::get(opr0->getType(), 1.0), 1092 opr0, 1093 "__rootn2div"); 1094 replaceCall(FPOp, nval); 1095 return true; 1096 } else if (ci_opr1 == -2) { // rootn(x, -2) = rsqrt(x) 1097 if (FunctionCallee FPExpr = 1098 getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_RSQRT, FInfo))) { 1099 LLVM_DEBUG(errs() << "AMDIC: " << *FPOp << " ---> rsqrt(" << *opr0 1100 << ")\n"); 1101 Value *nval = CreateCallEx(B,FPExpr, opr0, "__rootn2rsqrt"); 1102 replaceCall(FPOp, nval); 1103 return true; 1104 } 1105 } 1106 return false; 1107 } 1108 1109 // Get a scalar native builtin single argument FP function 1110 FunctionCallee AMDGPULibCalls::getNativeFunction(Module *M, 1111 const FuncInfo &FInfo) { 1112 if (getArgType(FInfo) == AMDGPULibFunc::F64 || !HasNative(FInfo.getId())) 1113 return nullptr; 1114 FuncInfo nf = FInfo; 1115 nf.setPrefix(AMDGPULibFunc::NATIVE); 1116 return getFunction(M, nf); 1117 } 1118 1119 // Some library calls are just wrappers around llvm intrinsics, but compiled 1120 // conservatively. Preserve the flags from the original call site by 1121 // substituting them with direct calls with all the flags. 1122 bool AMDGPULibCalls::shouldReplaceLibcallWithIntrinsic(const CallInst *CI, 1123 bool AllowMinSizeF32, 1124 bool AllowF64, 1125 bool AllowStrictFP) { 1126 Type *FltTy = CI->getType()->getScalarType(); 1127 const bool IsF32 = FltTy->isFloatTy(); 1128 1129 // f64 intrinsics aren't implemented for most operations. 1130 if (!IsF32 && !FltTy->isHalfTy() && (!AllowF64 || !FltTy->isDoubleTy())) 1131 return false; 1132 1133 // We're implicitly inlining by replacing the libcall with the intrinsic, so 1134 // don't do it for noinline call sites. 1135 if (CI->isNoInline()) 1136 return false; 1137 1138 const Function *ParentF = CI->getFunction(); 1139 // TODO: Handle strictfp 1140 if (!AllowStrictFP && ParentF->hasFnAttribute(Attribute::StrictFP)) 1141 return false; 1142 1143 if (IsF32 && !AllowMinSizeF32 && ParentF->hasMinSize()) 1144 return false; 1145 return true; 1146 } 1147 1148 void AMDGPULibCalls::replaceLibCallWithSimpleIntrinsic(IRBuilder<> &B, 1149 CallInst *CI, 1150 Intrinsic::ID IntrID) { 1151 if (CI->arg_size() == 2) { 1152 Value *Arg0 = CI->getArgOperand(0); 1153 Value *Arg1 = CI->getArgOperand(1); 1154 VectorType *Arg0VecTy = dyn_cast<VectorType>(Arg0->getType()); 1155 VectorType *Arg1VecTy = dyn_cast<VectorType>(Arg1->getType()); 1156 if (Arg0VecTy && !Arg1VecTy) { 1157 Value *SplatRHS = B.CreateVectorSplat(Arg0VecTy->getElementCount(), Arg1); 1158 CI->setArgOperand(1, SplatRHS); 1159 } else if (!Arg0VecTy && Arg1VecTy) { 1160 Value *SplatLHS = B.CreateVectorSplat(Arg1VecTy->getElementCount(), Arg0); 1161 CI->setArgOperand(0, SplatLHS); 1162 } 1163 } 1164 1165 CI->setCalledFunction( 1166 Intrinsic::getDeclaration(CI->getModule(), IntrID, {CI->getType()})); 1167 } 1168 1169 bool AMDGPULibCalls::tryReplaceLibcallWithSimpleIntrinsic( 1170 IRBuilder<> &B, CallInst *CI, Intrinsic::ID IntrID, bool AllowMinSizeF32, 1171 bool AllowF64, bool AllowStrictFP) { 1172 if (!shouldReplaceLibcallWithIntrinsic(CI, AllowMinSizeF32, AllowF64, 1173 AllowStrictFP)) 1174 return false; 1175 replaceLibCallWithSimpleIntrinsic(B, CI, IntrID); 1176 return true; 1177 } 1178 1179 // fold sqrt -> native_sqrt (x) 1180 bool AMDGPULibCalls::fold_sqrt(FPMathOperator *FPOp, IRBuilder<> &B, 1181 const FuncInfo &FInfo) { 1182 if (!isUnsafeMath(FPOp)) 1183 return false; 1184 1185 if (getArgType(FInfo) == AMDGPULibFunc::F32 && (getVecSize(FInfo) == 1) && 1186 (FInfo.getPrefix() != AMDGPULibFunc::NATIVE)) { 1187 Module *M = B.GetInsertBlock()->getModule(); 1188 1189 if (FunctionCallee FPExpr = getNativeFunction( 1190 M, AMDGPULibFunc(AMDGPULibFunc::EI_SQRT, FInfo))) { 1191 Value *opr0 = FPOp->getOperand(0); 1192 LLVM_DEBUG(errs() << "AMDIC: " << *FPOp << " ---> " 1193 << "sqrt(" << *opr0 << ")\n"); 1194 Value *nval = CreateCallEx(B,FPExpr, opr0, "__sqrt"); 1195 replaceCall(FPOp, nval); 1196 return true; 1197 } 1198 } 1199 return false; 1200 } 1201 1202 std::tuple<Value *, Value *, Value *> 1203 AMDGPULibCalls::insertSinCos(Value *Arg, FastMathFlags FMF, IRBuilder<> &B, 1204 FunctionCallee Fsincos) { 1205 DebugLoc DL = B.getCurrentDebugLocation(); 1206 Function *F = B.GetInsertBlock()->getParent(); 1207 B.SetInsertPointPastAllocas(F); 1208 1209 AllocaInst *Alloc = B.CreateAlloca(Arg->getType(), nullptr, "__sincos_"); 1210 1211 if (Instruction *ArgInst = dyn_cast<Instruction>(Arg)) { 1212 // If the argument is an instruction, it must dominate all uses so put our 1213 // sincos call there. Otherwise, right after the allocas works well enough 1214 // if it's an argument or constant. 1215 1216 B.SetInsertPoint(ArgInst->getParent(), ++ArgInst->getIterator()); 1217 1218 // SetInsertPoint unwelcomely always tries to set the debug loc. 1219 B.SetCurrentDebugLocation(DL); 1220 } 1221 1222 Type *CosPtrTy = Fsincos.getFunctionType()->getParamType(1); 1223 1224 // The allocaInst allocates the memory in private address space. This need 1225 // to be addrspacecasted to point to the address space of cos pointer type. 1226 // In OpenCL 2.0 this is generic, while in 1.2 that is private. 1227 Value *CastAlloc = B.CreateAddrSpaceCast(Alloc, CosPtrTy); 1228 1229 CallInst *SinCos = CreateCallEx2(B, Fsincos, Arg, CastAlloc); 1230 1231 // TODO: Is it worth trying to preserve the location for the cos calls for the 1232 // load? 1233 1234 LoadInst *LoadCos = B.CreateLoad(Alloc->getAllocatedType(), Alloc); 1235 return {SinCos, LoadCos, SinCos}; 1236 } 1237 1238 // fold sin, cos -> sincos. 1239 bool AMDGPULibCalls::fold_sincos(FPMathOperator *FPOp, IRBuilder<> &B, 1240 const FuncInfo &fInfo) { 1241 assert(fInfo.getId() == AMDGPULibFunc::EI_SIN || 1242 fInfo.getId() == AMDGPULibFunc::EI_COS); 1243 1244 if ((getArgType(fInfo) != AMDGPULibFunc::F32 && 1245 getArgType(fInfo) != AMDGPULibFunc::F64) || 1246 fInfo.getPrefix() != AMDGPULibFunc::NOPFX) 1247 return false; 1248 1249 bool const isSin = fInfo.getId() == AMDGPULibFunc::EI_SIN; 1250 1251 Value *CArgVal = FPOp->getOperand(0); 1252 CallInst *CI = cast<CallInst>(FPOp); 1253 1254 Function *F = B.GetInsertBlock()->getParent(); 1255 Module *M = F->getParent(); 1256 1257 // Merge the sin and cos. For OpenCL 2.0, there may only be a generic pointer 1258 // implementation. Prefer the private form if available. 1259 AMDGPULibFunc SinCosLibFuncPrivate(AMDGPULibFunc::EI_SINCOS, fInfo); 1260 SinCosLibFuncPrivate.getLeads()[0].PtrKind = 1261 AMDGPULibFunc::getEPtrKindFromAddrSpace(AMDGPUAS::PRIVATE_ADDRESS); 1262 1263 AMDGPULibFunc SinCosLibFuncGeneric(AMDGPULibFunc::EI_SINCOS, fInfo); 1264 SinCosLibFuncGeneric.getLeads()[0].PtrKind = 1265 AMDGPULibFunc::getEPtrKindFromAddrSpace(AMDGPUAS::FLAT_ADDRESS); 1266 1267 FunctionCallee FSinCosPrivate = getFunction(M, SinCosLibFuncPrivate); 1268 FunctionCallee FSinCosGeneric = getFunction(M, SinCosLibFuncGeneric); 1269 FunctionCallee FSinCos = FSinCosPrivate ? FSinCosPrivate : FSinCosGeneric; 1270 if (!FSinCos) 1271 return false; 1272 1273 SmallVector<CallInst *> SinCalls; 1274 SmallVector<CallInst *> CosCalls; 1275 SmallVector<CallInst *> SinCosCalls; 1276 FuncInfo PartnerInfo(isSin ? AMDGPULibFunc::EI_COS : AMDGPULibFunc::EI_SIN, 1277 fInfo); 1278 const std::string PairName = PartnerInfo.mangle(); 1279 1280 StringRef SinName = isSin ? CI->getCalledFunction()->getName() : PairName; 1281 StringRef CosName = isSin ? PairName : CI->getCalledFunction()->getName(); 1282 const std::string SinCosPrivateName = SinCosLibFuncPrivate.mangle(); 1283 const std::string SinCosGenericName = SinCosLibFuncGeneric.mangle(); 1284 1285 // Intersect the two sets of flags. 1286 FastMathFlags FMF = FPOp->getFastMathFlags(); 1287 MDNode *FPMath = CI->getMetadata(LLVMContext::MD_fpmath); 1288 1289 SmallVector<DILocation *> MergeDbgLocs = {CI->getDebugLoc()}; 1290 1291 for (User* U : CArgVal->users()) { 1292 CallInst *XI = dyn_cast<CallInst>(U); 1293 if (!XI || XI->getFunction() != F || XI->isNoBuiltin()) 1294 continue; 1295 1296 Function *UCallee = XI->getCalledFunction(); 1297 if (!UCallee) 1298 continue; 1299 1300 bool Handled = true; 1301 1302 if (UCallee->getName() == SinName) 1303 SinCalls.push_back(XI); 1304 else if (UCallee->getName() == CosName) 1305 CosCalls.push_back(XI); 1306 else if (UCallee->getName() == SinCosPrivateName || 1307 UCallee->getName() == SinCosGenericName) 1308 SinCosCalls.push_back(XI); 1309 else 1310 Handled = false; 1311 1312 if (Handled) { 1313 MergeDbgLocs.push_back(XI->getDebugLoc()); 1314 auto *OtherOp = cast<FPMathOperator>(XI); 1315 FMF &= OtherOp->getFastMathFlags(); 1316 FPMath = MDNode::getMostGenericFPMath( 1317 FPMath, XI->getMetadata(LLVMContext::MD_fpmath)); 1318 } 1319 } 1320 1321 if (SinCalls.empty() || CosCalls.empty()) 1322 return false; 1323 1324 B.setFastMathFlags(FMF); 1325 B.setDefaultFPMathTag(FPMath); 1326 DILocation *DbgLoc = DILocation::getMergedLocations(MergeDbgLocs); 1327 B.SetCurrentDebugLocation(DbgLoc); 1328 1329 auto [Sin, Cos, SinCos] = insertSinCos(CArgVal, FMF, B, FSinCos); 1330 1331 auto replaceTrigInsts = [](ArrayRef<CallInst *> Calls, Value *Res) { 1332 for (CallInst *C : Calls) 1333 C->replaceAllUsesWith(Res); 1334 1335 // Leave the other dead instructions to avoid clobbering iterators. 1336 }; 1337 1338 replaceTrigInsts(SinCalls, Sin); 1339 replaceTrigInsts(CosCalls, Cos); 1340 replaceTrigInsts(SinCosCalls, SinCos); 1341 1342 // It's safe to delete the original now. 1343 CI->eraseFromParent(); 1344 return true; 1345 } 1346 1347 bool AMDGPULibCalls::evaluateScalarMathFunc(const FuncInfo &FInfo, double &Res0, 1348 double &Res1, Constant *copr0, 1349 Constant *copr1) { 1350 // By default, opr0/opr1/opr3 holds values of float/double type. 1351 // If they are not float/double, each function has to its 1352 // operand separately. 1353 double opr0 = 0.0, opr1 = 0.0; 1354 ConstantFP *fpopr0 = dyn_cast_or_null<ConstantFP>(copr0); 1355 ConstantFP *fpopr1 = dyn_cast_or_null<ConstantFP>(copr1); 1356 if (fpopr0) { 1357 opr0 = (getArgType(FInfo) == AMDGPULibFunc::F64) 1358 ? fpopr0->getValueAPF().convertToDouble() 1359 : (double)fpopr0->getValueAPF().convertToFloat(); 1360 } 1361 1362 if (fpopr1) { 1363 opr1 = (getArgType(FInfo) == AMDGPULibFunc::F64) 1364 ? fpopr1->getValueAPF().convertToDouble() 1365 : (double)fpopr1->getValueAPF().convertToFloat(); 1366 } 1367 1368 switch (FInfo.getId()) { 1369 default : return false; 1370 1371 case AMDGPULibFunc::EI_ACOS: 1372 Res0 = acos(opr0); 1373 return true; 1374 1375 case AMDGPULibFunc::EI_ACOSH: 1376 // acosh(x) == log(x + sqrt(x*x - 1)) 1377 Res0 = log(opr0 + sqrt(opr0*opr0 - 1.0)); 1378 return true; 1379 1380 case AMDGPULibFunc::EI_ACOSPI: 1381 Res0 = acos(opr0) / MATH_PI; 1382 return true; 1383 1384 case AMDGPULibFunc::EI_ASIN: 1385 Res0 = asin(opr0); 1386 return true; 1387 1388 case AMDGPULibFunc::EI_ASINH: 1389 // asinh(x) == log(x + sqrt(x*x + 1)) 1390 Res0 = log(opr0 + sqrt(opr0*opr0 + 1.0)); 1391 return true; 1392 1393 case AMDGPULibFunc::EI_ASINPI: 1394 Res0 = asin(opr0) / MATH_PI; 1395 return true; 1396 1397 case AMDGPULibFunc::EI_ATAN: 1398 Res0 = atan(opr0); 1399 return true; 1400 1401 case AMDGPULibFunc::EI_ATANH: 1402 // atanh(x) == (log(x+1) - log(x-1))/2; 1403 Res0 = (log(opr0 + 1.0) - log(opr0 - 1.0))/2.0; 1404 return true; 1405 1406 case AMDGPULibFunc::EI_ATANPI: 1407 Res0 = atan(opr0) / MATH_PI; 1408 return true; 1409 1410 case AMDGPULibFunc::EI_CBRT: 1411 Res0 = (opr0 < 0.0) ? -pow(-opr0, 1.0/3.0) : pow(opr0, 1.0/3.0); 1412 return true; 1413 1414 case AMDGPULibFunc::EI_COS: 1415 Res0 = cos(opr0); 1416 return true; 1417 1418 case AMDGPULibFunc::EI_COSH: 1419 Res0 = cosh(opr0); 1420 return true; 1421 1422 case AMDGPULibFunc::EI_COSPI: 1423 Res0 = cos(MATH_PI * opr0); 1424 return true; 1425 1426 case AMDGPULibFunc::EI_EXP: 1427 Res0 = exp(opr0); 1428 return true; 1429 1430 case AMDGPULibFunc::EI_EXP2: 1431 Res0 = pow(2.0, opr0); 1432 return true; 1433 1434 case AMDGPULibFunc::EI_EXP10: 1435 Res0 = pow(10.0, opr0); 1436 return true; 1437 1438 case AMDGPULibFunc::EI_LOG: 1439 Res0 = log(opr0); 1440 return true; 1441 1442 case AMDGPULibFunc::EI_LOG2: 1443 Res0 = log(opr0) / log(2.0); 1444 return true; 1445 1446 case AMDGPULibFunc::EI_LOG10: 1447 Res0 = log(opr0) / log(10.0); 1448 return true; 1449 1450 case AMDGPULibFunc::EI_RSQRT: 1451 Res0 = 1.0 / sqrt(opr0); 1452 return true; 1453 1454 case AMDGPULibFunc::EI_SIN: 1455 Res0 = sin(opr0); 1456 return true; 1457 1458 case AMDGPULibFunc::EI_SINH: 1459 Res0 = sinh(opr0); 1460 return true; 1461 1462 case AMDGPULibFunc::EI_SINPI: 1463 Res0 = sin(MATH_PI * opr0); 1464 return true; 1465 1466 case AMDGPULibFunc::EI_TAN: 1467 Res0 = tan(opr0); 1468 return true; 1469 1470 case AMDGPULibFunc::EI_TANH: 1471 Res0 = tanh(opr0); 1472 return true; 1473 1474 case AMDGPULibFunc::EI_TANPI: 1475 Res0 = tan(MATH_PI * opr0); 1476 return true; 1477 1478 // two-arg functions 1479 case AMDGPULibFunc::EI_POW: 1480 case AMDGPULibFunc::EI_POWR: 1481 Res0 = pow(opr0, opr1); 1482 return true; 1483 1484 case AMDGPULibFunc::EI_POWN: { 1485 if (ConstantInt *iopr1 = dyn_cast_or_null<ConstantInt>(copr1)) { 1486 double val = (double)iopr1->getSExtValue(); 1487 Res0 = pow(opr0, val); 1488 return true; 1489 } 1490 return false; 1491 } 1492 1493 case AMDGPULibFunc::EI_ROOTN: { 1494 if (ConstantInt *iopr1 = dyn_cast_or_null<ConstantInt>(copr1)) { 1495 double val = (double)iopr1->getSExtValue(); 1496 Res0 = pow(opr0, 1.0 / val); 1497 return true; 1498 } 1499 return false; 1500 } 1501 1502 // with ptr arg 1503 case AMDGPULibFunc::EI_SINCOS: 1504 Res0 = sin(opr0); 1505 Res1 = cos(opr0); 1506 return true; 1507 } 1508 1509 return false; 1510 } 1511 1512 bool AMDGPULibCalls::evaluateCall(CallInst *aCI, const FuncInfo &FInfo) { 1513 int numArgs = (int)aCI->arg_size(); 1514 if (numArgs > 3) 1515 return false; 1516 1517 Constant *copr0 = nullptr; 1518 Constant *copr1 = nullptr; 1519 if (numArgs > 0) { 1520 if ((copr0 = dyn_cast<Constant>(aCI->getArgOperand(0))) == nullptr) 1521 return false; 1522 } 1523 1524 if (numArgs > 1) { 1525 if ((copr1 = dyn_cast<Constant>(aCI->getArgOperand(1))) == nullptr) { 1526 if (FInfo.getId() != AMDGPULibFunc::EI_SINCOS) 1527 return false; 1528 } 1529 } 1530 1531 // At this point, all arguments to aCI are constants. 1532 1533 // max vector size is 16, and sincos will generate two results. 1534 double DVal0[16], DVal1[16]; 1535 int FuncVecSize = getVecSize(FInfo); 1536 bool hasTwoResults = (FInfo.getId() == AMDGPULibFunc::EI_SINCOS); 1537 if (FuncVecSize == 1) { 1538 if (!evaluateScalarMathFunc(FInfo, DVal0[0], DVal1[0], copr0, copr1)) { 1539 return false; 1540 } 1541 } else { 1542 ConstantDataVector *CDV0 = dyn_cast_or_null<ConstantDataVector>(copr0); 1543 ConstantDataVector *CDV1 = dyn_cast_or_null<ConstantDataVector>(copr1); 1544 for (int i = 0; i < FuncVecSize; ++i) { 1545 Constant *celt0 = CDV0 ? CDV0->getElementAsConstant(i) : nullptr; 1546 Constant *celt1 = CDV1 ? CDV1->getElementAsConstant(i) : nullptr; 1547 if (!evaluateScalarMathFunc(FInfo, DVal0[i], DVal1[i], celt0, celt1)) { 1548 return false; 1549 } 1550 } 1551 } 1552 1553 LLVMContext &context = aCI->getContext(); 1554 Constant *nval0, *nval1; 1555 if (FuncVecSize == 1) { 1556 nval0 = ConstantFP::get(aCI->getType(), DVal0[0]); 1557 if (hasTwoResults) 1558 nval1 = ConstantFP::get(aCI->getType(), DVal1[0]); 1559 } else { 1560 if (getArgType(FInfo) == AMDGPULibFunc::F32) { 1561 SmallVector <float, 0> FVal0, FVal1; 1562 for (int i = 0; i < FuncVecSize; ++i) 1563 FVal0.push_back((float)DVal0[i]); 1564 ArrayRef<float> tmp0(FVal0); 1565 nval0 = ConstantDataVector::get(context, tmp0); 1566 if (hasTwoResults) { 1567 for (int i = 0; i < FuncVecSize; ++i) 1568 FVal1.push_back((float)DVal1[i]); 1569 ArrayRef<float> tmp1(FVal1); 1570 nval1 = ConstantDataVector::get(context, tmp1); 1571 } 1572 } else { 1573 ArrayRef<double> tmp0(DVal0); 1574 nval0 = ConstantDataVector::get(context, tmp0); 1575 if (hasTwoResults) { 1576 ArrayRef<double> tmp1(DVal1); 1577 nval1 = ConstantDataVector::get(context, tmp1); 1578 } 1579 } 1580 } 1581 1582 if (hasTwoResults) { 1583 // sincos 1584 assert(FInfo.getId() == AMDGPULibFunc::EI_SINCOS && 1585 "math function with ptr arg not supported yet"); 1586 new StoreInst(nval1, aCI->getArgOperand(1), aCI); 1587 } 1588 1589 replaceCall(aCI, nval0); 1590 return true; 1591 } 1592 1593 PreservedAnalyses AMDGPUSimplifyLibCallsPass::run(Function &F, 1594 FunctionAnalysisManager &AM) { 1595 AMDGPULibCalls Simplifier; 1596 Simplifier.initNativeFuncs(); 1597 Simplifier.initFunction(F); 1598 1599 bool Changed = false; 1600 1601 LLVM_DEBUG(dbgs() << "AMDIC: process function "; 1602 F.printAsOperand(dbgs(), false, F.getParent()); dbgs() << '\n';); 1603 1604 for (auto &BB : F) { 1605 for (BasicBlock::iterator I = BB.begin(), E = BB.end(); I != E;) { 1606 // Ignore non-calls. 1607 CallInst *CI = dyn_cast<CallInst>(I); 1608 ++I; 1609 1610 if (CI) { 1611 if (Simplifier.fold(CI)) 1612 Changed = true; 1613 } 1614 } 1615 } 1616 return Changed ? PreservedAnalyses::none() : PreservedAnalyses::all(); 1617 } 1618 1619 PreservedAnalyses AMDGPUUseNativeCallsPass::run(Function &F, 1620 FunctionAnalysisManager &AM) { 1621 if (UseNative.empty()) 1622 return PreservedAnalyses::all(); 1623 1624 AMDGPULibCalls Simplifier; 1625 Simplifier.initNativeFuncs(); 1626 Simplifier.initFunction(F); 1627 1628 bool Changed = false; 1629 for (auto &BB : F) { 1630 for (BasicBlock::iterator I = BB.begin(), E = BB.end(); I != E;) { 1631 // Ignore non-calls. 1632 CallInst *CI = dyn_cast<CallInst>(I); 1633 ++I; 1634 if (CI && Simplifier.useNative(CI)) 1635 Changed = true; 1636 } 1637 } 1638 return Changed ? PreservedAnalyses::none() : PreservedAnalyses::all(); 1639 } 1640