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