ConstantFolding.cpp revision 309f87e34a12e3398932e4c2c9e3c47cad0e8f0f
1651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines//===-- ConstantFolding.cpp - Analyze constant folding possibilities ------===// 26bcf27bb9a4b5c3f79cb44c0e4654a6d7619ad89Stephen Hines// 36bcf27bb9a4b5c3f79cb44c0e4654a6d7619ad89Stephen Hines// The LLVM Compiler Infrastructure 4560ba1472cb6dc574ad726bbe01c8311f6fa9187Bob Wilson// 5560ba1472cb6dc574ad726bbe01c8311f6fa9187Bob Wilson// This file was developed by the LLVM research group and is distributed under 6651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines// the University of Illinois Open Source License. See LICENSE.TXT for details. 7b793f0d3448a15277cd6b6cc4ba558ded39a8084Tim Northover// 8651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines//===----------------------------------------------------------------------===// 9651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines// 10651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines// This family of functions determines the possibility of performing constant 11651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines// folding. 12560ba1472cb6dc574ad726bbe01c8311f6fa9187Bob Wilson// 13560ba1472cb6dc574ad726bbe01c8311f6fa9187Bob Wilson//===----------------------------------------------------------------------===// 14651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines 15651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines#include "llvm/Analysis/ConstantFolding.h" 16560ba1472cb6dc574ad726bbe01c8311f6fa9187Bob Wilson#include "llvm/Constants.h" 17560ba1472cb6dc574ad726bbe01c8311f6fa9187Bob Wilson#include "llvm/DerivedTypes.h" 18560ba1472cb6dc574ad726bbe01c8311f6fa9187Bob Wilson#include "llvm/Function.h" 19560ba1472cb6dc574ad726bbe01c8311f6fa9187Bob Wilson#include "llvm/Instructions.h" 20560ba1472cb6dc574ad726bbe01c8311f6fa9187Bob Wilson#include "llvm/Intrinsics.h" 21560ba1472cb6dc574ad726bbe01c8311f6fa9187Bob Wilson#include "llvm/ADT/SmallVector.h" 22560ba1472cb6dc574ad726bbe01c8311f6fa9187Bob Wilson#include "llvm/Target/TargetData.h" 23b793f0d3448a15277cd6b6cc4ba558ded39a8084Tim Northover#include "llvm/Support/GetElementPtrTypeIterator.h" 24b793f0d3448a15277cd6b6cc4ba558ded39a8084Tim Northover#include "llvm/Support/MathExtras.h" 25651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines#include <cerrno> 26651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines#include <cmath> 27651f13cea278ec967336033dd032faef0e9fc2ecStephen Hinesusing namespace llvm; 28651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines 29651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines//===----------------------------------------------------------------------===// 30560ba1472cb6dc574ad726bbe01c8311f6fa9187Bob Wilson// Constant Folding internal helper functions 31560ba1472cb6dc574ad726bbe01c8311f6fa9187Bob Wilson//===----------------------------------------------------------------------===// 32651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines 33560ba1472cb6dc574ad726bbe01c8311f6fa9187Bob Wilson/// IsConstantOffsetFromGlobal - If this constant is actually a constant offset 34651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines/// from a global, return the global and the constant. Because of 35560ba1472cb6dc574ad726bbe01c8311f6fa9187Bob Wilson/// constantexprs, this function is recursive. 36651f13cea278ec967336033dd032faef0e9fc2ecStephen Hinesstatic bool IsConstantOffsetFromGlobal(Constant *C, GlobalValue *&GV, 37560ba1472cb6dc574ad726bbe01c8311f6fa9187Bob Wilson int64_t &Offset, const TargetData &TD) { 38651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines // Trivial case, constant is the global. 39560ba1472cb6dc574ad726bbe01c8311f6fa9187Bob Wilson if ((GV = dyn_cast<GlobalValue>(C))) { 40651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines Offset = 0; 41560ba1472cb6dc574ad726bbe01c8311f6fa9187Bob Wilson return true; 42651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines } 43560ba1472cb6dc574ad726bbe01c8311f6fa9187Bob Wilson 44651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines // Otherwise, if this isn't a constant expr, bail out. 45560ba1472cb6dc574ad726bbe01c8311f6fa9187Bob Wilson ConstantExpr *CE = dyn_cast<ConstantExpr>(C); 46651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines if (!CE) return false; 47560ba1472cb6dc574ad726bbe01c8311f6fa9187Bob Wilson 48651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines // Look through ptr->int and ptr->ptr casts. 49560ba1472cb6dc574ad726bbe01c8311f6fa9187Bob Wilson if (CE->getOpcode() == Instruction::PtrToInt || 50651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines CE->getOpcode() == Instruction::BitCast) 51560ba1472cb6dc574ad726bbe01c8311f6fa9187Bob Wilson return IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD); 52651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines 53560ba1472cb6dc574ad726bbe01c8311f6fa9187Bob Wilson // i32* getelementptr ([5 x i32]* @a, i32 0, i32 5) 54651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines if (CE->getOpcode() == Instruction::GetElementPtr) { 55b793f0d3448a15277cd6b6cc4ba558ded39a8084Tim Northover // Cannot compute this if the element type of the pointer is missing size 56651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines // info. 57b793f0d3448a15277cd6b6cc4ba558ded39a8084Tim Northover if (!cast<PointerType>(CE->getOperand(0)->getType())->getElementType()->isSized()) 58651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines return false; 59b793f0d3448a15277cd6b6cc4ba558ded39a8084Tim Northover 60651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines // If the base isn't a global+constant, we aren't either. 61b793f0d3448a15277cd6b6cc4ba558ded39a8084Tim Northover if (!IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD)) 62651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines return false; 63560ba1472cb6dc574ad726bbe01c8311f6fa9187Bob Wilson 64651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines // Otherwise, add any offset that our operands provide. 65b793f0d3448a15277cd6b6cc4ba558ded39a8084Tim Northover gep_type_iterator GTI = gep_type_begin(CE); 66651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines for (unsigned i = 1, e = CE->getNumOperands(); i != e; ++i, ++GTI) { 67560ba1472cb6dc574ad726bbe01c8311f6fa9187Bob Wilson ConstantInt *CI = dyn_cast<ConstantInt>(CE->getOperand(i)); 68651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines if (!CI) return false; // Index isn't a simple constant? 69b793f0d3448a15277cd6b6cc4ba558ded39a8084Tim Northover if (CI->getZExtValue() == 0) continue; // Not adding anything. 70651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines 71651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines if (const StructType *ST = dyn_cast<StructType>(*GTI)) { 72651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines // N = N + Offset 73651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines Offset += TD.getStructLayout(ST)->getElementOffset(CI->getZExtValue()); 74651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines } else { 75 const SequentialType *ST = cast<SequentialType>(*GTI); 76 Offset += TD.getTypeSize(ST->getElementType())*CI->getSExtValue(); 77 } 78 } 79 return true; 80 } 81 82 return false; 83} 84 85 86/// SymbolicallyEvaluateBinop - One of Op0/Op1 is a constant expression. 87/// Attempt to symbolically evaluate the result of a binary operator merging 88/// these together. If target data info is available, it is provided as TD, 89/// otherwise TD is null. 90static Constant *SymbolicallyEvaluateBinop(unsigned Opc, Constant *Op0, 91 Constant *Op1, const TargetData *TD){ 92 // SROA 93 94 // Fold (and 0xffffffff00000000, (shl x, 32)) -> shl. 95 // Fold (lshr (or X, Y), 32) -> (lshr [X/Y], 32) if one doesn't contribute 96 // bits. 97 98 99 // If the constant expr is something like &A[123] - &A[4].f, fold this into a 100 // constant. This happens frequently when iterating over a global array. 101 if (Opc == Instruction::Sub && TD) { 102 GlobalValue *GV1, *GV2; 103 int64_t Offs1, Offs2; 104 105 if (IsConstantOffsetFromGlobal(Op0, GV1, Offs1, *TD)) 106 if (IsConstantOffsetFromGlobal(Op1, GV2, Offs2, *TD) && 107 GV1 == GV2) { 108 // (&GV+C1) - (&GV+C2) -> C1-C2, pointer arithmetic cannot overflow. 109 return ConstantInt::get(Op0->getType(), Offs1-Offs2); 110 } 111 } 112 113 // TODO: Fold icmp setne/seteq as well. 114 return 0; 115} 116 117/// SymbolicallyEvaluateGEP - If we can symbolically evaluate the specified GEP 118/// constant expression, do so. 119static Constant *SymbolicallyEvaluateGEP(Constant** Ops, unsigned NumOps, 120 const Type *ResultTy, 121 const TargetData *TD) { 122 Constant *Ptr = Ops[0]; 123 if (!cast<PointerType>(Ptr->getType())->getElementType()->isSized()) 124 return 0; 125 126 if (TD && Ptr->isNullValue()) { 127 // If this is a constant expr gep that is effectively computing an 128 // "offsetof", fold it into 'cast int Size to T*' instead of 'gep 0, 0, 12' 129 bool isFoldableGEP = true; 130 for (unsigned i = 1; i != NumOps; ++i) 131 if (!isa<ConstantInt>(Ops[i])) { 132 isFoldableGEP = false; 133 break; 134 } 135 if (isFoldableGEP) { 136 uint64_t Offset = TD->getIndexedOffset(Ptr->getType(), 137 (Value**)Ops+1, NumOps-1); 138 Constant *C = ConstantInt::get(TD->getIntPtrType(), Offset); 139 return ConstantExpr::getIntToPtr(C, ResultTy); 140 } 141 } 142 143 return 0; 144} 145 146 147//===----------------------------------------------------------------------===// 148// Constant Folding public APIs 149//===----------------------------------------------------------------------===// 150 151 152/// ConstantFoldInstruction - Attempt to constant fold the specified 153/// instruction. If successful, the constant result is returned, if not, null 154/// is returned. Note that this function can only fail when attempting to fold 155/// instructions like loads and stores, which have no constant expression form. 156/// 157Constant *llvm::ConstantFoldInstruction(Instruction *I, const TargetData *TD) { 158 if (PHINode *PN = dyn_cast<PHINode>(I)) { 159 if (PN->getNumIncomingValues() == 0) 160 return Constant::getNullValue(PN->getType()); 161 162 Constant *Result = dyn_cast<Constant>(PN->getIncomingValue(0)); 163 if (Result == 0) return 0; 164 165 // Handle PHI nodes specially here... 166 for (unsigned i = 1, e = PN->getNumIncomingValues(); i != e; ++i) 167 if (PN->getIncomingValue(i) != Result && PN->getIncomingValue(i) != PN) 168 return 0; // Not all the same incoming constants... 169 170 // If we reach here, all incoming values are the same constant. 171 return Result; 172 } 173 174 // Scan the operand list, checking to see if they are all constants, if so, 175 // hand off to ConstantFoldInstOperands. 176 SmallVector<Constant*, 8> Ops; 177 for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) 178 if (Constant *Op = dyn_cast<Constant>(I->getOperand(i))) 179 Ops.push_back(Op); 180 else 181 return 0; // All operands not constant! 182 183 return ConstantFoldInstOperands(I, &Ops[0], Ops.size(), TD); 184} 185 186/// ConstantFoldInstOperands - Attempt to constant fold an instruction with the 187/// specified opcode and operands. If successful, the constant result is 188/// returned, if not, null is returned. Note that this function can fail when 189/// attempting to fold instructions like loads and stores, which have no 190/// constant expression form. 191/// 192Constant *llvm::ConstantFoldInstOperands(const Instruction* I, 193 Constant** Ops, unsigned NumOps, 194 const TargetData *TD) { 195 unsigned Opc = I->getOpcode(); 196 const Type *DestTy = I->getType(); 197 198 // Handle easy binops first. 199 if (isa<BinaryOperator>(I)) { 200 if (isa<ConstantExpr>(Ops[0]) || isa<ConstantExpr>(Ops[1])) 201 if (Constant *C = SymbolicallyEvaluateBinop(I->getOpcode(), Ops[0], 202 Ops[1], TD)) 203 return C; 204 205 return ConstantExpr::get(Opc, Ops[0], Ops[1]); 206 } 207 208 switch (Opc) { 209 default: return 0; 210 case Instruction::Call: 211 if (Function *F = dyn_cast<Function>(Ops[0])) 212 if (canConstantFoldCallTo(F)) 213 return ConstantFoldCall(F, Ops+1, NumOps-1); 214 return 0; 215 case Instruction::ICmp: 216 case Instruction::FCmp: 217 return ConstantExpr::getCompare(cast<CmpInst>(I)->getPredicate(), Ops[0], 218 Ops[1]); 219 case Instruction::Trunc: 220 case Instruction::ZExt: 221 case Instruction::SExt: 222 case Instruction::FPTrunc: 223 case Instruction::FPExt: 224 case Instruction::UIToFP: 225 case Instruction::SIToFP: 226 case Instruction::FPToUI: 227 case Instruction::FPToSI: 228 case Instruction::PtrToInt: 229 case Instruction::IntToPtr: 230 case Instruction::BitCast: 231 return ConstantExpr::getCast(Opc, Ops[0], DestTy); 232 case Instruction::Select: 233 return ConstantExpr::getSelect(Ops[0], Ops[1], Ops[2]); 234 case Instruction::ExtractElement: 235 return ConstantExpr::getExtractElement(Ops[0], Ops[1]); 236 case Instruction::InsertElement: 237 return ConstantExpr::getInsertElement(Ops[0], Ops[1], Ops[2]); 238 case Instruction::ShuffleVector: 239 return ConstantExpr::getShuffleVector(Ops[0], Ops[1], Ops[2]); 240 case Instruction::GetElementPtr: 241 if (Constant *C = SymbolicallyEvaluateGEP(Ops, NumOps, I->getType(), TD)) 242 return C; 243 244 return ConstantExpr::getGetElementPtr(Ops[0], Ops+1, NumOps-1); 245 } 246} 247 248/// ConstantFoldLoadThroughGEPConstantExpr - Given a constant and a 249/// getelementptr constantexpr, return the constant value being addressed by the 250/// constant expression, or null if something is funny and we can't decide. 251Constant *llvm::ConstantFoldLoadThroughGEPConstantExpr(Constant *C, 252 ConstantExpr *CE) { 253 if (CE->getOperand(1) != Constant::getNullValue(CE->getOperand(1)->getType())) 254 return 0; // Do not allow stepping over the value! 255 256 // Loop over all of the operands, tracking down which value we are 257 // addressing... 258 gep_type_iterator I = gep_type_begin(CE), E = gep_type_end(CE); 259 for (++I; I != E; ++I) 260 if (const StructType *STy = dyn_cast<StructType>(*I)) { 261 ConstantInt *CU = cast<ConstantInt>(I.getOperand()); 262 assert(CU->getZExtValue() < STy->getNumElements() && 263 "Struct index out of range!"); 264 unsigned El = (unsigned)CU->getZExtValue(); 265 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) { 266 C = CS->getOperand(El); 267 } else if (isa<ConstantAggregateZero>(C)) { 268 C = Constant::getNullValue(STy->getElementType(El)); 269 } else if (isa<UndefValue>(C)) { 270 C = UndefValue::get(STy->getElementType(El)); 271 } else { 272 return 0; 273 } 274 } else if (ConstantInt *CI = dyn_cast<ConstantInt>(I.getOperand())) { 275 if (const ArrayType *ATy = dyn_cast<ArrayType>(*I)) { 276 if (CI->getZExtValue() >= ATy->getNumElements()) 277 return 0; 278 if (ConstantArray *CA = dyn_cast<ConstantArray>(C)) 279 C = CA->getOperand(CI->getZExtValue()); 280 else if (isa<ConstantAggregateZero>(C)) 281 C = Constant::getNullValue(ATy->getElementType()); 282 else if (isa<UndefValue>(C)) 283 C = UndefValue::get(ATy->getElementType()); 284 else 285 return 0; 286 } else if (const PackedType *PTy = dyn_cast<PackedType>(*I)) { 287 if (CI->getZExtValue() >= PTy->getNumElements()) 288 return 0; 289 if (ConstantPacked *CP = dyn_cast<ConstantPacked>(C)) 290 C = CP->getOperand(CI->getZExtValue()); 291 else if (isa<ConstantAggregateZero>(C)) 292 C = Constant::getNullValue(PTy->getElementType()); 293 else if (isa<UndefValue>(C)) 294 C = UndefValue::get(PTy->getElementType()); 295 else 296 return 0; 297 } else { 298 return 0; 299 } 300 } else { 301 return 0; 302 } 303 return C; 304} 305 306 307//===----------------------------------------------------------------------===// 308// Constant Folding for Calls 309// 310 311/// canConstantFoldCallTo - Return true if its even possible to fold a call to 312/// the specified function. 313bool 314llvm::canConstantFoldCallTo(Function *F) { 315 const std::string &Name = F->getName(); 316 317 switch (F->getIntrinsicID()) { 318 case Intrinsic::sqrt_f32: 319 case Intrinsic::sqrt_f64: 320 case Intrinsic::bswap_i16: 321 case Intrinsic::bswap_i32: 322 case Intrinsic::bswap_i64: 323 case Intrinsic::powi_f32: 324 case Intrinsic::powi_f64: 325 // FIXME: these should be constant folded as well 326 //case Intrinsic::ctpop_i8: 327 //case Intrinsic::ctpop_i16: 328 //case Intrinsic::ctpop_i32: 329 //case Intrinsic::ctpop_i64: 330 //case Intrinsic::ctlz_i8: 331 //case Intrinsic::ctlz_i16: 332 //case Intrinsic::ctlz_i32: 333 //case Intrinsic::ctlz_i64: 334 //case Intrinsic::cttz_i8: 335 //case Intrinsic::cttz_i16: 336 //case Intrinsic::cttz_i32: 337 //case Intrinsic::cttz_i64: 338 return true; 339 default: break; 340 } 341 342 switch (Name[0]) 343 { 344 case 'a': 345 return Name == "acos" || Name == "asin" || Name == "atan" || 346 Name == "atan2"; 347 case 'c': 348 return Name == "ceil" || Name == "cos" || Name == "cosf" || 349 Name == "cosh"; 350 case 'e': 351 return Name == "exp"; 352 case 'f': 353 return Name == "fabs" || Name == "fmod" || Name == "floor"; 354 case 'l': 355 return Name == "log" || Name == "log10"; 356 case 'p': 357 return Name == "pow"; 358 case 's': 359 return Name == "sin" || Name == "sinh" || 360 Name == "sqrt" || Name == "sqrtf"; 361 case 't': 362 return Name == "tan" || Name == "tanh"; 363 default: 364 return false; 365 } 366} 367 368static Constant *ConstantFoldFP(double (*NativeFP)(double), double V, 369 const Type *Ty) { 370 errno = 0; 371 V = NativeFP(V); 372 if (errno == 0) 373 return ConstantFP::get(Ty, V); 374 errno = 0; 375 return 0; 376} 377 378/// ConstantFoldCall - Attempt to constant fold a call to the specified function 379/// with the specified arguments, returning null if unsuccessful. 380Constant * 381llvm::ConstantFoldCall(Function *F, Constant** Operands, unsigned NumOperands) { 382 const std::string &Name = F->getName(); 383 const Type *Ty = F->getReturnType(); 384 385 if (NumOperands == 1) { 386 if (ConstantFP *Op = dyn_cast<ConstantFP>(Operands[0])) { 387 double V = Op->getValue(); 388 switch (Name[0]) 389 { 390 case 'a': 391 if (Name == "acos") 392 return ConstantFoldFP(acos, V, Ty); 393 else if (Name == "asin") 394 return ConstantFoldFP(asin, V, Ty); 395 else if (Name == "atan") 396 return ConstantFP::get(Ty, atan(V)); 397 break; 398 case 'c': 399 if (Name == "ceil") 400 return ConstantFoldFP(ceil, V, Ty); 401 else if (Name == "cos") 402 return ConstantFP::get(Ty, cos(V)); 403 else if (Name == "cosh") 404 return ConstantFP::get(Ty, cosh(V)); 405 break; 406 case 'e': 407 if (Name == "exp") 408 return ConstantFP::get(Ty, exp(V)); 409 break; 410 case 'f': 411 if (Name == "fabs") 412 return ConstantFP::get(Ty, fabs(V)); 413 else if (Name == "floor") 414 return ConstantFoldFP(floor, V, Ty); 415 break; 416 case 'l': 417 if (Name == "log" && V > 0) 418 return ConstantFP::get(Ty, log(V)); 419 else if (Name == "log10" && V > 0) 420 return ConstantFoldFP(log10, V, Ty); 421 else if (Name == "llvm.sqrt.f32" || Name == "llvm.sqrt.f64") { 422 if (V >= -0.0) 423 return ConstantFP::get(Ty, sqrt(V)); 424 else // Undefined 425 return ConstantFP::get(Ty, 0.0); 426 } 427 break; 428 case 's': 429 if (Name == "sin") 430 return ConstantFP::get(Ty, sin(V)); 431 else if (Name == "sinh") 432 return ConstantFP::get(Ty, sinh(V)); 433 else if (Name == "sqrt" && V >= 0) 434 return ConstantFP::get(Ty, sqrt(V)); 435 else if (Name == "sqrtf" && V >= 0) 436 return ConstantFP::get(Ty, sqrt((float)V)); 437 break; 438 case 't': 439 if (Name == "tan") 440 return ConstantFP::get(Ty, tan(V)); 441 else if (Name == "tanh") 442 return ConstantFP::get(Ty, tanh(V)); 443 break; 444 default: 445 break; 446 } 447 } else if (ConstantInt *Op = dyn_cast<ConstantInt>(Operands[0])) { 448 uint64_t V = Op->getZExtValue(); 449 if (Name == "llvm.bswap.i16") 450 return ConstantInt::get(Ty, ByteSwap_16(V)); 451 else if (Name == "llvm.bswap.i32") 452 return ConstantInt::get(Ty, ByteSwap_32(V)); 453 else if (Name == "llvm.bswap.i64") 454 return ConstantInt::get(Ty, ByteSwap_64(V)); 455 } 456 } else if (NumOperands == 2) { 457 if (ConstantFP *Op1 = dyn_cast<ConstantFP>(Operands[0])) { 458 double Op1V = Op1->getValue(); 459 if (ConstantFP *Op2 = dyn_cast<ConstantFP>(Operands[1])) { 460 double Op2V = Op2->getValue(); 461 462 if (Name == "pow") { 463 errno = 0; 464 double V = pow(Op1V, Op2V); 465 if (errno == 0) 466 return ConstantFP::get(Ty, V); 467 } else if (Name == "fmod") { 468 errno = 0; 469 double V = fmod(Op1V, Op2V); 470 if (errno == 0) 471 return ConstantFP::get(Ty, V); 472 } else if (Name == "atan2") { 473 return ConstantFP::get(Ty, atan2(Op1V,Op2V)); 474 } 475 } else if (ConstantInt *Op2C = dyn_cast<ConstantInt>(Operands[1])) { 476 if (Name == "llvm.powi.f32") { 477 return ConstantFP::get(Ty, std::pow((float)Op1V, 478 (int)Op2C->getZExtValue())); 479 } else if (Name == "llvm.powi.f64") { 480 return ConstantFP::get(Ty, std::pow((double)Op1V, 481 (int)Op2C->getZExtValue())); 482 } 483 } 484 } 485 } 486 return 0; 487} 488 489