ConstantFolding.cpp revision 04aa2c3520c049333ca216fb794d700310c4a33d
1bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell//===-- ConstantFolding.cpp - Analyze constant folding possibilities ------===// 2bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell// 3bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell// The LLVM Compiler Infrastructure 4bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell// 54ee451de366474b9c228b4e5fa573795a715216dChris Lattner// This file is distributed under the University of Illinois Open Source 64ee451de366474b9c228b4e5fa573795a715216dChris Lattner// License. See LICENSE.TXT for details. 7bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell// 8bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell//===----------------------------------------------------------------------===// 9bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell// 10bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell// This family of functions determines the possibility of performing constant 11bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell// folding. 12bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell// 13bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell//===----------------------------------------------------------------------===// 14bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 15bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell#include "llvm/Analysis/ConstantFolding.h" 16bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell#include "llvm/Constants.h" 17bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell#include "llvm/DerivedTypes.h" 185520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner#include "llvm/Function.h" 19bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell#include "llvm/Instructions.h" 20bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell#include "llvm/Intrinsics.h" 215520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner#include "llvm/ADT/SmallVector.h" 22c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner#include "llvm/ADT/StringMap.h" 2303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner#include "llvm/Target/TargetData.h" 24bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell#include "llvm/Support/GetElementPtrTypeIterator.h" 25bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell#include "llvm/Support/MathExtras.h" 26bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell#include <cerrno> 2797af751deb9b26fd42fbcee082da9ccc4ded5b45Jeff Cohen#include <cmath> 28bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswellusing namespace llvm; 29bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 3003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner//===----------------------------------------------------------------------===// 3103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner// Constant Folding internal helper functions 3203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner//===----------------------------------------------------------------------===// 3303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 3403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// IsConstantOffsetFromGlobal - If this constant is actually a constant offset 3503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// from a global, return the global and the constant. Because of 3603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// constantexprs, this function is recursive. 3703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattnerstatic bool IsConstantOffsetFromGlobal(Constant *C, GlobalValue *&GV, 3803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner int64_t &Offset, const TargetData &TD) { 3903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Trivial case, constant is the global. 4003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if ((GV = dyn_cast<GlobalValue>(C))) { 4103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner Offset = 0; 4203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return true; 4303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 4403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 4503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Otherwise, if this isn't a constant expr, bail out. 4603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner ConstantExpr *CE = dyn_cast<ConstantExpr>(C); 4703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (!CE) return false; 4803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 4903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Look through ptr->int and ptr->ptr casts. 5003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (CE->getOpcode() == Instruction::PtrToInt || 5103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner CE->getOpcode() == Instruction::BitCast) 5203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD); 5303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 5403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // i32* getelementptr ([5 x i32]* @a, i32 0, i32 5) 5503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (CE->getOpcode() == Instruction::GetElementPtr) { 5603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Cannot compute this if the element type of the pointer is missing size 5703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // info. 58f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (!cast<PointerType>(CE->getOperand(0)->getType()) 59f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner ->getElementType()->isSized()) 6003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return false; 6103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 6203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // If the base isn't a global+constant, we aren't either. 6303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (!IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD)) 6403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return false; 6503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 6603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Otherwise, add any offset that our operands provide. 6703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner gep_type_iterator GTI = gep_type_begin(CE); 68de2d74b213844b17eb5327fba27f21e699d3af66Gabor Greif for (User::const_op_iterator i = CE->op_begin() + 1, e = CE->op_end(); 69785c6af9797fcf551feef70f2ecb5cd075b6e3c4Gabor Greif i != e; ++i, ++GTI) { 70de2d74b213844b17eb5327fba27f21e699d3af66Gabor Greif ConstantInt *CI = dyn_cast<ConstantInt>(*i); 7103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (!CI) return false; // Index isn't a simple constant? 7203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (CI->getZExtValue() == 0) continue; // Not adding anything. 7303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 7403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (const StructType *ST = dyn_cast<StructType>(*GTI)) { 7503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // N = N + Offset 76b1919e2f08ecb37140af676fd2916f8d5ed7df3dChris Lattner Offset += TD.getStructLayout(ST)->getElementOffset(CI->getZExtValue()); 7703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } else { 78ca5183d445954a9b2a570d6bbba1bc2b00ad6442Jeff Cohen const SequentialType *SQT = cast<SequentialType>(*GTI); 79514ab348fddcdffa8367685dc608b2f8d5de986dDuncan Sands Offset += TD.getABITypeSize(SQT->getElementType())*CI->getSExtValue(); 8003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 8103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 8203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return true; 8303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 8403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 8503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return false; 8603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner} 8703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 8803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 8903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// SymbolicallyEvaluateBinop - One of Op0/Op1 is a constant expression. 9003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// Attempt to symbolically evaluate the result of a binary operator merging 9103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// these together. If target data info is available, it is provided as TD, 9203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// otherwise TD is null. 9303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattnerstatic Constant *SymbolicallyEvaluateBinop(unsigned Opc, Constant *Op0, 9403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner Constant *Op1, const TargetData *TD){ 9503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // SROA 9603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 9703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Fold (and 0xffffffff00000000, (shl x, 32)) -> shl. 9803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Fold (lshr (or X, Y), 32) -> (lshr [X/Y], 32) if one doesn't contribute 9903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // bits. 10003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 10103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 10203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // If the constant expr is something like &A[123] - &A[4].f, fold this into a 10303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // constant. This happens frequently when iterating over a global array. 10403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (Opc == Instruction::Sub && TD) { 10503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner GlobalValue *GV1, *GV2; 10603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner int64_t Offs1, Offs2; 10703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 10803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (IsConstantOffsetFromGlobal(Op0, GV1, Offs1, *TD)) 10903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (IsConstantOffsetFromGlobal(Op1, GV2, Offs2, *TD) && 11003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner GV1 == GV2) { 11103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // (&GV+C1) - (&GV+C2) -> C1-C2, pointer arithmetic cannot overflow. 11203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return ConstantInt::get(Op0->getType(), Offs1-Offs2); 11303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 11403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 11503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 11603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // TODO: Fold icmp setne/seteq as well. 11703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return 0; 11803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner} 11903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 12003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// SymbolicallyEvaluateGEP - If we can symbolically evaluate the specified GEP 12103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// constant expression, do so. 122f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattnerstatic Constant *SymbolicallyEvaluateGEP(Constant* const* Ops, unsigned NumOps, 12303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner const Type *ResultTy, 12403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner const TargetData *TD) { 12503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner Constant *Ptr = Ops[0]; 126268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner if (!TD || !cast<PointerType>(Ptr->getType())->getElementType()->isSized()) 12703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return 0; 12803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 129268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner uint64_t BasePtr = 0; 130268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner if (!Ptr->isNullValue()) { 131268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner // If this is a inttoptr from a constant int, we can fold this as the base, 132268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner // otherwise we can't. 133268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr)) 134268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner if (CE->getOpcode() == Instruction::IntToPtr) 135268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner if (ConstantInt *Base = dyn_cast<ConstantInt>(CE->getOperand(0))) 136268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner BasePtr = Base->getZExtValue(); 137268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner 138268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner if (BasePtr == 0) 139268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner return 0; 14003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 141268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner 142268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner // If this is a constant expr gep that is effectively computing an 143268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner // "offsetof", fold it into 'cast int Size to T*' instead of 'gep 0, 0, 12' 144268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner for (unsigned i = 1; i != NumOps; ++i) 145268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner if (!isa<ConstantInt>(Ops[i])) 146268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner return false; 147268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner 148268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner uint64_t Offset = TD->getIndexedOffset(Ptr->getType(), 149268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner (Value**)Ops+1, NumOps-1); 150268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner Constant *C = ConstantInt::get(TD->getIntPtrType(), Offset+BasePtr); 151268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner return ConstantExpr::getIntToPtr(C, ResultTy); 15203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner} 15303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 1541afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner/// FoldBitCast - Constant fold bitcast, symbolically evaluating it with 1551afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner/// targetdata. Return 0 if unfoldable. 1561afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattnerstatic Constant *FoldBitCast(Constant *C, const Type *DestTy, 1571afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner const TargetData &TD) { 1581afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // If this is a bitcast from constant vector -> vector, fold it. 1591afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (ConstantVector *CV = dyn_cast<ConstantVector>(C)) { 1601afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (const VectorType *DestVTy = dyn_cast<VectorType>(DestTy)) { 1611afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // If the element types match, VMCore can fold it. 1621afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner unsigned NumDstElt = DestVTy->getNumElements(); 1631afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner unsigned NumSrcElt = CV->getNumOperands(); 1641afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (NumDstElt == NumSrcElt) 1651afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner return 0; 1661afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 1671afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner const Type *SrcEltTy = CV->getType()->getElementType(); 1681afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner const Type *DstEltTy = DestVTy->getElementType(); 1691afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 1701afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Otherwise, we're changing the number of elements in a vector, which 1711afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // requires endianness information to do the right thing. For example, 1721afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>) 1731afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // folds to (little endian): 1741afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // <4 x i32> <i32 0, i32 0, i32 1, i32 0> 1751afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // and to (big endian): 1761afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // <4 x i32> <i32 0, i32 0, i32 0, i32 1> 1771afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 1781afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // First thing is first. We only want to think about integer here, so if 1791afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // we have something in FP form, recast it as integer. 1801afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (DstEltTy->isFloatingPoint()) { 1811afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Fold to an vector of integers with same size as our FP type. 1821afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner unsigned FPWidth = DstEltTy->getPrimitiveSizeInBits(); 1831afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner const Type *DestIVTy = VectorType::get(IntegerType::get(FPWidth), 1841afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner NumDstElt); 1851afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Recursively handle this integer conversion, if possible. 1861afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner C = FoldBitCast(C, DestIVTy, TD); 1871afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (!C) return 0; 1881afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 1891afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Finally, VMCore can handle this now that #elts line up. 1901afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner return ConstantExpr::getBitCast(C, DestTy); 1911afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner } 1921afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 1931afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Okay, we know the destination is integer, if the input is FP, convert 1941afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // it to integer first. 1951afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (SrcEltTy->isFloatingPoint()) { 1961afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner unsigned FPWidth = SrcEltTy->getPrimitiveSizeInBits(); 1971afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner const Type *SrcIVTy = VectorType::get(IntegerType::get(FPWidth), 1981afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner NumSrcElt); 1991afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Ask VMCore to do the conversion now that #elts line up. 2001afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner C = ConstantExpr::getBitCast(C, SrcIVTy); 2011afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner CV = dyn_cast<ConstantVector>(C); 2021afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (!CV) return 0; // If VMCore wasn't able to fold it, bail out. 2031afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner } 2041afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 2051afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Now we know that the input and output vectors are both integer vectors 2061afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // of the same size, and that their #elements is not the same. Do the 2071afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // conversion here, which depends on whether the input or output has 2081afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // more elements. 2091afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner bool isLittleEndian = TD.isLittleEndian(); 2101afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 2111afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner SmallVector<Constant*, 32> Result; 2121afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (NumDstElt < NumSrcElt) { 2131afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Handle: bitcast (<4 x i32> <i32 0, i32 1, i32 2, i32 3> to <2 x i64>) 2141afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner Constant *Zero = Constant::getNullValue(DstEltTy); 2151afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner unsigned Ratio = NumSrcElt/NumDstElt; 2161afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner unsigned SrcBitSize = SrcEltTy->getPrimitiveSizeInBits(); 2171afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner unsigned SrcElt = 0; 2181afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner for (unsigned i = 0; i != NumDstElt; ++i) { 2191afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Build each element of the result. 2201afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner Constant *Elt = Zero; 2211afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner unsigned ShiftAmt = isLittleEndian ? 0 : SrcBitSize*(Ratio-1); 2221afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner for (unsigned j = 0; j != Ratio; ++j) { 2231afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner Constant *Src = dyn_cast<ConstantInt>(CV->getOperand(SrcElt++)); 2241afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (!Src) return 0; // Reject constantexpr elements. 2251afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 2261afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Zero extend the element to the right size. 2271afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner Src = ConstantExpr::getZExt(Src, Elt->getType()); 2281afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 2291afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Shift it to the right place, depending on endianness. 2301afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner Src = ConstantExpr::getShl(Src, 2311afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner ConstantInt::get(Src->getType(), ShiftAmt)); 2321afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner ShiftAmt += isLittleEndian ? SrcBitSize : -SrcBitSize; 2331afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 2341afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Mix it in. 2351afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner Elt = ConstantExpr::getOr(Elt, Src); 2361afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner } 2371afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner Result.push_back(Elt); 2381afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner } 2391afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner } else { 2401afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Handle: bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>) 2411afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner unsigned Ratio = NumDstElt/NumSrcElt; 2421afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner unsigned DstBitSize = DstEltTy->getPrimitiveSizeInBits(); 2431afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 2441afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Loop over each source value, expanding into multiple results. 2451afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner for (unsigned i = 0; i != NumSrcElt; ++i) { 2461afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner Constant *Src = dyn_cast<ConstantInt>(CV->getOperand(i)); 2471afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (!Src) return 0; // Reject constantexpr elements. 2481afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 2491afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner unsigned ShiftAmt = isLittleEndian ? 0 : DstBitSize*(Ratio-1); 2501afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner for (unsigned j = 0; j != Ratio; ++j) { 2511afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Shift the piece of the value into the right place, depending on 2521afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // endianness. 2531afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner Constant *Elt = ConstantExpr::getLShr(Src, 2541afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner ConstantInt::get(Src->getType(), ShiftAmt)); 2551afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner ShiftAmt += isLittleEndian ? DstBitSize : -DstBitSize; 2561afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 2571afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Truncate and remember this piece. 2581afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner Result.push_back(ConstantExpr::getTrunc(Elt, DstEltTy)); 2591afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner } 2601afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner } 2611afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner } 2621afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 2631afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner return ConstantVector::get(&Result[0], Result.size()); 2641afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner } 2651afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner } 2661afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 2671afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner return 0; 2681afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner} 2691afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 27003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 27103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner//===----------------------------------------------------------------------===// 27203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner// Constant Folding public APIs 27303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner//===----------------------------------------------------------------------===// 27403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 27503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 2765520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// ConstantFoldInstruction - Attempt to constant fold the specified 2775520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// instruction. If successful, the constant result is returned, if not, null 2785520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// is returned. Note that this function can only fail when attempting to fold 2795520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// instructions like loads and stores, which have no constant expression form. 2805520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// 2815520732b24a5a321140dd79af70d321c7ff3dec9Chris LattnerConstant *llvm::ConstantFoldInstruction(Instruction *I, const TargetData *TD) { 2825520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (PHINode *PN = dyn_cast<PHINode>(I)) { 2835520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (PN->getNumIncomingValues() == 0) 2845520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return Constant::getNullValue(PN->getType()); 2855520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 2865520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner Constant *Result = dyn_cast<Constant>(PN->getIncomingValue(0)); 2875520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (Result == 0) return 0; 2885520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 2895520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // Handle PHI nodes specially here... 2905520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner for (unsigned i = 1, e = PN->getNumIncomingValues(); i != e; ++i) 2915520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (PN->getIncomingValue(i) != Result && PN->getIncomingValue(i) != PN) 2925520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; // Not all the same incoming constants... 2935520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 2945520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // If we reach here, all incoming values are the same constant. 2955520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return Result; 2965520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 2975520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 2985520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // Scan the operand list, checking to see if they are all constants, if so, 2995520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // hand off to ConstantFoldInstOperands. 3005520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner SmallVector<Constant*, 8> Ops; 301de2d74b213844b17eb5327fba27f21e699d3af66Gabor Greif for (User::op_iterator i = I->op_begin(), e = I->op_end(); i != e; ++i) 302de2d74b213844b17eb5327fba27f21e699d3af66Gabor Greif if (Constant *Op = dyn_cast<Constant>(*i)) 3035520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner Ops.push_back(Op); 3045520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else 3055520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; // All operands not constant! 3065520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 307f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (const CmpInst *CI = dyn_cast<CmpInst>(I)) 308f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner return ConstantFoldCompareInstOperands(CI->getPredicate(), 309f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner &Ops[0], Ops.size(), TD); 310f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner else 311f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner return ConstantFoldInstOperands(I->getOpcode(), I->getType(), 312f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner &Ops[0], Ops.size(), TD); 3135520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner} 3145520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 3153dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky/// ConstantFoldConstantExpression - Attempt to fold the constant expression 3163dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky/// using the specified TargetData. If successful, the constant result is 3173dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky/// result is returned, if not, null is returned. 3183dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick LewyckyConstant *llvm::ConstantFoldConstantExpression(ConstantExpr *CE, 3193dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky const TargetData *TD) { 3203dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky assert(TD && "ConstantFoldConstantExpression requires a valid TargetData."); 3213dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky 3223dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky SmallVector<Constant*, 8> Ops; 3233dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky for (User::op_iterator i = CE->op_begin(), e = CE->op_end(); i != e; ++i) 3243dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky Ops.push_back(cast<Constant>(*i)); 3253dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky 3263dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky if (CE->isCompare()) 3273dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky return ConstantFoldCompareInstOperands(CE->getPredicate(), 3283dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky &Ops[0], Ops.size(), TD); 3293dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky else 3303dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky return ConstantFoldInstOperands(CE->getOpcode(), CE->getType(), 3313dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky &Ops[0], Ops.size(), TD); 3323dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky} 3333dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky 3345520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// ConstantFoldInstOperands - Attempt to constant fold an instruction with the 3355520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// specified opcode and operands. If successful, the constant result is 3365520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// returned, if not, null is returned. Note that this function can fail when 3375520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// attempting to fold instructions like loads and stores, which have no 3385520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// constant expression form. 3395520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// 340f286f6fd93d569befe6e77c94a947e6e04e95685Chris LattnerConstant *llvm::ConstantFoldInstOperands(unsigned Opcode, const Type *DestTy, 341f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner Constant* const* Ops, unsigned NumOps, 3425520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner const TargetData *TD) { 34303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Handle easy binops first. 344f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (Instruction::isBinaryOp(Opcode)) { 34503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (isa<ConstantExpr>(Ops[0]) || isa<ConstantExpr>(Ops[1])) 346f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (Constant *C = SymbolicallyEvaluateBinop(Opcode, Ops[0], Ops[1], TD)) 34703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return C; 34803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 349f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner return ConstantExpr::get(Opcode, Ops[0], Ops[1]); 35003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 3515520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 352f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner switch (Opcode) { 3535520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner default: return 0; 3545520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::Call: 3555520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (Function *F = dyn_cast<Function>(Ops[0])) 3565520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (canConstantFoldCallTo(F)) 357ad58eb34342f70f094008e6d08cb4ed814754e64Chris Lattner return ConstantFoldCall(F, Ops+1, NumOps-1); 3585520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 3595520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::ICmp: 3605520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FCmp: 361b5557abcf13a7b375cae683e9ec200d499645d02Nate Begeman case Instruction::VICmp: 362b5557abcf13a7b375cae683e9ec200d499645d02Nate Begeman case Instruction::VFCmp: 363f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner assert(0 &&"This function is invalid for compares: no predicate specified"); 364001f7534e0311508cc93831a595785bb177f8a18Chris Lattner case Instruction::PtrToInt: 365001f7534e0311508cc93831a595785bb177f8a18Chris Lattner // If the input is a inttoptr, eliminate the pair. This requires knowing 366001f7534e0311508cc93831a595785bb177f8a18Chris Lattner // the width of a pointer, so it can't be done in ConstantExpr::getCast. 367001f7534e0311508cc93831a595785bb177f8a18Chris Lattner if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[0])) { 368001f7534e0311508cc93831a595785bb177f8a18Chris Lattner if (TD && CE->getOpcode() == Instruction::IntToPtr) { 369001f7534e0311508cc93831a595785bb177f8a18Chris Lattner Constant *Input = CE->getOperand(0); 370001f7534e0311508cc93831a595785bb177f8a18Chris Lattner unsigned InWidth = Input->getType()->getPrimitiveSizeInBits(); 37104aa2c3520c049333ca216fb794d700310c4a33dNick Lewycky if (TD->getPointerSizeInBits() < InWidth) { 37204aa2c3520c049333ca216fb794d700310c4a33dNick Lewycky Constant *Mask = 37304aa2c3520c049333ca216fb794d700310c4a33dNick Lewycky ConstantInt::get(APInt::getLowBitsSet(InWidth, 37404aa2c3520c049333ca216fb794d700310c4a33dNick Lewycky TD->getPointerSizeInBits())); 37504aa2c3520c049333ca216fb794d700310c4a33dNick Lewycky Input = ConstantExpr::getAnd(Input, Mask); 37604aa2c3520c049333ca216fb794d700310c4a33dNick Lewycky } 377001f7534e0311508cc93831a595785bb177f8a18Chris Lattner // Do a zext or trunc to get to the dest size. 378f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner return ConstantExpr::getIntegerCast(Input, DestTy, false); 379001f7534e0311508cc93831a595785bb177f8a18Chris Lattner } 380001f7534e0311508cc93831a595785bb177f8a18Chris Lattner } 3811afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner return ConstantExpr::getCast(Opcode, Ops[0], DestTy); 382001f7534e0311508cc93831a595785bb177f8a18Chris Lattner case Instruction::IntToPtr: 38381b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands // If the input is a ptrtoint, turn the pair into a ptr to ptr bitcast if 38481b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands // the int size is >= the ptr size. This requires knowing the width of a 38581b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands // pointer, so it can't be done in ConstantExpr::getCast. 38681b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[0])) { 38781b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands if (TD && CE->getOpcode() == Instruction::PtrToInt && 38881b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands TD->getPointerSizeInBits() <= 38981b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands CE->getType()->getPrimitiveSizeInBits()) { 39081b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands Constant *Input = CE->getOperand(0); 39181b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands Constant *C = FoldBitCast(Input, DestTy, *TD); 39281b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands return C ? C : ConstantExpr::getBitCast(Input, DestTy); 39381b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands } 39481b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands } 39581b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands return ConstantExpr::getCast(Opcode, Ops[0], DestTy); 3965520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::Trunc: 3975520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::ZExt: 3985520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::SExt: 3995520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FPTrunc: 4005520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FPExt: 4015520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::UIToFP: 4025520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::SIToFP: 4035520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FPToUI: 4045520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FPToSI: 4051afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner return ConstantExpr::getCast(Opcode, Ops[0], DestTy); 4065520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::BitCast: 4071afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (TD) 4081afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (Constant *C = FoldBitCast(Ops[0], DestTy, *TD)) 4091afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner return C; 4101afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner return ConstantExpr::getBitCast(Ops[0], DestTy); 4115520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::Select: 4125520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return ConstantExpr::getSelect(Ops[0], Ops[1], Ops[2]); 4135520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::ExtractElement: 4145520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return ConstantExpr::getExtractElement(Ops[0], Ops[1]); 4155520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::InsertElement: 4165520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return ConstantExpr::getInsertElement(Ops[0], Ops[1], Ops[2]); 4175520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::ShuffleVector: 4185520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return ConstantExpr::getShuffleVector(Ops[0], Ops[1], Ops[2]); 4195520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::GetElementPtr: 420f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (Constant *C = SymbolicallyEvaluateGEP(Ops, NumOps, DestTy, TD)) 42103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return C; 42203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 423d917fe56926f2f80665fd154eb23ca41e9df6f67Chris Lattner return ConstantExpr::getGetElementPtr(Ops[0], Ops+1, NumOps-1); 4245520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 4255520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner} 4265520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 427f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner/// ConstantFoldCompareInstOperands - Attempt to constant fold a compare 428f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner/// instruction (icmp/fcmp) with the specified operands. If it fails, it 429f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner/// returns a constant expression of the specified operands. 430f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner/// 431f286f6fd93d569befe6e77c94a947e6e04e95685Chris LattnerConstant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate, 432f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner Constant*const * Ops, 433f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner unsigned NumOps, 434f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner const TargetData *TD) { 435f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // fold: icmp (inttoptr x), null -> icmp x, 0 436f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // fold: icmp (ptrtoint x), 0 -> icmp x, null 4373dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky // fold: icmp (inttoptr x), (inttoptr y) -> icmp trunc/zext x, trunc/zext y 438f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // fold: icmp (ptrtoint x), (ptrtoint y) -> icmp x, y 439f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // 440f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // ConstantExpr::getCompare cannot do this, because it doesn't have TD 441f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // around to know if bit truncation is happening. 442f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (ConstantExpr *CE0 = dyn_cast<ConstantExpr>(Ops[0])) { 443f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (TD && Ops[1]->isNullValue()) { 444f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner const Type *IntPtrTy = TD->getIntPtrType(); 445f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (CE0->getOpcode() == Instruction::IntToPtr) { 446f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // Convert the integer value to the right size to ensure we get the 447f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // proper extension or truncation. 448f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner Constant *C = ConstantExpr::getIntegerCast(CE0->getOperand(0), 449f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner IntPtrTy, false); 450f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner Constant *NewOps[] = { C, Constant::getNullValue(C->getType()) }; 451f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner return ConstantFoldCompareInstOperands(Predicate, NewOps, 2, TD); 452f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 453f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner 454f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // Only do this transformation if the int is intptrty in size, otherwise 455f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // there is a truncation or extension that we aren't modeling. 456f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (CE0->getOpcode() == Instruction::PtrToInt && 457f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner CE0->getType() == IntPtrTy) { 458f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner Constant *C = CE0->getOperand(0); 459f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner Constant *NewOps[] = { C, Constant::getNullValue(C->getType()) }; 460f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // FIXME! 461f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner return ConstantFoldCompareInstOperands(Predicate, NewOps, 2, TD); 462f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 463f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 464f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner 4653dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(Ops[1])) { 4663dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky if (TD && CE0->getOpcode() == CE1->getOpcode()) { 4673dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky const Type *IntPtrTy = TD->getIntPtrType(); 4683dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky 4693dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky if (CE0->getOpcode() == Instruction::IntToPtr) { 4703dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky // Convert the integer value to the right size to ensure we get the 4713dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky // proper extension or truncation. 4723dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky Constant *C0 = ConstantExpr::getIntegerCast(CE0->getOperand(0), 4733dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky IntPtrTy, false); 4743dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky Constant *C1 = ConstantExpr::getIntegerCast(CE1->getOperand(0), 4753dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky IntPtrTy, false); 4763dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky Constant *NewOps[] = { C0, C1 }; 4773dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky return ConstantFoldCompareInstOperands(Predicate, NewOps, 2, TD); 4783dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky } 4793dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky 4803dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky // Only do this transformation if the int is intptrty in size, otherwise 4813dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky // there is a truncation or extension that we aren't modeling. 4823dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky if ((CE0->getOpcode() == Instruction::PtrToInt && 4833dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky CE0->getType() == IntPtrTy && 4843dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky CE0->getOperand(0)->getType() == CE1->getOperand(0)->getType())) { 4853dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky Constant *NewOps[] = { 4863dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky CE0->getOperand(0), CE1->getOperand(0) 4873dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky }; 4883dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky return ConstantFoldCompareInstOperands(Predicate, NewOps, 2, TD); 4893dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky } 490f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 491f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 492f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 493b5557abcf13a7b375cae683e9ec200d499645d02Nate Begeman return ConstantExpr::getCompare(Predicate, Ops[0], Ops[1]); 494f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner} 495f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner 496f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner 4975520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// ConstantFoldLoadThroughGEPConstantExpr - Given a constant and a 4985520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// getelementptr constantexpr, return the constant value being addressed by the 4995520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// constant expression, or null if something is funny and we can't decide. 5005520732b24a5a321140dd79af70d321c7ff3dec9Chris LattnerConstant *llvm::ConstantFoldLoadThroughGEPConstantExpr(Constant *C, 5015520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner ConstantExpr *CE) { 5025520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (CE->getOperand(1) != Constant::getNullValue(CE->getOperand(1)->getType())) 5035520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; // Do not allow stepping over the value! 5045520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 5055520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // Loop over all of the operands, tracking down which value we are 5065520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // addressing... 5075520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner gep_type_iterator I = gep_type_begin(CE), E = gep_type_end(CE); 5085520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner for (++I; I != E; ++I) 5095520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (const StructType *STy = dyn_cast<StructType>(*I)) { 5105520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner ConstantInt *CU = cast<ConstantInt>(I.getOperand()); 5115520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner assert(CU->getZExtValue() < STy->getNumElements() && 5125520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner "Struct index out of range!"); 5135520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner unsigned El = (unsigned)CU->getZExtValue(); 5145520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) { 5155520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = CS->getOperand(El); 5165520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else if (isa<ConstantAggregateZero>(C)) { 5175520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = Constant::getNullValue(STy->getElementType(El)); 5185520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else if (isa<UndefValue>(C)) { 5195520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = UndefValue::get(STy->getElementType(El)); 5205520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else { 5215520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 5225520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 5235520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else if (ConstantInt *CI = dyn_cast<ConstantInt>(I.getOperand())) { 5245520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (const ArrayType *ATy = dyn_cast<ArrayType>(*I)) { 5255520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (CI->getZExtValue() >= ATy->getNumElements()) 5265520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 5275520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (ConstantArray *CA = dyn_cast<ConstantArray>(C)) 5285520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = CA->getOperand(CI->getZExtValue()); 5295520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else if (isa<ConstantAggregateZero>(C)) 5305520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = Constant::getNullValue(ATy->getElementType()); 5315520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else if (isa<UndefValue>(C)) 5325520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = UndefValue::get(ATy->getElementType()); 5335520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else 5345520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 5359d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer } else if (const VectorType *PTy = dyn_cast<VectorType>(*I)) { 5365520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (CI->getZExtValue() >= PTy->getNumElements()) 5375520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 5389d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer if (ConstantVector *CP = dyn_cast<ConstantVector>(C)) 5395520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = CP->getOperand(CI->getZExtValue()); 5405520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else if (isa<ConstantAggregateZero>(C)) 5415520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = Constant::getNullValue(PTy->getElementType()); 5425520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else if (isa<UndefValue>(C)) 5435520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = UndefValue::get(PTy->getElementType()); 5445520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else 5455520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 5465520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else { 5475520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 5485520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 5495520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else { 5505520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 5515520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 5525520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return C; 5535520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner} 5545520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 5555520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 556bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell//===----------------------------------------------------------------------===// 5575520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner// Constant Folding for Calls 558bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell// 559bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 560bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell/// canConstantFoldCallTo - Return true if its even possible to fold a call to 561bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell/// the specified function. 562bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswellbool 563fa9b80eb64127b3d9691e18537975635520e51e9Dan Gohmanllvm::canConstantFoldCallTo(const Function *F) { 564bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell switch (F->getIntrinsicID()) { 5659ab7fb3ba47442d521a5bed09a27a5e8e7a786edDale Johannesen case Intrinsic::sqrt: 5669ab7fb3ba47442d521a5bed09a27a5e8e7a786edDale Johannesen case Intrinsic::powi: 567e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer case Intrinsic::bswap: 568e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer case Intrinsic::ctpop: 569e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer case Intrinsic::ctlz: 570e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer case Intrinsic::cttz: 571bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell return true; 572bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell default: break; 573bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 574bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 575c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner const ValueName *NameVal = F->getValueName(); 576a099b6c7bb574f22bc002e0b3c65c25abccca1d5Chris Lattner if (NameVal == 0) return false; 577c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner const char *Str = NameVal->getKeyData(); 578c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner unsigned Len = NameVal->getKeyLength(); 579c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner 580c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner // In these cases, the check of the length is required. We don't want to 581c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner // return true for a name like "cos\0blah" which strcmp would return equal to 582c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner // "cos", but has length 8. 583c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner switch (Str[0]) { 584c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner default: return false; 585c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'a': 586c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 4) 587c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "acos") || !strcmp(Str, "asin") || 588c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner !strcmp(Str, "atan"); 589c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 5) 590c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "atan2"); 591c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return false; 592c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'c': 593c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3) 594c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "cos"); 595c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 4) 596c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "ceil") || !strcmp(Str, "cosf") || 597c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner !strcmp(Str, "cosh"); 598c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return false; 599c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'e': 600c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3) 601c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "exp"); 602c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return false; 603c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'f': 604c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 4) 605c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "fabs") || !strcmp(Str, "fmod"); 606c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 5) 607c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "floor"); 608c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return false; 609c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 610c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'l': 611c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3 && !strcmp(Str, "log")) 612c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return true; 613c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 5 && !strcmp(Str, "log10")) 614c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return true; 615c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return false; 616c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'p': 617c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3 && !strcmp(Str, "pow")) 618c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return true; 619c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return false; 620c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 's': 621c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3) 622c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "sin"); 623c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 4) 624f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner return !strcmp(Str, "sinh") || !strcmp(Str, "sqrt") || 625f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner !strcmp(Str, "sinf"); 626c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 5) 627c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "sqrtf"); 628c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return false; 629c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 't': 630c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3 && !strcmp(Str, "tan")) 631c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return true; 632c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 4 && !strcmp(Str, "tanh")) 633c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return true; 634c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return false; 635bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 636bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell} 637bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 63872d88ae5447a3929c97e88f4c806213847b5d988Chris Lattnerstatic Constant *ConstantFoldFP(double (*NativeFP)(double), double V, 63972d88ae5447a3929c97e88f4c806213847b5d988Chris Lattner const Type *Ty) { 640bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell errno = 0; 641bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell V = NativeFP(V); 642f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner if (errno != 0) { 643f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner errno = 0; 644f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner return 0; 64543421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen } 646f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner 647f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner if (Ty == Type::FloatTy) 64802a260aa11a2e1b2c14335274d3c42ca3f3eabc0Chris Lattner return ConstantFP::get(APFloat((float)V)); 649f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner if (Ty == Type::DoubleTy) 65002a260aa11a2e1b2c14335274d3c42ca3f3eabc0Chris Lattner return ConstantFP::get(APFloat(V)); 651f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner assert(0 && "Can only constant fold float/double"); 65233e456d5f3909e0c7b96e04e5674c25a182da100Gabor Greif return 0; // dummy return to suppress warning 653bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell} 654bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 655384152444d22d356f7b4090a158da4cbc1f79464Dan Gohmanstatic Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double), 656384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman double V, double W, 657384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman const Type *Ty) { 658384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman errno = 0; 659384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman V = NativeFP(V, W); 660f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner if (errno != 0) { 661f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner errno = 0; 662f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner return 0; 66343421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen } 664f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner 665f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner if (Ty == Type::FloatTy) 66602a260aa11a2e1b2c14335274d3c42ca3f3eabc0Chris Lattner return ConstantFP::get(APFloat((float)V)); 667f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner if (Ty == Type::DoubleTy) 66802a260aa11a2e1b2c14335274d3c42ca3f3eabc0Chris Lattner return ConstantFP::get(APFloat(V)); 669f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner assert(0 && "Can only constant fold float/double"); 67033e456d5f3909e0c7b96e04e5674c25a182da100Gabor Greif return 0; // dummy return to suppress warning 671384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman} 672384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman 673bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell/// ConstantFoldCall - Attempt to constant fold a call to the specified function 674bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell/// with the specified arguments, returning null if unsuccessful. 67543421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen 676bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John CriswellConstant * 677f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattnerllvm::ConstantFoldCall(Function *F, 678f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner Constant* const* Operands, unsigned NumOperands) { 679c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner const ValueName *NameVal = F->getValueName(); 680a099b6c7bb574f22bc002e0b3c65c25abccca1d5Chris Lattner if (NameVal == 0) return 0; 681c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner const char *Str = NameVal->getKeyData(); 682c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner unsigned Len = NameVal->getKeyLength(); 683c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner 684bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell const Type *Ty = F->getReturnType(); 68572d88ae5447a3929c97e88f4c806213847b5d988Chris Lattner if (NumOperands == 1) { 686bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell if (ConstantFP *Op = dyn_cast<ConstantFP>(Operands[0])) { 68743421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen if (Ty!=Type::FloatTy && Ty!=Type::DoubleTy) 68843421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen return 0; 68943421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen /// Currently APFloat versions of these functions do not exist, so we use 69043421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen /// the host native double versions. Float versions are not called 69143421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen /// directly but for all these it is true (float)(f((double)arg)) == 69243421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen /// f(arg). Long double not supported yet. 69343421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen double V = Ty==Type::FloatTy ? (double)Op->getValueAPF().convertToFloat(): 69443421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen Op->getValueAPF().convertToDouble(); 695c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner switch (Str[0]) { 696c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'a': 697c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 4 && !strcmp(Str, "acos")) 698c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(acos, V, Ty); 699c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 4 && !strcmp(Str, "asin")) 700c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(asin, V, Ty); 701c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 4 && !strcmp(Str, "atan")) 702c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(atan, V, Ty); 703c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 704c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'c': 705c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 4 && !strcmp(Str, "ceil")) 706c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(ceil, V, Ty); 707c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 3 && !strcmp(Str, "cos")) 708c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(cos, V, Ty); 709c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 4 && !strcmp(Str, "cosh")) 710c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(cosh, V, Ty); 711f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner else if (Len == 4 && !strcmp(Str, "cosf")) 712f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner return ConstantFoldFP(cos, V, Ty); 713c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 714c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'e': 715c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3 && !strcmp(Str, "exp")) 716c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(exp, V, Ty); 717c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 718c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'f': 719c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 4 && !strcmp(Str, "fabs")) 72043421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen return ConstantFoldFP(fabs, V, Ty); 721c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 5 && !strcmp(Str, "floor")) 722c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(floor, V, Ty); 723c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 724c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'l': 725c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3 && !strcmp(Str, "log") && V > 0) 726c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(log, V, Ty); 727c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 5 && !strcmp(Str, "log10") && V > 0) 728c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(log10, V, Ty); 729c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (!strcmp(Str, "llvm.sqrt.f32") || 730c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner !strcmp(Str, "llvm.sqrt.f64")) { 731c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (V >= -0.0) 73243421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen return ConstantFoldFP(sqrt, V, Ty); 733c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else // Undefined 73402a260aa11a2e1b2c14335274d3c42ca3f3eabc0Chris Lattner return Constant::getNullValue(Ty); 735c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner } 736c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 737c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 's': 738c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3 && !strcmp(Str, "sin")) 739c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(sin, V, Ty); 740c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 4 && !strcmp(Str, "sinh")) 741c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(sinh, V, Ty); 742c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 4 && !strcmp(Str, "sqrt") && V >= 0) 743c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(sqrt, V, Ty); 744c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 5 && !strcmp(Str, "sqrtf") && V >= 0) 745c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(sqrt, V, Ty); 746f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner else if (Len == 4 && !strcmp(Str, "sinf")) 747f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner return ConstantFoldFP(sin, V, Ty); 748c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 749c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 't': 750c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3 && !strcmp(Str, "tan")) 751c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(tan, V, Ty); 752c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 4 && !strcmp(Str, "tanh")) 753c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(tanh, V, Ty); 754c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 755c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner default: 756c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 757bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 758b83eb6447ba155342598f0fabe1f08f5baa9164aReid Spencer } else if (ConstantInt *Op = dyn_cast<ConstantInt>(Operands[0])) { 759ecc0274a54658a4ee76d783b285a0690ad760928Chris Lattner if (Len > 11 && !memcmp(Str, "llvm.bswap", 10)) 760e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer return ConstantInt::get(Op->getValue().byteSwap()); 761ecc0274a54658a4ee76d783b285a0690ad760928Chris Lattner else if (Len > 11 && !memcmp(Str, "llvm.ctpop", 10)) 762ecc0274a54658a4ee76d783b285a0690ad760928Chris Lattner return ConstantInt::get(Ty, Op->getValue().countPopulation()); 763ecc0274a54658a4ee76d783b285a0690ad760928Chris Lattner else if (Len > 10 && !memcmp(Str, "llvm.cttz", 9)) 764ecc0274a54658a4ee76d783b285a0690ad760928Chris Lattner return ConstantInt::get(Ty, Op->getValue().countTrailingZeros()); 765ecc0274a54658a4ee76d783b285a0690ad760928Chris Lattner else if (Len > 10 && !memcmp(Str, "llvm.ctlz", 9)) 766ecc0274a54658a4ee76d783b285a0690ad760928Chris Lattner return ConstantInt::get(Ty, Op->getValue().countLeadingZeros()); 767bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 76872d88ae5447a3929c97e88f4c806213847b5d988Chris Lattner } else if (NumOperands == 2) { 769bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell if (ConstantFP *Op1 = dyn_cast<ConstantFP>(Operands[0])) { 7709ab7fb3ba47442d521a5bed09a27a5e8e7a786edDale Johannesen if (Ty!=Type::FloatTy && Ty!=Type::DoubleTy) 7719ab7fb3ba47442d521a5bed09a27a5e8e7a786edDale Johannesen return 0; 77243421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen double Op1V = Ty==Type::FloatTy ? 77343421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen (double)Op1->getValueAPF().convertToFloat(): 77443421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen Op1->getValueAPF().convertToDouble(); 775bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell if (ConstantFP *Op2 = dyn_cast<ConstantFP>(Operands[1])) { 77643421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen double Op2V = Ty==Type::FloatTy ? 77743421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen (double)Op2->getValueAPF().convertToFloat(): 77843421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen Op2->getValueAPF().convertToDouble(); 779bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 780c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3 && !strcmp(Str, "pow")) { 781384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty); 782c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner } else if (Len == 4 && !strcmp(Str, "fmod")) { 783384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman return ConstantFoldBinaryFP(fmod, Op1V, Op2V, Ty); 784c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner } else if (Len == 5 && !strcmp(Str, "atan2")) { 785384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman return ConstantFoldBinaryFP(atan2, Op1V, Op2V, Ty); 786b5282dcf4745be59046f440980a1c0f0a50c9c09Chris Lattner } 787b5282dcf4745be59046f440980a1c0f0a50c9c09Chris Lattner } else if (ConstantInt *Op2C = dyn_cast<ConstantInt>(Operands[1])) { 788c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (!strcmp(Str, "llvm.powi.f32")) { 78902a260aa11a2e1b2c14335274d3c42ca3f3eabc0Chris Lattner return ConstantFP::get(APFloat((float)std::pow((float)Op1V, 79002a260aa11a2e1b2c14335274d3c42ca3f3eabc0Chris Lattner (int)Op2C->getZExtValue()))); 791c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner } else if (!strcmp(Str, "llvm.powi.f64")) { 79202a260aa11a2e1b2c14335274d3c42ca3f3eabc0Chris Lattner return ConstantFP::get(APFloat((double)std::pow((double)Op1V, 79302a260aa11a2e1b2c14335274d3c42ca3f3eabc0Chris Lattner (int)Op2C->getZExtValue()))); 794b5282dcf4745be59046f440980a1c0f0a50c9c09Chris Lattner } 795bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 796bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 797bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 798bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell return 0; 799bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell} 800bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 801