ConstantFolding.cpp revision 4ee451de366474b9c228b4e5fa573795a715216d
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); 6803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner for (unsigned i = 1, e = CE->getNumOperands(); i != e; ++i, ++GTI) { 6903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner ConstantInt *CI = dyn_cast<ConstantInt>(CE->getOperand(i)); 7003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (!CI) return false; // Index isn't a simple constant? 7103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (CI->getZExtValue() == 0) continue; // Not adding anything. 7203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 7303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (const StructType *ST = dyn_cast<StructType>(*GTI)) { 7403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // N = N + Offset 75b1919e2f08ecb37140af676fd2916f8d5ed7df3dChris Lattner Offset += TD.getStructLayout(ST)->getElementOffset(CI->getZExtValue()); 7603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } else { 77ca5183d445954a9b2a570d6bbba1bc2b00ad6442Jeff Cohen const SequentialType *SQT = cast<SequentialType>(*GTI); 78514ab348fddcdffa8367685dc608b2f8d5de986dDuncan Sands Offset += TD.getABITypeSize(SQT->getElementType())*CI->getSExtValue(); 7903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 8003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 8103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return true; 8203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 8303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 8403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return false; 8503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner} 8603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 8703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 8803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// SymbolicallyEvaluateBinop - One of Op0/Op1 is a constant expression. 8903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// Attempt to symbolically evaluate the result of a binary operator merging 9003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// these together. If target data info is available, it is provided as TD, 9103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// otherwise TD is null. 9203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattnerstatic Constant *SymbolicallyEvaluateBinop(unsigned Opc, Constant *Op0, 9303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner Constant *Op1, const TargetData *TD){ 9403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // SROA 9503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 9603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Fold (and 0xffffffff00000000, (shl x, 32)) -> shl. 9703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Fold (lshr (or X, Y), 32) -> (lshr [X/Y], 32) if one doesn't contribute 9803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // bits. 9903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 10003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 10103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // If the constant expr is something like &A[123] - &A[4].f, fold this into a 10203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // constant. This happens frequently when iterating over a global array. 10303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (Opc == Instruction::Sub && TD) { 10403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner GlobalValue *GV1, *GV2; 10503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner int64_t Offs1, Offs2; 10603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 10703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (IsConstantOffsetFromGlobal(Op0, GV1, Offs1, *TD)) 10803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (IsConstantOffsetFromGlobal(Op1, GV2, Offs2, *TD) && 10903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner GV1 == GV2) { 11003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // (&GV+C1) - (&GV+C2) -> C1-C2, pointer arithmetic cannot overflow. 11103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return ConstantInt::get(Op0->getType(), Offs1-Offs2); 11203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 11303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 11403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 11503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // TODO: Fold icmp setne/seteq as well. 11603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return 0; 11703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner} 11803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 11903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// SymbolicallyEvaluateGEP - If we can symbolically evaluate the specified GEP 12003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// constant expression, do so. 121f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattnerstatic Constant *SymbolicallyEvaluateGEP(Constant* const* Ops, unsigned NumOps, 12203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner const Type *ResultTy, 12303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner const TargetData *TD) { 12403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner Constant *Ptr = Ops[0]; 12503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (!cast<PointerType>(Ptr->getType())->getElementType()->isSized()) 12603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return 0; 12703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 12803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (TD && Ptr->isNullValue()) { 12903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // If this is a constant expr gep that is effectively computing an 13003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // "offsetof", fold it into 'cast int Size to T*' instead of 'gep 0, 0, 12' 13103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner bool isFoldableGEP = true; 13203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner for (unsigned i = 1; i != NumOps; ++i) 13303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (!isa<ConstantInt>(Ops[i])) { 13403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner isFoldableGEP = false; 13503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner break; 13603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 13703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (isFoldableGEP) { 138309f87e34a12e3398932e4c2c9e3c47cad0e8f0fChris Lattner uint64_t Offset = TD->getIndexedOffset(Ptr->getType(), 139309f87e34a12e3398932e4c2c9e3c47cad0e8f0fChris Lattner (Value**)Ops+1, NumOps-1); 14003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner Constant *C = ConstantInt::get(TD->getIntPtrType(), Offset); 14103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return ConstantExpr::getIntToPtr(C, ResultTy); 14203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 14303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 14403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 14503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return 0; 14603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner} 14703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 1481afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner/// FoldBitCast - Constant fold bitcast, symbolically evaluating it with 1491afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner/// targetdata. Return 0 if unfoldable. 1501afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattnerstatic Constant *FoldBitCast(Constant *C, const Type *DestTy, 1511afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner const TargetData &TD) { 1521afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // If this is a bitcast from constant vector -> vector, fold it. 1531afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (ConstantVector *CV = dyn_cast<ConstantVector>(C)) { 1541afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (const VectorType *DestVTy = dyn_cast<VectorType>(DestTy)) { 1551afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // If the element types match, VMCore can fold it. 1561afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner unsigned NumDstElt = DestVTy->getNumElements(); 1571afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner unsigned NumSrcElt = CV->getNumOperands(); 1581afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (NumDstElt == NumSrcElt) 1591afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner return 0; 1601afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 1611afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner const Type *SrcEltTy = CV->getType()->getElementType(); 1621afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner const Type *DstEltTy = DestVTy->getElementType(); 1631afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 1641afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Otherwise, we're changing the number of elements in a vector, which 1651afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // requires endianness information to do the right thing. For example, 1661afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>) 1671afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // folds to (little endian): 1681afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // <4 x i32> <i32 0, i32 0, i32 1, i32 0> 1691afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // and to (big endian): 1701afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // <4 x i32> <i32 0, i32 0, i32 0, i32 1> 1711afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 1721afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // First thing is first. We only want to think about integer here, so if 1731afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // we have something in FP form, recast it as integer. 1741afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (DstEltTy->isFloatingPoint()) { 1751afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Fold to an vector of integers with same size as our FP type. 1761afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner unsigned FPWidth = DstEltTy->getPrimitiveSizeInBits(); 1771afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner const Type *DestIVTy = VectorType::get(IntegerType::get(FPWidth), 1781afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner NumDstElt); 1791afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Recursively handle this integer conversion, if possible. 1801afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner C = FoldBitCast(C, DestIVTy, TD); 1811afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (!C) return 0; 1821afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 1831afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Finally, VMCore can handle this now that #elts line up. 1841afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner return ConstantExpr::getBitCast(C, DestTy); 1851afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner } 1861afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 1871afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Okay, we know the destination is integer, if the input is FP, convert 1881afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // it to integer first. 1891afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (SrcEltTy->isFloatingPoint()) { 1901afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner unsigned FPWidth = SrcEltTy->getPrimitiveSizeInBits(); 1911afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner const Type *SrcIVTy = VectorType::get(IntegerType::get(FPWidth), 1921afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner NumSrcElt); 1931afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Ask VMCore to do the conversion now that #elts line up. 1941afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner C = ConstantExpr::getBitCast(C, SrcIVTy); 1951afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner CV = dyn_cast<ConstantVector>(C); 1961afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (!CV) return 0; // If VMCore wasn't able to fold it, bail out. 1971afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner } 1981afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 1991afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Now we know that the input and output vectors are both integer vectors 2001afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // of the same size, and that their #elements is not the same. Do the 2011afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // conversion here, which depends on whether the input or output has 2021afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // more elements. 2031afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner bool isLittleEndian = TD.isLittleEndian(); 2041afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 2051afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner SmallVector<Constant*, 32> Result; 2061afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (NumDstElt < NumSrcElt) { 2071afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Handle: bitcast (<4 x i32> <i32 0, i32 1, i32 2, i32 3> to <2 x i64>) 2081afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner Constant *Zero = Constant::getNullValue(DstEltTy); 2091afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner unsigned Ratio = NumSrcElt/NumDstElt; 2101afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner unsigned SrcBitSize = SrcEltTy->getPrimitiveSizeInBits(); 2111afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner unsigned SrcElt = 0; 2121afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner for (unsigned i = 0; i != NumDstElt; ++i) { 2131afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Build each element of the result. 2141afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner Constant *Elt = Zero; 2151afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner unsigned ShiftAmt = isLittleEndian ? 0 : SrcBitSize*(Ratio-1); 2161afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner for (unsigned j = 0; j != Ratio; ++j) { 2171afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner Constant *Src = dyn_cast<ConstantInt>(CV->getOperand(SrcElt++)); 2181afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (!Src) return 0; // Reject constantexpr elements. 2191afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 2201afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Zero extend the element to the right size. 2211afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner Src = ConstantExpr::getZExt(Src, Elt->getType()); 2221afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 2231afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Shift it to the right place, depending on endianness. 2241afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner Src = ConstantExpr::getShl(Src, 2251afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner ConstantInt::get(Src->getType(), ShiftAmt)); 2261afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner ShiftAmt += isLittleEndian ? SrcBitSize : -SrcBitSize; 2271afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 2281afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Mix it in. 2291afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner Elt = ConstantExpr::getOr(Elt, Src); 2301afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner } 2311afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner Result.push_back(Elt); 2321afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner } 2331afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner } else { 2341afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Handle: bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>) 2351afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner unsigned Ratio = NumDstElt/NumSrcElt; 2361afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner unsigned DstBitSize = DstEltTy->getPrimitiveSizeInBits(); 2371afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 2381afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Loop over each source value, expanding into multiple results. 2391afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner for (unsigned i = 0; i != NumSrcElt; ++i) { 2401afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner Constant *Src = dyn_cast<ConstantInt>(CV->getOperand(i)); 2411afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (!Src) return 0; // Reject constantexpr elements. 2421afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 2431afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner unsigned ShiftAmt = isLittleEndian ? 0 : DstBitSize*(Ratio-1); 2441afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner for (unsigned j = 0; j != Ratio; ++j) { 2451afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Shift the piece of the value into the right place, depending on 2461afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // endianness. 2471afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner Constant *Elt = ConstantExpr::getLShr(Src, 2481afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner ConstantInt::get(Src->getType(), ShiftAmt)); 2491afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner ShiftAmt += isLittleEndian ? DstBitSize : -DstBitSize; 2501afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 2511afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner // Truncate and remember this piece. 2521afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner Result.push_back(ConstantExpr::getTrunc(Elt, DstEltTy)); 2531afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner } 2541afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner } 2551afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner } 2561afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 2571afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner return ConstantVector::get(&Result[0], Result.size()); 2581afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner } 2591afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner } 2601afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 2611afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner return 0; 2621afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner} 2631afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 26403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 26503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner//===----------------------------------------------------------------------===// 26603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner// Constant Folding public APIs 26703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner//===----------------------------------------------------------------------===// 26803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 26903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 2705520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// ConstantFoldInstruction - Attempt to constant fold the specified 2715520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// instruction. If successful, the constant result is returned, if not, null 2725520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// is returned. Note that this function can only fail when attempting to fold 2735520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// instructions like loads and stores, which have no constant expression form. 2745520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// 2755520732b24a5a321140dd79af70d321c7ff3dec9Chris LattnerConstant *llvm::ConstantFoldInstruction(Instruction *I, const TargetData *TD) { 2765520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (PHINode *PN = dyn_cast<PHINode>(I)) { 2775520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (PN->getNumIncomingValues() == 0) 2785520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return Constant::getNullValue(PN->getType()); 2795520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 2805520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner Constant *Result = dyn_cast<Constant>(PN->getIncomingValue(0)); 2815520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (Result == 0) return 0; 2825520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 2835520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // Handle PHI nodes specially here... 2845520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner for (unsigned i = 1, e = PN->getNumIncomingValues(); i != e; ++i) 2855520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (PN->getIncomingValue(i) != Result && PN->getIncomingValue(i) != PN) 2865520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; // Not all the same incoming constants... 2875520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 2885520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // If we reach here, all incoming values are the same constant. 2895520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return Result; 2905520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 2915520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 2925520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // Scan the operand list, checking to see if they are all constants, if so, 2935520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // hand off to ConstantFoldInstOperands. 2945520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner SmallVector<Constant*, 8> Ops; 2955520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) 2965520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (Constant *Op = dyn_cast<Constant>(I->getOperand(i))) 2975520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner Ops.push_back(Op); 2985520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else 2995520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; // All operands not constant! 3005520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 301f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (const CmpInst *CI = dyn_cast<CmpInst>(I)) 302f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner return ConstantFoldCompareInstOperands(CI->getPredicate(), 303f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner &Ops[0], Ops.size(), TD); 304f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner else 305f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner return ConstantFoldInstOperands(I->getOpcode(), I->getType(), 306f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner &Ops[0], Ops.size(), TD); 3075520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner} 3085520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 3095520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// ConstantFoldInstOperands - Attempt to constant fold an instruction with the 3105520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// specified opcode and operands. If successful, the constant result is 3115520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// returned, if not, null is returned. Note that this function can fail when 3125520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// attempting to fold instructions like loads and stores, which have no 3135520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// constant expression form. 3145520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// 315f286f6fd93d569befe6e77c94a947e6e04e95685Chris LattnerConstant *llvm::ConstantFoldInstOperands(unsigned Opcode, const Type *DestTy, 316f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner Constant* const* Ops, unsigned NumOps, 3175520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner const TargetData *TD) { 31803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Handle easy binops first. 319f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (Instruction::isBinaryOp(Opcode)) { 32003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (isa<ConstantExpr>(Ops[0]) || isa<ConstantExpr>(Ops[1])) 321f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (Constant *C = SymbolicallyEvaluateBinop(Opcode, Ops[0], Ops[1], TD)) 32203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return C; 32303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 324f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner return ConstantExpr::get(Opcode, Ops[0], Ops[1]); 32503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 3265520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 327f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner switch (Opcode) { 3285520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner default: return 0; 3295520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::Call: 3305520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (Function *F = dyn_cast<Function>(Ops[0])) 3315520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (canConstantFoldCallTo(F)) 332ad58eb34342f70f094008e6d08cb4ed814754e64Chris Lattner return ConstantFoldCall(F, Ops+1, NumOps-1); 3335520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 3345520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::ICmp: 3355520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FCmp: 336f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner assert(0 &&"This function is invalid for compares: no predicate specified"); 337001f7534e0311508cc93831a595785bb177f8a18Chris Lattner case Instruction::PtrToInt: 338001f7534e0311508cc93831a595785bb177f8a18Chris Lattner // If the input is a inttoptr, eliminate the pair. This requires knowing 339001f7534e0311508cc93831a595785bb177f8a18Chris Lattner // the width of a pointer, so it can't be done in ConstantExpr::getCast. 340001f7534e0311508cc93831a595785bb177f8a18Chris Lattner if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[0])) { 341001f7534e0311508cc93831a595785bb177f8a18Chris Lattner if (TD && CE->getOpcode() == Instruction::IntToPtr) { 342001f7534e0311508cc93831a595785bb177f8a18Chris Lattner Constant *Input = CE->getOperand(0); 343001f7534e0311508cc93831a595785bb177f8a18Chris Lattner unsigned InWidth = Input->getType()->getPrimitiveSizeInBits(); 344001f7534e0311508cc93831a595785bb177f8a18Chris Lattner Constant *Mask = 345001f7534e0311508cc93831a595785bb177f8a18Chris Lattner ConstantInt::get(APInt::getLowBitsSet(InWidth, 346001f7534e0311508cc93831a595785bb177f8a18Chris Lattner TD->getPointerSizeInBits())); 347001f7534e0311508cc93831a595785bb177f8a18Chris Lattner Input = ConstantExpr::getAnd(Input, Mask); 348001f7534e0311508cc93831a595785bb177f8a18Chris Lattner // Do a zext or trunc to get to the dest size. 349f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner return ConstantExpr::getIntegerCast(Input, DestTy, false); 350001f7534e0311508cc93831a595785bb177f8a18Chris Lattner } 351001f7534e0311508cc93831a595785bb177f8a18Chris Lattner } 3521afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner return ConstantExpr::getCast(Opcode, Ops[0], DestTy); 353001f7534e0311508cc93831a595785bb177f8a18Chris Lattner case Instruction::IntToPtr: 3545520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::Trunc: 3555520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::ZExt: 3565520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::SExt: 3575520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FPTrunc: 3585520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FPExt: 3595520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::UIToFP: 3605520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::SIToFP: 3615520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FPToUI: 3625520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FPToSI: 3631afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner return ConstantExpr::getCast(Opcode, Ops[0], DestTy); 3645520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::BitCast: 3651afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (TD) 3661afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (Constant *C = FoldBitCast(Ops[0], DestTy, *TD)) 3671afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner return C; 3681afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner return ConstantExpr::getBitCast(Ops[0], DestTy); 3695520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::Select: 3705520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return ConstantExpr::getSelect(Ops[0], Ops[1], Ops[2]); 3715520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::ExtractElement: 3725520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return ConstantExpr::getExtractElement(Ops[0], Ops[1]); 3735520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::InsertElement: 3745520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return ConstantExpr::getInsertElement(Ops[0], Ops[1], Ops[2]); 3755520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::ShuffleVector: 3765520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return ConstantExpr::getShuffleVector(Ops[0], Ops[1], Ops[2]); 3775520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::GetElementPtr: 378f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (Constant *C = SymbolicallyEvaluateGEP(Ops, NumOps, DestTy, TD)) 37903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return C; 38003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 381d917fe56926f2f80665fd154eb23ca41e9df6f67Chris Lattner return ConstantExpr::getGetElementPtr(Ops[0], Ops+1, NumOps-1); 3825520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 3835520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner} 3845520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 385f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner/// ConstantFoldCompareInstOperands - Attempt to constant fold a compare 386f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner/// instruction (icmp/fcmp) with the specified operands. If it fails, it 387f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner/// returns a constant expression of the specified operands. 388f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner/// 389f286f6fd93d569befe6e77c94a947e6e04e95685Chris LattnerConstant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate, 390f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner Constant*const * Ops, 391f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner unsigned NumOps, 392f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner const TargetData *TD) { 393f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // fold: icmp (inttoptr x), null -> icmp x, 0 394f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // fold: icmp (ptrtoint x), 0 -> icmp x, null 395f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // fold: icmp (inttoptr x), (inttoptr y) -> icmp x, y 396f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // fold: icmp (ptrtoint x), (ptrtoint y) -> icmp x, y 397f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // 398f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // ConstantExpr::getCompare cannot do this, because it doesn't have TD 399f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // around to know if bit truncation is happening. 400f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (ConstantExpr *CE0 = dyn_cast<ConstantExpr>(Ops[0])) { 401f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (TD && Ops[1]->isNullValue()) { 402f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner const Type *IntPtrTy = TD->getIntPtrType(); 403f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (CE0->getOpcode() == Instruction::IntToPtr) { 404f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // Convert the integer value to the right size to ensure we get the 405f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // proper extension or truncation. 406f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner Constant *C = ConstantExpr::getIntegerCast(CE0->getOperand(0), 407f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner IntPtrTy, false); 408f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner Constant *NewOps[] = { C, Constant::getNullValue(C->getType()) }; 409f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner return ConstantFoldCompareInstOperands(Predicate, NewOps, 2, TD); 410f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 411f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner 412f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // Only do this transformation if the int is intptrty in size, otherwise 413f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // there is a truncation or extension that we aren't modeling. 414f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (CE0->getOpcode() == Instruction::PtrToInt && 415f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner CE0->getType() == IntPtrTy) { 416f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner Constant *C = CE0->getOperand(0); 417f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner Constant *NewOps[] = { C, Constant::getNullValue(C->getType()) }; 418f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // FIXME! 419f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner return ConstantFoldCompareInstOperands(Predicate, NewOps, 2, TD); 420f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 421f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 422f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner 423f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (TD && isa<ConstantExpr>(Ops[1]) && 424f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner cast<ConstantExpr>(Ops[1])->getOpcode() == CE0->getOpcode()) { 425f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner const Type *IntPtrTy = TD->getIntPtrType(); 426f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // Only do this transformation if the int is intptrty in size, otherwise 427f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // there is a truncation or extension that we aren't modeling. 428f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if ((CE0->getOpcode() == Instruction::IntToPtr && 429f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner CE0->getOperand(0)->getType() == IntPtrTy && 4307f135cc802435171ab09ebd6a514db26a122b99aChris Lattner Ops[1]->getOperand(0)->getType() == IntPtrTy) || 431f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner (CE0->getOpcode() == Instruction::PtrToInt && 432f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner CE0->getType() == IntPtrTy && 4337f135cc802435171ab09ebd6a514db26a122b99aChris Lattner CE0->getOperand(0)->getType() == Ops[1]->getOperand(0)->getType())) { 434f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner Constant *NewOps[] = { 435f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner CE0->getOperand(0), cast<ConstantExpr>(Ops[1])->getOperand(0) 436f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner }; 437f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner return ConstantFoldCompareInstOperands(Predicate, NewOps, 2, TD); 438f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 439f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 440f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 441f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner return ConstantExpr::getCompare(Predicate, Ops[0], Ops[1]); 442f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner} 443f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner 444f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner 4455520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// ConstantFoldLoadThroughGEPConstantExpr - Given a constant and a 4465520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// getelementptr constantexpr, return the constant value being addressed by the 4475520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// constant expression, or null if something is funny and we can't decide. 4485520732b24a5a321140dd79af70d321c7ff3dec9Chris LattnerConstant *llvm::ConstantFoldLoadThroughGEPConstantExpr(Constant *C, 4495520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner ConstantExpr *CE) { 4505520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (CE->getOperand(1) != Constant::getNullValue(CE->getOperand(1)->getType())) 4515520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; // Do not allow stepping over the value! 4525520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 4535520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // Loop over all of the operands, tracking down which value we are 4545520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // addressing... 4555520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner gep_type_iterator I = gep_type_begin(CE), E = gep_type_end(CE); 4565520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner for (++I; I != E; ++I) 4575520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (const StructType *STy = dyn_cast<StructType>(*I)) { 4585520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner ConstantInt *CU = cast<ConstantInt>(I.getOperand()); 4595520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner assert(CU->getZExtValue() < STy->getNumElements() && 4605520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner "Struct index out of range!"); 4615520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner unsigned El = (unsigned)CU->getZExtValue(); 4625520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) { 4635520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = CS->getOperand(El); 4645520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else if (isa<ConstantAggregateZero>(C)) { 4655520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = Constant::getNullValue(STy->getElementType(El)); 4665520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else if (isa<UndefValue>(C)) { 4675520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = UndefValue::get(STy->getElementType(El)); 4685520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else { 4695520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 4705520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 4715520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else if (ConstantInt *CI = dyn_cast<ConstantInt>(I.getOperand())) { 4725520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (const ArrayType *ATy = dyn_cast<ArrayType>(*I)) { 4735520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (CI->getZExtValue() >= ATy->getNumElements()) 4745520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 4755520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (ConstantArray *CA = dyn_cast<ConstantArray>(C)) 4765520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = CA->getOperand(CI->getZExtValue()); 4775520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else if (isa<ConstantAggregateZero>(C)) 4785520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = Constant::getNullValue(ATy->getElementType()); 4795520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else if (isa<UndefValue>(C)) 4805520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = UndefValue::get(ATy->getElementType()); 4815520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else 4825520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 4839d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer } else if (const VectorType *PTy = dyn_cast<VectorType>(*I)) { 4845520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (CI->getZExtValue() >= PTy->getNumElements()) 4855520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 4869d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer if (ConstantVector *CP = dyn_cast<ConstantVector>(C)) 4875520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = CP->getOperand(CI->getZExtValue()); 4885520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else if (isa<ConstantAggregateZero>(C)) 4895520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = Constant::getNullValue(PTy->getElementType()); 4905520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else if (isa<UndefValue>(C)) 4915520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = UndefValue::get(PTy->getElementType()); 4925520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else 4935520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 4945520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else { 4955520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 4965520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 4975520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else { 4985520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 4995520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 5005520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return C; 5015520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner} 5025520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 5035520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 504bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell//===----------------------------------------------------------------------===// 5055520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner// Constant Folding for Calls 506bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell// 507bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 508bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell/// canConstantFoldCallTo - Return true if its even possible to fold a call to 509bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell/// the specified function. 510bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswellbool 511bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswellllvm::canConstantFoldCallTo(Function *F) { 512bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell switch (F->getIntrinsicID()) { 5139ab7fb3ba47442d521a5bed09a27a5e8e7a786edDale Johannesen case Intrinsic::sqrt: 5149ab7fb3ba47442d521a5bed09a27a5e8e7a786edDale Johannesen case Intrinsic::powi: 515e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer case Intrinsic::bswap: 516e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer case Intrinsic::ctpop: 517e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer case Intrinsic::ctlz: 518e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer case Intrinsic::cttz: 519bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell return true; 520bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell default: break; 521bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 522bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 523c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner const ValueName *NameVal = F->getValueName(); 524a099b6c7bb574f22bc002e0b3c65c25abccca1d5Chris Lattner if (NameVal == 0) return false; 525c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner const char *Str = NameVal->getKeyData(); 526c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner unsigned Len = NameVal->getKeyLength(); 527c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner 528c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner // In these cases, the check of the length is required. We don't want to 529c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner // return true for a name like "cos\0blah" which strcmp would return equal to 530c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner // "cos", but has length 8. 531c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner switch (Str[0]) { 532c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner default: return false; 533c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'a': 534c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 4) 535c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "acos") || !strcmp(Str, "asin") || 536c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner !strcmp(Str, "atan"); 537c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 5) 538c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "atan2"); 539c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return false; 540c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'c': 541c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3) 542c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "cos"); 543c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 4) 544c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "ceil") || !strcmp(Str, "cosf") || 545c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner !strcmp(Str, "cosh"); 546c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return false; 547c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'e': 548c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3) 549c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "exp"); 550c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return false; 551c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'f': 552c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 4) 553c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "fabs") || !strcmp(Str, "fmod"); 554c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 5) 555c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "floor"); 556c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return false; 557c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 558c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'l': 559c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3 && !strcmp(Str, "log")) 560c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return true; 561c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 5 && !strcmp(Str, "log10")) 562c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return true; 563c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return false; 564c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'p': 565c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3 && !strcmp(Str, "pow")) 566c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return true; 567c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return false; 568c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 's': 569c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3) 570c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "sin"); 571c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 4) 572c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "sinh") || !strcmp(Str, "sqrt"); 573c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 5) 574c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "sqrtf"); 575c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return false; 576c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 't': 577c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3 && !strcmp(Str, "tan")) 578c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return true; 579c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 4 && !strcmp(Str, "tanh")) 580c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return true; 581c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return false; 582bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 583bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell} 584bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 58572d88ae5447a3929c97e88f4c806213847b5d988Chris Lattnerstatic Constant *ConstantFoldFP(double (*NativeFP)(double), double V, 58672d88ae5447a3929c97e88f4c806213847b5d988Chris Lattner const Type *Ty) { 587bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell errno = 0; 588bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell V = NativeFP(V); 58943421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen if (errno == 0) { 59043421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen if (Ty==Type::FloatTy) 59143421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen return ConstantFP::get(Ty, APFloat((float)V)); 59243421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen else if (Ty==Type::DoubleTy) 59343421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen return ConstantFP::get(Ty, APFloat(V)); 59443421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen else 59543421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen assert(0); 59643421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen } 59772d88ae5447a3929c97e88f4c806213847b5d988Chris Lattner errno = 0; 598bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell return 0; 599bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell} 600bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 601384152444d22d356f7b4090a158da4cbc1f79464Dan Gohmanstatic Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double), 602384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman double V, double W, 603384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman const Type *Ty) { 604384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman errno = 0; 605384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman V = NativeFP(V, W); 60643421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen if (errno == 0) { 60743421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen if (Ty==Type::FloatTy) 60843421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen return ConstantFP::get(Ty, APFloat((float)V)); 60943421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen else if (Ty==Type::DoubleTy) 61043421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen return ConstantFP::get(Ty, APFloat(V)); 61143421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen else 61243421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen assert(0); 61343421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen } 614384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman errno = 0; 615384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman return 0; 616384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman} 617384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman 618bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell/// ConstantFoldCall - Attempt to constant fold a call to the specified function 619bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell/// with the specified arguments, returning null if unsuccessful. 62043421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen 621bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John CriswellConstant * 622f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattnerllvm::ConstantFoldCall(Function *F, 623f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner Constant* const* Operands, unsigned NumOperands) { 624c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner const ValueName *NameVal = F->getValueName(); 625a099b6c7bb574f22bc002e0b3c65c25abccca1d5Chris Lattner if (NameVal == 0) return 0; 626c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner const char *Str = NameVal->getKeyData(); 627c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner unsigned Len = NameVal->getKeyLength(); 628c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner 629bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell const Type *Ty = F->getReturnType(); 63072d88ae5447a3929c97e88f4c806213847b5d988Chris Lattner if (NumOperands == 1) { 631bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell if (ConstantFP *Op = dyn_cast<ConstantFP>(Operands[0])) { 63243421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen if (Ty!=Type::FloatTy && Ty!=Type::DoubleTy) 63343421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen return 0; 63443421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen /// Currently APFloat versions of these functions do not exist, so we use 63543421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen /// the host native double versions. Float versions are not called 63643421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen /// directly but for all these it is true (float)(f((double)arg)) == 63743421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen /// f(arg). Long double not supported yet. 63843421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen double V = Ty==Type::FloatTy ? (double)Op->getValueAPF().convertToFloat(): 63943421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen Op->getValueAPF().convertToDouble(); 640c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner switch (Str[0]) { 641c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'a': 642c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 4 && !strcmp(Str, "acos")) 643c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(acos, V, Ty); 644c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 4 && !strcmp(Str, "asin")) 645c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(asin, V, Ty); 646c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 4 && !strcmp(Str, "atan")) 647c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(atan, V, Ty); 648c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 649c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'c': 650c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 4 && !strcmp(Str, "ceil")) 651c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(ceil, V, Ty); 652c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 3 && !strcmp(Str, "cos")) 653c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(cos, V, Ty); 654c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 4 && !strcmp(Str, "cosh")) 655c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(cosh, V, Ty); 656c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 657c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'e': 658c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3 && !strcmp(Str, "exp")) 659c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(exp, V, Ty); 660c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 661c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'f': 662c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 4 && !strcmp(Str, "fabs")) 66343421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen return ConstantFoldFP(fabs, V, Ty); 664c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 5 && !strcmp(Str, "floor")) 665c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(floor, V, Ty); 666c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 667c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'l': 668c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3 && !strcmp(Str, "log") && V > 0) 669c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(log, V, Ty); 670c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 5 && !strcmp(Str, "log10") && V > 0) 671c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(log10, V, Ty); 672c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (!strcmp(Str, "llvm.sqrt.f32") || 673c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner !strcmp(Str, "llvm.sqrt.f64")) { 674c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (V >= -0.0) 67543421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen return ConstantFoldFP(sqrt, V, Ty); 676c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else // Undefined 67743421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen return ConstantFP::get(Ty, Ty==Type::FloatTy ? APFloat(0.0f) : 67843421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen APFloat(0.0)); 679c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner } 680c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 681c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 's': 682c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3 && !strcmp(Str, "sin")) 683c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(sin, V, Ty); 684c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 4 && !strcmp(Str, "sinh")) 685c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(sinh, V, Ty); 686c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 4 && !strcmp(Str, "sqrt") && V >= 0) 687c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(sqrt, V, Ty); 688c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 5 && !strcmp(Str, "sqrtf") && V >= 0) 689c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(sqrt, V, Ty); 690c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 691c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 't': 692c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3 && !strcmp(Str, "tan")) 693c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(tan, V, Ty); 694c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 4 && !strcmp(Str, "tanh")) 695c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(tanh, V, Ty); 696c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 697c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner default: 698c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 699bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 700b83eb6447ba155342598f0fabe1f08f5baa9164aReid Spencer } else if (ConstantInt *Op = dyn_cast<ConstantInt>(Operands[0])) { 701ecc0274a54658a4ee76d783b285a0690ad760928Chris Lattner if (Len > 11 && !memcmp(Str, "llvm.bswap", 10)) 702e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer return ConstantInt::get(Op->getValue().byteSwap()); 703ecc0274a54658a4ee76d783b285a0690ad760928Chris Lattner else if (Len > 11 && !memcmp(Str, "llvm.ctpop", 10)) 704ecc0274a54658a4ee76d783b285a0690ad760928Chris Lattner return ConstantInt::get(Ty, Op->getValue().countPopulation()); 705ecc0274a54658a4ee76d783b285a0690ad760928Chris Lattner else if (Len > 10 && !memcmp(Str, "llvm.cttz", 9)) 706ecc0274a54658a4ee76d783b285a0690ad760928Chris Lattner return ConstantInt::get(Ty, Op->getValue().countTrailingZeros()); 707ecc0274a54658a4ee76d783b285a0690ad760928Chris Lattner else if (Len > 10 && !memcmp(Str, "llvm.ctlz", 9)) 708ecc0274a54658a4ee76d783b285a0690ad760928Chris Lattner return ConstantInt::get(Ty, Op->getValue().countLeadingZeros()); 709bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 71072d88ae5447a3929c97e88f4c806213847b5d988Chris Lattner } else if (NumOperands == 2) { 711bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell if (ConstantFP *Op1 = dyn_cast<ConstantFP>(Operands[0])) { 7129ab7fb3ba47442d521a5bed09a27a5e8e7a786edDale Johannesen if (Ty!=Type::FloatTy && Ty!=Type::DoubleTy) 7139ab7fb3ba47442d521a5bed09a27a5e8e7a786edDale Johannesen return 0; 71443421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen double Op1V = Ty==Type::FloatTy ? 71543421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen (double)Op1->getValueAPF().convertToFloat(): 71643421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen Op1->getValueAPF().convertToDouble(); 717bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell if (ConstantFP *Op2 = dyn_cast<ConstantFP>(Operands[1])) { 71843421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen double Op2V = Ty==Type::FloatTy ? 71943421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen (double)Op2->getValueAPF().convertToFloat(): 72043421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen Op2->getValueAPF().convertToDouble(); 721bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 722c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3 && !strcmp(Str, "pow")) { 723384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty); 724c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner } else if (Len == 4 && !strcmp(Str, "fmod")) { 725384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman return ConstantFoldBinaryFP(fmod, Op1V, Op2V, Ty); 726c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner } else if (Len == 5 && !strcmp(Str, "atan2")) { 727384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman return ConstantFoldBinaryFP(atan2, Op1V, Op2V, Ty); 728b5282dcf4745be59046f440980a1c0f0a50c9c09Chris Lattner } 729b5282dcf4745be59046f440980a1c0f0a50c9c09Chris Lattner } else if (ConstantInt *Op2C = dyn_cast<ConstantInt>(Operands[1])) { 730c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (!strcmp(Str, "llvm.powi.f32")) { 73143421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen return ConstantFP::get(Ty, APFloat((float)std::pow((float)Op1V, 73243421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen (int)Op2C->getZExtValue()))); 733c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner } else if (!strcmp(Str, "llvm.powi.f64")) { 73443421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen return ConstantFP::get(Ty, APFloat((double)std::pow((double)Op1V, 73543421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen (int)Op2C->getZExtValue()))); 736b5282dcf4745be59046f440980a1c0f0a50c9c09Chris Lattner } 737bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 738bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 739bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 740bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell return 0; 741bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell} 742bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 743