ConstantFolding.cpp revision 9ab7fb3ba47442d521a5bed09a27a5e8e7a786ed
1bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell//===-- ConstantFolding.cpp - Analyze constant folding possibilities ------===// 2bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell// 3bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell// The LLVM Compiler Infrastructure 4bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell// 5bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell// This file was developed by the LLVM research group and is distributed under 6bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell// the University of Illinois Open Source 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. 5803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (!cast<PointerType>(CE->getOperand(0)->getType())->getElementType()->isSized()) 5903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return false; 6003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 6103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // If the base isn't a global+constant, we aren't either. 6203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (!IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD)) 6303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return false; 6403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 6503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Otherwise, add any offset that our operands provide. 6603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner gep_type_iterator GTI = gep_type_begin(CE); 6703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner for (unsigned i = 1, e = CE->getNumOperands(); i != e; ++i, ++GTI) { 6803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner ConstantInt *CI = dyn_cast<ConstantInt>(CE->getOperand(i)); 6903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (!CI) return false; // Index isn't a simple constant? 7003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (CI->getZExtValue() == 0) continue; // Not adding anything. 7103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 7203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (const StructType *ST = dyn_cast<StructType>(*GTI)) { 7303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // N = N + Offset 74b1919e2f08ecb37140af676fd2916f8d5ed7df3dChris Lattner Offset += TD.getStructLayout(ST)->getElementOffset(CI->getZExtValue()); 7503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } else { 76ca5183d445954a9b2a570d6bbba1bc2b00ad6442Jeff Cohen const SequentialType *SQT = cast<SequentialType>(*GTI); 77ca5183d445954a9b2a570d6bbba1bc2b00ad6442Jeff Cohen Offset += TD.getTypeSize(SQT->getElementType())*CI->getSExtValue(); 7803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 7903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 8003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return true; 8103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 8203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 8303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return false; 8403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner} 8503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 8603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 8703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// SymbolicallyEvaluateBinop - One of Op0/Op1 is a constant expression. 8803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// Attempt to symbolically evaluate the result of a binary operator merging 8903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// these together. If target data info is available, it is provided as TD, 9003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// otherwise TD is null. 9103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattnerstatic Constant *SymbolicallyEvaluateBinop(unsigned Opc, Constant *Op0, 9203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner Constant *Op1, const TargetData *TD){ 9303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // SROA 9403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 9503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Fold (and 0xffffffff00000000, (shl x, 32)) -> shl. 9603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Fold (lshr (or X, Y), 32) -> (lshr [X/Y], 32) if one doesn't contribute 9703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // bits. 9803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 9903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 10003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // If the constant expr is something like &A[123] - &A[4].f, fold this into a 10103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // constant. This happens frequently when iterating over a global array. 10203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (Opc == Instruction::Sub && TD) { 10303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner GlobalValue *GV1, *GV2; 10403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner int64_t Offs1, Offs2; 10503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 10603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (IsConstantOffsetFromGlobal(Op0, GV1, Offs1, *TD)) 10703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (IsConstantOffsetFromGlobal(Op1, GV2, Offs2, *TD) && 10803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner GV1 == GV2) { 10903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // (&GV+C1) - (&GV+C2) -> C1-C2, pointer arithmetic cannot overflow. 11003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return ConstantInt::get(Op0->getType(), Offs1-Offs2); 11103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 11203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 11303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 11403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // TODO: Fold icmp setne/seteq as well. 11503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return 0; 11603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner} 11703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 11803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// SymbolicallyEvaluateGEP - If we can symbolically evaluate the specified GEP 11903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// constant expression, do so. 12003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattnerstatic Constant *SymbolicallyEvaluateGEP(Constant** Ops, unsigned NumOps, 12103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner const Type *ResultTy, 12203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner const TargetData *TD) { 12303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner Constant *Ptr = Ops[0]; 12403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (!cast<PointerType>(Ptr->getType())->getElementType()->isSized()) 12503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return 0; 12603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 12703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (TD && Ptr->isNullValue()) { 12803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // If this is a constant expr gep that is effectively computing an 12903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // "offsetof", fold it into 'cast int Size to T*' instead of 'gep 0, 0, 12' 13003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner bool isFoldableGEP = true; 13103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner for (unsigned i = 1; i != NumOps; ++i) 13203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (!isa<ConstantInt>(Ops[i])) { 13303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner isFoldableGEP = false; 13403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner break; 13503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 13603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (isFoldableGEP) { 137309f87e34a12e3398932e4c2c9e3c47cad0e8f0fChris Lattner uint64_t Offset = TD->getIndexedOffset(Ptr->getType(), 138309f87e34a12e3398932e4c2c9e3c47cad0e8f0fChris Lattner (Value**)Ops+1, NumOps-1); 13903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner Constant *C = ConstantInt::get(TD->getIntPtrType(), Offset); 14003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return ConstantExpr::getIntToPtr(C, ResultTy); 14103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 14203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 14303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 14403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return 0; 14503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner} 14603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 14703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 14803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner//===----------------------------------------------------------------------===// 14903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner// Constant Folding public APIs 15003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner//===----------------------------------------------------------------------===// 15103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 15203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 1535520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// ConstantFoldInstruction - Attempt to constant fold the specified 1545520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// instruction. If successful, the constant result is returned, if not, null 1555520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// is returned. Note that this function can only fail when attempting to fold 1565520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// instructions like loads and stores, which have no constant expression form. 1575520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// 1585520732b24a5a321140dd79af70d321c7ff3dec9Chris LattnerConstant *llvm::ConstantFoldInstruction(Instruction *I, const TargetData *TD) { 1595520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (PHINode *PN = dyn_cast<PHINode>(I)) { 1605520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (PN->getNumIncomingValues() == 0) 1615520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return Constant::getNullValue(PN->getType()); 1625520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 1635520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner Constant *Result = dyn_cast<Constant>(PN->getIncomingValue(0)); 1645520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (Result == 0) return 0; 1655520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 1665520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // Handle PHI nodes specially here... 1675520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner for (unsigned i = 1, e = PN->getNumIncomingValues(); i != e; ++i) 1685520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (PN->getIncomingValue(i) != Result && PN->getIncomingValue(i) != PN) 1695520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; // Not all the same incoming constants... 1705520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 1715520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // If we reach here, all incoming values are the same constant. 1725520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return Result; 1735520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 1745520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 1755520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // Scan the operand list, checking to see if they are all constants, if so, 1765520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // hand off to ConstantFoldInstOperands. 1775520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner SmallVector<Constant*, 8> Ops; 1785520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) 1795520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (Constant *Op = dyn_cast<Constant>(I->getOperand(i))) 1805520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner Ops.push_back(Op); 1815520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else 1825520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; // All operands not constant! 1835520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 18403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return ConstantFoldInstOperands(I, &Ops[0], Ops.size(), TD); 1855520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner} 1865520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 1875520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// ConstantFoldInstOperands - Attempt to constant fold an instruction with the 1885520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// specified opcode and operands. If successful, the constant result is 1895520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// returned, if not, null is returned. Note that this function can fail when 1905520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// attempting to fold instructions like loads and stores, which have no 1915520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// constant expression form. 1925520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// 1935520732b24a5a321140dd79af70d321c7ff3dec9Chris LattnerConstant *llvm::ConstantFoldInstOperands(const Instruction* I, 1945520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner Constant** Ops, unsigned NumOps, 1955520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner const TargetData *TD) { 1965520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner unsigned Opc = I->getOpcode(); 1975520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner const Type *DestTy = I->getType(); 1985520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 19903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Handle easy binops first. 20003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (isa<BinaryOperator>(I)) { 20103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (isa<ConstantExpr>(Ops[0]) || isa<ConstantExpr>(Ops[1])) 20203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (Constant *C = SymbolicallyEvaluateBinop(I->getOpcode(), Ops[0], 20303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner Ops[1], TD)) 20403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return C; 20503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 2065520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return ConstantExpr::get(Opc, Ops[0], Ops[1]); 20703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 2085520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 2095520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner switch (Opc) { 2105520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner default: return 0; 2115520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::Call: 2125520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (Function *F = dyn_cast<Function>(Ops[0])) 2135520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (canConstantFoldCallTo(F)) 214ad58eb34342f70f094008e6d08cb4ed814754e64Chris Lattner return ConstantFoldCall(F, Ops+1, NumOps-1); 2155520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 2165520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::ICmp: 2175520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FCmp: 2185520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return ConstantExpr::getCompare(cast<CmpInst>(I)->getPredicate(), Ops[0], 2195520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner Ops[1]); 220001f7534e0311508cc93831a595785bb177f8a18Chris Lattner case Instruction::PtrToInt: 221001f7534e0311508cc93831a595785bb177f8a18Chris Lattner // If the input is a inttoptr, eliminate the pair. This requires knowing 222001f7534e0311508cc93831a595785bb177f8a18Chris Lattner // the width of a pointer, so it can't be done in ConstantExpr::getCast. 223001f7534e0311508cc93831a595785bb177f8a18Chris Lattner if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[0])) { 224001f7534e0311508cc93831a595785bb177f8a18Chris Lattner if (TD && CE->getOpcode() == Instruction::IntToPtr) { 225001f7534e0311508cc93831a595785bb177f8a18Chris Lattner Constant *Input = CE->getOperand(0); 226001f7534e0311508cc93831a595785bb177f8a18Chris Lattner unsigned InWidth = Input->getType()->getPrimitiveSizeInBits(); 227001f7534e0311508cc93831a595785bb177f8a18Chris Lattner Constant *Mask = 228001f7534e0311508cc93831a595785bb177f8a18Chris Lattner ConstantInt::get(APInt::getLowBitsSet(InWidth, 229001f7534e0311508cc93831a595785bb177f8a18Chris Lattner TD->getPointerSizeInBits())); 230001f7534e0311508cc93831a595785bb177f8a18Chris Lattner Input = ConstantExpr::getAnd(Input, Mask); 231001f7534e0311508cc93831a595785bb177f8a18Chris Lattner // Do a zext or trunc to get to the dest size. 232001f7534e0311508cc93831a595785bb177f8a18Chris Lattner return ConstantExpr::getIntegerCast(Input, I->getType(), false); 233001f7534e0311508cc93831a595785bb177f8a18Chris Lattner } 234001f7534e0311508cc93831a595785bb177f8a18Chris Lattner } 235001f7534e0311508cc93831a595785bb177f8a18Chris Lattner // FALL THROUGH. 236001f7534e0311508cc93831a595785bb177f8a18Chris Lattner case Instruction::IntToPtr: 2375520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::Trunc: 2385520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::ZExt: 2395520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::SExt: 2405520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FPTrunc: 2415520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FPExt: 2425520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::UIToFP: 2435520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::SIToFP: 2445520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FPToUI: 2455520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FPToSI: 2465520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::BitCast: 2475520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return ConstantExpr::getCast(Opc, Ops[0], DestTy); 2485520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::Select: 2495520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return ConstantExpr::getSelect(Ops[0], Ops[1], Ops[2]); 2505520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::ExtractElement: 2515520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return ConstantExpr::getExtractElement(Ops[0], Ops[1]); 2525520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::InsertElement: 2535520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return ConstantExpr::getInsertElement(Ops[0], Ops[1], Ops[2]); 2545520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::ShuffleVector: 2555520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return ConstantExpr::getShuffleVector(Ops[0], Ops[1], Ops[2]); 2565520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::GetElementPtr: 25703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (Constant *C = SymbolicallyEvaluateGEP(Ops, NumOps, I->getType(), TD)) 25803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return C; 25903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 260d917fe56926f2f80665fd154eb23ca41e9df6f67Chris Lattner return ConstantExpr::getGetElementPtr(Ops[0], Ops+1, NumOps-1); 2615520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 2625520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner} 2635520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 2645520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// ConstantFoldLoadThroughGEPConstantExpr - Given a constant and a 2655520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// getelementptr constantexpr, return the constant value being addressed by the 2665520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// constant expression, or null if something is funny and we can't decide. 2675520732b24a5a321140dd79af70d321c7ff3dec9Chris LattnerConstant *llvm::ConstantFoldLoadThroughGEPConstantExpr(Constant *C, 2685520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner ConstantExpr *CE) { 2695520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (CE->getOperand(1) != Constant::getNullValue(CE->getOperand(1)->getType())) 2705520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; // Do not allow stepping over the value! 2715520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 2725520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // Loop over all of the operands, tracking down which value we are 2735520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // addressing... 2745520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner gep_type_iterator I = gep_type_begin(CE), E = gep_type_end(CE); 2755520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner for (++I; I != E; ++I) 2765520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (const StructType *STy = dyn_cast<StructType>(*I)) { 2775520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner ConstantInt *CU = cast<ConstantInt>(I.getOperand()); 2785520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner assert(CU->getZExtValue() < STy->getNumElements() && 2795520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner "Struct index out of range!"); 2805520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner unsigned El = (unsigned)CU->getZExtValue(); 2815520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) { 2825520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = CS->getOperand(El); 2835520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else if (isa<ConstantAggregateZero>(C)) { 2845520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = Constant::getNullValue(STy->getElementType(El)); 2855520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else if (isa<UndefValue>(C)) { 2865520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = UndefValue::get(STy->getElementType(El)); 2875520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else { 2885520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 2895520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 2905520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else if (ConstantInt *CI = dyn_cast<ConstantInt>(I.getOperand())) { 2915520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (const ArrayType *ATy = dyn_cast<ArrayType>(*I)) { 2925520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (CI->getZExtValue() >= ATy->getNumElements()) 2935520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 2945520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (ConstantArray *CA = dyn_cast<ConstantArray>(C)) 2955520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = CA->getOperand(CI->getZExtValue()); 2965520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else if (isa<ConstantAggregateZero>(C)) 2975520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = Constant::getNullValue(ATy->getElementType()); 2985520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else if (isa<UndefValue>(C)) 2995520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = UndefValue::get(ATy->getElementType()); 3005520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else 3015520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 3029d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer } else if (const VectorType *PTy = dyn_cast<VectorType>(*I)) { 3035520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (CI->getZExtValue() >= PTy->getNumElements()) 3045520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 3059d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer if (ConstantVector *CP = dyn_cast<ConstantVector>(C)) 3065520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = CP->getOperand(CI->getZExtValue()); 3075520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else if (isa<ConstantAggregateZero>(C)) 3085520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = Constant::getNullValue(PTy->getElementType()); 3095520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else if (isa<UndefValue>(C)) 3105520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = UndefValue::get(PTy->getElementType()); 3115520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else 3125520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 3135520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else { 3145520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 3155520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 3165520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else { 3175520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 3185520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 3195520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return C; 3205520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner} 3215520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 3225520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 323bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell//===----------------------------------------------------------------------===// 3245520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner// Constant Folding for Calls 325bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell// 326bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 327bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell/// canConstantFoldCallTo - Return true if its even possible to fold a call to 328bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell/// the specified function. 329bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswellbool 330bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswellllvm::canConstantFoldCallTo(Function *F) { 331bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell switch (F->getIntrinsicID()) { 3329ab7fb3ba47442d521a5bed09a27a5e8e7a786edDale Johannesen case Intrinsic::sqrt: 3339ab7fb3ba47442d521a5bed09a27a5e8e7a786edDale Johannesen case Intrinsic::powi: 334e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer case Intrinsic::bswap: 335e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer case Intrinsic::ctpop: 336e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer case Intrinsic::ctlz: 337e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer case Intrinsic::cttz: 338bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell return true; 339bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell default: break; 340bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 341bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 342c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner const ValueName *NameVal = F->getValueName(); 343a099b6c7bb574f22bc002e0b3c65c25abccca1d5Chris Lattner if (NameVal == 0) return false; 344c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner const char *Str = NameVal->getKeyData(); 345c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner unsigned Len = NameVal->getKeyLength(); 346c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner 347c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner // In these cases, the check of the length is required. We don't want to 348c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner // return true for a name like "cos\0blah" which strcmp would return equal to 349c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner // "cos", but has length 8. 350c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner switch (Str[0]) { 351c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner default: return false; 352c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'a': 353c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 4) 354c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "acos") || !strcmp(Str, "asin") || 355c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner !strcmp(Str, "atan"); 356c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 5) 357c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "atan2"); 358c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return false; 359c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'c': 360c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3) 361c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "cos"); 362c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 4) 363c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "ceil") || !strcmp(Str, "cosf") || 364c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner !strcmp(Str, "cosh"); 365c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return false; 366c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'e': 367c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3) 368c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "exp"); 369c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return false; 370c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'f': 371c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 4) 372c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "fabs") || !strcmp(Str, "fmod"); 373c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 5) 374c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "floor"); 375c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return false; 376c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 377c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'l': 378c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3 && !strcmp(Str, "log")) 379c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return true; 380c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 5 && !strcmp(Str, "log10")) 381c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return true; 382c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return false; 383c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'p': 384c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3 && !strcmp(Str, "pow")) 385c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return true; 386c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return false; 387c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 's': 388c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3) 389c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "sin"); 390c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 4) 391c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "sinh") || !strcmp(Str, "sqrt"); 392c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 5) 393c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return !strcmp(Str, "sqrtf"); 394c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return false; 395c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 't': 396c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3 && !strcmp(Str, "tan")) 397c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return true; 398c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 4 && !strcmp(Str, "tanh")) 399c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return true; 400c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return false; 401bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 402bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell} 403bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 40472d88ae5447a3929c97e88f4c806213847b5d988Chris Lattnerstatic Constant *ConstantFoldFP(double (*NativeFP)(double), double V, 40572d88ae5447a3929c97e88f4c806213847b5d988Chris Lattner const Type *Ty) { 406bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell errno = 0; 407bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell V = NativeFP(V); 40843421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen if (errno == 0) { 40943421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen if (Ty==Type::FloatTy) 41043421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen return ConstantFP::get(Ty, APFloat((float)V)); 41143421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen else if (Ty==Type::DoubleTy) 41243421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen return ConstantFP::get(Ty, APFloat(V)); 41343421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen else 41443421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen assert(0); 41543421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen } 41672d88ae5447a3929c97e88f4c806213847b5d988Chris Lattner errno = 0; 417bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell return 0; 418bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell} 419bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 420384152444d22d356f7b4090a158da4cbc1f79464Dan Gohmanstatic Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double), 421384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman double V, double W, 422384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman const Type *Ty) { 423384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman errno = 0; 424384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman V = NativeFP(V, W); 42543421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen if (errno == 0) { 42643421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen if (Ty==Type::FloatTy) 42743421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen return ConstantFP::get(Ty, APFloat((float)V)); 42843421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen else if (Ty==Type::DoubleTy) 42943421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen return ConstantFP::get(Ty, APFloat(V)); 43043421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen else 43143421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen assert(0); 43243421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen } 433384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman errno = 0; 434384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman return 0; 435384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman} 436384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman 437bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell/// ConstantFoldCall - Attempt to constant fold a call to the specified function 438bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell/// with the specified arguments, returning null if unsuccessful. 43943421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen 440bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John CriswellConstant * 44172d88ae5447a3929c97e88f4c806213847b5d988Chris Lattnerllvm::ConstantFoldCall(Function *F, Constant** Operands, unsigned NumOperands) { 442c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner const ValueName *NameVal = F->getValueName(); 443a099b6c7bb574f22bc002e0b3c65c25abccca1d5Chris Lattner if (NameVal == 0) return 0; 444c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner const char *Str = NameVal->getKeyData(); 445c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner unsigned Len = NameVal->getKeyLength(); 446c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner 447bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell const Type *Ty = F->getReturnType(); 44872d88ae5447a3929c97e88f4c806213847b5d988Chris Lattner if (NumOperands == 1) { 449bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell if (ConstantFP *Op = dyn_cast<ConstantFP>(Operands[0])) { 45043421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen if (Ty!=Type::FloatTy && Ty!=Type::DoubleTy) 45143421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen return 0; 45243421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen /// Currently APFloat versions of these functions do not exist, so we use 45343421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen /// the host native double versions. Float versions are not called 45443421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen /// directly but for all these it is true (float)(f((double)arg)) == 45543421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen /// f(arg). Long double not supported yet. 45643421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen double V = Ty==Type::FloatTy ? (double)Op->getValueAPF().convertToFloat(): 45743421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen Op->getValueAPF().convertToDouble(); 458c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner switch (Str[0]) { 459c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'a': 460c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 4 && !strcmp(Str, "acos")) 461c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(acos, V, Ty); 462c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 4 && !strcmp(Str, "asin")) 463c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(asin, V, Ty); 464c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 4 && !strcmp(Str, "atan")) 465c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(atan, V, Ty); 466c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 467c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'c': 468c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 4 && !strcmp(Str, "ceil")) 469c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(ceil, V, Ty); 470c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 3 && !strcmp(Str, "cos")) 471c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(cos, V, Ty); 472c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 4 && !strcmp(Str, "cosh")) 473c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(cosh, V, Ty); 474c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 475c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'e': 476c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3 && !strcmp(Str, "exp")) 477c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(exp, V, Ty); 478c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 479c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'f': 480c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 4 && !strcmp(Str, "fabs")) 48143421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen return ConstantFoldFP(fabs, V, Ty); 482c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 5 && !strcmp(Str, "floor")) 483c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(floor, V, Ty); 484c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 485c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'l': 486c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3 && !strcmp(Str, "log") && V > 0) 487c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(log, V, Ty); 488c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 5 && !strcmp(Str, "log10") && V > 0) 489c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(log10, V, Ty); 490c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (!strcmp(Str, "llvm.sqrt.f32") || 491c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner !strcmp(Str, "llvm.sqrt.f64")) { 492c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (V >= -0.0) 49343421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen return ConstantFoldFP(sqrt, V, Ty); 494c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else // Undefined 49543421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen return ConstantFP::get(Ty, Ty==Type::FloatTy ? APFloat(0.0f) : 49643421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen APFloat(0.0)); 497c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner } 498c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 499c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 's': 500c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3 && !strcmp(Str, "sin")) 501c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(sin, V, Ty); 502c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 4 && !strcmp(Str, "sinh")) 503c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(sinh, V, Ty); 504c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 4 && !strcmp(Str, "sqrt") && V >= 0) 505c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(sqrt, V, Ty); 506c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 5 && !strcmp(Str, "sqrtf") && V >= 0) 507c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(sqrt, V, Ty); 508c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 509c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 't': 510c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3 && !strcmp(Str, "tan")) 511c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(tan, V, Ty); 512c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else if (Len == 4 && !strcmp(Str, "tanh")) 513c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner return ConstantFoldFP(tanh, V, Ty); 514c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 515c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner default: 516c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 517bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 518b83eb6447ba155342598f0fabe1f08f5baa9164aReid Spencer } else if (ConstantInt *Op = dyn_cast<ConstantInt>(Operands[0])) { 519c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len > 11 && !memcmp(Str, "llvm.bswap", 10)) { 520e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer return ConstantInt::get(Op->getValue().byteSwap()); 521c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner } else if (Len > 11 && !memcmp(Str, "llvm.ctpop", 10)) { 522e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer uint64_t ctpop = Op->getValue().countPopulation(); 5236994040a952e5fb27605eb3cf29ed86c4e59cf62Chandler Carruth return ConstantInt::get(Ty, ctpop); 524c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner } else if (Len > 10 && !memcmp(Str, "llvm.cttz", 9)) { 525e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer uint64_t cttz = Op->getValue().countTrailingZeros(); 5266994040a952e5fb27605eb3cf29ed86c4e59cf62Chandler Carruth return ConstantInt::get(Ty, cttz); 527c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner } else if (Len > 10 && !memcmp(Str, "llvm.ctlz", 9)) { 528e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer uint64_t ctlz = Op->getValue().countLeadingZeros(); 5296994040a952e5fb27605eb3cf29ed86c4e59cf62Chandler Carruth return ConstantInt::get(Ty, ctlz); 530e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer } 531bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 53272d88ae5447a3929c97e88f4c806213847b5d988Chris Lattner } else if (NumOperands == 2) { 533bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell if (ConstantFP *Op1 = dyn_cast<ConstantFP>(Operands[0])) { 5349ab7fb3ba47442d521a5bed09a27a5e8e7a786edDale Johannesen if (Ty!=Type::FloatTy && Ty!=Type::DoubleTy) 5359ab7fb3ba47442d521a5bed09a27a5e8e7a786edDale Johannesen return 0; 53643421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen double Op1V = Ty==Type::FloatTy ? 53743421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen (double)Op1->getValueAPF().convertToFloat(): 53843421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen Op1->getValueAPF().convertToDouble(); 539bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell if (ConstantFP *Op2 = dyn_cast<ConstantFP>(Operands[1])) { 54043421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen double Op2V = Ty==Type::FloatTy ? 54143421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen (double)Op2->getValueAPF().convertToFloat(): 54243421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen Op2->getValueAPF().convertToDouble(); 543bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 544c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (Len == 3 && !strcmp(Str, "pow")) { 545384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty); 546c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner } else if (Len == 4 && !strcmp(Str, "fmod")) { 547384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman return ConstantFoldBinaryFP(fmod, Op1V, Op2V, Ty); 548c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner } else if (Len == 5 && !strcmp(Str, "atan2")) { 549384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman return ConstantFoldBinaryFP(atan2, Op1V, Op2V, Ty); 550b5282dcf4745be59046f440980a1c0f0a50c9c09Chris Lattner } 551b5282dcf4745be59046f440980a1c0f0a50c9c09Chris Lattner } else if (ConstantInt *Op2C = dyn_cast<ConstantInt>(Operands[1])) { 552c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (!strcmp(Str, "llvm.powi.f32")) { 55343421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen return ConstantFP::get(Ty, APFloat((float)std::pow((float)Op1V, 55443421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen (int)Op2C->getZExtValue()))); 555c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner } else if (!strcmp(Str, "llvm.powi.f64")) { 55643421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen return ConstantFP::get(Ty, APFloat((double)std::pow((double)Op1V, 55743421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen (int)Op2C->getZExtValue()))); 558b5282dcf4745be59046f440980a1c0f0a50c9c09Chris Lattner } 559bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 560bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 561bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 562bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell return 0; 563bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell} 564bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 565