ConstantFolding.cpp revision fac554a1317bf32daf5698740670025ae14e6bcc
183e3c4f9d796a5da223a3ebd5d4ba985c7ecc39dDan Gohman//===-- ConstantFolding.cpp - Fold instructions into constants ------------===// 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// 1083e3c4f9d796a5da223a3ebd5d4ba985c7ecc39dDan Gohman// This file defines routines for folding instructions into constants. 1183e3c4f9d796a5da223a3ebd5d4ba985c7ecc39dDan Gohman// 1283e3c4f9d796a5da223a3ebd5d4ba985c7ecc39dDan Gohman// Also, to supplement the basic VMCore ConstantExpr simplifications, 1383e3c4f9d796a5da223a3ebd5d4ba985c7ecc39dDan Gohman// this file defines some additional folding routines that can make use of 1483e3c4f9d796a5da223a3ebd5d4ba985c7ecc39dDan Gohman// TargetData information. These functions cannot go in VMCore due to library 1583e3c4f9d796a5da223a3ebd5d4ba985c7ecc39dDan Gohman// dependency issues. 16bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell// 17bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell//===----------------------------------------------------------------------===// 18bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 19bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell#include "llvm/Analysis/ConstantFolding.h" 20bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell#include "llvm/Constants.h" 21bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell#include "llvm/DerivedTypes.h" 225520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner#include "llvm/Function.h" 239a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman#include "llvm/GlobalVariable.h" 24bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell#include "llvm/Instructions.h" 25bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell#include "llvm/Intrinsics.h" 2662d327e241f59735eed836e98c8f11ffaa6cf6f8Chris Lattner#include "llvm/Analysis/ValueTracking.h" 2762d327e241f59735eed836e98c8f11ffaa6cf6f8Chris Lattner#include "llvm/Target/TargetData.h" 285520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner#include "llvm/ADT/SmallVector.h" 29c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner#include "llvm/ADT/StringMap.h" 30c25e7581b9b8088910da31702d4ca21c4734c6d7Torok Edwin#include "llvm/Support/ErrorHandling.h" 31bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell#include "llvm/Support/GetElementPtrTypeIterator.h" 32bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell#include "llvm/Support/MathExtras.h" 33bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell#include <cerrno> 3497af751deb9b26fd42fbcee082da9ccc4ded5b45Jeff Cohen#include <cmath> 35bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswellusing namespace llvm; 36bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 3703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner//===----------------------------------------------------------------------===// 3803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner// Constant Folding internal helper functions 3903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner//===----------------------------------------------------------------------===// 4003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 416333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner/// FoldBitCast - Constant fold bitcast, symbolically evaluating it with 426333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner/// TargetData. This always returns a non-null constant, but it may be a 436333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner/// ConstantExpr if unfoldable. 446333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattnerstatic Constant *FoldBitCast(Constant *C, const Type *DestTy, 456333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner const TargetData &TD) { 466333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 4793798daa3ecbfb29624052d3e54d2404ab65897aChris Lattner // This only handles casts to vectors currently. 486333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner const VectorType *DestVTy = dyn_cast<VectorType>(DestTy); 496333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner if (DestVTy == 0) 506333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner return ConstantExpr::getBitCast(C, DestTy); 516333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 5293798daa3ecbfb29624052d3e54d2404ab65897aChris Lattner // If this is a scalar -> vector cast, convert the input into a <1 x scalar> 5393798daa3ecbfb29624052d3e54d2404ab65897aChris Lattner // vector so the code below can handle it uniformly. 5493798daa3ecbfb29624052d3e54d2404ab65897aChris Lattner if (isa<ConstantFP>(C) || isa<ConstantInt>(C)) { 5593798daa3ecbfb29624052d3e54d2404ab65897aChris Lattner Constant *Ops = C; // don't take the address of C! 5693798daa3ecbfb29624052d3e54d2404ab65897aChris Lattner return FoldBitCast(ConstantVector::get(&Ops, 1), DestTy, TD); 5793798daa3ecbfb29624052d3e54d2404ab65897aChris Lattner } 5893798daa3ecbfb29624052d3e54d2404ab65897aChris Lattner 5993798daa3ecbfb29624052d3e54d2404ab65897aChris Lattner // If this is a bitcast from constant vector -> vector, fold it. 6093798daa3ecbfb29624052d3e54d2404ab65897aChris Lattner ConstantVector *CV = dyn_cast<ConstantVector>(C); 6193798daa3ecbfb29624052d3e54d2404ab65897aChris Lattner if (CV == 0) 6293798daa3ecbfb29624052d3e54d2404ab65897aChris Lattner return ConstantExpr::getBitCast(C, DestTy); 6393798daa3ecbfb29624052d3e54d2404ab65897aChris Lattner 646333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // If the element types match, VMCore can fold it. 656333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner unsigned NumDstElt = DestVTy->getNumElements(); 666333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner unsigned NumSrcElt = CV->getNumOperands(); 676333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner if (NumDstElt == NumSrcElt) 686333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner return ConstantExpr::getBitCast(C, DestTy); 696333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 706333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner const Type *SrcEltTy = CV->getType()->getElementType(); 716333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner const Type *DstEltTy = DestVTy->getElementType(); 726333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 736333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Otherwise, we're changing the number of elements in a vector, which 746333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // requires endianness information to do the right thing. For example, 756333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>) 766333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // folds to (little endian): 776333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // <4 x i32> <i32 0, i32 0, i32 1, i32 0> 786333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // and to (big endian): 796333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // <4 x i32> <i32 0, i32 0, i32 0, i32 1> 806333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 816333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // First thing is first. We only want to think about integer here, so if 826333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // we have something in FP form, recast it as integer. 836333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner if (DstEltTy->isFloatingPoint()) { 846333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Fold to an vector of integers with same size as our FP type. 856333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner unsigned FPWidth = DstEltTy->getPrimitiveSizeInBits(); 866333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner const Type *DestIVTy = 876333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner VectorType::get(IntegerType::get(C->getContext(), FPWidth), NumDstElt); 886333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Recursively handle this integer conversion, if possible. 896333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner C = FoldBitCast(C, DestIVTy, TD); 906333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner if (!C) return ConstantExpr::getBitCast(C, DestTy); 916333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 926333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Finally, VMCore can handle this now that #elts line up. 936333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner return ConstantExpr::getBitCast(C, DestTy); 946333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner } 956333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 966333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Okay, we know the destination is integer, if the input is FP, convert 976333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // it to integer first. 986333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner if (SrcEltTy->isFloatingPoint()) { 996333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner unsigned FPWidth = SrcEltTy->getPrimitiveSizeInBits(); 1006333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner const Type *SrcIVTy = 1016333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner VectorType::get(IntegerType::get(C->getContext(), FPWidth), NumSrcElt); 1026333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Ask VMCore to do the conversion now that #elts line up. 1036333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner C = ConstantExpr::getBitCast(C, SrcIVTy); 1046333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner CV = dyn_cast<ConstantVector>(C); 1056333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner if (!CV) // If VMCore wasn't able to fold it, bail out. 1066333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner return C; 1076333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner } 1086333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 1096333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Now we know that the input and output vectors are both integer vectors 1106333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // of the same size, and that their #elements is not the same. Do the 1116333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // conversion here, which depends on whether the input or output has 1126333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // more elements. 1136333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner bool isLittleEndian = TD.isLittleEndian(); 1146333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 1156333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner SmallVector<Constant*, 32> Result; 1166333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner if (NumDstElt < NumSrcElt) { 1176333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Handle: bitcast (<4 x i32> <i32 0, i32 1, i32 2, i32 3> to <2 x i64>) 1186333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner Constant *Zero = Constant::getNullValue(DstEltTy); 1196333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner unsigned Ratio = NumSrcElt/NumDstElt; 1206333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner unsigned SrcBitSize = SrcEltTy->getPrimitiveSizeInBits(); 1216333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner unsigned SrcElt = 0; 1226333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner for (unsigned i = 0; i != NumDstElt; ++i) { 1236333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Build each element of the result. 1246333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner Constant *Elt = Zero; 1256333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner unsigned ShiftAmt = isLittleEndian ? 0 : SrcBitSize*(Ratio-1); 1266333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner for (unsigned j = 0; j != Ratio; ++j) { 1276333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner Constant *Src = dyn_cast<ConstantInt>(CV->getOperand(SrcElt++)); 1286333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner if (!Src) // Reject constantexpr elements. 1296333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner return ConstantExpr::getBitCast(C, DestTy); 1306333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 1316333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Zero extend the element to the right size. 1326333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner Src = ConstantExpr::getZExt(Src, Elt->getType()); 1336333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 1346333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Shift it to the right place, depending on endianness. 1356333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner Src = ConstantExpr::getShl(Src, 1366333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner ConstantInt::get(Src->getType(), ShiftAmt)); 1376333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner ShiftAmt += isLittleEndian ? SrcBitSize : -SrcBitSize; 1386333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 1396333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Mix it in. 1406333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner Elt = ConstantExpr::getOr(Elt, Src); 1416333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner } 1426333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner Result.push_back(Elt); 1436333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner } 1446333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner } else { 1456333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Handle: bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>) 1466333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner unsigned Ratio = NumDstElt/NumSrcElt; 1476333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner unsigned DstBitSize = DstEltTy->getPrimitiveSizeInBits(); 1486333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 1496333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Loop over each source value, expanding into multiple results. 1506333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner for (unsigned i = 0; i != NumSrcElt; ++i) { 1516333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner Constant *Src = dyn_cast<ConstantInt>(CV->getOperand(i)); 1526333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner if (!Src) // Reject constantexpr elements. 1536333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner return ConstantExpr::getBitCast(C, DestTy); 1546333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 1556333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner unsigned ShiftAmt = isLittleEndian ? 0 : DstBitSize*(Ratio-1); 1566333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner for (unsigned j = 0; j != Ratio; ++j) { 1576333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Shift the piece of the value into the right place, depending on 1586333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // endianness. 1596333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner Constant *Elt = ConstantExpr::getLShr(Src, 1606333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner ConstantInt::get(Src->getType(), ShiftAmt)); 1616333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner ShiftAmt += isLittleEndian ? DstBitSize : -DstBitSize; 1626333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 1636333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Truncate and remember this piece. 1646333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner Result.push_back(ConstantExpr::getTrunc(Elt, DstEltTy)); 1656333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner } 1666333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner } 1676333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner } 1686333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 1696333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner return ConstantVector::get(Result.data(), Result.size()); 1706333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner} 1716333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 1726333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 17303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// IsConstantOffsetFromGlobal - If this constant is actually a constant offset 17403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// from a global, return the global and the constant. Because of 17503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// constantexprs, this function is recursive. 17603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattnerstatic bool IsConstantOffsetFromGlobal(Constant *C, GlobalValue *&GV, 17703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner int64_t &Offset, const TargetData &TD) { 17803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Trivial case, constant is the global. 17903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if ((GV = dyn_cast<GlobalValue>(C))) { 18003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner Offset = 0; 18103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return true; 18203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 18303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 18403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Otherwise, if this isn't a constant expr, bail out. 18503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner ConstantExpr *CE = dyn_cast<ConstantExpr>(C); 18603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (!CE) return false; 18703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 18803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Look through ptr->int and ptr->ptr casts. 18903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (CE->getOpcode() == Instruction::PtrToInt || 19003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner CE->getOpcode() == Instruction::BitCast) 19103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD); 19203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 19303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // i32* getelementptr ([5 x i32]* @a, i32 0, i32 5) 19403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (CE->getOpcode() == Instruction::GetElementPtr) { 19503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Cannot compute this if the element type of the pointer is missing size 19603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // info. 197f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (!cast<PointerType>(CE->getOperand(0)->getType()) 198f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner ->getElementType()->isSized()) 19903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return false; 20003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 20103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // If the base isn't a global+constant, we aren't either. 20203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (!IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD)) 20303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return false; 20403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 20503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Otherwise, add any offset that our operands provide. 20603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner gep_type_iterator GTI = gep_type_begin(CE); 207de2d74b213844b17eb5327fba27f21e699d3af66Gabor Greif for (User::const_op_iterator i = CE->op_begin() + 1, e = CE->op_end(); 208785c6af9797fcf551feef70f2ecb5cd075b6e3c4Gabor Greif i != e; ++i, ++GTI) { 209de2d74b213844b17eb5327fba27f21e699d3af66Gabor Greif ConstantInt *CI = dyn_cast<ConstantInt>(*i); 21003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (!CI) return false; // Index isn't a simple constant? 21103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (CI->getZExtValue() == 0) continue; // Not adding anything. 21203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 21303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (const StructType *ST = dyn_cast<StructType>(*GTI)) { 21403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // N = N + Offset 215b1919e2f08ecb37140af676fd2916f8d5ed7df3dChris Lattner Offset += TD.getStructLayout(ST)->getElementOffset(CI->getZExtValue()); 21603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } else { 217ca5183d445954a9b2a570d6bbba1bc2b00ad6442Jeff Cohen const SequentialType *SQT = cast<SequentialType>(*GTI); 218777d2306b36816a53bc1ae1244c0dc7d998ae691Duncan Sands Offset += TD.getTypeAllocSize(SQT->getElementType())*CI->getSExtValue(); 21903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 22003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 22103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return true; 22203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 22303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 22403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return false; 22503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner} 22603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 227fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner/// ReadDataFromGlobal - Recursive helper to read bits out of global. C is the 228fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner/// constant being copied out of. ByteOffset is an offset into C. CurPtr is the 229fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner/// pointer to copy results into and BytesLeft is the number of bytes left in 230fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner/// the CurPtr buffer. TD is the target data. 231fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattnerstatic bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset, 232fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner unsigned char *CurPtr, unsigned BytesLeft, 233fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner const TargetData &TD) { 234fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner assert(ByteOffset <= TD.getTypeAllocSize(C->getType()) && 235fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner "Out of range access"); 236fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 237c7b1382e351249774be63bd73839e8a0671635e1Chris Lattner // If this element is zero or undefined, we can just return since *CurPtr is 238c7b1382e351249774be63bd73839e8a0671635e1Chris Lattner // zero initialized. 239fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (isa<ConstantAggregateZero>(C) || isa<UndefValue>(C)) 240fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return true; 241fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 242fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) { 243fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (CI->getBitWidth() > 64 || 244fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner (CI->getBitWidth() & 7) != 0) 245fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return false; 246fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 247fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner uint64_t Val = CI->getZExtValue(); 248fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner unsigned IntBytes = unsigned(CI->getBitWidth()/8); 249fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 250fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner for (unsigned i = 0; i != BytesLeft && ByteOffset != IntBytes; ++i) { 251c7b1382e351249774be63bd73839e8a0671635e1Chris Lattner CurPtr[i] = (unsigned char)(Val >> (ByteOffset * 8)); 252fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner ++ByteOffset; 253fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner } 254fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return true; 255fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner } 256fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 257fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (ConstantFP *CFP = dyn_cast<ConstantFP>(C)) { 258fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (CFP->getType()->isDoubleTy()) { 2596333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner C = FoldBitCast(C, Type::getInt64Ty(C->getContext()), TD); 260fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, TD); 261fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner } 262fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (CFP->getType()->isFloatTy()){ 2636333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner C = FoldBitCast(C, Type::getInt32Ty(C->getContext()), TD); 264fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, TD); 265fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner } 266c7b1382e351249774be63bd73839e8a0671635e1Chris Lattner return false; 267fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner } 268fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 269fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) { 270fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner const StructLayout *SL = TD.getStructLayout(CS->getType()); 271fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner unsigned Index = SL->getElementContainingOffset(ByteOffset); 272fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner uint64_t CurEltOffset = SL->getElementOffset(Index); 273fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner ByteOffset -= CurEltOffset; 274fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 275fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner while (1) { 276fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // If the element access is to the element itself and not to tail padding, 277fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // read the bytes from the element. 278fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner uint64_t EltSize = TD.getTypeAllocSize(CS->getOperand(Index)->getType()); 279fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 280fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (ByteOffset < EltSize && 281fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner !ReadDataFromGlobal(CS->getOperand(Index), ByteOffset, CurPtr, 282fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner BytesLeft, TD)) 283fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return false; 284fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 285fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner ++Index; 286fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 287fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // Check to see if we read from the last struct element, if so we're done. 288fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (Index == CS->getType()->getNumElements()) 289fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return true; 290fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 291fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // If we read all of the bytes we needed from this element we're done. 292fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner uint64_t NextEltOffset = SL->getElementOffset(Index); 293fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 294fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (BytesLeft <= NextEltOffset-CurEltOffset-ByteOffset) 295fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return true; 296fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 297fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // Move to the next element of the struct. 298c5af649758ac8c6ffb896d7d5c570640a9fa1deeChris Lattner CurPtr += NextEltOffset-CurEltOffset-ByteOffset; 299fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner BytesLeft -= NextEltOffset-CurEltOffset-ByteOffset; 300fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner ByteOffset = 0; 301fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner CurEltOffset = NextEltOffset; 302fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner } 303fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // not reached. 304fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner } 305fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 306fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (ConstantArray *CA = dyn_cast<ConstantArray>(C)) { 307fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner uint64_t EltSize = TD.getTypeAllocSize(CA->getType()->getElementType()); 308fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner uint64_t Index = ByteOffset / EltSize; 309fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner uint64_t Offset = ByteOffset - Index * EltSize; 310fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner for (; Index != CA->getType()->getNumElements(); ++Index) { 311fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (!ReadDataFromGlobal(CA->getOperand(Index), Offset, CurPtr, 312fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner BytesLeft, TD)) 313fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return false; 314fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (EltSize >= BytesLeft) 315fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return true; 316fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 317fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner Offset = 0; 318fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner BytesLeft -= EltSize; 319fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner CurPtr += EltSize; 320fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner } 321fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return true; 322fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner } 323fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 324fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (ConstantVector *CV = dyn_cast<ConstantVector>(C)) { 325fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner uint64_t EltSize = TD.getTypeAllocSize(CV->getType()->getElementType()); 326fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner uint64_t Index = ByteOffset / EltSize; 327fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner uint64_t Offset = ByteOffset - Index * EltSize; 328fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner for (; Index != CV->getType()->getNumElements(); ++Index) { 329fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (!ReadDataFromGlobal(CV->getOperand(Index), Offset, CurPtr, 330fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner BytesLeft, TD)) 331fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return false; 332fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (EltSize >= BytesLeft) 333fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return true; 334fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 335fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner Offset = 0; 336fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner BytesLeft -= EltSize; 337fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner CurPtr += EltSize; 338fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner } 339fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return true; 340fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner } 341fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 342fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // Otherwise, unknown initializer type. 343fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return false; 344fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner} 345fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 346fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattnerstatic Constant *FoldReinterpretLoadFromConstPtr(Constant *C, 347fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner const TargetData &TD) { 34817f0cd3cc1432231f2bc5601e7e463986a59d817Chris Lattner const Type *LoadTy = cast<PointerType>(C->getType())->getElementType(); 34917f0cd3cc1432231f2bc5601e7e463986a59d817Chris Lattner const IntegerType *IntType = dyn_cast<IntegerType>(LoadTy); 350fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 351fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // If this isn't an integer load we can't fold it directly. 352fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (!IntType) { 353fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // If this is a float/double load, we can try folding it as an int32/64 load 35417f0cd3cc1432231f2bc5601e7e463986a59d817Chris Lattner // and then bitcast the result. This can be useful for union cases. Note 35517f0cd3cc1432231f2bc5601e7e463986a59d817Chris Lattner // that address spaces don't matter here since we're not going to result in 35617f0cd3cc1432231f2bc5601e7e463986a59d817Chris Lattner // an actual new load. 357fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner const Type *MapTy; 35817f0cd3cc1432231f2bc5601e7e463986a59d817Chris Lattner if (LoadTy->isFloatTy()) 359fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner MapTy = Type::getInt32PtrTy(C->getContext()); 36017f0cd3cc1432231f2bc5601e7e463986a59d817Chris Lattner else if (LoadTy->isDoubleTy()) 361fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner MapTy = Type::getInt64PtrTy(C->getContext()); 36217f0cd3cc1432231f2bc5601e7e463986a59d817Chris Lattner else if (isa<VectorType>(LoadTy)) { 36317f0cd3cc1432231f2bc5601e7e463986a59d817Chris Lattner MapTy = IntegerType::get(C->getContext(), 36417f0cd3cc1432231f2bc5601e7e463986a59d817Chris Lattner TD.getTypeAllocSizeInBits(LoadTy)); 36517f0cd3cc1432231f2bc5601e7e463986a59d817Chris Lattner MapTy = PointerType::getUnqual(MapTy); 36617f0cd3cc1432231f2bc5601e7e463986a59d817Chris Lattner } else 367fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return 0; 368fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 3696333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner C = FoldBitCast(C, MapTy, TD); 370fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (Constant *Res = FoldReinterpretLoadFromConstPtr(C, TD)) 3716333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner return FoldBitCast(Res, LoadTy, TD); 372fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return 0; 373fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner } 374fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 375fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner unsigned BytesLoaded = (IntType->getBitWidth() + 7) / 8; 376739208a790398cf1f9da05149c768371e48781e8Chris Lattner if (BytesLoaded > 32 || BytesLoaded == 0) return 0; 377fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 378fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner GlobalValue *GVal; 379fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner int64_t Offset; 380fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (!IsConstantOffsetFromGlobal(C, GVal, Offset, TD)) 381fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return 0; 382fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 383fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner GlobalVariable *GV = dyn_cast<GlobalVariable>(GVal); 384c7b1382e351249774be63bd73839e8a0671635e1Chris Lattner if (!GV || !GV->isConstant() || !GV->hasDefinitiveInitializer() || 385fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner !GV->getInitializer()->getType()->isSized()) 386fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return 0; 387fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 388fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // If we're loading off the beginning of the global, some bytes may be valid, 389fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // but we don't try to handle this. 390fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (Offset < 0) return 0; 391fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 392fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // If we're not accessing anything in this constant, the result is undefined. 393fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (uint64_t(Offset) >= TD.getTypeAllocSize(GV->getInitializer()->getType())) 394fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return UndefValue::get(IntType); 395fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 396739208a790398cf1f9da05149c768371e48781e8Chris Lattner unsigned char RawBytes[32] = {0}; 397fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (!ReadDataFromGlobal(GV->getInitializer(), Offset, RawBytes, 398fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner BytesLoaded, TD)) 399fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return 0; 400fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 401739208a790398cf1f9da05149c768371e48781e8Chris Lattner APInt ResultVal(IntType->getBitWidth(), 0); 402739208a790398cf1f9da05149c768371e48781e8Chris Lattner for (unsigned i = 0; i != BytesLoaded; ++i) { 403739208a790398cf1f9da05149c768371e48781e8Chris Lattner ResultVal <<= 8; 404739208a790398cf1f9da05149c768371e48781e8Chris Lattner ResultVal |= APInt(IntType->getBitWidth(), RawBytes[BytesLoaded-1-i]); 405739208a790398cf1f9da05149c768371e48781e8Chris Lattner } 406fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 407739208a790398cf1f9da05149c768371e48781e8Chris Lattner return ConstantInt::get(IntType->getContext(), ResultVal); 408fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner} 409fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 410878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner/// ConstantFoldLoadFromConstPtr - Return the value that a load from C would 411878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner/// produce if it is constant and determinable. If this is not determinable, 412878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner/// return null. 413878e4946700824954d7eb7f3ff660353db8e0d17Chris LattnerConstant *llvm::ConstantFoldLoadFromConstPtr(Constant *C, 414878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner const TargetData *TD) { 415878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner // First, try the easy cases: 416878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner if (GlobalVariable *GV = dyn_cast<GlobalVariable>(C)) 417878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner if (GV->isConstant() && GV->hasDefinitiveInitializer()) 418878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner return GV->getInitializer(); 419878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner 420e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner // If the loaded value isn't a constant expr, we can't handle it. 421e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner ConstantExpr *CE = dyn_cast<ConstantExpr>(C); 422e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner if (!CE) return 0; 423e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner 424e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner if (CE->getOpcode() == Instruction::GetElementPtr) { 425e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner if (GlobalVariable *GV = dyn_cast<GlobalVariable>(CE->getOperand(0))) 426e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner if (GV->isConstant() && GV->hasDefinitiveInitializer()) 427e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner if (Constant *V = 428e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner ConstantFoldLoadThroughGEPConstantExpr(GV->getInitializer(), CE)) 429e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner return V; 430e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner } 431e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner 432e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner // Instead of loading constant c string, use corresponding integer value 433e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner // directly if string length is small enough. 434e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner std::string Str; 435e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner if (TD && GetConstantStringInfo(CE->getOperand(0), Str) && !Str.empty()) { 436fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner unsigned StrLen = Str.length(); 437e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner const Type *Ty = cast<PointerType>(CE->getType())->getElementType(); 438fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner unsigned NumBits = Ty->getPrimitiveSizeInBits(); 439e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner // Replace LI with immediate integer store. 440fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if ((NumBits >> 3) == StrLen + 1) { 441fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner APInt StrVal(NumBits, 0); 442fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner APInt SingleChar(NumBits, 0); 443e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner if (TD->isLittleEndian()) { 444fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner for (signed i = StrLen-1; i >= 0; i--) { 445e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner SingleChar = (uint64_t) Str[i] & UCHAR_MAX; 44662d327e241f59735eed836e98c8f11ffaa6cf6f8Chris Lattner StrVal = (StrVal << 8) | SingleChar; 44762d327e241f59735eed836e98c8f11ffaa6cf6f8Chris Lattner } 448e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner } else { 449fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner for (unsigned i = 0; i < StrLen; i++) { 450e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner SingleChar = (uint64_t) Str[i] & UCHAR_MAX; 451e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner StrVal = (StrVal << 8) | SingleChar; 452e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner } 453e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner // Append NULL at the end. 454e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner SingleChar = 0; 455e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner StrVal = (StrVal << 8) | SingleChar; 45662d327e241f59735eed836e98c8f11ffaa6cf6f8Chris Lattner } 457e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner return ConstantInt::get(CE->getContext(), StrVal); 45862d327e241f59735eed836e98c8f11ffaa6cf6f8Chris Lattner } 459878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner } 460e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner 461e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner // If this load comes from anywhere in a constant global, and if the global 462e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner // is all undef or zero, we know what it loads. 463e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner if (GlobalVariable *GV = dyn_cast<GlobalVariable>(CE->getUnderlyingObject())){ 464e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner if (GV->isConstant() && GV->hasDefinitiveInitializer()) { 465e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner const Type *ResTy = cast<PointerType>(C->getType())->getElementType(); 466e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner if (GV->getInitializer()->isNullValue()) 467e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner return Constant::getNullValue(ResTy); 468e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner if (isa<UndefValue>(GV->getInitializer())) 469e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner return UndefValue::get(ResTy); 470e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner } 471e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner } 472e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner 473fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // Try hard to fold loads from bitcasted strange and non-type-safe things. We 474fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // currently don't do any of this for big endian systems. It can be 475fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // generalized in the future if someone is interested. 476fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (TD && TD->isLittleEndian()) 477fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return FoldReinterpretLoadFromConstPtr(CE, *TD); 478878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner return 0; 479878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner} 480878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner 481878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattnerstatic Constant *ConstantFoldLoadInst(const LoadInst *LI, const TargetData *TD){ 482878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner if (LI->isVolatile()) return 0; 483878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner 484878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner if (Constant *C = dyn_cast<Constant>(LI->getOperand(0))) 485878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner return ConstantFoldLoadFromConstPtr(C, TD); 486fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 487878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner return 0; 488878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner} 48903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 49003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// SymbolicallyEvaluateBinop - One of Op0/Op1 is a constant expression. 49167e3566d8f6875e9c92d224f493023408a66227eNick Lewycky/// Attempt to symbolically evaluate the result of a binary operator merging 49203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// these together. If target data info is available, it is provided as TD, 49303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// otherwise TD is null. 49403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattnerstatic Constant *SymbolicallyEvaluateBinop(unsigned Opc, Constant *Op0, 4957b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner Constant *Op1, const TargetData *TD){ 49603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // SROA 49703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 49803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Fold (and 0xffffffff00000000, (shl x, 32)) -> shl. 49903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Fold (lshr (or X, Y), 32) -> (lshr [X/Y], 32) if one doesn't contribute 50003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // bits. 50103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 50203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 50303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // If the constant expr is something like &A[123] - &A[4].f, fold this into a 50403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // constant. This happens frequently when iterating over a global array. 50503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (Opc == Instruction::Sub && TD) { 50603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner GlobalValue *GV1, *GV2; 50703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner int64_t Offs1, Offs2; 50803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 50903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (IsConstantOffsetFromGlobal(Op0, GV1, Offs1, *TD)) 51003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (IsConstantOffsetFromGlobal(Op1, GV2, Offs2, *TD) && 51103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner GV1 == GV2) { 51203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // (&GV+C1) - (&GV+C2) -> C1-C2, pointer arithmetic cannot overflow. 513eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson return ConstantInt::get(Op0->getType(), Offs1-Offs2); 51403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 51503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 51603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 51703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return 0; 51803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner} 51903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 52003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// SymbolicallyEvaluateGEP - If we can symbolically evaluate the specified GEP 52103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// constant expression, do so. 5227b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattnerstatic Constant *SymbolicallyEvaluateGEP(Constant *const *Ops, unsigned NumOps, 52303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner const Type *ResultTy, 52403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner const TargetData *TD) { 52503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner Constant *Ptr = Ops[0]; 526268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner if (!TD || !cast<PointerType>(Ptr->getType())->getElementType()->isSized()) 52703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return 0; 528cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman 5297b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner unsigned BitWidth = 5307b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner TD->getTypeSizeInBits(TD->getIntPtrType(Ptr->getContext())); 531cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman APInt BasePtr(BitWidth, 0); 532de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman bool BaseIsInt = true; 533268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner if (!Ptr->isNullValue()) { 534268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner // If this is a inttoptr from a constant int, we can fold this as the base, 535268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner // otherwise we can't. 536268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr)) 537268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner if (CE->getOpcode() == Instruction::IntToPtr) 5387178010a168a378df5d9be95956093a3e5f963fdDan Gohman if (ConstantInt *Base = dyn_cast<ConstantInt>(CE->getOperand(0))) { 539cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman BasePtr = Base->getValue(); 5407178010a168a378df5d9be95956093a3e5f963fdDan Gohman BasePtr.zextOrTrunc(BitWidth); 5417178010a168a378df5d9be95956093a3e5f963fdDan Gohman } 542268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner 543268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner if (BasePtr == 0) 544de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman BaseIsInt = false; 54503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 546268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner 547268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner // If this is a constant expr gep that is effectively computing an 548268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner // "offsetof", fold it into 'cast int Size to T*' instead of 'gep 0, 0, 12' 549268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner for (unsigned i = 1; i != NumOps; ++i) 550268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner if (!isa<ConstantInt>(Ops[i])) 551de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman return 0; 552268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner 553cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman APInt Offset = APInt(BitWidth, 554cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman TD->getIndexedOffset(Ptr->getType(), 555cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman (Value**)Ops+1, NumOps-1)); 556de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman // If the base value for this address is a literal integer value, fold the 557de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman // getelementptr to the resulting integer value casted to the pointer type. 558de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman if (BaseIsInt) { 5597b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner Constant *C = ConstantInt::get(Ptr->getContext(), Offset+BasePtr); 560de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman return ConstantExpr::getIntToPtr(C, ResultTy); 561de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman } 562de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman 563de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman // Otherwise form a regular getelementptr. Recompute the indices so that 564de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman // we eliminate over-indexing of the notional static type array bounds. 565de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman // This makes it easy to determine if the getelementptr is "inbounds". 566de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman // Also, this helps GlobalOpt do SROA on GlobalVariables. 567fac554a1317bf32daf5698740670025ae14e6bccNick Lewycky Ptr = cast<Constant>(Ptr->stripPointerCasts()); 568de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman const Type *Ty = Ptr->getType(); 569de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman SmallVector<Constant*, 32> NewIdxs; 5703d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman do { 571de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman if (const SequentialType *ATy = dyn_cast<SequentialType>(Ty)) { 5723d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman // The only pointer indexing we'll do is on the first index of the GEP. 573f19f9347b85279100f7d549154e37b6d726c3c94Chris Lattner if (isa<PointerType>(ATy) && !NewIdxs.empty()) 5743d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman break; 575de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman // Determine which element of the array the offset points into. 576cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman APInt ElemSize(BitWidth, TD->getTypeAllocSize(ATy->getElementType())); 577de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman if (ElemSize == 0) 578de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman return 0; 579cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman APInt NewIdx = Offset.udiv(ElemSize); 580de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman Offset -= NewIdx * ElemSize; 5817b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner NewIdxs.push_back(ConstantInt::get(TD->getIntPtrType(Ty->getContext()), 5827b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner NewIdx)); 583de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman Ty = ATy->getElementType(); 584de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman } else if (const StructType *STy = dyn_cast<StructType>(Ty)) { 585cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman // Determine which field of the struct the offset points into. The 586cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman // getZExtValue is at least as safe as the StructLayout API because we 587cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman // know the offset is within the struct at this point. 588de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman const StructLayout &SL = *TD->getStructLayout(STy); 589cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman unsigned ElIdx = SL.getElementContainingOffset(Offset.getZExtValue()); 5907b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner NewIdxs.push_back(ConstantInt::get(Type::getInt32Ty(Ty->getContext()), 5917b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner ElIdx)); 592cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman Offset -= APInt(BitWidth, SL.getElementOffset(ElIdx)); 593de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman Ty = STy->getTypeAtIndex(ElIdx); 594de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman } else { 5953d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman // We've reached some non-indexable type. 5963d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman break; 597de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman } 5983d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman } while (Ty != cast<PointerType>(ResultTy)->getElementType()); 5993d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman 6003d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman // If we haven't used up the entire offset by descending the static 6013d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman // type, then the offset is pointing into the middle of an indivisible 6023d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman // member, so we can't simplify it. 6033d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman if (Offset != 0) 6043d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman return 0; 605de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman 6063bfbc4587a7e79f08f8c126a9e62c3475fb90f8bDan Gohman // Create a GEP. 6073bfbc4587a7e79f08f8c126a9e62c3475fb90f8bDan Gohman Constant *C = 6086e7ad958683f34bf6c014c88fef723e5a2d741beDan Gohman ConstantExpr::getGetElementPtr(Ptr, &NewIdxs[0], NewIdxs.size()); 6096e7ad958683f34bf6c014c88fef723e5a2d741beDan Gohman assert(cast<PointerType>(C->getType())->getElementType() == Ty && 6106e7ad958683f34bf6c014c88fef723e5a2d741beDan Gohman "Computed GetElementPtr has unexpected type!"); 6113d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman 6123d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman // If we ended up indexing a member with a type that doesn't match 6134c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman // the type of what the original indices indexed, add a cast. 6143d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman if (Ty != cast<PointerType>(ResultTy)->getElementType()) 6156333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner C = FoldBitCast(C, ResultTy, *TD); 616de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman 6173d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman return C; 61803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner} 61903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 6201afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 62103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 62203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner//===----------------------------------------------------------------------===// 62303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner// Constant Folding public APIs 62403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner//===----------------------------------------------------------------------===// 62503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 62603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 6275520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// ConstantFoldInstruction - Attempt to constant fold the specified 6285520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// instruction. If successful, the constant result is returned, if not, null 6295520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// is returned. Note that this function can only fail when attempting to fold 6305520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// instructions like loads and stores, which have no constant expression form. 6315520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// 6327b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris LattnerConstant *llvm::ConstantFoldInstruction(Instruction *I, const TargetData *TD) { 6335520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (PHINode *PN = dyn_cast<PHINode>(I)) { 6345520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (PN->getNumIncomingValues() == 0) 6359e9a0d5fc26878e51a58a8b57900fcbf952c2691Owen Anderson return UndefValue::get(PN->getType()); 6365520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 6375520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner Constant *Result = dyn_cast<Constant>(PN->getIncomingValue(0)); 6385520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (Result == 0) return 0; 6395520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 6405520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // Handle PHI nodes specially here... 6415520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner for (unsigned i = 1, e = PN->getNumIncomingValues(); i != e; ++i) 6425520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (PN->getIncomingValue(i) != Result && PN->getIncomingValue(i) != PN) 6435520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; // Not all the same incoming constants... 6445520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 6455520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // If we reach here, all incoming values are the same constant. 6465520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return Result; 6475520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 6485520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 6495520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // Scan the operand list, checking to see if they are all constants, if so, 6505520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // hand off to ConstantFoldInstOperands. 6515520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner SmallVector<Constant*, 8> Ops; 652de2d74b213844b17eb5327fba27f21e699d3af66Gabor Greif for (User::op_iterator i = I->op_begin(), e = I->op_end(); i != e; ++i) 653de2d74b213844b17eb5327fba27f21e699d3af66Gabor Greif if (Constant *Op = dyn_cast<Constant>(*i)) 6545520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner Ops.push_back(Op); 6555520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else 6565520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; // All operands not constant! 6575520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 658f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (const CmpInst *CI = dyn_cast<CmpInst>(I)) 6598f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner return ConstantFoldCompareInstOperands(CI->getPredicate(), Ops[0], Ops[1], 6608f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner TD); 66158665d47aea69875c433fb039c8f10106abc1ceeChris Lattner 662878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner if (const LoadInst *LI = dyn_cast<LoadInst>(I)) 663878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner return ConstantFoldLoadInst(LI, TD); 664878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner 66558665d47aea69875c433fb039c8f10106abc1ceeChris Lattner return ConstantFoldInstOperands(I->getOpcode(), I->getType(), 6667b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner Ops.data(), Ops.size(), TD); 6675520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner} 6685520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 6693dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky/// ConstantFoldConstantExpression - Attempt to fold the constant expression 6703dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky/// using the specified TargetData. If successful, the constant result is 6713dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky/// result is returned, if not, null is returned. 6723dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick LewyckyConstant *llvm::ConstantFoldConstantExpression(ConstantExpr *CE, 6733dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky const TargetData *TD) { 6743dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky SmallVector<Constant*, 8> Ops; 67501b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman for (User::op_iterator i = CE->op_begin(), e = CE->op_end(); i != e; ++i) { 67601b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman Constant *NewC = cast<Constant>(*i); 67701b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman // Recursively fold the ConstantExpr's operands. 67801b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman if (ConstantExpr *NewCE = dyn_cast<ConstantExpr>(NewC)) 67901b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman NewC = ConstantFoldConstantExpression(NewCE, TD); 68001b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman Ops.push_back(NewC); 68101b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman } 6823dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky 6833dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky if (CE->isCompare()) 6848f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner return ConstantFoldCompareInstOperands(CE->getPredicate(), Ops[0], Ops[1], 6858f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner TD); 68658665d47aea69875c433fb039c8f10106abc1ceeChris Lattner return ConstantFoldInstOperands(CE->getOpcode(), CE->getType(), 6877b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner Ops.data(), Ops.size(), TD); 6883dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky} 6893dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky 6905520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// ConstantFoldInstOperands - Attempt to constant fold an instruction with the 6915520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// specified opcode and operands. If successful, the constant result is 6925520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// returned, if not, null is returned. Note that this function can fail when 6935520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// attempting to fold instructions like loads and stores, which have no 6945520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// constant expression form. 6955520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// 69601b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman/// TODO: This function neither utilizes nor preserves nsw/nuw/inbounds/etc 69701b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman/// information, due to only being passed an opcode and operands. Constant 69801b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman/// folding using this function strips this information. 69901b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman/// 700f286f6fd93d569befe6e77c94a947e6e04e95685Chris LattnerConstant *llvm::ConstantFoldInstOperands(unsigned Opcode, const Type *DestTy, 701f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner Constant* const* Ops, unsigned NumOps, 7025520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner const TargetData *TD) { 70303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Handle easy binops first. 704f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (Instruction::isBinaryOp(Opcode)) { 70503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (isa<ConstantExpr>(Ops[0]) || isa<ConstantExpr>(Ops[1])) 7067b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner if (Constant *C = SymbolicallyEvaluateBinop(Opcode, Ops[0], Ops[1], TD)) 70703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return C; 70803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 709baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::get(Opcode, Ops[0], Ops[1]); 71003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 7115520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 712f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner switch (Opcode) { 7135520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner default: return 0; 7145520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::Call: 7155520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (Function *F = dyn_cast<Function>(Ops[0])) 7165520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (canConstantFoldCallTo(F)) 717ad58eb34342f70f094008e6d08cb4ed814754e64Chris Lattner return ConstantFoldCall(F, Ops+1, NumOps-1); 7185520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 7195520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::ICmp: 7205520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FCmp: 721c23197a26f34f559ea9797de51e187087c039c42Torok Edwin llvm_unreachable("This function is invalid for compares: no predicate specified"); 722001f7534e0311508cc93831a595785bb177f8a18Chris Lattner case Instruction::PtrToInt: 723001f7534e0311508cc93831a595785bb177f8a18Chris Lattner // If the input is a inttoptr, eliminate the pair. This requires knowing 724001f7534e0311508cc93831a595785bb177f8a18Chris Lattner // the width of a pointer, so it can't be done in ConstantExpr::getCast. 725001f7534e0311508cc93831a595785bb177f8a18Chris Lattner if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[0])) { 726001f7534e0311508cc93831a595785bb177f8a18Chris Lattner if (TD && CE->getOpcode() == Instruction::IntToPtr) { 727001f7534e0311508cc93831a595785bb177f8a18Chris Lattner Constant *Input = CE->getOperand(0); 7286de29f8d960505421d61c80cdb738e16720b6c0eDan Gohman unsigned InWidth = Input->getType()->getScalarSizeInBits(); 72904aa2c3520c049333ca216fb794d700310c4a33dNick Lewycky if (TD->getPointerSizeInBits() < InWidth) { 73004aa2c3520c049333ca216fb794d700310c4a33dNick Lewycky Constant *Mask = 7317b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner ConstantInt::get(CE->getContext(), APInt::getLowBitsSet(InWidth, 73204aa2c3520c049333ca216fb794d700310c4a33dNick Lewycky TD->getPointerSizeInBits())); 733baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson Input = ConstantExpr::getAnd(Input, Mask); 73404aa2c3520c049333ca216fb794d700310c4a33dNick Lewycky } 735001f7534e0311508cc93831a595785bb177f8a18Chris Lattner // Do a zext or trunc to get to the dest size. 736baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getIntegerCast(Input, DestTy, false); 737001f7534e0311508cc93831a595785bb177f8a18Chris Lattner } 738001f7534e0311508cc93831a595785bb177f8a18Chris Lattner } 739baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getCast(Opcode, Ops[0], DestTy); 740001f7534e0311508cc93831a595785bb177f8a18Chris Lattner case Instruction::IntToPtr: 74181b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands // If the input is a ptrtoint, turn the pair into a ptr to ptr bitcast if 74281b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands // the int size is >= the ptr size. This requires knowing the width of a 74381b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands // pointer, so it can't be done in ConstantExpr::getCast. 74481b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[0])) { 7459a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman if (TD && 74681b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands TD->getPointerSizeInBits() <= 7476de29f8d960505421d61c80cdb738e16720b6c0eDan Gohman CE->getType()->getScalarSizeInBits()) { 7486333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner if (CE->getOpcode() == Instruction::PtrToInt) 7496333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner return FoldBitCast(CE->getOperand(0), DestTy, *TD); 7506333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 7519a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman // If there's a constant offset added to the integer value before 7529a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman // it is casted back to a pointer, see if the expression can be 7539a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman // converted into a GEP. 7549a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman if (CE->getOpcode() == Instruction::Add) 7559a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman if (ConstantInt *L = dyn_cast<ConstantInt>(CE->getOperand(0))) 7569a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman if (ConstantExpr *R = dyn_cast<ConstantExpr>(CE->getOperand(1))) 7579a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman if (R->getOpcode() == Instruction::PtrToInt) 7589a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman if (GlobalVariable *GV = 7599a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman dyn_cast<GlobalVariable>(R->getOperand(0))) { 7609a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman const PointerType *GVTy = cast<PointerType>(GV->getType()); 7619a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman if (const ArrayType *AT = 7629a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman dyn_cast<ArrayType>(GVTy->getElementType())) { 7639a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman const Type *ElTy = AT->getElementType(); 764777d2306b36816a53bc1ae1244c0dc7d998ae691Duncan Sands uint64_t AllocSize = TD->getTypeAllocSize(ElTy); 765777d2306b36816a53bc1ae1244c0dc7d998ae691Duncan Sands APInt PSA(L->getValue().getBitWidth(), AllocSize); 7669a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman if (ElTy == cast<PointerType>(DestTy)->getElementType() && 7679a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman L->getValue().urem(PSA) == 0) { 7689a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman APInt ElemIdx = L->getValue().udiv(PSA); 7699a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman if (ElemIdx.ult(APInt(ElemIdx.getBitWidth(), 7709a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman AT->getNumElements()))) { 7719a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman Constant *Index[] = { 772a7235ea7245028a0723e8ab7fd011386b3900777Owen Anderson Constant::getNullValue(CE->getType()), 7737b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner ConstantInt::get(ElTy->getContext(), ElemIdx) 7749a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman }; 775508955156a25a9abc470a29e1760aa176d341cf9Owen Anderson return 776baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson ConstantExpr::getGetElementPtr(GV, &Index[0], 2); 7779a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman } 7789a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman } 7799a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman } 7809a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman } 78181b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands } 78281b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands } 783baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getCast(Opcode, Ops[0], DestTy); 7845520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::Trunc: 7855520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::ZExt: 7865520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::SExt: 7875520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FPTrunc: 7885520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FPExt: 7895520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::UIToFP: 7905520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::SIToFP: 7915520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FPToUI: 7925520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FPToSI: 793baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getCast(Opcode, Ops[0], DestTy); 7945520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::BitCast: 7951afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (TD) 7966333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner return FoldBitCast(Ops[0], DestTy, *TD); 797baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getBitCast(Ops[0], DestTy); 7985520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::Select: 799baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getSelect(Ops[0], Ops[1], Ops[2]); 8005520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::ExtractElement: 801baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getExtractElement(Ops[0], Ops[1]); 8025520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::InsertElement: 803baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getInsertElement(Ops[0], Ops[1], Ops[2]); 8045520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::ShuffleVector: 805baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getShuffleVector(Ops[0], Ops[1], Ops[2]); 8065520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::GetElementPtr: 8077b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner if (Constant *C = SymbolicallyEvaluateGEP(Ops, NumOps, DestTy, TD)) 80803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return C; 80903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 810baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getGetElementPtr(Ops[0], Ops+1, NumOps-1); 8115520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 8125520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner} 8135520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 814f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner/// ConstantFoldCompareInstOperands - Attempt to constant fold a compare 815f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner/// instruction (icmp/fcmp) with the specified operands. If it fails, it 816f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner/// returns a constant expression of the specified operands. 817f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner/// 818f286f6fd93d569befe6e77c94a947e6e04e95685Chris LattnerConstant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate, 8198f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner Constant *Ops0, Constant *Ops1, 820f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner const TargetData *TD) { 821f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // fold: icmp (inttoptr x), null -> icmp x, 0 822f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // fold: icmp (ptrtoint x), 0 -> icmp x, null 8233dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky // fold: icmp (inttoptr x), (inttoptr y) -> icmp trunc/zext x, trunc/zext y 824f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // fold: icmp (ptrtoint x), (ptrtoint y) -> icmp x, y 825f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // 826f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // ConstantExpr::getCompare cannot do this, because it doesn't have TD 827f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // around to know if bit truncation is happening. 8288f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner if (ConstantExpr *CE0 = dyn_cast<ConstantExpr>(Ops0)) { 8298f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner if (TD && Ops1->isNullValue()) { 8307b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner const Type *IntPtrTy = TD->getIntPtrType(CE0->getContext()); 831f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (CE0->getOpcode() == Instruction::IntToPtr) { 832f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // Convert the integer value to the right size to ensure we get the 833f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // proper extension or truncation. 834baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson Constant *C = ConstantExpr::getIntegerCast(CE0->getOperand(0), 835f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner IntPtrTy, false); 8368f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner Constant *Null = Constant::getNullValue(C->getType()); 8378f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner return ConstantFoldCompareInstOperands(Predicate, C, Null, TD); 838f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 839f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner 840f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // Only do this transformation if the int is intptrty in size, otherwise 841f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // there is a truncation or extension that we aren't modeling. 842f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (CE0->getOpcode() == Instruction::PtrToInt && 843f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner CE0->getType() == IntPtrTy) { 844f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner Constant *C = CE0->getOperand(0); 8458f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner Constant *Null = Constant::getNullValue(C->getType()); 8468f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner return ConstantFoldCompareInstOperands(Predicate, C, Null, TD); 847f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 848f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 849f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner 8508f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(Ops1)) { 8513dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky if (TD && CE0->getOpcode() == CE1->getOpcode()) { 8527b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner const Type *IntPtrTy = TD->getIntPtrType(CE0->getContext()); 8533dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky 8543dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky if (CE0->getOpcode() == Instruction::IntToPtr) { 8553dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky // Convert the integer value to the right size to ensure we get the 8563dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky // proper extension or truncation. 857baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson Constant *C0 = ConstantExpr::getIntegerCast(CE0->getOperand(0), 8583dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky IntPtrTy, false); 859baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson Constant *C1 = ConstantExpr::getIntegerCast(CE1->getOperand(0), 8603dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky IntPtrTy, false); 8618f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner return ConstantFoldCompareInstOperands(Predicate, C0, C1, TD); 8623dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky } 8633dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky 8643dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky // Only do this transformation if the int is intptrty in size, otherwise 8653dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky // there is a truncation or extension that we aren't modeling. 8663dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky if ((CE0->getOpcode() == Instruction::PtrToInt && 8673dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky CE0->getType() == IntPtrTy && 8688f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner CE0->getOperand(0)->getType() == CE1->getOperand(0)->getType())) 8698f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner return ConstantFoldCompareInstOperands(Predicate, CE0->getOperand(0), 8708f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner CE1->getOperand(0), TD); 871f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 872f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 873f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 8748f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner 8758f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner return ConstantExpr::getCompare(Predicate, Ops0, Ops1); 876f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner} 877f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner 878f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner 8795520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// ConstantFoldLoadThroughGEPConstantExpr - Given a constant and a 8805520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// getelementptr constantexpr, return the constant value being addressed by the 8815520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// constant expression, or null if something is funny and we can't decide. 8825520732b24a5a321140dd79af70d321c7ff3dec9Chris LattnerConstant *llvm::ConstantFoldLoadThroughGEPConstantExpr(Constant *C, 883c6f69e94fa46f585b59bb9d7ace3224b0e638c95Dan Gohman ConstantExpr *CE) { 884a7235ea7245028a0723e8ab7fd011386b3900777Owen Anderson if (CE->getOperand(1) != Constant::getNullValue(CE->getOperand(1)->getType())) 8855520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; // Do not allow stepping over the value! 8865520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 8875520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // Loop over all of the operands, tracking down which value we are 8885520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // addressing... 8895520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner gep_type_iterator I = gep_type_begin(CE), E = gep_type_end(CE); 8905520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner for (++I; I != E; ++I) 8915520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (const StructType *STy = dyn_cast<StructType>(*I)) { 8925520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner ConstantInt *CU = cast<ConstantInt>(I.getOperand()); 8935520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner assert(CU->getZExtValue() < STy->getNumElements() && 8945520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner "Struct index out of range!"); 8955520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner unsigned El = (unsigned)CU->getZExtValue(); 8965520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) { 8975520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = CS->getOperand(El); 8985520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else if (isa<ConstantAggregateZero>(C)) { 899a7235ea7245028a0723e8ab7fd011386b3900777Owen Anderson C = Constant::getNullValue(STy->getElementType(El)); 9005520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else if (isa<UndefValue>(C)) { 9019e9a0d5fc26878e51a58a8b57900fcbf952c2691Owen Anderson C = UndefValue::get(STy->getElementType(El)); 9025520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else { 9035520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 9045520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 9055520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else if (ConstantInt *CI = dyn_cast<ConstantInt>(I.getOperand())) { 9065520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (const ArrayType *ATy = dyn_cast<ArrayType>(*I)) { 9075520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (CI->getZExtValue() >= ATy->getNumElements()) 9085520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 9095520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (ConstantArray *CA = dyn_cast<ConstantArray>(C)) 9105520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = CA->getOperand(CI->getZExtValue()); 9115520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else if (isa<ConstantAggregateZero>(C)) 912a7235ea7245028a0723e8ab7fd011386b3900777Owen Anderson C = Constant::getNullValue(ATy->getElementType()); 9135520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else if (isa<UndefValue>(C)) 9149e9a0d5fc26878e51a58a8b57900fcbf952c2691Owen Anderson C = UndefValue::get(ATy->getElementType()); 9155520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else 9165520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 91762d327e241f59735eed836e98c8f11ffaa6cf6f8Chris Lattner } else if (const VectorType *VTy = dyn_cast<VectorType>(*I)) { 91862d327e241f59735eed836e98c8f11ffaa6cf6f8Chris Lattner if (CI->getZExtValue() >= VTy->getNumElements()) 9195520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 9209d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer if (ConstantVector *CP = dyn_cast<ConstantVector>(C)) 9215520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = CP->getOperand(CI->getZExtValue()); 9225520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else if (isa<ConstantAggregateZero>(C)) 92362d327e241f59735eed836e98c8f11ffaa6cf6f8Chris Lattner C = Constant::getNullValue(VTy->getElementType()); 9245520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else if (isa<UndefValue>(C)) 92562d327e241f59735eed836e98c8f11ffaa6cf6f8Chris Lattner C = UndefValue::get(VTy->getElementType()); 9265520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else 9275520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 9285520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else { 9295520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 9305520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 9315520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else { 9325520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 9335520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 9345520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return C; 9355520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner} 9365520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 9375520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 938bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell//===----------------------------------------------------------------------===// 9395520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner// Constant Folding for Calls 940bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell// 941bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 942bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell/// canConstantFoldCallTo - Return true if its even possible to fold a call to 943bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell/// the specified function. 944bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswellbool 945fa9b80eb64127b3d9691e18537975635520e51e9Dan Gohmanllvm::canConstantFoldCallTo(const Function *F) { 946bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell switch (F->getIntrinsicID()) { 9479ab7fb3ba47442d521a5bed09a27a5e8e7a786edDale Johannesen case Intrinsic::sqrt: 9489ab7fb3ba47442d521a5bed09a27a5e8e7a786edDale Johannesen case Intrinsic::powi: 949e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer case Intrinsic::bswap: 950e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer case Intrinsic::ctpop: 951e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer case Intrinsic::ctlz: 952e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer case Intrinsic::cttz: 953e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner case Intrinsic::uadd_with_overflow: 954e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner case Intrinsic::usub_with_overflow: 9551614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix case Intrinsic::sadd_with_overflow: 9561614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix case Intrinsic::ssub_with_overflow: 957bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell return true; 95868a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner default: 95968a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner return false; 96068a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner case 0: break; 961bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 962bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 9636f532a988e5c02fcb271fb65e9e7b83f0147d3f2Chris Lattner if (!F->hasName()) return false; 964f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar StringRef Name = F->getName(); 965c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner 966c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner // In these cases, the check of the length is required. We don't want to 967c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner // return true for a name like "cos\0blah" which strcmp would return equal to 968c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner // "cos", but has length 8. 969f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar switch (Name[0]) { 970c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner default: return false; 971c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'a': 972f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar return Name == "acos" || Name == "asin" || 973f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar Name == "atan" || Name == "atan2"; 974c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'c': 975f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar return Name == "cos" || Name == "ceil" || Name == "cosf" || Name == "cosh"; 976c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'e': 977f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar return Name == "exp"; 978c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'f': 979f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar return Name == "fabs" || Name == "fmod" || Name == "floor"; 980c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'l': 981f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar return Name == "log" || Name == "log10"; 982c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'p': 983f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar return Name == "pow"; 984c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 's': 985f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar return Name == "sin" || Name == "sinh" || Name == "sqrt" || 986f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar Name == "sinf" || Name == "sqrtf"; 987c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 't': 988f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar return Name == "tan" || Name == "tanh"; 989bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 990bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell} 991bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 99272d88ae5447a3929c97e88f4c806213847b5d988Chris Lattnerstatic Constant *ConstantFoldFP(double (*NativeFP)(double), double V, 9937b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner const Type *Ty) { 994bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell errno = 0; 995bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell V = NativeFP(V); 996f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner if (errno != 0) { 997f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner errno = 0; 998f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner return 0; 99943421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen } 1000f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner 1001d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner if (Ty->isFloatTy()) 10027b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFP::get(Ty->getContext(), APFloat((float)V)); 1003d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner if (Ty->isDoubleTy()) 10047b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFP::get(Ty->getContext(), APFloat(V)); 1005c23197a26f34f559ea9797de51e187087c039c42Torok Edwin llvm_unreachable("Can only constant fold float/double"); 100633e456d5f3909e0c7b96e04e5674c25a182da100Gabor Greif return 0; // dummy return to suppress warning 1007bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell} 1008bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 1009384152444d22d356f7b4090a158da4cbc1f79464Dan Gohmanstatic Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double), 10107b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner double V, double W, const Type *Ty) { 1011384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman errno = 0; 1012384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman V = NativeFP(V, W); 1013f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner if (errno != 0) { 1014f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner errno = 0; 1015f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner return 0; 101643421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen } 1017f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner 1018d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner if (Ty->isFloatTy()) 10197b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFP::get(Ty->getContext(), APFloat((float)V)); 1020d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner if (Ty->isDoubleTy()) 10217b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFP::get(Ty->getContext(), APFloat(V)); 1022c23197a26f34f559ea9797de51e187087c039c42Torok Edwin llvm_unreachable("Can only constant fold float/double"); 102333e456d5f3909e0c7b96e04e5674c25a182da100Gabor Greif return 0; // dummy return to suppress warning 1024384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman} 1025384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman 1026bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell/// ConstantFoldCall - Attempt to constant fold a call to the specified function 1027bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell/// with the specified arguments, returning null if unsuccessful. 1028bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John CriswellConstant * 1029f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattnerllvm::ConstantFoldCall(Function *F, 103068a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner Constant *const *Operands, unsigned NumOperands) { 10316f532a988e5c02fcb271fb65e9e7b83f0147d3f2Chris Lattner if (!F->hasName()) return 0; 1032f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar StringRef Name = F->getName(); 1033e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner 1034bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell const Type *Ty = F->getReturnType(); 103572d88ae5447a3929c97e88f4c806213847b5d988Chris Lattner if (NumOperands == 1) { 1036bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell if (ConstantFP *Op = dyn_cast<ConstantFP>(Operands[0])) { 1037d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner if (!Ty->isFloatTy() && !Ty->isDoubleTy()) 103843421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen return 0; 103943421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen /// Currently APFloat versions of these functions do not exist, so we use 104043421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen /// the host native double versions. Float versions are not called 104143421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen /// directly but for all these it is true (float)(f((double)arg)) == 104243421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen /// f(arg). Long double not supported yet. 1043d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner double V = Ty->isFloatTy() ? (double)Op->getValueAPF().convertToFloat() : 104443421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen Op->getValueAPF().convertToDouble(); 1045f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar switch (Name[0]) { 1046c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'a': 1047f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar if (Name == "acos") 10487b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(acos, V, Ty); 1049f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "asin") 10507b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(asin, V, Ty); 1051f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "atan") 10527b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(atan, V, Ty); 1053c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 1054c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'c': 1055f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar if (Name == "ceil") 10567b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(ceil, V, Ty); 1057f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "cos") 10587b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(cos, V, Ty); 1059f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "cosh") 10607b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(cosh, V, Ty); 1061f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "cosf") 10627b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(cos, V, Ty); 1063c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 1064c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'e': 1065f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar if (Name == "exp") 10667b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(exp, V, Ty); 1067c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 1068c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'f': 1069f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar if (Name == "fabs") 10707b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(fabs, V, Ty); 1071f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "floor") 10727b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(floor, V, Ty); 1073c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 1074c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'l': 1075f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar if (Name == "log" && V > 0) 10767b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(log, V, Ty); 1077f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "log10" && V > 0) 10787b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(log10, V, Ty); 1079f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "llvm.sqrt.f32" || 1080f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar Name == "llvm.sqrt.f64") { 1081c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (V >= -0.0) 10827b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(sqrt, V, Ty); 1083c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else // Undefined 1084a7235ea7245028a0723e8ab7fd011386b3900777Owen Anderson return Constant::getNullValue(Ty); 1085c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner } 1086c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 1087c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 's': 1088f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar if (Name == "sin") 10897b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(sin, V, Ty); 1090f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "sinh") 10917b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(sinh, V, Ty); 1092f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "sqrt" && V >= 0) 10937b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(sqrt, V, Ty); 1094f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "sqrtf" && V >= 0) 10957b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(sqrt, V, Ty); 1096f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "sinf") 10977b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(sin, V, Ty); 1098c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 1099c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 't': 1100f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar if (Name == "tan") 11017b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(tan, V, Ty); 1102f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "tanh") 11037b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(tanh, V, Ty); 1104c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 1105c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner default: 1106c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 1107bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 110868a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner return 0; 110968a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner } 111068a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner 111168a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner 111268a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner if (ConstantInt *Op = dyn_cast<ConstantInt>(Operands[0])) { 1113f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar if (Name.startswith("llvm.bswap")) 11147b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantInt::get(F->getContext(), Op->getValue().byteSwap()); 1115f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name.startswith("llvm.ctpop")) 1116eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson return ConstantInt::get(Ty, Op->getValue().countPopulation()); 1117f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name.startswith("llvm.cttz")) 1118eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson return ConstantInt::get(Ty, Op->getValue().countTrailingZeros()); 1119f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name.startswith("llvm.ctlz")) 1120eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson return ConstantInt::get(Ty, Op->getValue().countLeadingZeros()); 112168a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner return 0; 1122bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 112368a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner 112468a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner return 0; 112568a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner } 112668a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner 112768a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner if (NumOperands == 2) { 1128bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell if (ConstantFP *Op1 = dyn_cast<ConstantFP>(Operands[0])) { 1129d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner if (!Ty->isFloatTy() && !Ty->isDoubleTy()) 11309ab7fb3ba47442d521a5bed09a27a5e8e7a786edDale Johannesen return 0; 1131d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner double Op1V = Ty->isFloatTy() ? 1132d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner (double)Op1->getValueAPF().convertToFloat() : 113343421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen Op1->getValueAPF().convertToDouble(); 1134bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell if (ConstantFP *Op2 = dyn_cast<ConstantFP>(Operands[1])) { 1135d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner if (Op2->getType() != Op1->getType()) 1136d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner return 0; 1137d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner 1138d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner double Op2V = Ty->isFloatTy() ? 113943421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen (double)Op2->getValueAPF().convertToFloat(): 114043421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen Op2->getValueAPF().convertToDouble(); 1141bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 114268a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner if (Name == "pow") 11437b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty); 114468a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner if (Name == "fmod") 11457b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldBinaryFP(fmod, Op1V, Op2V, Ty); 114668a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner if (Name == "atan2") 11477b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldBinaryFP(atan2, Op1V, Op2V, Ty); 1148b5282dcf4745be59046f440980a1c0f0a50c9c09Chris Lattner } else if (ConstantInt *Op2C = dyn_cast<ConstantInt>(Operands[1])) { 114968a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner if (Name == "llvm.powi.f32") 11507b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFP::get(F->getContext(), 11517b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner APFloat((float)std::pow((float)Op1V, 115202a260aa11a2e1b2c14335274d3c42ca3f3eabc0Chris Lattner (int)Op2C->getZExtValue()))); 115368a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner if (Name == "llvm.powi.f64") 11547b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFP::get(F->getContext(), 11557b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner APFloat((double)std::pow((double)Op1V, 11567b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner (int)Op2C->getZExtValue()))); 1157bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 115868a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner return 0; 1159bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 1160e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner 1161e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner 1162e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner if (ConstantInt *Op1 = dyn_cast<ConstantInt>(Operands[0])) { 1163e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner if (ConstantInt *Op2 = dyn_cast<ConstantInt>(Operands[1])) { 1164e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner switch (F->getIntrinsicID()) { 1165e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner default: break; 1166e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner case Intrinsic::uadd_with_overflow: { 1167e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner Constant *Res = ConstantExpr::getAdd(Op1, Op2); // result. 1168e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner Constant *Ops[] = { 1169e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner Res, ConstantExpr::getICmp(CmpInst::ICMP_ULT, Res, Op1) // overflow. 1170e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner }; 1171e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner return ConstantStruct::get(F->getContext(), Ops, 2, false); 1172e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner } 1173e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner case Intrinsic::usub_with_overflow: { 1174e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner Constant *Res = ConstantExpr::getSub(Op1, Op2); // result. 1175e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner Constant *Ops[] = { 1176e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner Res, ConstantExpr::getICmp(CmpInst::ICMP_UGT, Res, Op1) // overflow. 1177e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner }; 1178e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner return ConstantStruct::get(F->getContext(), Ops, 2, false); 1179e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner } 11801614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix case Intrinsic::sadd_with_overflow: { 11811614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix Constant *Res = ConstantExpr::getAdd(Op1, Op2); // result. 11821614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix Constant *Overflow = ConstantExpr::getSelect( 11831614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix ConstantExpr::getICmp(CmpInst::ICMP_SGT, 11841614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix ConstantInt::get(Op1->getType(), 0), Op1), 11851614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix ConstantExpr::getICmp(CmpInst::ICMP_SGT, Res, Op2), 11861614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix ConstantExpr::getICmp(CmpInst::ICMP_SLT, Res, Op2)); // overflow. 11871614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix 11881614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix Constant *Ops[] = { Res, Overflow }; 11891614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix return ConstantStruct::get(F->getContext(), Ops, 2, false); 11901614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix } 11911614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix case Intrinsic::ssub_with_overflow: { 11921614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix Constant *Res = ConstantExpr::getSub(Op1, Op2); // result. 11931614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix Constant *Overflow = ConstantExpr::getSelect( 11941614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix ConstantExpr::getICmp(CmpInst::ICMP_SGT, 11951614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix ConstantInt::get(Op2->getType(), 0), Op2), 11961614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix ConstantExpr::getICmp(CmpInst::ICMP_SLT, Res, Op1), 11971614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix ConstantExpr::getICmp(CmpInst::ICMP_SGT, Res, Op1)); // overflow. 11981614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix 11991614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix Constant *Ops[] = { Res, Overflow }; 12001614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix return ConstantStruct::get(F->getContext(), Ops, 2, false); 12011614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix } 1202e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner } 1203e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner } 1204e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner 1205e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner return 0; 1206e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner } 1207e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner return 0; 1208bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 1209bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell return 0; 1210bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell} 1211bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 1212