ConstantFolding.cpp revision 9ee7123ab462d97a2b242280e9bf0b47883531cb
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. 83b0bc6c361da9009e8414efde317d9bbff755f6c0Duncan Sands if (DstEltTy->isFloatingPointTy()) { 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. 98b0bc6c361da9009e8414efde317d9bbff755f6c0Duncan Sands if (SrcEltTy->isFloatingPointTy()) { 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()); 3621df9859c40492511b8aa4321eb76496005d3b75bDuncan Sands else if (LoadTy->isVectorTy()) { 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 401b31189f26297fe30214da3e8d14a4575d5fdd262Chris Lattner APInt ResultVal = APInt(IntType->getBitWidth(), RawBytes[BytesLoaded-1]); 402b31189f26297fe30214da3e8d14a4575d5fdd262Chris Lattner for (unsigned i = 1; 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; 43544a7a380aa9fbb303f57f4f8269062b7b56be980Chris Lattner if (TD && GetConstantStringInfo(CE, 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 5204f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman/// CastGEPIndices - If array indices are not pointer-sized integers, 5214f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman/// explicitly cast them so that they aren't implicitly casted by the 5224f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman/// getelementptr. 5234f8eea82d8967cffa85b9df6c9255717b059009eDan Gohmanstatic Constant *CastGEPIndices(Constant *const *Ops, unsigned NumOps, 5244f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman const Type *ResultTy, 5254f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman const TargetData *TD) { 5264f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman if (!TD) return 0; 5274f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman const Type *IntPtrTy = TD->getIntPtrType(ResultTy->getContext()); 5284f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman 5294f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman bool Any = false; 5304f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman SmallVector<Constant*, 32> NewIdxs; 5314f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman for (unsigned i = 1; i != NumOps; ++i) { 5324f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman if ((i == 1 || 5334f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman !isa<StructType>(GetElementPtrInst::getIndexedType(Ops[0]->getType(), 5344f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman reinterpret_cast<Value *const *>(Ops+1), 5354f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman i-1))) && 5364f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman Ops[i]->getType() != IntPtrTy) { 5374f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman Any = true; 5384f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman NewIdxs.push_back(ConstantExpr::getCast(CastInst::getCastOpcode(Ops[i], 5394f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman true, 5404f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman IntPtrTy, 5414f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman true), 5424f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman Ops[i], IntPtrTy)); 5434f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman } else 5444f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman NewIdxs.push_back(Ops[i]); 5454f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman } 5464f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman if (!Any) return 0; 5474f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman 5484f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman Constant *C = 5494f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman ConstantExpr::getGetElementPtr(Ops[0], &NewIdxs[0], NewIdxs.size()); 5504f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) 5514f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman if (Constant *Folded = ConstantFoldConstantExpression(CE, TD)) 5524f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman C = Folded; 5534f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman return C; 5544f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman} 5554f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman 55603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// SymbolicallyEvaluateGEP - If we can symbolically evaluate the specified GEP 55703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// constant expression, do so. 5587b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattnerstatic Constant *SymbolicallyEvaluateGEP(Constant *const *Ops, unsigned NumOps, 55903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner const Type *ResultTy, 56003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner const TargetData *TD) { 56103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner Constant *Ptr = Ops[0]; 562268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner if (!TD || !cast<PointerType>(Ptr->getType())->getElementType()->isSized()) 56303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return 0; 564cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman 5657b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner unsigned BitWidth = 5667b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner TD->getTypeSizeInBits(TD->getIntPtrType(Ptr->getContext())); 567cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman APInt BasePtr(BitWidth, 0); 568de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman bool BaseIsInt = true; 569268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner if (!Ptr->isNullValue()) { 570268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner // If this is a inttoptr from a constant int, we can fold this as the base, 571268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner // otherwise we can't. 572268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr)) 573268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner if (CE->getOpcode() == Instruction::IntToPtr) 5747178010a168a378df5d9be95956093a3e5f963fdDan Gohman if (ConstantInt *Base = dyn_cast<ConstantInt>(CE->getOperand(0))) { 575cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman BasePtr = Base->getValue(); 5767178010a168a378df5d9be95956093a3e5f963fdDan Gohman BasePtr.zextOrTrunc(BitWidth); 5777178010a168a378df5d9be95956093a3e5f963fdDan Gohman } 578268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner 579268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner if (BasePtr == 0) 580de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman BaseIsInt = false; 58103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 582268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner 583268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner // If this is a constant expr gep that is effectively computing an 584268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner // "offsetof", fold it into 'cast int Size to T*' instead of 'gep 0, 0, 12' 585268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner for (unsigned i = 1; i != NumOps; ++i) 586268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner if (!isa<ConstantInt>(Ops[i])) 587de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman return 0; 588268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner 589cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman APInt Offset = APInt(BitWidth, 590cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman TD->getIndexedOffset(Ptr->getType(), 591cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman (Value**)Ops+1, NumOps-1)); 592de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman // If the base value for this address is a literal integer value, fold the 593de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman // getelementptr to the resulting integer value casted to the pointer type. 594de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman if (BaseIsInt) { 5957b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner Constant *C = ConstantInt::get(Ptr->getContext(), Offset+BasePtr); 596de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman return ConstantExpr::getIntToPtr(C, ResultTy); 597de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman } 598de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman 599de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman // Otherwise form a regular getelementptr. Recompute the indices so that 600de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman // we eliminate over-indexing of the notional static type array bounds. 601de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman // This makes it easy to determine if the getelementptr is "inbounds". 602de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman // Also, this helps GlobalOpt do SROA on GlobalVariables. 603fac554a1317bf32daf5698740670025ae14e6bccNick Lewycky Ptr = cast<Constant>(Ptr->stripPointerCasts()); 604de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman const Type *Ty = Ptr->getType(); 605de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman SmallVector<Constant*, 32> NewIdxs; 6063d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman do { 607de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman if (const SequentialType *ATy = dyn_cast<SequentialType>(Ty)) { 6081df9859c40492511b8aa4321eb76496005d3b75bDuncan Sands if (ATy->isPointerTy()) { 609e568fa2d29c58aaedcaa832f805949d5e4371b4bChris Lattner // The only pointer indexing we'll do is on the first index of the GEP. 610e568fa2d29c58aaedcaa832f805949d5e4371b4bChris Lattner if (!NewIdxs.empty()) 611e568fa2d29c58aaedcaa832f805949d5e4371b4bChris Lattner break; 612e568fa2d29c58aaedcaa832f805949d5e4371b4bChris Lattner 613e568fa2d29c58aaedcaa832f805949d5e4371b4bChris Lattner // Only handle pointers to sized types, not pointers to functions. 614e568fa2d29c58aaedcaa832f805949d5e4371b4bChris Lattner if (!ATy->getElementType()->isSized()) 615e568fa2d29c58aaedcaa832f805949d5e4371b4bChris Lattner return 0; 616e568fa2d29c58aaedcaa832f805949d5e4371b4bChris Lattner } 617e568fa2d29c58aaedcaa832f805949d5e4371b4bChris Lattner 618de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman // Determine which element of the array the offset points into. 619cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman APInt ElemSize(BitWidth, TD->getTypeAllocSize(ATy->getElementType())); 620de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman if (ElemSize == 0) 621de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman return 0; 622cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman APInt NewIdx = Offset.udiv(ElemSize); 623de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman Offset -= NewIdx * ElemSize; 6247b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner NewIdxs.push_back(ConstantInt::get(TD->getIntPtrType(Ty->getContext()), 6257b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner NewIdx)); 626de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman Ty = ATy->getElementType(); 627de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman } else if (const StructType *STy = dyn_cast<StructType>(Ty)) { 628cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman // Determine which field of the struct the offset points into. The 629cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman // getZExtValue is at least as safe as the StructLayout API because we 630cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman // know the offset is within the struct at this point. 631de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman const StructLayout &SL = *TD->getStructLayout(STy); 632cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman unsigned ElIdx = SL.getElementContainingOffset(Offset.getZExtValue()); 6337b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner NewIdxs.push_back(ConstantInt::get(Type::getInt32Ty(Ty->getContext()), 6347b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner ElIdx)); 635cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman Offset -= APInt(BitWidth, SL.getElementOffset(ElIdx)); 636de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman Ty = STy->getTypeAtIndex(ElIdx); 637de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman } else { 6383d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman // We've reached some non-indexable type. 6393d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman break; 640de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman } 6413d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman } while (Ty != cast<PointerType>(ResultTy)->getElementType()); 6423d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman 6433d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman // If we haven't used up the entire offset by descending the static 6443d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman // type, then the offset is pointing into the middle of an indivisible 6453d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman // member, so we can't simplify it. 6463d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman if (Offset != 0) 6473d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman return 0; 648de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman 6493bfbc4587a7e79f08f8c126a9e62c3475fb90f8bDan Gohman // Create a GEP. 6503bfbc4587a7e79f08f8c126a9e62c3475fb90f8bDan Gohman Constant *C = 6516e7ad958683f34bf6c014c88fef723e5a2d741beDan Gohman ConstantExpr::getGetElementPtr(Ptr, &NewIdxs[0], NewIdxs.size()); 6526e7ad958683f34bf6c014c88fef723e5a2d741beDan Gohman assert(cast<PointerType>(C->getType())->getElementType() == Ty && 6536e7ad958683f34bf6c014c88fef723e5a2d741beDan Gohman "Computed GetElementPtr has unexpected type!"); 6543d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman 6553d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman // If we ended up indexing a member with a type that doesn't match 6564c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman // the type of what the original indices indexed, add a cast. 6573d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman if (Ty != cast<PointerType>(ResultTy)->getElementType()) 6586333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner C = FoldBitCast(C, ResultTy, *TD); 659de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman 6603d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman return C; 66103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner} 66203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 6631afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 66403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 66503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner//===----------------------------------------------------------------------===// 66603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner// Constant Folding public APIs 66703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner//===----------------------------------------------------------------------===// 66803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 66903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 6705520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// ConstantFoldInstruction - Attempt to constant fold the specified 6715520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// instruction. If successful, the constant result is returned, if not, null 6725520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// is returned. Note that this function can only fail when attempting to fold 6735520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// instructions like loads and stores, which have no constant expression form. 6745520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// 6757b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris LattnerConstant *llvm::ConstantFoldInstruction(Instruction *I, const TargetData *TD) { 6765520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (PHINode *PN = dyn_cast<PHINode>(I)) { 6775520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (PN->getNumIncomingValues() == 0) 6789e9a0d5fc26878e51a58a8b57900fcbf952c2691Owen Anderson return UndefValue::get(PN->getType()); 6795520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 6805520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner Constant *Result = dyn_cast<Constant>(PN->getIncomingValue(0)); 6815520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (Result == 0) return 0; 6825520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 6835520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // Handle PHI nodes specially here... 6845520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner for (unsigned i = 1, e = PN->getNumIncomingValues(); i != e; ++i) 6855520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (PN->getIncomingValue(i) != Result && PN->getIncomingValue(i) != PN) 6865520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; // Not all the same incoming constants... 6875520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 6885520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // If we reach here, all incoming values are the same constant. 6895520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return Result; 6905520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 6915520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 6925520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // Scan the operand list, checking to see if they are all constants, if so, 6935520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // hand off to ConstantFoldInstOperands. 6945520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner SmallVector<Constant*, 8> Ops; 695de2d74b213844b17eb5327fba27f21e699d3af66Gabor Greif for (User::op_iterator i = I->op_begin(), e = I->op_end(); i != e; ++i) 696de2d74b213844b17eb5327fba27f21e699d3af66Gabor Greif if (Constant *Op = dyn_cast<Constant>(*i)) 6975520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner Ops.push_back(Op); 6985520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else 6995520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; // All operands not constant! 7005520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 701f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (const CmpInst *CI = dyn_cast<CmpInst>(I)) 7028f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner return ConstantFoldCompareInstOperands(CI->getPredicate(), Ops[0], Ops[1], 7038f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner TD); 70458665d47aea69875c433fb039c8f10106abc1ceeChris Lattner 705878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner if (const LoadInst *LI = dyn_cast<LoadInst>(I)) 706878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner return ConstantFoldLoadInst(LI, TD); 707878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner 70858665d47aea69875c433fb039c8f10106abc1ceeChris Lattner return ConstantFoldInstOperands(I->getOpcode(), I->getType(), 7097b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner Ops.data(), Ops.size(), TD); 7105520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner} 7115520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 7123dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky/// ConstantFoldConstantExpression - Attempt to fold the constant expression 7133dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky/// using the specified TargetData. If successful, the constant result is 7143dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky/// result is returned, if not, null is returned. 715baf0c67988feec5b7698f89dce499ddb7d0c3c42Dan GohmanConstant *llvm::ConstantFoldConstantExpression(const ConstantExpr *CE, 7163dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky const TargetData *TD) { 7173dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky SmallVector<Constant*, 8> Ops; 718baf0c67988feec5b7698f89dce499ddb7d0c3c42Dan Gohman for (User::const_op_iterator i = CE->op_begin(), e = CE->op_end(); i != e; ++i) { 71901b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman Constant *NewC = cast<Constant>(*i); 72001b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman // Recursively fold the ConstantExpr's operands. 72101b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman if (ConstantExpr *NewCE = dyn_cast<ConstantExpr>(NewC)) 72201b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman NewC = ConstantFoldConstantExpression(NewCE, TD); 72301b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman Ops.push_back(NewC); 72401b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman } 7253dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky 7263dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky if (CE->isCompare()) 7278f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner return ConstantFoldCompareInstOperands(CE->getPredicate(), Ops[0], Ops[1], 7288f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner TD); 72958665d47aea69875c433fb039c8f10106abc1ceeChris Lattner return ConstantFoldInstOperands(CE->getOpcode(), CE->getType(), 7307b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner Ops.data(), Ops.size(), TD); 7313dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky} 7323dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky 7335520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// ConstantFoldInstOperands - Attempt to constant fold an instruction with the 7345520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// specified opcode and operands. If successful, the constant result is 7355520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// returned, if not, null is returned. Note that this function can fail when 7365520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// attempting to fold instructions like loads and stores, which have no 7375520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// constant expression form. 7385520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// 73901b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman/// TODO: This function neither utilizes nor preserves nsw/nuw/inbounds/etc 74001b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman/// information, due to only being passed an opcode and operands. Constant 74101b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman/// folding using this function strips this information. 74201b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman/// 743f286f6fd93d569befe6e77c94a947e6e04e95685Chris LattnerConstant *llvm::ConstantFoldInstOperands(unsigned Opcode, const Type *DestTy, 744f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner Constant* const* Ops, unsigned NumOps, 7455520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner const TargetData *TD) { 74603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Handle easy binops first. 747f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (Instruction::isBinaryOp(Opcode)) { 74803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (isa<ConstantExpr>(Ops[0]) || isa<ConstantExpr>(Ops[1])) 7497b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner if (Constant *C = SymbolicallyEvaluateBinop(Opcode, Ops[0], Ops[1], TD)) 75003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return C; 75103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 752baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::get(Opcode, Ops[0], Ops[1]); 75303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 7545520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 755f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner switch (Opcode) { 7565520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner default: return 0; 75779fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner case Instruction::ICmp: 75879fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner case Instruction::FCmp: assert(0 && "Invalid for compares"); 7595520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::Call: 7605520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (Function *F = dyn_cast<Function>(Ops[0])) 7615520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (canConstantFoldCallTo(F)) 762ad58eb34342f70f094008e6d08cb4ed814754e64Chris Lattner return ConstantFoldCall(F, Ops+1, NumOps-1); 7635520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 764001f7534e0311508cc93831a595785bb177f8a18Chris Lattner case Instruction::PtrToInt: 765001f7534e0311508cc93831a595785bb177f8a18Chris Lattner // If the input is a inttoptr, eliminate the pair. This requires knowing 766001f7534e0311508cc93831a595785bb177f8a18Chris Lattner // the width of a pointer, so it can't be done in ConstantExpr::getCast. 767001f7534e0311508cc93831a595785bb177f8a18Chris Lattner if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[0])) { 768001f7534e0311508cc93831a595785bb177f8a18Chris Lattner if (TD && CE->getOpcode() == Instruction::IntToPtr) { 769001f7534e0311508cc93831a595785bb177f8a18Chris Lattner Constant *Input = CE->getOperand(0); 7706de29f8d960505421d61c80cdb738e16720b6c0eDan Gohman unsigned InWidth = Input->getType()->getScalarSizeInBits(); 77104aa2c3520c049333ca216fb794d700310c4a33dNick Lewycky if (TD->getPointerSizeInBits() < InWidth) { 77204aa2c3520c049333ca216fb794d700310c4a33dNick Lewycky Constant *Mask = 7737b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner ConstantInt::get(CE->getContext(), APInt::getLowBitsSet(InWidth, 77404aa2c3520c049333ca216fb794d700310c4a33dNick Lewycky TD->getPointerSizeInBits())); 775baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson Input = ConstantExpr::getAnd(Input, Mask); 77604aa2c3520c049333ca216fb794d700310c4a33dNick Lewycky } 777001f7534e0311508cc93831a595785bb177f8a18Chris Lattner // Do a zext or trunc to get to the dest size. 778baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getIntegerCast(Input, DestTy, false); 779001f7534e0311508cc93831a595785bb177f8a18Chris Lattner } 780001f7534e0311508cc93831a595785bb177f8a18Chris Lattner } 781baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getCast(Opcode, Ops[0], DestTy); 782001f7534e0311508cc93831a595785bb177f8a18Chris Lattner case Instruction::IntToPtr: 78381b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands // If the input is a ptrtoint, turn the pair into a ptr to ptr bitcast if 78481b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands // the int size is >= the ptr size. This requires knowing the width of a 78581b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands // pointer, so it can't be done in ConstantExpr::getCast. 78681b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[0])) { 7879a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman if (TD && 78881b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands TD->getPointerSizeInBits() <= 7896de29f8d960505421d61c80cdb738e16720b6c0eDan Gohman CE->getType()->getScalarSizeInBits()) { 7906333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner if (CE->getOpcode() == Instruction::PtrToInt) 7916333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner return FoldBitCast(CE->getOperand(0), DestTy, *TD); 7926333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 7939a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman // If there's a constant offset added to the integer value before 7949a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman // it is casted back to a pointer, see if the expression can be 7959a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman // converted into a GEP. 7969a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman if (CE->getOpcode() == Instruction::Add) 7979a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman if (ConstantInt *L = dyn_cast<ConstantInt>(CE->getOperand(0))) 7989a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman if (ConstantExpr *R = dyn_cast<ConstantExpr>(CE->getOperand(1))) 7999a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman if (R->getOpcode() == Instruction::PtrToInt) 8009a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman if (GlobalVariable *GV = 8019a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman dyn_cast<GlobalVariable>(R->getOperand(0))) { 8029a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman const PointerType *GVTy = cast<PointerType>(GV->getType()); 8039a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman if (const ArrayType *AT = 8049a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman dyn_cast<ArrayType>(GVTy->getElementType())) { 8059a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman const Type *ElTy = AT->getElementType(); 806777d2306b36816a53bc1ae1244c0dc7d998ae691Duncan Sands uint64_t AllocSize = TD->getTypeAllocSize(ElTy); 807777d2306b36816a53bc1ae1244c0dc7d998ae691Duncan Sands APInt PSA(L->getValue().getBitWidth(), AllocSize); 8089a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman if (ElTy == cast<PointerType>(DestTy)->getElementType() && 8099a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman L->getValue().urem(PSA) == 0) { 8109a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman APInt ElemIdx = L->getValue().udiv(PSA); 8119a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman if (ElemIdx.ult(APInt(ElemIdx.getBitWidth(), 8129a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman AT->getNumElements()))) { 8139a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman Constant *Index[] = { 814a7235ea7245028a0723e8ab7fd011386b3900777Owen Anderson Constant::getNullValue(CE->getType()), 8157b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner ConstantInt::get(ElTy->getContext(), ElemIdx) 8169a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman }; 817508955156a25a9abc470a29e1760aa176d341cf9Owen Anderson return 818baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson ConstantExpr::getGetElementPtr(GV, &Index[0], 2); 8199a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman } 8209a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman } 8219a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman } 8229a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman } 82381b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands } 82481b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands } 825baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getCast(Opcode, Ops[0], DestTy); 8265520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::Trunc: 8275520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::ZExt: 8285520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::SExt: 8295520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FPTrunc: 8305520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FPExt: 8315520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::UIToFP: 8325520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::SIToFP: 8335520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FPToUI: 8345520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FPToSI: 835baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getCast(Opcode, Ops[0], DestTy); 8365520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::BitCast: 8371afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (TD) 8386333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner return FoldBitCast(Ops[0], DestTy, *TD); 839baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getBitCast(Ops[0], DestTy); 8405520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::Select: 841baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getSelect(Ops[0], Ops[1], Ops[2]); 8425520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::ExtractElement: 843baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getExtractElement(Ops[0], Ops[1]); 8445520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::InsertElement: 845baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getInsertElement(Ops[0], Ops[1], Ops[2]); 8465520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::ShuffleVector: 847baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getShuffleVector(Ops[0], Ops[1], Ops[2]); 8485520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::GetElementPtr: 8494f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman if (Constant *C = CastGEPIndices(Ops, NumOps, DestTy, TD)) 8504f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman return C; 8517b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner if (Constant *C = SymbolicallyEvaluateGEP(Ops, NumOps, DestTy, TD)) 85203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return C; 85303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 854baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getGetElementPtr(Ops[0], Ops+1, NumOps-1); 8555520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 8565520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner} 8575520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 858f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner/// ConstantFoldCompareInstOperands - Attempt to constant fold a compare 859f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner/// instruction (icmp/fcmp) with the specified operands. If it fails, it 860f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner/// returns a constant expression of the specified operands. 861f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner/// 862f286f6fd93d569befe6e77c94a947e6e04e95685Chris LattnerConstant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate, 8638f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner Constant *Ops0, Constant *Ops1, 864f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner const TargetData *TD) { 865f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // fold: icmp (inttoptr x), null -> icmp x, 0 866f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // fold: icmp (ptrtoint x), 0 -> icmp x, null 8673dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky // fold: icmp (inttoptr x), (inttoptr y) -> icmp trunc/zext x, trunc/zext y 868f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // fold: icmp (ptrtoint x), (ptrtoint y) -> icmp x, y 869f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // 870f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // ConstantExpr::getCompare cannot do this, because it doesn't have TD 871f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // around to know if bit truncation is happening. 8728f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner if (ConstantExpr *CE0 = dyn_cast<ConstantExpr>(Ops0)) { 8738f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner if (TD && Ops1->isNullValue()) { 8747b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner const Type *IntPtrTy = TD->getIntPtrType(CE0->getContext()); 875f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (CE0->getOpcode() == Instruction::IntToPtr) { 876f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // Convert the integer value to the right size to ensure we get the 877f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // proper extension or truncation. 878baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson Constant *C = ConstantExpr::getIntegerCast(CE0->getOperand(0), 879f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner IntPtrTy, false); 8808f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner Constant *Null = Constant::getNullValue(C->getType()); 8818f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner return ConstantFoldCompareInstOperands(Predicate, C, Null, TD); 882f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 883f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner 884f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // Only do this transformation if the int is intptrty in size, otherwise 885f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // there is a truncation or extension that we aren't modeling. 886f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (CE0->getOpcode() == Instruction::PtrToInt && 887f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner CE0->getType() == IntPtrTy) { 888f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner Constant *C = CE0->getOperand(0); 8898f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner Constant *Null = Constant::getNullValue(C->getType()); 8908f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner return ConstantFoldCompareInstOperands(Predicate, C, Null, TD); 891f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 892f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 893f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner 8948f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(Ops1)) { 8953dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky if (TD && CE0->getOpcode() == CE1->getOpcode()) { 8967b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner const Type *IntPtrTy = TD->getIntPtrType(CE0->getContext()); 8973dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky 8983dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky if (CE0->getOpcode() == Instruction::IntToPtr) { 8993dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky // Convert the integer value to the right size to ensure we get the 9003dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky // proper extension or truncation. 901baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson Constant *C0 = ConstantExpr::getIntegerCast(CE0->getOperand(0), 9023dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky IntPtrTy, false); 903baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson Constant *C1 = ConstantExpr::getIntegerCast(CE1->getOperand(0), 9043dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky IntPtrTy, false); 9058f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner return ConstantFoldCompareInstOperands(Predicate, C0, C1, TD); 9063dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky } 9073dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky 9083dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky // Only do this transformation if the int is intptrty in size, otherwise 9093dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky // there is a truncation or extension that we aren't modeling. 9103dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky if ((CE0->getOpcode() == Instruction::PtrToInt && 9113dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky CE0->getType() == IntPtrTy && 9128f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner CE0->getOperand(0)->getType() == CE1->getOperand(0)->getType())) 9138f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner return ConstantFoldCompareInstOperands(Predicate, CE0->getOperand(0), 9148f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner CE1->getOperand(0), TD); 915f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 916f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 91779fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner 91879fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner // icmp eq (or x, y), 0 -> (icmp eq x, 0) & (icmp eq y, 0) 91979fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner // icmp ne (or x, y), 0 -> (icmp ne x, 0) | (icmp ne y, 0) 92079fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner if ((Predicate == ICmpInst::ICMP_EQ || Predicate == ICmpInst::ICMP_NE) && 92179fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner CE0->getOpcode() == Instruction::Or && Ops1->isNullValue()) { 92279fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner Constant *LHS = 92379fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner ConstantFoldCompareInstOperands(Predicate, CE0->getOperand(0), Ops1,TD); 92479fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner Constant *RHS = 92579fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner ConstantFoldCompareInstOperands(Predicate, CE0->getOperand(1), Ops1,TD); 92679fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner unsigned OpC = 92779fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner Predicate == ICmpInst::ICMP_EQ ? Instruction::And : Instruction::Or; 92879fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner Constant *Ops[] = { LHS, RHS }; 92979fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner return ConstantFoldInstOperands(OpC, LHS->getType(), Ops, 2, TD); 93079fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner } 931f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 9328f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner 9338f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner return ConstantExpr::getCompare(Predicate, Ops0, Ops1); 934f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner} 935f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner 936f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner 9375520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// ConstantFoldLoadThroughGEPConstantExpr - Given a constant and a 9385520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// getelementptr constantexpr, return the constant value being addressed by the 9395520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// constant expression, or null if something is funny and we can't decide. 9405520732b24a5a321140dd79af70d321c7ff3dec9Chris LattnerConstant *llvm::ConstantFoldLoadThroughGEPConstantExpr(Constant *C, 941c6f69e94fa46f585b59bb9d7ace3224b0e638c95Dan Gohman ConstantExpr *CE) { 942a7235ea7245028a0723e8ab7fd011386b3900777Owen Anderson if (CE->getOperand(1) != Constant::getNullValue(CE->getOperand(1)->getType())) 9435520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; // Do not allow stepping over the value! 9445520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 9455520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // Loop over all of the operands, tracking down which value we are 9465520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // addressing... 9475520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner gep_type_iterator I = gep_type_begin(CE), E = gep_type_end(CE); 9485520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner for (++I; I != E; ++I) 9495520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (const StructType *STy = dyn_cast<StructType>(*I)) { 9505520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner ConstantInt *CU = cast<ConstantInt>(I.getOperand()); 9515520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner assert(CU->getZExtValue() < STy->getNumElements() && 9525520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner "Struct index out of range!"); 9535520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner unsigned El = (unsigned)CU->getZExtValue(); 9545520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) { 9555520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = CS->getOperand(El); 9565520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else if (isa<ConstantAggregateZero>(C)) { 957a7235ea7245028a0723e8ab7fd011386b3900777Owen Anderson C = Constant::getNullValue(STy->getElementType(El)); 9585520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else if (isa<UndefValue>(C)) { 9599e9a0d5fc26878e51a58a8b57900fcbf952c2691Owen Anderson C = UndefValue::get(STy->getElementType(El)); 9605520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else { 9615520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 9625520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 9635520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else if (ConstantInt *CI = dyn_cast<ConstantInt>(I.getOperand())) { 9645520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (const ArrayType *ATy = dyn_cast<ArrayType>(*I)) { 9655520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (CI->getZExtValue() >= ATy->getNumElements()) 9665520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 9675520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (ConstantArray *CA = dyn_cast<ConstantArray>(C)) 9685520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = CA->getOperand(CI->getZExtValue()); 9695520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else if (isa<ConstantAggregateZero>(C)) 970a7235ea7245028a0723e8ab7fd011386b3900777Owen Anderson C = Constant::getNullValue(ATy->getElementType()); 9715520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else if (isa<UndefValue>(C)) 9729e9a0d5fc26878e51a58a8b57900fcbf952c2691Owen Anderson C = UndefValue::get(ATy->getElementType()); 9735520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else 9745520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 97562d327e241f59735eed836e98c8f11ffaa6cf6f8Chris Lattner } else if (const VectorType *VTy = dyn_cast<VectorType>(*I)) { 97662d327e241f59735eed836e98c8f11ffaa6cf6f8Chris Lattner if (CI->getZExtValue() >= VTy->getNumElements()) 9775520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 9789d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer if (ConstantVector *CP = dyn_cast<ConstantVector>(C)) 9795520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = CP->getOperand(CI->getZExtValue()); 9805520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else if (isa<ConstantAggregateZero>(C)) 98162d327e241f59735eed836e98c8f11ffaa6cf6f8Chris Lattner C = Constant::getNullValue(VTy->getElementType()); 9825520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else if (isa<UndefValue>(C)) 98362d327e241f59735eed836e98c8f11ffaa6cf6f8Chris Lattner C = UndefValue::get(VTy->getElementType()); 9845520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else 9855520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 9865520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else { 9875520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 9885520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 9895520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else { 9905520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 9915520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 9925520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return C; 9935520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner} 9945520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 9955520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 996bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell//===----------------------------------------------------------------------===// 9975520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner// Constant Folding for Calls 998bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell// 999bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 1000bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell/// canConstantFoldCallTo - Return true if its even possible to fold a call to 1001bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell/// the specified function. 1002bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswellbool 1003fa9b80eb64127b3d9691e18537975635520e51e9Dan Gohmanllvm::canConstantFoldCallTo(const Function *F) { 1004bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell switch (F->getIntrinsicID()) { 10059ab7fb3ba47442d521a5bed09a27a5e8e7a786edDale Johannesen case Intrinsic::sqrt: 10069ab7fb3ba47442d521a5bed09a27a5e8e7a786edDale Johannesen case Intrinsic::powi: 1007e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer case Intrinsic::bswap: 1008e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer case Intrinsic::ctpop: 1009e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer case Intrinsic::ctlz: 1010e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer case Intrinsic::cttz: 1011e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner case Intrinsic::uadd_with_overflow: 1012e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner case Intrinsic::usub_with_overflow: 10131614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix case Intrinsic::sadd_with_overflow: 10141614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix case Intrinsic::ssub_with_overflow: 1015bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell return true; 101668a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner default: 101768a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner return false; 101868a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner case 0: break; 1019bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 1020bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 10216f532a988e5c02fcb271fb65e9e7b83f0147d3f2Chris Lattner if (!F->hasName()) return false; 1022f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar StringRef Name = F->getName(); 1023c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner 1024c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner // In these cases, the check of the length is required. We don't want to 1025c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner // return true for a name like "cos\0blah" which strcmp would return equal to 1026c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner // "cos", but has length 8. 1027f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar switch (Name[0]) { 1028c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner default: return false; 1029c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'a': 1030f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar return Name == "acos" || Name == "asin" || 1031f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar Name == "atan" || Name == "atan2"; 1032c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'c': 1033f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar return Name == "cos" || Name == "ceil" || Name == "cosf" || Name == "cosh"; 1034c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'e': 1035f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar return Name == "exp"; 1036c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'f': 1037f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar return Name == "fabs" || Name == "fmod" || Name == "floor"; 1038c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'l': 1039f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar return Name == "log" || Name == "log10"; 1040c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'p': 1041f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar return Name == "pow"; 1042c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 's': 1043f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar return Name == "sin" || Name == "sinh" || Name == "sqrt" || 1044f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar Name == "sinf" || Name == "sqrtf"; 1045c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 't': 1046f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar return Name == "tan" || Name == "tanh"; 1047bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 1048bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell} 1049bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 105072d88ae5447a3929c97e88f4c806213847b5d988Chris Lattnerstatic Constant *ConstantFoldFP(double (*NativeFP)(double), double V, 10517b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner const Type *Ty) { 1052bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell errno = 0; 1053bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell V = NativeFP(V); 1054f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner if (errno != 0) { 1055f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner errno = 0; 1056f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner return 0; 105743421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen } 1058f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner 1059d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner if (Ty->isFloatTy()) 10607b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFP::get(Ty->getContext(), APFloat((float)V)); 1061d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner if (Ty->isDoubleTy()) 10627b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFP::get(Ty->getContext(), APFloat(V)); 1063c23197a26f34f559ea9797de51e187087c039c42Torok Edwin llvm_unreachable("Can only constant fold float/double"); 106433e456d5f3909e0c7b96e04e5674c25a182da100Gabor Greif return 0; // dummy return to suppress warning 1065bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell} 1066bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 1067384152444d22d356f7b4090a158da4cbc1f79464Dan Gohmanstatic Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double), 10687b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner double V, double W, const Type *Ty) { 1069384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman errno = 0; 1070384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman V = NativeFP(V, W); 1071f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner if (errno != 0) { 1072f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner errno = 0; 1073f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner return 0; 107443421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen } 1075f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner 1076d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner if (Ty->isFloatTy()) 10777b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFP::get(Ty->getContext(), APFloat((float)V)); 1078d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner if (Ty->isDoubleTy()) 10797b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFP::get(Ty->getContext(), APFloat(V)); 1080c23197a26f34f559ea9797de51e187087c039c42Torok Edwin llvm_unreachable("Can only constant fold float/double"); 108133e456d5f3909e0c7b96e04e5674c25a182da100Gabor Greif return 0; // dummy return to suppress warning 1082384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman} 1083384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman 1084bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell/// ConstantFoldCall - Attempt to constant fold a call to the specified function 1085bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell/// with the specified arguments, returning null if unsuccessful. 1086bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John CriswellConstant * 1087f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattnerllvm::ConstantFoldCall(Function *F, 108868a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner Constant *const *Operands, unsigned NumOperands) { 10896f532a988e5c02fcb271fb65e9e7b83f0147d3f2Chris Lattner if (!F->hasName()) return 0; 1090f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar StringRef Name = F->getName(); 1091e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner 1092bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell const Type *Ty = F->getReturnType(); 109372d88ae5447a3929c97e88f4c806213847b5d988Chris Lattner if (NumOperands == 1) { 1094bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell if (ConstantFP *Op = dyn_cast<ConstantFP>(Operands[0])) { 1095d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner if (!Ty->isFloatTy() && !Ty->isDoubleTy()) 109643421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen return 0; 109743421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen /// Currently APFloat versions of these functions do not exist, so we use 109843421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen /// the host native double versions. Float versions are not called 109943421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen /// directly but for all these it is true (float)(f((double)arg)) == 110043421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen /// f(arg). Long double not supported yet. 1101d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner double V = Ty->isFloatTy() ? (double)Op->getValueAPF().convertToFloat() : 110243421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen Op->getValueAPF().convertToDouble(); 1103f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar switch (Name[0]) { 1104c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'a': 1105f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar if (Name == "acos") 11067b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(acos, V, Ty); 1107f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "asin") 11087b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(asin, V, Ty); 1109f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "atan") 11107b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(atan, V, Ty); 1111c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 1112c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'c': 1113f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar if (Name == "ceil") 11147b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(ceil, V, Ty); 1115f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "cos") 11167b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(cos, V, Ty); 1117f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "cosh") 11187b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(cosh, V, Ty); 1119f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "cosf") 11207b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(cos, V, Ty); 1121c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 1122c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'e': 1123f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar if (Name == "exp") 11247b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(exp, V, Ty); 1125c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 1126c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'f': 1127f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar if (Name == "fabs") 11287b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(fabs, V, Ty); 1129f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "floor") 11307b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(floor, V, Ty); 1131c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 1132c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'l': 1133f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar if (Name == "log" && V > 0) 11347b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(log, V, Ty); 1135f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "log10" && V > 0) 11367b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(log10, V, Ty); 1137f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "llvm.sqrt.f32" || 1138f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar Name == "llvm.sqrt.f64") { 1139c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (V >= -0.0) 11407b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(sqrt, V, Ty); 1141c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else // Undefined 1142a7235ea7245028a0723e8ab7fd011386b3900777Owen Anderson return Constant::getNullValue(Ty); 1143c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner } 1144c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 1145c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 's': 1146f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar if (Name == "sin") 11477b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(sin, V, Ty); 1148f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "sinh") 11497b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(sinh, V, Ty); 1150f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "sqrt" && V >= 0) 11517b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(sqrt, V, Ty); 1152f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "sqrtf" && V >= 0) 11537b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(sqrt, V, Ty); 1154f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "sinf") 11557b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(sin, V, Ty); 1156c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 1157c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 't': 1158f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar if (Name == "tan") 11597b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(tan, V, Ty); 1160f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "tanh") 11617b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(tanh, V, Ty); 1162c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 1163c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner default: 1164c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 1165bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 116668a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner return 0; 116768a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner } 116868a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner 116968a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner 117068a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner if (ConstantInt *Op = dyn_cast<ConstantInt>(Operands[0])) { 1171f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar if (Name.startswith("llvm.bswap")) 11727b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantInt::get(F->getContext(), Op->getValue().byteSwap()); 1173f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name.startswith("llvm.ctpop")) 1174eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson return ConstantInt::get(Ty, Op->getValue().countPopulation()); 1175f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name.startswith("llvm.cttz")) 1176eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson return ConstantInt::get(Ty, Op->getValue().countTrailingZeros()); 1177f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name.startswith("llvm.ctlz")) 1178eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson return ConstantInt::get(Ty, Op->getValue().countLeadingZeros()); 117968a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner return 0; 1180bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 118168a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner 11829ee7123ab462d97a2b242280e9bf0b47883531cbDan Gohman if (isa<UndefValue>(Operands[0])) { 11839ee7123ab462d97a2b242280e9bf0b47883531cbDan Gohman if (Name.startswith("llvm.bswap")) 11849ee7123ab462d97a2b242280e9bf0b47883531cbDan Gohman return Operands[0]; 11859ee7123ab462d97a2b242280e9bf0b47883531cbDan Gohman return 0; 11869ee7123ab462d97a2b242280e9bf0b47883531cbDan Gohman } 11879ee7123ab462d97a2b242280e9bf0b47883531cbDan Gohman 118868a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner return 0; 118968a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner } 119068a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner 119168a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner if (NumOperands == 2) { 1192bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell if (ConstantFP *Op1 = dyn_cast<ConstantFP>(Operands[0])) { 1193d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner if (!Ty->isFloatTy() && !Ty->isDoubleTy()) 11949ab7fb3ba47442d521a5bed09a27a5e8e7a786edDale Johannesen return 0; 1195d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner double Op1V = Ty->isFloatTy() ? 1196d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner (double)Op1->getValueAPF().convertToFloat() : 119743421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen Op1->getValueAPF().convertToDouble(); 1198bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell if (ConstantFP *Op2 = dyn_cast<ConstantFP>(Operands[1])) { 1199d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner if (Op2->getType() != Op1->getType()) 1200d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner return 0; 1201d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner 1202d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner double Op2V = Ty->isFloatTy() ? 120343421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen (double)Op2->getValueAPF().convertToFloat(): 120443421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen Op2->getValueAPF().convertToDouble(); 1205bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 120668a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner if (Name == "pow") 12077b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty); 120868a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner if (Name == "fmod") 12097b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldBinaryFP(fmod, Op1V, Op2V, Ty); 121068a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner if (Name == "atan2") 12117b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldBinaryFP(atan2, Op1V, Op2V, Ty); 1212b5282dcf4745be59046f440980a1c0f0a50c9c09Chris Lattner } else if (ConstantInt *Op2C = dyn_cast<ConstantInt>(Operands[1])) { 121368a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner if (Name == "llvm.powi.f32") 12147b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFP::get(F->getContext(), 12157b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner APFloat((float)std::pow((float)Op1V, 121602a260aa11a2e1b2c14335274d3c42ca3f3eabc0Chris Lattner (int)Op2C->getZExtValue()))); 121768a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner if (Name == "llvm.powi.f64") 12187b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFP::get(F->getContext(), 12197b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner APFloat((double)std::pow((double)Op1V, 12207b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner (int)Op2C->getZExtValue()))); 1221bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 122268a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner return 0; 1223bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 1224e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner 1225e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner 1226e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner if (ConstantInt *Op1 = dyn_cast<ConstantInt>(Operands[0])) { 1227e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner if (ConstantInt *Op2 = dyn_cast<ConstantInt>(Operands[1])) { 1228e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner switch (F->getIntrinsicID()) { 1229e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner default: break; 1230e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner case Intrinsic::uadd_with_overflow: { 1231e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner Constant *Res = ConstantExpr::getAdd(Op1, Op2); // result. 1232e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner Constant *Ops[] = { 1233e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner Res, ConstantExpr::getICmp(CmpInst::ICMP_ULT, Res, Op1) // overflow. 1234e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner }; 1235e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner return ConstantStruct::get(F->getContext(), Ops, 2, false); 1236e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner } 1237e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner case Intrinsic::usub_with_overflow: { 1238e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner Constant *Res = ConstantExpr::getSub(Op1, Op2); // result. 1239e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner Constant *Ops[] = { 1240e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner Res, ConstantExpr::getICmp(CmpInst::ICMP_UGT, Res, Op1) // overflow. 1241e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner }; 1242e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner return ConstantStruct::get(F->getContext(), Ops, 2, false); 1243e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner } 12441614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix case Intrinsic::sadd_with_overflow: { 12451614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix Constant *Res = ConstantExpr::getAdd(Op1, Op2); // result. 12461614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix Constant *Overflow = ConstantExpr::getSelect( 12471614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix ConstantExpr::getICmp(CmpInst::ICMP_SGT, 12481614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix ConstantInt::get(Op1->getType(), 0), Op1), 12491614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix ConstantExpr::getICmp(CmpInst::ICMP_SGT, Res, Op2), 12501614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix ConstantExpr::getICmp(CmpInst::ICMP_SLT, Res, Op2)); // overflow. 12511614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix 12521614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix Constant *Ops[] = { Res, Overflow }; 12531614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix return ConstantStruct::get(F->getContext(), Ops, 2, false); 12541614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix } 12551614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix case Intrinsic::ssub_with_overflow: { 12561614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix Constant *Res = ConstantExpr::getSub(Op1, Op2); // result. 12571614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix Constant *Overflow = ConstantExpr::getSelect( 12581614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix ConstantExpr::getICmp(CmpInst::ICMP_SGT, 12591614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix ConstantInt::get(Op2->getType(), 0), Op2), 12601614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix ConstantExpr::getICmp(CmpInst::ICMP_SLT, Res, Op1), 12611614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix ConstantExpr::getICmp(CmpInst::ICMP_SGT, Res, Op1)); // overflow. 12621614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix 12631614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix Constant *Ops[] = { Res, Overflow }; 12641614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix return ConstantStruct::get(F->getContext(), Ops, 2, false); 12651614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix } 1266e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner } 1267e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner } 1268e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner 1269e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner return 0; 1270e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner } 1271e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner return 0; 1272bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 1273bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell return 0; 1274bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell} 1275bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 1276