ConstantFolding.cpp revision 8cd4efb6a5e51b4e77039c17338f290ca3a8ee92
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" 331f6efa3996dd1929fbc129203ce5009b620e6969Michael J. Spencer#include "llvm/Support/FEnv.h" 34bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell#include <cerrno> 3597af751deb9b26fd42fbcee082da9ccc4ded5b45Jeff Cohen#include <cmath> 36bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswellusing namespace llvm; 37bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 3803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner//===----------------------------------------------------------------------===// 3903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner// Constant Folding internal helper functions 4003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner//===----------------------------------------------------------------------===// 4103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 426333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner/// FoldBitCast - Constant fold bitcast, symbolically evaluating it with 436333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner/// TargetData. This always returns a non-null constant, but it may be a 446333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner/// ConstantExpr if unfoldable. 456333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattnerstatic Constant *FoldBitCast(Constant *C, const Type *DestTy, 466333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner const TargetData &TD) { 476333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 4893798daa3ecbfb29624052d3e54d2404ab65897aChris Lattner // This only handles casts to vectors currently. 496333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner const VectorType *DestVTy = dyn_cast<VectorType>(DestTy); 506333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner if (DestVTy == 0) 516333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner return ConstantExpr::getBitCast(C, DestTy); 526333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 5393798daa3ecbfb29624052d3e54d2404ab65897aChris Lattner // If this is a scalar -> vector cast, convert the input into a <1 x scalar> 5493798daa3ecbfb29624052d3e54d2404ab65897aChris Lattner // vector so the code below can handle it uniformly. 5593798daa3ecbfb29624052d3e54d2404ab65897aChris Lattner if (isa<ConstantFP>(C) || isa<ConstantInt>(C)) { 5693798daa3ecbfb29624052d3e54d2404ab65897aChris Lattner Constant *Ops = C; // don't take the address of C! 5793798daa3ecbfb29624052d3e54d2404ab65897aChris Lattner return FoldBitCast(ConstantVector::get(&Ops, 1), DestTy, TD); 5893798daa3ecbfb29624052d3e54d2404ab65897aChris Lattner } 5993798daa3ecbfb29624052d3e54d2404ab65897aChris Lattner 6093798daa3ecbfb29624052d3e54d2404ab65897aChris Lattner // If this is a bitcast from constant vector -> vector, fold it. 6193798daa3ecbfb29624052d3e54d2404ab65897aChris Lattner ConstantVector *CV = dyn_cast<ConstantVector>(C); 6293798daa3ecbfb29624052d3e54d2404ab65897aChris Lattner if (CV == 0) 6393798daa3ecbfb29624052d3e54d2404ab65897aChris Lattner return ConstantExpr::getBitCast(C, DestTy); 6493798daa3ecbfb29624052d3e54d2404ab65897aChris Lattner 656333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // If the element types match, VMCore can fold it. 666333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner unsigned NumDstElt = DestVTy->getNumElements(); 676333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner unsigned NumSrcElt = CV->getNumOperands(); 686333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner if (NumDstElt == NumSrcElt) 696333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner return ConstantExpr::getBitCast(C, DestTy); 706333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 716333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner const Type *SrcEltTy = CV->getType()->getElementType(); 726333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner const Type *DstEltTy = DestVTy->getElementType(); 736333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 746333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Otherwise, we're changing the number of elements in a vector, which 756333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // requires endianness information to do the right thing. For example, 766333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>) 776333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // folds to (little endian): 786333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // <4 x i32> <i32 0, i32 0, i32 1, i32 0> 796333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // and to (big endian): 806333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // <4 x i32> <i32 0, i32 0, i32 0, i32 1> 816333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 826333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // First thing is first. We only want to think about integer here, so if 836333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // we have something in FP form, recast it as integer. 84b0bc6c361da9009e8414efde317d9bbff755f6c0Duncan Sands if (DstEltTy->isFloatingPointTy()) { 856333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Fold to an vector of integers with same size as our FP type. 866333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner unsigned FPWidth = DstEltTy->getPrimitiveSizeInBits(); 876333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner const Type *DestIVTy = 886333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner VectorType::get(IntegerType::get(C->getContext(), FPWidth), NumDstElt); 896333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Recursively handle this integer conversion, if possible. 906333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner C = FoldBitCast(C, DestIVTy, TD); 916333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner if (!C) return ConstantExpr::getBitCast(C, DestTy); 926333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 936333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Finally, VMCore can handle this now that #elts line up. 946333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner return ConstantExpr::getBitCast(C, DestTy); 956333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner } 966333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 976333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Okay, we know the destination is integer, if the input is FP, convert 986333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // it to integer first. 99b0bc6c361da9009e8414efde317d9bbff755f6c0Duncan Sands if (SrcEltTy->isFloatingPointTy()) { 1006333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner unsigned FPWidth = SrcEltTy->getPrimitiveSizeInBits(); 1016333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner const Type *SrcIVTy = 1026333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner VectorType::get(IntegerType::get(C->getContext(), FPWidth), NumSrcElt); 1036333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Ask VMCore to do the conversion now that #elts line up. 1046333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner C = ConstantExpr::getBitCast(C, SrcIVTy); 1056333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner CV = dyn_cast<ConstantVector>(C); 1066333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner if (!CV) // If VMCore wasn't able to fold it, bail out. 1076333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner return C; 1086333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner } 1096333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 1106333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Now we know that the input and output vectors are both integer vectors 1116333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // of the same size, and that their #elements is not the same. Do the 1126333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // conversion here, which depends on whether the input or output has 1136333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // more elements. 1146333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner bool isLittleEndian = TD.isLittleEndian(); 1156333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 1166333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner SmallVector<Constant*, 32> Result; 1176333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner if (NumDstElt < NumSrcElt) { 1186333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Handle: bitcast (<4 x i32> <i32 0, i32 1, i32 2, i32 3> to <2 x i64>) 1196333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner Constant *Zero = Constant::getNullValue(DstEltTy); 1206333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner unsigned Ratio = NumSrcElt/NumDstElt; 1216333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner unsigned SrcBitSize = SrcEltTy->getPrimitiveSizeInBits(); 1226333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner unsigned SrcElt = 0; 1236333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner for (unsigned i = 0; i != NumDstElt; ++i) { 1246333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Build each element of the result. 1256333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner Constant *Elt = Zero; 1266333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner unsigned ShiftAmt = isLittleEndian ? 0 : SrcBitSize*(Ratio-1); 1276333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner for (unsigned j = 0; j != Ratio; ++j) { 1286333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner Constant *Src = dyn_cast<ConstantInt>(CV->getOperand(SrcElt++)); 1296333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner if (!Src) // Reject constantexpr elements. 1306333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner return ConstantExpr::getBitCast(C, DestTy); 1316333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 1326333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Zero extend the element to the right size. 1336333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner Src = ConstantExpr::getZExt(Src, Elt->getType()); 1346333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 1356333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Shift it to the right place, depending on endianness. 1366333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner Src = ConstantExpr::getShl(Src, 1376333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner ConstantInt::get(Src->getType(), ShiftAmt)); 1386333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner ShiftAmt += isLittleEndian ? SrcBitSize : -SrcBitSize; 1396333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 1406333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Mix it in. 1416333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner Elt = ConstantExpr::getOr(Elt, Src); 1426333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner } 1436333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner Result.push_back(Elt); 1446333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner } 1456333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner } else { 1466333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Handle: bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>) 1476333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner unsigned Ratio = NumDstElt/NumSrcElt; 1486333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner unsigned DstBitSize = DstEltTy->getPrimitiveSizeInBits(); 1496333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 1506333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Loop over each source value, expanding into multiple results. 1516333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner for (unsigned i = 0; i != NumSrcElt; ++i) { 1526333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner Constant *Src = dyn_cast<ConstantInt>(CV->getOperand(i)); 1536333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner if (!Src) // Reject constantexpr elements. 1546333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner return ConstantExpr::getBitCast(C, DestTy); 1556333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 1566333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner unsigned ShiftAmt = isLittleEndian ? 0 : DstBitSize*(Ratio-1); 1576333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner for (unsigned j = 0; j != Ratio; ++j) { 1586333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Shift the piece of the value into the right place, depending on 1596333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // endianness. 1606333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner Constant *Elt = ConstantExpr::getLShr(Src, 1616333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner ConstantInt::get(Src->getType(), ShiftAmt)); 1626333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner ShiftAmt += isLittleEndian ? DstBitSize : -DstBitSize; 1636333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 1646333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner // Truncate and remember this piece. 1656333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner Result.push_back(ConstantExpr::getTrunc(Elt, DstEltTy)); 1666333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner } 1676333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner } 1686333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner } 1696333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 1706333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner return ConstantVector::get(Result.data(), Result.size()); 1716333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner} 1726333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 1736333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner 17403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// IsConstantOffsetFromGlobal - If this constant is actually a constant offset 17503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// from a global, return the global and the constant. Because of 17603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// constantexprs, this function is recursive. 17703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattnerstatic bool IsConstantOffsetFromGlobal(Constant *C, GlobalValue *&GV, 17803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner int64_t &Offset, const TargetData &TD) { 17903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Trivial case, constant is the global. 18003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if ((GV = dyn_cast<GlobalValue>(C))) { 18103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner Offset = 0; 18203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return true; 18303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 18403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 18503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Otherwise, if this isn't a constant expr, bail out. 18603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner ConstantExpr *CE = dyn_cast<ConstantExpr>(C); 18703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (!CE) return false; 18803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 18903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Look through ptr->int and ptr->ptr casts. 19003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (CE->getOpcode() == Instruction::PtrToInt || 19103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner CE->getOpcode() == Instruction::BitCast) 19203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD); 19303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 19403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // i32* getelementptr ([5 x i32]* @a, i32 0, i32 5) 19503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (CE->getOpcode() == Instruction::GetElementPtr) { 19603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Cannot compute this if the element type of the pointer is missing size 19703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // info. 198f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (!cast<PointerType>(CE->getOperand(0)->getType()) 199f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner ->getElementType()->isSized()) 20003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return false; 20103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 20203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // If the base isn't a global+constant, we aren't either. 20303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (!IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD)) 20403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return false; 20503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 20603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Otherwise, add any offset that our operands provide. 20703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner gep_type_iterator GTI = gep_type_begin(CE); 208de2d74b213844b17eb5327fba27f21e699d3af66Gabor Greif for (User::const_op_iterator i = CE->op_begin() + 1, e = CE->op_end(); 209785c6af9797fcf551feef70f2ecb5cd075b6e3c4Gabor Greif i != e; ++i, ++GTI) { 210de2d74b213844b17eb5327fba27f21e699d3af66Gabor Greif ConstantInt *CI = dyn_cast<ConstantInt>(*i); 21103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (!CI) return false; // Index isn't a simple constant? 212e368b460a206fafa0d31d5d059b1779b94f7df8cDan Gohman if (CI->isZero()) continue; // Not adding anything. 21303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 21403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (const StructType *ST = dyn_cast<StructType>(*GTI)) { 21503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // N = N + Offset 216b1919e2f08ecb37140af676fd2916f8d5ed7df3dChris Lattner Offset += TD.getStructLayout(ST)->getElementOffset(CI->getZExtValue()); 21703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } else { 218ca5183d445954a9b2a570d6bbba1bc2b00ad6442Jeff Cohen const SequentialType *SQT = cast<SequentialType>(*GTI); 219777d2306b36816a53bc1ae1244c0dc7d998ae691Duncan Sands Offset += TD.getTypeAllocSize(SQT->getElementType())*CI->getSExtValue(); 22003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 22103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 22203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return true; 22303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 22403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 22503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return false; 22603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner} 22703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 228fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner/// ReadDataFromGlobal - Recursive helper to read bits out of global. C is the 229fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner/// constant being copied out of. ByteOffset is an offset into C. CurPtr is the 230fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner/// pointer to copy results into and BytesLeft is the number of bytes left in 231fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner/// the CurPtr buffer. TD is the target data. 232fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattnerstatic bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset, 233fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner unsigned char *CurPtr, unsigned BytesLeft, 234fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner const TargetData &TD) { 235fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner assert(ByteOffset <= TD.getTypeAllocSize(C->getType()) && 236fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner "Out of range access"); 237fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 238c7b1382e351249774be63bd73839e8a0671635e1Chris Lattner // If this element is zero or undefined, we can just return since *CurPtr is 239c7b1382e351249774be63bd73839e8a0671635e1Chris Lattner // zero initialized. 240fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (isa<ConstantAggregateZero>(C) || isa<UndefValue>(C)) 241fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return true; 242fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 243fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) { 244fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (CI->getBitWidth() > 64 || 245fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner (CI->getBitWidth() & 7) != 0) 246fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return false; 247fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 248fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner uint64_t Val = CI->getZExtValue(); 249fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner unsigned IntBytes = unsigned(CI->getBitWidth()/8); 250fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 251fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner for (unsigned i = 0; i != BytesLeft && ByteOffset != IntBytes; ++i) { 252c7b1382e351249774be63bd73839e8a0671635e1Chris Lattner CurPtr[i] = (unsigned char)(Val >> (ByteOffset * 8)); 253fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner ++ByteOffset; 254fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner } 255fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return true; 256fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner } 257fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 258fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (ConstantFP *CFP = dyn_cast<ConstantFP>(C)) { 259fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (CFP->getType()->isDoubleTy()) { 2606333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner C = FoldBitCast(C, Type::getInt64Ty(C->getContext()), TD); 261fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, TD); 262fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner } 263fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (CFP->getType()->isFloatTy()){ 2646333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner C = FoldBitCast(C, Type::getInt32Ty(C->getContext()), TD); 265fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, TD); 266fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner } 267c7b1382e351249774be63bd73839e8a0671635e1Chris Lattner return false; 268fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner } 269fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 270fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) { 271fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner const StructLayout *SL = TD.getStructLayout(CS->getType()); 272fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner unsigned Index = SL->getElementContainingOffset(ByteOffset); 273fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner uint64_t CurEltOffset = SL->getElementOffset(Index); 274fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner ByteOffset -= CurEltOffset; 275fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 276fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner while (1) { 277fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // If the element access is to the element itself and not to tail padding, 278fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // read the bytes from the element. 279fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner uint64_t EltSize = TD.getTypeAllocSize(CS->getOperand(Index)->getType()); 280fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 281fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (ByteOffset < EltSize && 282fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner !ReadDataFromGlobal(CS->getOperand(Index), ByteOffset, CurPtr, 283fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner BytesLeft, TD)) 284fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return false; 285fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 286fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner ++Index; 287fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 288fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // Check to see if we read from the last struct element, if so we're done. 289fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (Index == CS->getType()->getNumElements()) 290fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return true; 291fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 292fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // If we read all of the bytes we needed from this element we're done. 293fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner uint64_t NextEltOffset = SL->getElementOffset(Index); 294fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 295fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (BytesLeft <= NextEltOffset-CurEltOffset-ByteOffset) 296fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return true; 297fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 298fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // Move to the next element of the struct. 299c5af649758ac8c6ffb896d7d5c570640a9fa1deeChris Lattner CurPtr += NextEltOffset-CurEltOffset-ByteOffset; 300fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner BytesLeft -= NextEltOffset-CurEltOffset-ByteOffset; 301fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner ByteOffset = 0; 302fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner CurEltOffset = NextEltOffset; 303fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner } 304fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // not reached. 305fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner } 306fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 307fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (ConstantArray *CA = dyn_cast<ConstantArray>(C)) { 308fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner uint64_t EltSize = TD.getTypeAllocSize(CA->getType()->getElementType()); 309fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner uint64_t Index = ByteOffset / EltSize; 310fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner uint64_t Offset = ByteOffset - Index * EltSize; 311fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner for (; Index != CA->getType()->getNumElements(); ++Index) { 312fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (!ReadDataFromGlobal(CA->getOperand(Index), Offset, CurPtr, 313fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner BytesLeft, TD)) 314fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return false; 315fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (EltSize >= BytesLeft) 316fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return true; 317fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 318fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner Offset = 0; 319fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner BytesLeft -= EltSize; 320fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner CurPtr += EltSize; 321fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner } 322fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return true; 323fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner } 324fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 325fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (ConstantVector *CV = dyn_cast<ConstantVector>(C)) { 326fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner uint64_t EltSize = TD.getTypeAllocSize(CV->getType()->getElementType()); 327fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner uint64_t Index = ByteOffset / EltSize; 328fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner uint64_t Offset = ByteOffset - Index * EltSize; 329fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner for (; Index != CV->getType()->getNumElements(); ++Index) { 330fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (!ReadDataFromGlobal(CV->getOperand(Index), Offset, CurPtr, 331fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner BytesLeft, TD)) 332fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return false; 333fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (EltSize >= BytesLeft) 334fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return true; 335fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 336fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner Offset = 0; 337fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner BytesLeft -= EltSize; 338fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner CurPtr += EltSize; 339fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner } 340fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return true; 341fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner } 342fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 343fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // Otherwise, unknown initializer type. 344fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return false; 345fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner} 346fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 347fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattnerstatic Constant *FoldReinterpretLoadFromConstPtr(Constant *C, 348fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner const TargetData &TD) { 34917f0cd3cc1432231f2bc5601e7e463986a59d817Chris Lattner const Type *LoadTy = cast<PointerType>(C->getType())->getElementType(); 35017f0cd3cc1432231f2bc5601e7e463986a59d817Chris Lattner const IntegerType *IntType = dyn_cast<IntegerType>(LoadTy); 351fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 352fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // If this isn't an integer load we can't fold it directly. 353fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (!IntType) { 354fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // If this is a float/double load, we can try folding it as an int32/64 load 35517f0cd3cc1432231f2bc5601e7e463986a59d817Chris Lattner // and then bitcast the result. This can be useful for union cases. Note 35617f0cd3cc1432231f2bc5601e7e463986a59d817Chris Lattner // that address spaces don't matter here since we're not going to result in 35717f0cd3cc1432231f2bc5601e7e463986a59d817Chris Lattner // an actual new load. 358fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner const Type *MapTy; 35917f0cd3cc1432231f2bc5601e7e463986a59d817Chris Lattner if (LoadTy->isFloatTy()) 360fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner MapTy = Type::getInt32PtrTy(C->getContext()); 36117f0cd3cc1432231f2bc5601e7e463986a59d817Chris Lattner else if (LoadTy->isDoubleTy()) 362fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner MapTy = Type::getInt64PtrTy(C->getContext()); 3631df9859c40492511b8aa4321eb76496005d3b75bDuncan Sands else if (LoadTy->isVectorTy()) { 36417f0cd3cc1432231f2bc5601e7e463986a59d817Chris Lattner MapTy = IntegerType::get(C->getContext(), 36517f0cd3cc1432231f2bc5601e7e463986a59d817Chris Lattner TD.getTypeAllocSizeInBits(LoadTy)); 36617f0cd3cc1432231f2bc5601e7e463986a59d817Chris Lattner MapTy = PointerType::getUnqual(MapTy); 36717f0cd3cc1432231f2bc5601e7e463986a59d817Chris Lattner } else 368fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return 0; 369fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 3706333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner C = FoldBitCast(C, MapTy, TD); 371fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (Constant *Res = FoldReinterpretLoadFromConstPtr(C, TD)) 3726333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner return FoldBitCast(Res, LoadTy, TD); 373fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return 0; 374fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner } 375fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 376fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner unsigned BytesLoaded = (IntType->getBitWidth() + 7) / 8; 377739208a790398cf1f9da05149c768371e48781e8Chris Lattner if (BytesLoaded > 32 || BytesLoaded == 0) return 0; 378fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 379fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner GlobalValue *GVal; 380fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner int64_t Offset; 381fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (!IsConstantOffsetFromGlobal(C, GVal, Offset, TD)) 382fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return 0; 383fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 384fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner GlobalVariable *GV = dyn_cast<GlobalVariable>(GVal); 385c7b1382e351249774be63bd73839e8a0671635e1Chris Lattner if (!GV || !GV->isConstant() || !GV->hasDefinitiveInitializer() || 386fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner !GV->getInitializer()->getType()->isSized()) 387fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return 0; 388fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 389fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // If we're loading off the beginning of the global, some bytes may be valid, 390fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // but we don't try to handle this. 391fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (Offset < 0) return 0; 392fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 393fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // If we're not accessing anything in this constant, the result is undefined. 394fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (uint64_t(Offset) >= TD.getTypeAllocSize(GV->getInitializer()->getType())) 395fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return UndefValue::get(IntType); 396fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 397739208a790398cf1f9da05149c768371e48781e8Chris Lattner unsigned char RawBytes[32] = {0}; 398fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (!ReadDataFromGlobal(GV->getInitializer(), Offset, RawBytes, 399fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner BytesLoaded, TD)) 400fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return 0; 401fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 402b31189f26297fe30214da3e8d14a4575d5fdd262Chris Lattner APInt ResultVal = APInt(IntType->getBitWidth(), RawBytes[BytesLoaded-1]); 403b31189f26297fe30214da3e8d14a4575d5fdd262Chris Lattner for (unsigned i = 1; i != BytesLoaded; ++i) { 404739208a790398cf1f9da05149c768371e48781e8Chris Lattner ResultVal <<= 8; 405ce800511701135ed86845b451693a248c83a7973Dan Gohman ResultVal |= RawBytes[BytesLoaded-1-i]; 406739208a790398cf1f9da05149c768371e48781e8Chris Lattner } 407fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 408739208a790398cf1f9da05149c768371e48781e8Chris Lattner return ConstantInt::get(IntType->getContext(), ResultVal); 409fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner} 410fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 411878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner/// ConstantFoldLoadFromConstPtr - Return the value that a load from C would 412878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner/// produce if it is constant and determinable. If this is not determinable, 413878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner/// return null. 414878e4946700824954d7eb7f3ff660353db8e0d17Chris LattnerConstant *llvm::ConstantFoldLoadFromConstPtr(Constant *C, 415878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner const TargetData *TD) { 416878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner // First, try the easy cases: 417878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner if (GlobalVariable *GV = dyn_cast<GlobalVariable>(C)) 418878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner if (GV->isConstant() && GV->hasDefinitiveInitializer()) 419878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner return GV->getInitializer(); 420878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner 421e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner // If the loaded value isn't a constant expr, we can't handle it. 422e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner ConstantExpr *CE = dyn_cast<ConstantExpr>(C); 423e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner if (!CE) return 0; 424e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner 425e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner if (CE->getOpcode() == Instruction::GetElementPtr) { 426e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner if (GlobalVariable *GV = dyn_cast<GlobalVariable>(CE->getOperand(0))) 427e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner if (GV->isConstant() && GV->hasDefinitiveInitializer()) 428e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner if (Constant *V = 429e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner ConstantFoldLoadThroughGEPConstantExpr(GV->getInitializer(), CE)) 430e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner return V; 431e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner } 432e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner 433e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner // Instead of loading constant c string, use corresponding integer value 434e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner // directly if string length is small enough. 435e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner std::string Str; 43644a7a380aa9fbb303f57f4f8269062b7b56be980Chris Lattner if (TD && GetConstantStringInfo(CE, Str) && !Str.empty()) { 437fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner unsigned StrLen = Str.length(); 438e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner const Type *Ty = cast<PointerType>(CE->getType())->getElementType(); 439fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner unsigned NumBits = Ty->getPrimitiveSizeInBits(); 440eae2895120500d06bf6de9725efeeff498f60385Chris Lattner // Replace load with immediate integer if the result is an integer or fp 441eae2895120500d06bf6de9725efeeff498f60385Chris Lattner // value. 442eae2895120500d06bf6de9725efeeff498f60385Chris Lattner if ((NumBits >> 3) == StrLen + 1 && (NumBits & 7) == 0 && 443490b8f5d64823d998fc12ad3a91ecacd82c1901eChandler Carruth (isa<IntegerType>(Ty) || Ty->isFloatingPointTy())) { 444fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner APInt StrVal(NumBits, 0); 445fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner APInt SingleChar(NumBits, 0); 446e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner if (TD->isLittleEndian()) { 447fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner for (signed i = StrLen-1; i >= 0; i--) { 448e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner SingleChar = (uint64_t) Str[i] & UCHAR_MAX; 44962d327e241f59735eed836e98c8f11ffaa6cf6f8Chris Lattner StrVal = (StrVal << 8) | SingleChar; 45062d327e241f59735eed836e98c8f11ffaa6cf6f8Chris Lattner } 451e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner } else { 452fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner for (unsigned i = 0; i < StrLen; i++) { 453e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner SingleChar = (uint64_t) Str[i] & UCHAR_MAX; 454e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner StrVal = (StrVal << 8) | SingleChar; 455e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner } 456e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner // Append NULL at the end. 457e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner SingleChar = 0; 458e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner StrVal = (StrVal << 8) | SingleChar; 45962d327e241f59735eed836e98c8f11ffaa6cf6f8Chris Lattner } 460eae2895120500d06bf6de9725efeeff498f60385Chris Lattner 461eae2895120500d06bf6de9725efeeff498f60385Chris Lattner Constant *Res = ConstantInt::get(CE->getContext(), StrVal); 462eae2895120500d06bf6de9725efeeff498f60385Chris Lattner if (Ty->isFloatingPointTy()) 463eae2895120500d06bf6de9725efeeff498f60385Chris Lattner Res = ConstantExpr::getBitCast(Res, Ty); 464eae2895120500d06bf6de9725efeeff498f60385Chris Lattner return Res; 46562d327e241f59735eed836e98c8f11ffaa6cf6f8Chris Lattner } 466878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner } 467e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner 468e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner // If this load comes from anywhere in a constant global, and if the global 469e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner // is all undef or zero, we know what it loads. 4705034dd318a9dfa0dc45a3ac01e58e60f2aa2498dDan Gohman if (GlobalVariable *GV = dyn_cast<GlobalVariable>(GetUnderlyingObject(CE))){ 471e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner if (GV->isConstant() && GV->hasDefinitiveInitializer()) { 472e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner const Type *ResTy = cast<PointerType>(C->getType())->getElementType(); 473e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner if (GV->getInitializer()->isNullValue()) 474e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner return Constant::getNullValue(ResTy); 475e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner if (isa<UndefValue>(GV->getInitializer())) 476e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner return UndefValue::get(ResTy); 477e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner } 478e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner } 479e00c43fc35d64b2ee8d2b4692c02375d2d7b4aa4Chris Lattner 480fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // Try hard to fold loads from bitcasted strange and non-type-safe things. We 481fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // currently don't do any of this for big endian systems. It can be 482fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner // generalized in the future if someone is interested. 483fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner if (TD && TD->isLittleEndian()) 484fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner return FoldReinterpretLoadFromConstPtr(CE, *TD); 485878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner return 0; 486878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner} 487878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner 488878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattnerstatic Constant *ConstantFoldLoadInst(const LoadInst *LI, const TargetData *TD){ 489878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner if (LI->isVolatile()) return 0; 490878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner 491878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner if (Constant *C = dyn_cast<Constant>(LI->getOperand(0))) 492878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner return ConstantFoldLoadFromConstPtr(C, TD); 493fe8c7c807c6f815561bc2bdddfd330b05dbdfc93Chris Lattner 494878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner return 0; 495878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner} 49603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 49703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// SymbolicallyEvaluateBinop - One of Op0/Op1 is a constant expression. 49867e3566d8f6875e9c92d224f493023408a66227eNick Lewycky/// Attempt to symbolically evaluate the result of a binary operator merging 49903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// these together. If target data info is available, it is provided as TD, 50003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// otherwise TD is null. 50103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattnerstatic Constant *SymbolicallyEvaluateBinop(unsigned Opc, Constant *Op0, 5027b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner Constant *Op1, const TargetData *TD){ 50303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // SROA 50403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 50503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Fold (and 0xffffffff00000000, (shl x, 32)) -> shl. 50603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Fold (lshr (or X, Y), 32) -> (lshr [X/Y], 32) if one doesn't contribute 50703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // bits. 50803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 50903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 51003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // If the constant expr is something like &A[123] - &A[4].f, fold this into a 51103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // constant. This happens frequently when iterating over a global array. 51203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (Opc == Instruction::Sub && TD) { 51303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner GlobalValue *GV1, *GV2; 51403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner int64_t Offs1, Offs2; 51503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 51603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (IsConstantOffsetFromGlobal(Op0, GV1, Offs1, *TD)) 51703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (IsConstantOffsetFromGlobal(Op1, GV2, Offs2, *TD) && 51803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner GV1 == GV2) { 51903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // (&GV+C1) - (&GV+C2) -> C1-C2, pointer arithmetic cannot overflow. 520eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson return ConstantInt::get(Op0->getType(), Offs1-Offs2); 52103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 52203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 52303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 52403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return 0; 52503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner} 52603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 5274f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman/// CastGEPIndices - If array indices are not pointer-sized integers, 5284f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman/// explicitly cast them so that they aren't implicitly casted by the 5294f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman/// getelementptr. 5304f8eea82d8967cffa85b9df6c9255717b059009eDan Gohmanstatic Constant *CastGEPIndices(Constant *const *Ops, unsigned NumOps, 5314f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman const Type *ResultTy, 5324f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman const TargetData *TD) { 5334f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman if (!TD) return 0; 5344f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman const Type *IntPtrTy = TD->getIntPtrType(ResultTy->getContext()); 5354f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman 5364f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman bool Any = false; 5374f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman SmallVector<Constant*, 32> NewIdxs; 5384f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman for (unsigned i = 1; i != NumOps; ++i) { 5394f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman if ((i == 1 || 5404f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman !isa<StructType>(GetElementPtrInst::getIndexedType(Ops[0]->getType(), 541c1da204c433459713cbf4c62f0addf458e6b4b9fChris Lattner reinterpret_cast<Value *const *>(Ops+1), 5424f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman i-1))) && 5434f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman Ops[i]->getType() != IntPtrTy) { 5444f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman Any = true; 5454f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman NewIdxs.push_back(ConstantExpr::getCast(CastInst::getCastOpcode(Ops[i], 5464f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman true, 5474f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman IntPtrTy, 5484f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman true), 5494f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman Ops[i], IntPtrTy)); 5504f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman } else 5514f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman NewIdxs.push_back(Ops[i]); 5524f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman } 5534f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman if (!Any) return 0; 5544f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman 5554f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman Constant *C = 5564f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman ConstantExpr::getGetElementPtr(Ops[0], &NewIdxs[0], NewIdxs.size()); 5574f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) 5584f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman if (Constant *Folded = ConstantFoldConstantExpression(CE, TD)) 5594f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman C = Folded; 5604f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman return C; 5614f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman} 5624f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman 56303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// SymbolicallyEvaluateGEP - If we can symbolically evaluate the specified GEP 56403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner/// constant expression, do so. 5657b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattnerstatic Constant *SymbolicallyEvaluateGEP(Constant *const *Ops, unsigned NumOps, 56603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner const Type *ResultTy, 56703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner const TargetData *TD) { 56803dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner Constant *Ptr = Ops[0]; 569268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner if (!TD || !cast<PointerType>(Ptr->getType())->getElementType()->isSized()) 57003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return 0; 571cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman 5727b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner unsigned BitWidth = 5737b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner TD->getTypeSizeInBits(TD->getIntPtrType(Ptr->getContext())); 574268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner 575268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner // If this is a constant expr gep that is effectively computing an 576268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner // "offsetof", fold it into 'cast int Size to T*' instead of 'gep 0, 0, 12' 577268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner for (unsigned i = 1; i != NumOps; ++i) 5788cd4efb6a5e51b4e77039c17338f290ca3a8ee92Chris Lattner if (!isa<ConstantInt>(Ops[i])) { 5798cd4efb6a5e51b4e77039c17338f290ca3a8ee92Chris Lattner 5808cd4efb6a5e51b4e77039c17338f290ca3a8ee92Chris Lattner // If this is "gep i8* Ptr, (sub 0, V)", fold this as: 5818cd4efb6a5e51b4e77039c17338f290ca3a8ee92Chris Lattner // "inttoptr (sub (ptrtoint Ptr), V)" 5828cd4efb6a5e51b4e77039c17338f290ca3a8ee92Chris Lattner if (NumOps == 2 && 5838cd4efb6a5e51b4e77039c17338f290ca3a8ee92Chris Lattner cast<PointerType>(ResultTy)->getElementType()->isIntegerTy(8)) { 5848cd4efb6a5e51b4e77039c17338f290ca3a8ee92Chris Lattner ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[1]); 5858cd4efb6a5e51b4e77039c17338f290ca3a8ee92Chris Lattner if (CE && CE->getOpcode() == Instruction::Sub && 5868cd4efb6a5e51b4e77039c17338f290ca3a8ee92Chris Lattner isa<ConstantInt>(CE->getOperand(0)) && 5878cd4efb6a5e51b4e77039c17338f290ca3a8ee92Chris Lattner cast<ConstantInt>(CE->getOperand(0))->isZero()) { 5888cd4efb6a5e51b4e77039c17338f290ca3a8ee92Chris Lattner Constant *Res = ConstantExpr::getPtrToInt(Ptr, CE->getType()); 5898cd4efb6a5e51b4e77039c17338f290ca3a8ee92Chris Lattner Res = ConstantExpr::getSub(Res, CE->getOperand(1)); 5908cd4efb6a5e51b4e77039c17338f290ca3a8ee92Chris Lattner Res = ConstantExpr::getIntToPtr(Res, ResultTy); 5918cd4efb6a5e51b4e77039c17338f290ca3a8ee92Chris Lattner if (ConstantExpr *ResCE = dyn_cast<ConstantExpr>(Res)) 5928cd4efb6a5e51b4e77039c17338f290ca3a8ee92Chris Lattner Res = ConstantFoldConstantExpression(ResCE, TD); 5938cd4efb6a5e51b4e77039c17338f290ca3a8ee92Chris Lattner return Res; 5948cd4efb6a5e51b4e77039c17338f290ca3a8ee92Chris Lattner } 5958cd4efb6a5e51b4e77039c17338f290ca3a8ee92Chris Lattner } 596de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman return 0; 5978cd4efb6a5e51b4e77039c17338f290ca3a8ee92Chris Lattner } 598268e7d7a9446bb89b80472cdb7b9803f16c0191eChris Lattner 599cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman APInt Offset = APInt(BitWidth, 600cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman TD->getIndexedOffset(Ptr->getType(), 601cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman (Value**)Ops+1, NumOps-1)); 602890edda7c22dd8525f9fe44085cfd7080e67dfeeDuncan Sands Ptr = cast<Constant>(Ptr->stripPointerCasts()); 6030891d752a68a25025ffc3339aab1f0ad3221b0edDan Gohman 6040891d752a68a25025ffc3339aab1f0ad3221b0edDan Gohman // If this is a GEP of a GEP, fold it all into a single GEP. 6050891d752a68a25025ffc3339aab1f0ad3221b0edDan Gohman while (GEPOperator *GEP = dyn_cast<GEPOperator>(Ptr)) { 6060891d752a68a25025ffc3339aab1f0ad3221b0edDan Gohman SmallVector<Value *, 4> NestedOps(GEP->op_begin()+1, GEP->op_end()); 607890edda7c22dd8525f9fe44085cfd7080e67dfeeDuncan Sands 608890edda7c22dd8525f9fe44085cfd7080e67dfeeDuncan Sands // Do not try the incorporate the sub-GEP if some index is not a number. 609890edda7c22dd8525f9fe44085cfd7080e67dfeeDuncan Sands bool AllConstantInt = true; 610890edda7c22dd8525f9fe44085cfd7080e67dfeeDuncan Sands for (unsigned i = 0, e = NestedOps.size(); i != e; ++i) 611890edda7c22dd8525f9fe44085cfd7080e67dfeeDuncan Sands if (!isa<ConstantInt>(NestedOps[i])) { 612890edda7c22dd8525f9fe44085cfd7080e67dfeeDuncan Sands AllConstantInt = false; 613890edda7c22dd8525f9fe44085cfd7080e67dfeeDuncan Sands break; 614890edda7c22dd8525f9fe44085cfd7080e67dfeeDuncan Sands } 615890edda7c22dd8525f9fe44085cfd7080e67dfeeDuncan Sands if (!AllConstantInt) 616890edda7c22dd8525f9fe44085cfd7080e67dfeeDuncan Sands break; 617890edda7c22dd8525f9fe44085cfd7080e67dfeeDuncan Sands 6180891d752a68a25025ffc3339aab1f0ad3221b0edDan Gohman Ptr = cast<Constant>(GEP->getOperand(0)); 6190891d752a68a25025ffc3339aab1f0ad3221b0edDan Gohman Offset += APInt(BitWidth, 6200891d752a68a25025ffc3339aab1f0ad3221b0edDan Gohman TD->getIndexedOffset(Ptr->getType(), 6210891d752a68a25025ffc3339aab1f0ad3221b0edDan Gohman (Value**)NestedOps.data(), 6220891d752a68a25025ffc3339aab1f0ad3221b0edDan Gohman NestedOps.size())); 623890edda7c22dd8525f9fe44085cfd7080e67dfeeDuncan Sands Ptr = cast<Constant>(Ptr->stripPointerCasts()); 6240891d752a68a25025ffc3339aab1f0ad3221b0edDan Gohman } 6250891d752a68a25025ffc3339aab1f0ad3221b0edDan Gohman 626de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman // If the base value for this address is a literal integer value, fold the 627de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman // getelementptr to the resulting integer value casted to the pointer type. 62840b037ef611efc5c43ffc43a911d0eb57e0d444dDan Gohman APInt BasePtr(BitWidth, 0); 62940b037ef611efc5c43ffc43a911d0eb57e0d444dDan Gohman if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr)) 63040b037ef611efc5c43ffc43a911d0eb57e0d444dDan Gohman if (CE->getOpcode() == Instruction::IntToPtr) 63140f8f6264d5af2c38e797e0dc59827cd231e8ff7Jay Foad if (ConstantInt *Base = dyn_cast<ConstantInt>(CE->getOperand(0))) 63240f8f6264d5af2c38e797e0dc59827cd231e8ff7Jay Foad BasePtr = Base->getValue().zextOrTrunc(BitWidth); 63340b037ef611efc5c43ffc43a911d0eb57e0d444dDan Gohman if (Ptr->isNullValue() || BasePtr != 0) { 6347b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner Constant *C = ConstantInt::get(Ptr->getContext(), Offset+BasePtr); 635de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman return ConstantExpr::getIntToPtr(C, ResultTy); 636de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman } 637de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman 638de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman // Otherwise form a regular getelementptr. Recompute the indices so that 639de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman // we eliminate over-indexing of the notional static type array bounds. 640de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman // This makes it easy to determine if the getelementptr is "inbounds". 641de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman // Also, this helps GlobalOpt do SROA on GlobalVariables. 642de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman const Type *Ty = Ptr->getType(); 643de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman SmallVector<Constant*, 32> NewIdxs; 6443d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman do { 645de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman if (const SequentialType *ATy = dyn_cast<SequentialType>(Ty)) { 6461df9859c40492511b8aa4321eb76496005d3b75bDuncan Sands if (ATy->isPointerTy()) { 647e568fa2d29c58aaedcaa832f805949d5e4371b4bChris Lattner // The only pointer indexing we'll do is on the first index of the GEP. 648e568fa2d29c58aaedcaa832f805949d5e4371b4bChris Lattner if (!NewIdxs.empty()) 649e568fa2d29c58aaedcaa832f805949d5e4371b4bChris Lattner break; 650e568fa2d29c58aaedcaa832f805949d5e4371b4bChris Lattner 651e568fa2d29c58aaedcaa832f805949d5e4371b4bChris Lattner // Only handle pointers to sized types, not pointers to functions. 652e568fa2d29c58aaedcaa832f805949d5e4371b4bChris Lattner if (!ATy->getElementType()->isSized()) 653e568fa2d29c58aaedcaa832f805949d5e4371b4bChris Lattner return 0; 654e568fa2d29c58aaedcaa832f805949d5e4371b4bChris Lattner } 655e568fa2d29c58aaedcaa832f805949d5e4371b4bChris Lattner 656de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman // Determine which element of the array the offset points into. 657cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman APInt ElemSize(BitWidth, TD->getTypeAllocSize(ATy->getElementType())); 658c1da204c433459713cbf4c62f0addf458e6b4b9fChris Lattner const IntegerType *IntPtrTy = TD->getIntPtrType(Ty->getContext()); 659de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman if (ElemSize == 0) 660c1da204c433459713cbf4c62f0addf458e6b4b9fChris Lattner // The element size is 0. This may be [0 x Ty]*, so just use a zero 661e58391073f6e17cd1024f737618a6f6b8d1323ceDuncan Sands // index for this level and proceed to the next level to see if it can 662e58391073f6e17cd1024f737618a6f6b8d1323ceDuncan Sands // accommodate the offset. 663c1da204c433459713cbf4c62f0addf458e6b4b9fChris Lattner NewIdxs.push_back(ConstantInt::get(IntPtrTy, 0)); 664c1da204c433459713cbf4c62f0addf458e6b4b9fChris Lattner else { 665c1da204c433459713cbf4c62f0addf458e6b4b9fChris Lattner // The element size is non-zero divide the offset by the element 666c1da204c433459713cbf4c62f0addf458e6b4b9fChris Lattner // size (rounding down), to compute the index at this level. 667c1da204c433459713cbf4c62f0addf458e6b4b9fChris Lattner APInt NewIdx = Offset.udiv(ElemSize); 668c1da204c433459713cbf4c62f0addf458e6b4b9fChris Lattner Offset -= NewIdx * ElemSize; 669c1da204c433459713cbf4c62f0addf458e6b4b9fChris Lattner NewIdxs.push_back(ConstantInt::get(IntPtrTy, NewIdx)); 670c1da204c433459713cbf4c62f0addf458e6b4b9fChris Lattner } 671de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman Ty = ATy->getElementType(); 672de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman } else if (const StructType *STy = dyn_cast<StructType>(Ty)) { 673cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman // Determine which field of the struct the offset points into. The 674cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman // getZExtValue is at least as safe as the StructLayout API because we 675cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman // know the offset is within the struct at this point. 676de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman const StructLayout &SL = *TD->getStructLayout(STy); 677cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman unsigned ElIdx = SL.getElementContainingOffset(Offset.getZExtValue()); 6787b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner NewIdxs.push_back(ConstantInt::get(Type::getInt32Ty(Ty->getContext()), 6797b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner ElIdx)); 680cda9706cb74a65d2feb2175613cb0fe46acc5aa2Dan Gohman Offset -= APInt(BitWidth, SL.getElementOffset(ElIdx)); 681de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman Ty = STy->getTypeAtIndex(ElIdx); 682de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman } else { 6833d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman // We've reached some non-indexable type. 6843d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman break; 685de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman } 6863d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman } while (Ty != cast<PointerType>(ResultTy)->getElementType()); 6873d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman 6883d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman // If we haven't used up the entire offset by descending the static 6893d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman // type, then the offset is pointing into the middle of an indivisible 6903d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman // member, so we can't simplify it. 6913d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman if (Offset != 0) 6923d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman return 0; 693de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman 6943bfbc4587a7e79f08f8c126a9e62c3475fb90f8bDan Gohman // Create a GEP. 6953bfbc4587a7e79f08f8c126a9e62c3475fb90f8bDan Gohman Constant *C = 6966e7ad958683f34bf6c014c88fef723e5a2d741beDan Gohman ConstantExpr::getGetElementPtr(Ptr, &NewIdxs[0], NewIdxs.size()); 6976e7ad958683f34bf6c014c88fef723e5a2d741beDan Gohman assert(cast<PointerType>(C->getType())->getElementType() == Ty && 6986e7ad958683f34bf6c014c88fef723e5a2d741beDan Gohman "Computed GetElementPtr has unexpected type!"); 6993d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman 7003d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman // If we ended up indexing a member with a type that doesn't match 7014c0d5d5db876b0628bdf6a2174263a1c0a9130e2Dan Gohman // the type of what the original indices indexed, add a cast. 7023d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman if (Ty != cast<PointerType>(ResultTy)->getElementType()) 7036333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner C = FoldBitCast(C, ResultTy, *TD); 704de0e587e63f71afb2ac53c9880c262089fe798bbDan Gohman 7053d01334e6fa5caba1361d088fabf728c64b23c58Dan Gohman return C; 70603dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner} 70703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 7081afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner 70903dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 71003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner//===----------------------------------------------------------------------===// 71103dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner// Constant Folding public APIs 71203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner//===----------------------------------------------------------------------===// 71303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 714b9b369fa9983843c4ed77b3a35b6e9b7933955bbDuncan Sands/// ConstantFoldInstruction - Try to constant fold the specified instruction. 715b9b369fa9983843c4ed77b3a35b6e9b7933955bbDuncan Sands/// If successful, the constant result is returned, if not, null is returned. 716b9b369fa9983843c4ed77b3a35b6e9b7933955bbDuncan Sands/// Note that this fails if not all of the operands are constant. Otherwise, 717b9b369fa9983843c4ed77b3a35b6e9b7933955bbDuncan Sands/// this function can only fail when attempting to fold instructions like loads 718b9b369fa9983843c4ed77b3a35b6e9b7933955bbDuncan Sands/// and stores, which have no constant expression form. 7197b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris LattnerConstant *llvm::ConstantFoldInstruction(Instruction *I, const TargetData *TD) { 720b9b369fa9983843c4ed77b3a35b6e9b7933955bbDuncan Sands // Handle PHI nodes quickly here... 7215520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (PHINode *PN = dyn_cast<PHINode>(I)) { 722c0362d5c6e0066c741bce056a65d8b4c026de19fDuncan Sands Constant *CommonValue = 0; 723c0362d5c6e0066c741bce056a65d8b4c026de19fDuncan Sands 724c0362d5c6e0066c741bce056a65d8b4c026de19fDuncan Sands for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) { 725c0362d5c6e0066c741bce056a65d8b4c026de19fDuncan Sands Value *Incoming = PN->getIncomingValue(i); 726b9b369fa9983843c4ed77b3a35b6e9b7933955bbDuncan Sands // If the incoming value is undef then skip it. Note that while we could 727b9b369fa9983843c4ed77b3a35b6e9b7933955bbDuncan Sands // skip the value if it is equal to the phi node itself we choose not to 728b9b369fa9983843c4ed77b3a35b6e9b7933955bbDuncan Sands // because that would break the rule that constant folding only applies if 729b9b369fa9983843c4ed77b3a35b6e9b7933955bbDuncan Sands // all operands are constants. 730b9b369fa9983843c4ed77b3a35b6e9b7933955bbDuncan Sands if (isa<UndefValue>(Incoming)) 731c0362d5c6e0066c741bce056a65d8b4c026de19fDuncan Sands continue; 732c0362d5c6e0066c741bce056a65d8b4c026de19fDuncan Sands // If the incoming value is not a constant, or is a different constant to 733c0362d5c6e0066c741bce056a65d8b4c026de19fDuncan Sands // the one we saw previously, then give up. 734c0362d5c6e0066c741bce056a65d8b4c026de19fDuncan Sands Constant *C = dyn_cast<Constant>(Incoming); 735c0362d5c6e0066c741bce056a65d8b4c026de19fDuncan Sands if (!C || (CommonValue && C != CommonValue)) 736c0362d5c6e0066c741bce056a65d8b4c026de19fDuncan Sands return 0; 737c0362d5c6e0066c741bce056a65d8b4c026de19fDuncan Sands CommonValue = C; 738c0362d5c6e0066c741bce056a65d8b4c026de19fDuncan Sands } 7395520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 740c0362d5c6e0066c741bce056a65d8b4c026de19fDuncan Sands // If we reach here, all incoming values are the same constant or undef. 741c0362d5c6e0066c741bce056a65d8b4c026de19fDuncan Sands return CommonValue ? CommonValue : UndefValue::get(PN->getType()); 7425520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 7435520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 7445520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // Scan the operand list, checking to see if they are all constants, if so, 7455520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // hand off to ConstantFoldInstOperands. 7465520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner SmallVector<Constant*, 8> Ops; 747de2d74b213844b17eb5327fba27f21e699d3af66Gabor Greif for (User::op_iterator i = I->op_begin(), e = I->op_end(); i != e; ++i) 748de2d74b213844b17eb5327fba27f21e699d3af66Gabor Greif if (Constant *Op = dyn_cast<Constant>(*i)) 7495520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner Ops.push_back(Op); 7505520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else 7515520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; // All operands not constant! 7525520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 753f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (const CmpInst *CI = dyn_cast<CmpInst>(I)) 7548f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner return ConstantFoldCompareInstOperands(CI->getPredicate(), Ops[0], Ops[1], 7558f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner TD); 75658665d47aea69875c433fb039c8f10106abc1ceeChris Lattner 757878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner if (const LoadInst *LI = dyn_cast<LoadInst>(I)) 758878e4946700824954d7eb7f3ff660353db8e0d17Chris Lattner return ConstantFoldLoadInst(LI, TD); 7593ee0af35842999c1781052fe74fdcb19997de950Frits van Bommel 7603ee0af35842999c1781052fe74fdcb19997de950Frits van Bommel if (InsertValueInst *IVI = dyn_cast<InsertValueInst>(I)) 7613ee0af35842999c1781052fe74fdcb19997de950Frits van Bommel return ConstantExpr::getInsertValue( 7623ee0af35842999c1781052fe74fdcb19997de950Frits van Bommel cast<Constant>(IVI->getAggregateOperand()), 7633ee0af35842999c1781052fe74fdcb19997de950Frits van Bommel cast<Constant>(IVI->getInsertedValueOperand()), 7643ee0af35842999c1781052fe74fdcb19997de950Frits van Bommel IVI->idx_begin(), IVI->getNumIndices()); 7653ee0af35842999c1781052fe74fdcb19997de950Frits van Bommel 7663ee0af35842999c1781052fe74fdcb19997de950Frits van Bommel if (ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(I)) 7673ee0af35842999c1781052fe74fdcb19997de950Frits van Bommel return ConstantExpr::getExtractValue( 7683ee0af35842999c1781052fe74fdcb19997de950Frits van Bommel cast<Constant>(EVI->getAggregateOperand()), 7693ee0af35842999c1781052fe74fdcb19997de950Frits van Bommel EVI->idx_begin(), EVI->getNumIndices()); 7703ee0af35842999c1781052fe74fdcb19997de950Frits van Bommel 77158665d47aea69875c433fb039c8f10106abc1ceeChris Lattner return ConstantFoldInstOperands(I->getOpcode(), I->getType(), 7727b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner Ops.data(), Ops.size(), TD); 7735520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner} 7745520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 7753dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky/// ConstantFoldConstantExpression - Attempt to fold the constant expression 7763dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky/// using the specified TargetData. If successful, the constant result is 7773dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky/// result is returned, if not, null is returned. 778baf0c67988feec5b7698f89dce499ddb7d0c3c42Dan GohmanConstant *llvm::ConstantFoldConstantExpression(const ConstantExpr *CE, 7793dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky const TargetData *TD) { 7803dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky SmallVector<Constant*, 8> Ops; 781c1da204c433459713cbf4c62f0addf458e6b4b9fChris Lattner for (User::const_op_iterator i = CE->op_begin(), e = CE->op_end(); 782c1da204c433459713cbf4c62f0addf458e6b4b9fChris Lattner i != e; ++i) { 78301b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman Constant *NewC = cast<Constant>(*i); 78401b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman // Recursively fold the ConstantExpr's operands. 78501b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman if (ConstantExpr *NewCE = dyn_cast<ConstantExpr>(NewC)) 78601b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman NewC = ConstantFoldConstantExpression(NewCE, TD); 78701b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman Ops.push_back(NewC); 78801b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman } 7893dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky 7903dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky if (CE->isCompare()) 7918f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner return ConstantFoldCompareInstOperands(CE->getPredicate(), Ops[0], Ops[1], 7928f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner TD); 79358665d47aea69875c433fb039c8f10106abc1ceeChris Lattner return ConstantFoldInstOperands(CE->getOpcode(), CE->getType(), 7947b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner Ops.data(), Ops.size(), TD); 7953dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky} 7963dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky 7975520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// ConstantFoldInstOperands - Attempt to constant fold an instruction with the 7985520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// specified opcode and operands. If successful, the constant result is 7995520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// returned, if not, null is returned. Note that this function can fail when 8005520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// attempting to fold instructions like loads and stores, which have no 8015520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// constant expression form. 8025520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// 80301b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman/// TODO: This function neither utilizes nor preserves nsw/nuw/inbounds/etc 80401b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman/// information, due to only being passed an opcode and operands. Constant 80501b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman/// folding using this function strips this information. 80601b97dd01eec1197d79fceb7229f5ec233994de3Dan Gohman/// 807f286f6fd93d569befe6e77c94a947e6e04e95685Chris LattnerConstant *llvm::ConstantFoldInstOperands(unsigned Opcode, const Type *DestTy, 808f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner Constant* const* Ops, unsigned NumOps, 8095520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner const TargetData *TD) { 81003dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner // Handle easy binops first. 811f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (Instruction::isBinaryOp(Opcode)) { 81203dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner if (isa<ConstantExpr>(Ops[0]) || isa<ConstantExpr>(Ops[1])) 8137b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner if (Constant *C = SymbolicallyEvaluateBinop(Opcode, Ops[0], Ops[1], TD)) 81403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return C; 81503dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 816baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::get(Opcode, Ops[0], Ops[1]); 81703dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner } 8185520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 819f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner switch (Opcode) { 8205520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner default: return 0; 82179fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner case Instruction::ICmp: 82279fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner case Instruction::FCmp: assert(0 && "Invalid for compares"); 8235520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::Call: 824a6aac4c5bc22bb10c7adb11eee3f82c703af7002Gabor Greif if (Function *F = dyn_cast<Function>(Ops[NumOps - 1])) 8255520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (canConstantFoldCallTo(F)) 826a6aac4c5bc22bb10c7adb11eee3f82c703af7002Gabor Greif return ConstantFoldCall(F, Ops, NumOps - 1); 8275520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 828001f7534e0311508cc93831a595785bb177f8a18Chris Lattner case Instruction::PtrToInt: 829001f7534e0311508cc93831a595785bb177f8a18Chris Lattner // If the input is a inttoptr, eliminate the pair. This requires knowing 830001f7534e0311508cc93831a595785bb177f8a18Chris Lattner // the width of a pointer, so it can't be done in ConstantExpr::getCast. 831001f7534e0311508cc93831a595785bb177f8a18Chris Lattner if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[0])) { 832001f7534e0311508cc93831a595785bb177f8a18Chris Lattner if (TD && CE->getOpcode() == Instruction::IntToPtr) { 833001f7534e0311508cc93831a595785bb177f8a18Chris Lattner Constant *Input = CE->getOperand(0); 8346de29f8d960505421d61c80cdb738e16720b6c0eDan Gohman unsigned InWidth = Input->getType()->getScalarSizeInBits(); 83504aa2c3520c049333ca216fb794d700310c4a33dNick Lewycky if (TD->getPointerSizeInBits() < InWidth) { 83604aa2c3520c049333ca216fb794d700310c4a33dNick Lewycky Constant *Mask = 8377b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner ConstantInt::get(CE->getContext(), APInt::getLowBitsSet(InWidth, 83804aa2c3520c049333ca216fb794d700310c4a33dNick Lewycky TD->getPointerSizeInBits())); 839baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson Input = ConstantExpr::getAnd(Input, Mask); 84004aa2c3520c049333ca216fb794d700310c4a33dNick Lewycky } 841001f7534e0311508cc93831a595785bb177f8a18Chris Lattner // Do a zext or trunc to get to the dest size. 842baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getIntegerCast(Input, DestTy, false); 843001f7534e0311508cc93831a595785bb177f8a18Chris Lattner } 844001f7534e0311508cc93831a595785bb177f8a18Chris Lattner } 845baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getCast(Opcode, Ops[0], DestTy); 846001f7534e0311508cc93831a595785bb177f8a18Chris Lattner case Instruction::IntToPtr: 84781b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands // If the input is a ptrtoint, turn the pair into a ptr to ptr bitcast if 84881b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands // the int size is >= the ptr size. This requires knowing the width of a 84981b06be055e74a3c23a1c8f17ead97f9f76335eeDuncan Sands // pointer, so it can't be done in ConstantExpr::getCast. 850b80a2a686fe76496d71397f8bdda394d5718ab01Dan Gohman if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[0])) 8519a38e3e3991ea443e555d8060f91202a786acdd4Dan Gohman if (TD && 852b80a2a686fe76496d71397f8bdda394d5718ab01Dan Gohman TD->getPointerSizeInBits() <= CE->getType()->getScalarSizeInBits() && 853b80a2a686fe76496d71397f8bdda394d5718ab01Dan Gohman CE->getOpcode() == Instruction::PtrToInt) 854b80a2a686fe76496d71397f8bdda394d5718ab01Dan Gohman return FoldBitCast(CE->getOperand(0), DestTy, *TD); 855b80a2a686fe76496d71397f8bdda394d5718ab01Dan Gohman 856baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getCast(Opcode, Ops[0], DestTy); 8575520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::Trunc: 8585520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::ZExt: 8595520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::SExt: 8605520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FPTrunc: 8615520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FPExt: 8625520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::UIToFP: 8635520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::SIToFP: 8645520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FPToUI: 8655520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::FPToSI: 866baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getCast(Opcode, Ops[0], DestTy); 8675520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::BitCast: 8681afab9c1e0ae2d145ce01718aa14065393117e70Chris Lattner if (TD) 8696333c3959b7e3e43930ab523f0657791e9eb5d48Chris Lattner return FoldBitCast(Ops[0], DestTy, *TD); 870baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getBitCast(Ops[0], DestTy); 8715520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::Select: 872baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getSelect(Ops[0], Ops[1], Ops[2]); 8735520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::ExtractElement: 874baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getExtractElement(Ops[0], Ops[1]); 8755520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::InsertElement: 876baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getInsertElement(Ops[0], Ops[1], Ops[2]); 8775520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::ShuffleVector: 878baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getShuffleVector(Ops[0], Ops[1], Ops[2]); 8795520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner case Instruction::GetElementPtr: 8804f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman if (Constant *C = CastGEPIndices(Ops, NumOps, DestTy, TD)) 8814f8eea82d8967cffa85b9df6c9255717b059009eDan Gohman return C; 8827b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner if (Constant *C = SymbolicallyEvaluateGEP(Ops, NumOps, DestTy, TD)) 88303dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner return C; 88403dd25ca964813c8b9fe14479443b9c21fb92c55Chris Lattner 885baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson return ConstantExpr::getGetElementPtr(Ops[0], Ops+1, NumOps-1); 8865520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 8875520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner} 8885520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 889f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner/// ConstantFoldCompareInstOperands - Attempt to constant fold a compare 890f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner/// instruction (icmp/fcmp) with the specified operands. If it fails, it 891f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner/// returns a constant expression of the specified operands. 892f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner/// 893f286f6fd93d569befe6e77c94a947e6e04e95685Chris LattnerConstant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate, 8948f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner Constant *Ops0, Constant *Ops1, 895f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner const TargetData *TD) { 896f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // fold: icmp (inttoptr x), null -> icmp x, 0 897f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // fold: icmp (ptrtoint x), 0 -> icmp x, null 8983dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky // fold: icmp (inttoptr x), (inttoptr y) -> icmp trunc/zext x, trunc/zext y 899f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // fold: icmp (ptrtoint x), (ptrtoint y) -> icmp x, y 900f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // 901f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // ConstantExpr::getCompare cannot do this, because it doesn't have TD 902f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // around to know if bit truncation is happening. 9038f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner if (ConstantExpr *CE0 = dyn_cast<ConstantExpr>(Ops0)) { 9048f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner if (TD && Ops1->isNullValue()) { 9057b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner const Type *IntPtrTy = TD->getIntPtrType(CE0->getContext()); 906f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (CE0->getOpcode() == Instruction::IntToPtr) { 907f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // Convert the integer value to the right size to ensure we get the 908f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // proper extension or truncation. 909baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson Constant *C = ConstantExpr::getIntegerCast(CE0->getOperand(0), 910f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner IntPtrTy, false); 9118f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner Constant *Null = Constant::getNullValue(C->getType()); 9128f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner return ConstantFoldCompareInstOperands(Predicate, C, Null, TD); 913f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 914f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner 915f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // Only do this transformation if the int is intptrty in size, otherwise 916f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner // there is a truncation or extension that we aren't modeling. 917f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner if (CE0->getOpcode() == Instruction::PtrToInt && 918f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner CE0->getType() == IntPtrTy) { 919f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner Constant *C = CE0->getOperand(0); 9208f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner Constant *Null = Constant::getNullValue(C->getType()); 9218f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner return ConstantFoldCompareInstOperands(Predicate, C, Null, TD); 922f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 923f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 924f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner 9258f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(Ops1)) { 9263dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky if (TD && CE0->getOpcode() == CE1->getOpcode()) { 9277b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner const Type *IntPtrTy = TD->getIntPtrType(CE0->getContext()); 9283dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky 9293dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky if (CE0->getOpcode() == Instruction::IntToPtr) { 9303dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky // Convert the integer value to the right size to ensure we get the 9313dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky // proper extension or truncation. 932baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson Constant *C0 = ConstantExpr::getIntegerCast(CE0->getOperand(0), 9333dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky IntPtrTy, false); 934baf3c404409d5e47b13984a7f95bfbd6d1f2e79eOwen Anderson Constant *C1 = ConstantExpr::getIntegerCast(CE1->getOperand(0), 9353dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky IntPtrTy, false); 9368f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner return ConstantFoldCompareInstOperands(Predicate, C0, C1, TD); 9373dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky } 9383dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky 9393dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky // Only do this transformation if the int is intptrty in size, otherwise 9403dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky // there is a truncation or extension that we aren't modeling. 9413dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky if ((CE0->getOpcode() == Instruction::PtrToInt && 9423dfd7bf5110c47e99fd0fcce96122b90f699ca3aNick Lewycky CE0->getType() == IntPtrTy && 9438f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner CE0->getOperand(0)->getType() == CE1->getOperand(0)->getType())) 9448f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner return ConstantFoldCompareInstOperands(Predicate, CE0->getOperand(0), 9458f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner CE1->getOperand(0), TD); 946f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 947f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 94879fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner 94979fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner // icmp eq (or x, y), 0 -> (icmp eq x, 0) & (icmp eq y, 0) 95079fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner // icmp ne (or x, y), 0 -> (icmp ne x, 0) | (icmp ne y, 0) 95179fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner if ((Predicate == ICmpInst::ICMP_EQ || Predicate == ICmpInst::ICMP_NE) && 95279fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner CE0->getOpcode() == Instruction::Or && Ops1->isNullValue()) { 95379fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner Constant *LHS = 95479fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner ConstantFoldCompareInstOperands(Predicate, CE0->getOperand(0), Ops1,TD); 95579fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner Constant *RHS = 95679fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner ConstantFoldCompareInstOperands(Predicate, CE0->getOperand(1), Ops1,TD); 95779fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner unsigned OpC = 95879fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner Predicate == ICmpInst::ICMP_EQ ? Instruction::And : Instruction::Or; 95979fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner Constant *Ops[] = { LHS, RHS }; 96079fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner return ConstantFoldInstOperands(OpC, LHS->getType(), Ops, 2, TD); 96179fa3cf451a74dd1cec0be2d77d7ea9737dffc69Chris Lattner } 962f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner } 9638f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner 9648f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner return ConstantExpr::getCompare(Predicate, Ops0, Ops1); 965f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner} 966f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner 967f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattner 9685520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// ConstantFoldLoadThroughGEPConstantExpr - Given a constant and a 9695520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// getelementptr constantexpr, return the constant value being addressed by the 9705520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner/// constant expression, or null if something is funny and we can't decide. 9715520732b24a5a321140dd79af70d321c7ff3dec9Chris LattnerConstant *llvm::ConstantFoldLoadThroughGEPConstantExpr(Constant *C, 972c6f69e94fa46f585b59bb9d7ace3224b0e638c95Dan Gohman ConstantExpr *CE) { 973a7235ea7245028a0723e8ab7fd011386b3900777Owen Anderson if (CE->getOperand(1) != Constant::getNullValue(CE->getOperand(1)->getType())) 9745520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; // Do not allow stepping over the value! 9755520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 9765520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // Loop over all of the operands, tracking down which value we are 9775520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner // addressing... 9785520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner gep_type_iterator I = gep_type_begin(CE), E = gep_type_end(CE); 9795520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner for (++I; I != E; ++I) 9805520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (const StructType *STy = dyn_cast<StructType>(*I)) { 9815520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner ConstantInt *CU = cast<ConstantInt>(I.getOperand()); 9825520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner assert(CU->getZExtValue() < STy->getNumElements() && 9835520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner "Struct index out of range!"); 9845520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner unsigned El = (unsigned)CU->getZExtValue(); 9855520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) { 9865520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = CS->getOperand(El); 9875520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else if (isa<ConstantAggregateZero>(C)) { 988a7235ea7245028a0723e8ab7fd011386b3900777Owen Anderson C = Constant::getNullValue(STy->getElementType(El)); 9895520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else if (isa<UndefValue>(C)) { 9909e9a0d5fc26878e51a58a8b57900fcbf952c2691Owen Anderson C = UndefValue::get(STy->getElementType(El)); 9915520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else { 9925520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 9935520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 9945520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else if (ConstantInt *CI = dyn_cast<ConstantInt>(I.getOperand())) { 9955520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (const ArrayType *ATy = dyn_cast<ArrayType>(*I)) { 9965520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (CI->getZExtValue() >= ATy->getNumElements()) 9975520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 9985520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner if (ConstantArray *CA = dyn_cast<ConstantArray>(C)) 9995520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = CA->getOperand(CI->getZExtValue()); 10005520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else if (isa<ConstantAggregateZero>(C)) 1001a7235ea7245028a0723e8ab7fd011386b3900777Owen Anderson C = Constant::getNullValue(ATy->getElementType()); 10025520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else if (isa<UndefValue>(C)) 10039e9a0d5fc26878e51a58a8b57900fcbf952c2691Owen Anderson C = UndefValue::get(ATy->getElementType()); 10045520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else 10055520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 100662d327e241f59735eed836e98c8f11ffaa6cf6f8Chris Lattner } else if (const VectorType *VTy = dyn_cast<VectorType>(*I)) { 100762d327e241f59735eed836e98c8f11ffaa6cf6f8Chris Lattner if (CI->getZExtValue() >= VTy->getNumElements()) 10085520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 10099d6565a5b1fbc4286d6ee638d8f47a3171a9ed7eReid Spencer if (ConstantVector *CP = dyn_cast<ConstantVector>(C)) 10105520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner C = CP->getOperand(CI->getZExtValue()); 10115520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else if (isa<ConstantAggregateZero>(C)) 101262d327e241f59735eed836e98c8f11ffaa6cf6f8Chris Lattner C = Constant::getNullValue(VTy->getElementType()); 10135520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else if (isa<UndefValue>(C)) 101462d327e241f59735eed836e98c8f11ffaa6cf6f8Chris Lattner C = UndefValue::get(VTy->getElementType()); 10155520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner else 10165520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 10175520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else { 10185520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 10195520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 10205520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } else { 10215520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return 0; 10225520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner } 10235520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner return C; 10245520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner} 10255520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 10265520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner 1027bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell//===----------------------------------------------------------------------===// 10285520732b24a5a321140dd79af70d321c7ff3dec9Chris Lattner// Constant Folding for Calls 1029bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell// 1030bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 1031bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell/// canConstantFoldCallTo - Return true if its even possible to fold a call to 1032bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell/// the specified function. 1033bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswellbool 1034fa9b80eb64127b3d9691e18537975635520e51e9Dan Gohmanllvm::canConstantFoldCallTo(const Function *F) { 1035bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell switch (F->getIntrinsicID()) { 10369ab7fb3ba47442d521a5bed09a27a5e8e7a786edDale Johannesen case Intrinsic::sqrt: 10379ab7fb3ba47442d521a5bed09a27a5e8e7a786edDale Johannesen case Intrinsic::powi: 1038e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer case Intrinsic::bswap: 1039e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer case Intrinsic::ctpop: 1040e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer case Intrinsic::ctlz: 1041e9391fd9b52e93717b365bdd05c471101323a4dfReid Spencer case Intrinsic::cttz: 1042e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner case Intrinsic::uadd_with_overflow: 1043e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner case Intrinsic::usub_with_overflow: 10441614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix case Intrinsic::sadd_with_overflow: 10451614e50d9f6d48a38e4dafb4b1a51fd4b37614f3Evan Phoenix case Intrinsic::ssub_with_overflow: 1046eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner case Intrinsic::smul_with_overflow: 1047faa75f6e47350f491a44d5e8773acd9457185d51Anton Korobeynikov case Intrinsic::convert_from_fp16: 1048faa75f6e47350f491a44d5e8773acd9457185d51Anton Korobeynikov case Intrinsic::convert_to_fp16: 1049bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell return true; 105068a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner default: 105168a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner return false; 105268a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner case 0: break; 1053bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 1054bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 10556f532a988e5c02fcb271fb65e9e7b83f0147d3f2Chris Lattner if (!F->hasName()) return false; 1056f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar StringRef Name = F->getName(); 1057c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner 1058c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner // In these cases, the check of the length is required. We don't want to 1059c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner // return true for a name like "cos\0blah" which strcmp would return equal to 1060c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner // "cos", but has length 8. 1061f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar switch (Name[0]) { 1062c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner default: return false; 1063c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'a': 1064f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar return Name == "acos" || Name == "asin" || 1065f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar Name == "atan" || Name == "atan2"; 1066c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'c': 1067f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar return Name == "cos" || Name == "ceil" || Name == "cosf" || Name == "cosh"; 1068c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'e': 1069f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar return Name == "exp"; 1070c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'f': 1071f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar return Name == "fabs" || Name == "fmod" || Name == "floor"; 1072c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'l': 1073f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar return Name == "log" || Name == "log10"; 1074c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'p': 1075f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar return Name == "pow"; 1076c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 's': 1077f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar return Name == "sin" || Name == "sinh" || Name == "sqrt" || 1078f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar Name == "sinf" || Name == "sqrtf"; 1079c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 't': 1080f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar return Name == "tan" || Name == "tanh"; 1081bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 1082bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell} 1083bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 108472d88ae5447a3929c97e88f4c806213847b5d988Chris Lattnerstatic Constant *ConstantFoldFP(double (*NativeFP)(double), double V, 10857b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner const Type *Ty) { 10863f2f21e640682c604d9322ba0708e122d1fcf5eeDan Gohman sys::llvm_fenv_clearexcept(); 1087bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell V = NativeFP(V); 10883f2f21e640682c604d9322ba0708e122d1fcf5eeDan Gohman if (sys::llvm_fenv_testexcept()) { 10893f2f21e640682c604d9322ba0708e122d1fcf5eeDan Gohman sys::llvm_fenv_clearexcept(); 1090f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner return 0; 109143421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen } 1092f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner 1093d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner if (Ty->isFloatTy()) 10947b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFP::get(Ty->getContext(), APFloat((float)V)); 1095d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner if (Ty->isDoubleTy()) 10967b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFP::get(Ty->getContext(), APFloat(V)); 1097c23197a26f34f559ea9797de51e187087c039c42Torok Edwin llvm_unreachable("Can only constant fold float/double"); 109833e456d5f3909e0c7b96e04e5674c25a182da100Gabor Greif return 0; // dummy return to suppress warning 1099bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell} 1100bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 1101384152444d22d356f7b4090a158da4cbc1f79464Dan Gohmanstatic Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double), 11027b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner double V, double W, const Type *Ty) { 11033f2f21e640682c604d9322ba0708e122d1fcf5eeDan Gohman sys::llvm_fenv_clearexcept(); 1104384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman V = NativeFP(V, W); 11053f2f21e640682c604d9322ba0708e122d1fcf5eeDan Gohman if (sys::llvm_fenv_testexcept()) { 11063f2f21e640682c604d9322ba0708e122d1fcf5eeDan Gohman sys::llvm_fenv_clearexcept(); 1107f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner return 0; 110843421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen } 1109f19f58a9360927f8ef50b9a029e8efb780d3d8a8Chris Lattner 1110d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner if (Ty->isFloatTy()) 11117b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFP::get(Ty->getContext(), APFloat((float)V)); 1112d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner if (Ty->isDoubleTy()) 11137b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFP::get(Ty->getContext(), APFloat(V)); 1114c23197a26f34f559ea9797de51e187087c039c42Torok Edwin llvm_unreachable("Can only constant fold float/double"); 111533e456d5f3909e0c7b96e04e5674c25a182da100Gabor Greif return 0; // dummy return to suppress warning 1116384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman} 1117384152444d22d356f7b4090a158da4cbc1f79464Dan Gohman 1118bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell/// ConstantFoldCall - Attempt to constant fold a call to the specified function 1119bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell/// with the specified arguments, returning null if unsuccessful. 1120bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John CriswellConstant * 1121f286f6fd93d569befe6e77c94a947e6e04e95685Chris Lattnerllvm::ConstantFoldCall(Function *F, 112268a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner Constant *const *Operands, unsigned NumOperands) { 11236f532a988e5c02fcb271fb65e9e7b83f0147d3f2Chris Lattner if (!F->hasName()) return 0; 1124f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar StringRef Name = F->getName(); 1125e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner 1126bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell const Type *Ty = F->getReturnType(); 112772d88ae5447a3929c97e88f4c806213847b5d988Chris Lattner if (NumOperands == 1) { 1128bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell if (ConstantFP *Op = dyn_cast<ConstantFP>(Operands[0])) { 1129faa75f6e47350f491a44d5e8773acd9457185d51Anton Korobeynikov if (Name == "llvm.convert.to.fp16") { 1130faa75f6e47350f491a44d5e8773acd9457185d51Anton Korobeynikov APFloat Val(Op->getValueAPF()); 1131faa75f6e47350f491a44d5e8773acd9457185d51Anton Korobeynikov 1132faa75f6e47350f491a44d5e8773acd9457185d51Anton Korobeynikov bool lost = false; 1133faa75f6e47350f491a44d5e8773acd9457185d51Anton Korobeynikov Val.convert(APFloat::IEEEhalf, APFloat::rmNearestTiesToEven, &lost); 1134faa75f6e47350f491a44d5e8773acd9457185d51Anton Korobeynikov 1135faa75f6e47350f491a44d5e8773acd9457185d51Anton Korobeynikov return ConstantInt::get(F->getContext(), Val.bitcastToAPInt()); 1136faa75f6e47350f491a44d5e8773acd9457185d51Anton Korobeynikov } 1137faa75f6e47350f491a44d5e8773acd9457185d51Anton Korobeynikov 1138d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner if (!Ty->isFloatTy() && !Ty->isDoubleTy()) 113943421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen return 0; 11401f386c4ce1983c448320aecca8d3cd27d1497867Jakob Stoklund Olesen 11411f386c4ce1983c448320aecca8d3cd27d1497867Jakob Stoklund Olesen /// We only fold functions with finite arguments. Folding NaN and inf is 11421f386c4ce1983c448320aecca8d3cd27d1497867Jakob Stoklund Olesen /// likely to be aborted with an exception anyway, and some host libms 11431f386c4ce1983c448320aecca8d3cd27d1497867Jakob Stoklund Olesen /// have known errors raising exceptions. 11441f386c4ce1983c448320aecca8d3cd27d1497867Jakob Stoklund Olesen if (Op->getValueAPF().isNaN() || Op->getValueAPF().isInfinity()) 11451f386c4ce1983c448320aecca8d3cd27d1497867Jakob Stoklund Olesen return 0; 11461f386c4ce1983c448320aecca8d3cd27d1497867Jakob Stoklund Olesen 114743421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen /// Currently APFloat versions of these functions do not exist, so we use 114843421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen /// the host native double versions. Float versions are not called 114943421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen /// directly but for all these it is true (float)(f((double)arg)) == 115043421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen /// f(arg). Long double not supported yet. 1151d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner double V = Ty->isFloatTy() ? (double)Op->getValueAPF().convertToFloat() : 115243421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen Op->getValueAPF().convertToDouble(); 1153f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar switch (Name[0]) { 1154c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'a': 1155f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar if (Name == "acos") 11567b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(acos, V, Ty); 1157f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "asin") 11587b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(asin, V, Ty); 1159f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "atan") 11607b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(atan, V, Ty); 1161c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 1162c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'c': 1163f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar if (Name == "ceil") 11647b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(ceil, V, Ty); 1165f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "cos") 11667b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(cos, V, Ty); 1167f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "cosh") 11687b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(cosh, V, Ty); 1169f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "cosf") 11707b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(cos, V, Ty); 1171c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 1172c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'e': 1173f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar if (Name == "exp") 11747b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(exp, V, Ty); 1175c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 1176c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'f': 1177f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar if (Name == "fabs") 11787b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(fabs, V, Ty); 1179f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "floor") 11807b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(floor, V, Ty); 1181c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 1182c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 'l': 1183f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar if (Name == "log" && V > 0) 11847b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(log, V, Ty); 1185f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "log10" && V > 0) 11867b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(log10, V, Ty); 1187f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "llvm.sqrt.f32" || 1188f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar Name == "llvm.sqrt.f64") { 1189c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner if (V >= -0.0) 11907b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(sqrt, V, Ty); 1191c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner else // Undefined 1192a7235ea7245028a0723e8ab7fd011386b3900777Owen Anderson return Constant::getNullValue(Ty); 1193c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner } 1194c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 1195c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 's': 1196f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar if (Name == "sin") 11977b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(sin, V, Ty); 1198f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "sinh") 11997b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(sinh, V, Ty); 1200f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "sqrt" && V >= 0) 12017b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(sqrt, V, Ty); 1202f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "sqrtf" && V >= 0) 12037b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(sqrt, V, Ty); 1204f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "sinf") 12057b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(sin, V, Ty); 1206c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 1207c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner case 't': 1208f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar if (Name == "tan") 12097b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(tan, V, Ty); 1210f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name == "tanh") 12117b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldFP(tanh, V, Ty); 1212c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 1213c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner default: 1214c5f6a1f9d61d74017d90e149728cb3d283e0a0e0Chris Lattner break; 1215bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 121668a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner return 0; 121768a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner } 121868a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner 121968a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner 122068a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner if (ConstantInt *Op = dyn_cast<ConstantInt>(Operands[0])) { 1221f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar if (Name.startswith("llvm.bswap")) 12227b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantInt::get(F->getContext(), Op->getValue().byteSwap()); 1223f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name.startswith("llvm.ctpop")) 1224eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson return ConstantInt::get(Ty, Op->getValue().countPopulation()); 1225f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name.startswith("llvm.cttz")) 1226eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson return ConstantInt::get(Ty, Op->getValue().countTrailingZeros()); 1227f0443c1eb44d737d9bd78962932fc80f74c6113cDaniel Dunbar else if (Name.startswith("llvm.ctlz")) 1228eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson return ConstantInt::get(Ty, Op->getValue().countLeadingZeros()); 1229faa75f6e47350f491a44d5e8773acd9457185d51Anton Korobeynikov else if (Name == "llvm.convert.from.fp16") { 1230faa75f6e47350f491a44d5e8773acd9457185d51Anton Korobeynikov APFloat Val(Op->getValue()); 1231faa75f6e47350f491a44d5e8773acd9457185d51Anton Korobeynikov 1232faa75f6e47350f491a44d5e8773acd9457185d51Anton Korobeynikov bool lost = false; 1233faa75f6e47350f491a44d5e8773acd9457185d51Anton Korobeynikov APFloat::opStatus status = 1234faa75f6e47350f491a44d5e8773acd9457185d51Anton Korobeynikov Val.convert(APFloat::IEEEsingle, APFloat::rmNearestTiesToEven, &lost); 1235faa75f6e47350f491a44d5e8773acd9457185d51Anton Korobeynikov 1236faa75f6e47350f491a44d5e8773acd9457185d51Anton Korobeynikov // Conversion is always precise. 12378e68c3873549ca31533e2e3e40dda3a43cb79566Jeffrey Yasskin (void)status; 1238faa75f6e47350f491a44d5e8773acd9457185d51Anton Korobeynikov assert(status == APFloat::opOK && !lost && 1239faa75f6e47350f491a44d5e8773acd9457185d51Anton Korobeynikov "Precision lost during fp16 constfolding"); 1240faa75f6e47350f491a44d5e8773acd9457185d51Anton Korobeynikov 1241faa75f6e47350f491a44d5e8773acd9457185d51Anton Korobeynikov return ConstantFP::get(F->getContext(), Val); 1242faa75f6e47350f491a44d5e8773acd9457185d51Anton Korobeynikov } 124368a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner return 0; 1244bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 124568a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner 12469ee7123ab462d97a2b242280e9bf0b47883531cbDan Gohman if (isa<UndefValue>(Operands[0])) { 12479ee7123ab462d97a2b242280e9bf0b47883531cbDan Gohman if (Name.startswith("llvm.bswap")) 12489ee7123ab462d97a2b242280e9bf0b47883531cbDan Gohman return Operands[0]; 12499ee7123ab462d97a2b242280e9bf0b47883531cbDan Gohman return 0; 12509ee7123ab462d97a2b242280e9bf0b47883531cbDan Gohman } 12519ee7123ab462d97a2b242280e9bf0b47883531cbDan Gohman 125268a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner return 0; 125368a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner } 125468a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner 125568a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner if (NumOperands == 2) { 1256bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell if (ConstantFP *Op1 = dyn_cast<ConstantFP>(Operands[0])) { 1257d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner if (!Ty->isFloatTy() && !Ty->isDoubleTy()) 12589ab7fb3ba47442d521a5bed09a27a5e8e7a786edDale Johannesen return 0; 1259d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner double Op1V = Ty->isFloatTy() ? 1260d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner (double)Op1->getValueAPF().convertToFloat() : 126143421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen Op1->getValueAPF().convertToDouble(); 1262bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell if (ConstantFP *Op2 = dyn_cast<ConstantFP>(Operands[1])) { 1263d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner if (Op2->getType() != Op1->getType()) 1264d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner return 0; 1265d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner 1266d0806a1519f3bc450d2dea3e6f22db73fc797e4cChris Lattner double Op2V = Ty->isFloatTy() ? 126743421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen (double)Op2->getValueAPF().convertToFloat(): 126843421b3dd70af5b70e71816521f37502c397cc65Dale Johannesen Op2->getValueAPF().convertToDouble(); 1269bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell 127068a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner if (Name == "pow") 12717b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty); 127268a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner if (Name == "fmod") 12737b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldBinaryFP(fmod, Op1V, Op2V, Ty); 127468a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner if (Name == "atan2") 12757b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFoldBinaryFP(atan2, Op1V, Op2V, Ty); 1276b5282dcf4745be59046f440980a1c0f0a50c9c09Chris Lattner } else if (ConstantInt *Op2C = dyn_cast<ConstantInt>(Operands[1])) { 127768a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner if (Name == "llvm.powi.f32") 12787b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFP::get(F->getContext(), 12797b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner APFloat((float)std::pow((float)Op1V, 128002a260aa11a2e1b2c14335274d3c42ca3f3eabc0Chris Lattner (int)Op2C->getZExtValue()))); 128168a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner if (Name == "llvm.powi.f64") 12827b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner return ConstantFP::get(F->getContext(), 12837b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner APFloat((double)std::pow((double)Op1V, 12847b550ccfc5a3346c17e0390a59e2d6d19bc52705Chris Lattner (int)Op2C->getZExtValue()))); 1285bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 128668a0603dc5d3d79cd4de2195e950af26c3380cd7Chris Lattner return 0; 1287bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 1288e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner 1289e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner 1290e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner if (ConstantInt *Op1 = dyn_cast<ConstantInt>(Operands[0])) { 1291e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner if (ConstantInt *Op2 = dyn_cast<ConstantInt>(Operands[1])) { 1292e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner switch (F->getIntrinsicID()) { 1293e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner default: break; 1294eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner case Intrinsic::sadd_with_overflow: 1295eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner case Intrinsic::uadd_with_overflow: 1296eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner case Intrinsic::ssub_with_overflow: 1297eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner case Intrinsic::usub_with_overflow: 1298eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner case Intrinsic::smul_with_overflow: { 1299eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner APInt Res; 1300eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner bool Overflow; 1301eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner switch (F->getIntrinsicID()) { 1302eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner default: assert(0 && "Invalid case"); 1303eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner case Intrinsic::sadd_with_overflow: 1304eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner Res = Op1->getValue().sadd_ov(Op2->getValue(), Overflow); 1305eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner break; 1306eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner case Intrinsic::uadd_with_overflow: 1307eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner Res = Op1->getValue().uadd_ov(Op2->getValue(), Overflow); 1308eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner break; 1309eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner case Intrinsic::ssub_with_overflow: 1310eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner Res = Op1->getValue().ssub_ov(Op2->getValue(), Overflow); 1311eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner break; 1312eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner case Intrinsic::usub_with_overflow: 1313eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner Res = Op1->getValue().usub_ov(Op2->getValue(), Overflow); 1314eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner break; 1315eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner case Intrinsic::smul_with_overflow: 1316eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner Res = Op1->getValue().smul_ov(Op2->getValue(), Overflow); 1317eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner break; 1318eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner } 1319e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner Constant *Ops[] = { 1320eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner ConstantInt::get(F->getContext(), Res), 1321eafc5cb80d58cb9447623a557be4d4f55f42fbc3Chris Lattner ConstantInt::get(Type::getInt1Ty(F->getContext()), Overflow) 1322e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner }; 1323e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner return ConstantStruct::get(F->getContext(), Ops, 2, false); 1324e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner } 1325e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner } 1326e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner } 1327e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner 1328e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner return 0; 1329e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner } 1330e65cd40ab99c3bd43dc997873e500643d012bbadChris Lattner return 0; 1331bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell } 1332bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell return 0; 1333bd9d37026a5c17d9a51371a6a5446bf4761ee7d6John Criswell} 1334