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getelementptr. Despite only doing so in the case where x is a known array object and c can be converted to an index within range, this could still be invalid if c is actually the address of an object allocated outside of LLVM. Also, SCEVExpander, the original motivation for this code, has since been improved to avoid inttoptr+ptroint in more cases. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96950 91177308-0d34-0410-b5e6-96231b3b80d8
1243 lines
48 KiB
C++
1243 lines
48 KiB
C++
//===-- ConstantFolding.cpp - Fold instructions into constants ------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file defines routines for folding instructions into constants.
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//
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// Also, to supplement the basic VMCore ConstantExpr simplifications,
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// this file defines some additional folding routines that can make use of
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// TargetData information. These functions cannot go in VMCore due to library
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// dependency issues.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Analysis/ConstantFolding.h"
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#include "llvm/Constants.h"
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#include "llvm/DerivedTypes.h"
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#include "llvm/Function.h"
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#include "llvm/GlobalVariable.h"
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#include "llvm/Instructions.h"
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#include "llvm/Intrinsics.h"
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#include "llvm/Analysis/ValueTracking.h"
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#include "llvm/Target/TargetData.h"
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#include "llvm/ADT/SmallVector.h"
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#include "llvm/ADT/StringMap.h"
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#include "llvm/Support/ErrorHandling.h"
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#include "llvm/Support/GetElementPtrTypeIterator.h"
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#include "llvm/Support/MathExtras.h"
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#include <cerrno>
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#include <cmath>
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using namespace llvm;
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//===----------------------------------------------------------------------===//
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// Constant Folding internal helper functions
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//===----------------------------------------------------------------------===//
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/// FoldBitCast - Constant fold bitcast, symbolically evaluating it with
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/// TargetData. This always returns a non-null constant, but it may be a
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/// ConstantExpr if unfoldable.
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static Constant *FoldBitCast(Constant *C, const Type *DestTy,
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const TargetData &TD) {
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// This only handles casts to vectors currently.
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const VectorType *DestVTy = dyn_cast<VectorType>(DestTy);
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if (DestVTy == 0)
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return ConstantExpr::getBitCast(C, DestTy);
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// If this is a scalar -> vector cast, convert the input into a <1 x scalar>
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// vector so the code below can handle it uniformly.
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if (isa<ConstantFP>(C) || isa<ConstantInt>(C)) {
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Constant *Ops = C; // don't take the address of C!
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return FoldBitCast(ConstantVector::get(&Ops, 1), DestTy, TD);
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}
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// If this is a bitcast from constant vector -> vector, fold it.
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ConstantVector *CV = dyn_cast<ConstantVector>(C);
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if (CV == 0)
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return ConstantExpr::getBitCast(C, DestTy);
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// If the element types match, VMCore can fold it.
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unsigned NumDstElt = DestVTy->getNumElements();
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unsigned NumSrcElt = CV->getNumOperands();
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if (NumDstElt == NumSrcElt)
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return ConstantExpr::getBitCast(C, DestTy);
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const Type *SrcEltTy = CV->getType()->getElementType();
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const Type *DstEltTy = DestVTy->getElementType();
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// Otherwise, we're changing the number of elements in a vector, which
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// requires endianness information to do the right thing. For example,
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// bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>)
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// folds to (little endian):
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// <4 x i32> <i32 0, i32 0, i32 1, i32 0>
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// and to (big endian):
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// <4 x i32> <i32 0, i32 0, i32 0, i32 1>
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// First thing is first. We only want to think about integer here, so if
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// we have something in FP form, recast it as integer.
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if (DstEltTy->isFloatingPointTy()) {
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// Fold to an vector of integers with same size as our FP type.
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unsigned FPWidth = DstEltTy->getPrimitiveSizeInBits();
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const Type *DestIVTy =
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VectorType::get(IntegerType::get(C->getContext(), FPWidth), NumDstElt);
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// Recursively handle this integer conversion, if possible.
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C = FoldBitCast(C, DestIVTy, TD);
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if (!C) return ConstantExpr::getBitCast(C, DestTy);
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// Finally, VMCore can handle this now that #elts line up.
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return ConstantExpr::getBitCast(C, DestTy);
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}
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// Okay, we know the destination is integer, if the input is FP, convert
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// it to integer first.
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if (SrcEltTy->isFloatingPointTy()) {
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unsigned FPWidth = SrcEltTy->getPrimitiveSizeInBits();
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const Type *SrcIVTy =
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VectorType::get(IntegerType::get(C->getContext(), FPWidth), NumSrcElt);
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// Ask VMCore to do the conversion now that #elts line up.
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C = ConstantExpr::getBitCast(C, SrcIVTy);
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CV = dyn_cast<ConstantVector>(C);
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if (!CV) // If VMCore wasn't able to fold it, bail out.
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return C;
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}
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// Now we know that the input and output vectors are both integer vectors
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// of the same size, and that their #elements is not the same. Do the
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// conversion here, which depends on whether the input or output has
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// more elements.
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bool isLittleEndian = TD.isLittleEndian();
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SmallVector<Constant*, 32> Result;
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if (NumDstElt < NumSrcElt) {
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// Handle: bitcast (<4 x i32> <i32 0, i32 1, i32 2, i32 3> to <2 x i64>)
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Constant *Zero = Constant::getNullValue(DstEltTy);
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unsigned Ratio = NumSrcElt/NumDstElt;
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unsigned SrcBitSize = SrcEltTy->getPrimitiveSizeInBits();
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unsigned SrcElt = 0;
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for (unsigned i = 0; i != NumDstElt; ++i) {
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// Build each element of the result.
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Constant *Elt = Zero;
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unsigned ShiftAmt = isLittleEndian ? 0 : SrcBitSize*(Ratio-1);
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for (unsigned j = 0; j != Ratio; ++j) {
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Constant *Src = dyn_cast<ConstantInt>(CV->getOperand(SrcElt++));
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if (!Src) // Reject constantexpr elements.
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return ConstantExpr::getBitCast(C, DestTy);
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// Zero extend the element to the right size.
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Src = ConstantExpr::getZExt(Src, Elt->getType());
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// Shift it to the right place, depending on endianness.
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Src = ConstantExpr::getShl(Src,
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ConstantInt::get(Src->getType(), ShiftAmt));
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ShiftAmt += isLittleEndian ? SrcBitSize : -SrcBitSize;
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// Mix it in.
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Elt = ConstantExpr::getOr(Elt, Src);
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}
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Result.push_back(Elt);
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}
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} else {
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// Handle: bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>)
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unsigned Ratio = NumDstElt/NumSrcElt;
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unsigned DstBitSize = DstEltTy->getPrimitiveSizeInBits();
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// Loop over each source value, expanding into multiple results.
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for (unsigned i = 0; i != NumSrcElt; ++i) {
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Constant *Src = dyn_cast<ConstantInt>(CV->getOperand(i));
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if (!Src) // Reject constantexpr elements.
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return ConstantExpr::getBitCast(C, DestTy);
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unsigned ShiftAmt = isLittleEndian ? 0 : DstBitSize*(Ratio-1);
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for (unsigned j = 0; j != Ratio; ++j) {
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// Shift the piece of the value into the right place, depending on
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// endianness.
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Constant *Elt = ConstantExpr::getLShr(Src,
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ConstantInt::get(Src->getType(), ShiftAmt));
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ShiftAmt += isLittleEndian ? DstBitSize : -DstBitSize;
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// Truncate and remember this piece.
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Result.push_back(ConstantExpr::getTrunc(Elt, DstEltTy));
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}
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}
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}
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return ConstantVector::get(Result.data(), Result.size());
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}
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/// IsConstantOffsetFromGlobal - If this constant is actually a constant offset
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/// from a global, return the global and the constant. Because of
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/// constantexprs, this function is recursive.
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static bool IsConstantOffsetFromGlobal(Constant *C, GlobalValue *&GV,
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int64_t &Offset, const TargetData &TD) {
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// Trivial case, constant is the global.
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if ((GV = dyn_cast<GlobalValue>(C))) {
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Offset = 0;
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return true;
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}
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// Otherwise, if this isn't a constant expr, bail out.
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ConstantExpr *CE = dyn_cast<ConstantExpr>(C);
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if (!CE) return false;
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// Look through ptr->int and ptr->ptr casts.
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if (CE->getOpcode() == Instruction::PtrToInt ||
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CE->getOpcode() == Instruction::BitCast)
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return IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD);
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// i32* getelementptr ([5 x i32]* @a, i32 0, i32 5)
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if (CE->getOpcode() == Instruction::GetElementPtr) {
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// Cannot compute this if the element type of the pointer is missing size
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// info.
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if (!cast<PointerType>(CE->getOperand(0)->getType())
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->getElementType()->isSized())
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return false;
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// If the base isn't a global+constant, we aren't either.
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if (!IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD))
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return false;
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// Otherwise, add any offset that our operands provide.
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gep_type_iterator GTI = gep_type_begin(CE);
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for (User::const_op_iterator i = CE->op_begin() + 1, e = CE->op_end();
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i != e; ++i, ++GTI) {
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ConstantInt *CI = dyn_cast<ConstantInt>(*i);
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if (!CI) return false; // Index isn't a simple constant?
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if (CI->getZExtValue() == 0) continue; // Not adding anything.
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if (const StructType *ST = dyn_cast<StructType>(*GTI)) {
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// N = N + Offset
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Offset += TD.getStructLayout(ST)->getElementOffset(CI->getZExtValue());
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} else {
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const SequentialType *SQT = cast<SequentialType>(*GTI);
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Offset += TD.getTypeAllocSize(SQT->getElementType())*CI->getSExtValue();
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}
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}
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return true;
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}
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return false;
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}
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/// ReadDataFromGlobal - Recursive helper to read bits out of global. C is the
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/// constant being copied out of. ByteOffset is an offset into C. CurPtr is the
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/// pointer to copy results into and BytesLeft is the number of bytes left in
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/// the CurPtr buffer. TD is the target data.
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static bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset,
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unsigned char *CurPtr, unsigned BytesLeft,
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const TargetData &TD) {
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assert(ByteOffset <= TD.getTypeAllocSize(C->getType()) &&
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"Out of range access");
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// If this element is zero or undefined, we can just return since *CurPtr is
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// zero initialized.
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if (isa<ConstantAggregateZero>(C) || isa<UndefValue>(C))
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return true;
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if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) {
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if (CI->getBitWidth() > 64 ||
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(CI->getBitWidth() & 7) != 0)
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return false;
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uint64_t Val = CI->getZExtValue();
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unsigned IntBytes = unsigned(CI->getBitWidth()/8);
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for (unsigned i = 0; i != BytesLeft && ByteOffset != IntBytes; ++i) {
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CurPtr[i] = (unsigned char)(Val >> (ByteOffset * 8));
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++ByteOffset;
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}
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return true;
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}
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if (ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
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if (CFP->getType()->isDoubleTy()) {
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C = FoldBitCast(C, Type::getInt64Ty(C->getContext()), TD);
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return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, TD);
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}
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if (CFP->getType()->isFloatTy()){
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C = FoldBitCast(C, Type::getInt32Ty(C->getContext()), TD);
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return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, TD);
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}
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return false;
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}
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if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) {
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const StructLayout *SL = TD.getStructLayout(CS->getType());
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unsigned Index = SL->getElementContainingOffset(ByteOffset);
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uint64_t CurEltOffset = SL->getElementOffset(Index);
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ByteOffset -= CurEltOffset;
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while (1) {
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// If the element access is to the element itself and not to tail padding,
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// read the bytes from the element.
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uint64_t EltSize = TD.getTypeAllocSize(CS->getOperand(Index)->getType());
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if (ByteOffset < EltSize &&
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!ReadDataFromGlobal(CS->getOperand(Index), ByteOffset, CurPtr,
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BytesLeft, TD))
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return false;
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++Index;
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// Check to see if we read from the last struct element, if so we're done.
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if (Index == CS->getType()->getNumElements())
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return true;
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// If we read all of the bytes we needed from this element we're done.
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uint64_t NextEltOffset = SL->getElementOffset(Index);
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if (BytesLeft <= NextEltOffset-CurEltOffset-ByteOffset)
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return true;
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// Move to the next element of the struct.
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CurPtr += NextEltOffset-CurEltOffset-ByteOffset;
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BytesLeft -= NextEltOffset-CurEltOffset-ByteOffset;
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ByteOffset = 0;
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CurEltOffset = NextEltOffset;
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}
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// not reached.
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}
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if (ConstantArray *CA = dyn_cast<ConstantArray>(C)) {
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uint64_t EltSize = TD.getTypeAllocSize(CA->getType()->getElementType());
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uint64_t Index = ByteOffset / EltSize;
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uint64_t Offset = ByteOffset - Index * EltSize;
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for (; Index != CA->getType()->getNumElements(); ++Index) {
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if (!ReadDataFromGlobal(CA->getOperand(Index), Offset, CurPtr,
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BytesLeft, TD))
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return false;
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if (EltSize >= BytesLeft)
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return true;
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Offset = 0;
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BytesLeft -= EltSize;
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CurPtr += EltSize;
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}
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return true;
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}
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if (ConstantVector *CV = dyn_cast<ConstantVector>(C)) {
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uint64_t EltSize = TD.getTypeAllocSize(CV->getType()->getElementType());
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uint64_t Index = ByteOffset / EltSize;
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uint64_t Offset = ByteOffset - Index * EltSize;
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for (; Index != CV->getType()->getNumElements(); ++Index) {
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if (!ReadDataFromGlobal(CV->getOperand(Index), Offset, CurPtr,
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BytesLeft, TD))
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return false;
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if (EltSize >= BytesLeft)
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return true;
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Offset = 0;
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BytesLeft -= EltSize;
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CurPtr += EltSize;
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}
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return true;
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}
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// Otherwise, unknown initializer type.
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return false;
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}
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static Constant *FoldReinterpretLoadFromConstPtr(Constant *C,
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const TargetData &TD) {
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const Type *LoadTy = cast<PointerType>(C->getType())->getElementType();
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const IntegerType *IntType = dyn_cast<IntegerType>(LoadTy);
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// If this isn't an integer load we can't fold it directly.
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if (!IntType) {
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// If this is a float/double load, we can try folding it as an int32/64 load
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// and then bitcast the result. This can be useful for union cases. Note
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// that address spaces don't matter here since we're not going to result in
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// an actual new load.
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const Type *MapTy;
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if (LoadTy->isFloatTy())
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MapTy = Type::getInt32PtrTy(C->getContext());
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else if (LoadTy->isDoubleTy())
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MapTy = Type::getInt64PtrTy(C->getContext());
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else if (LoadTy->isVectorTy()) {
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MapTy = IntegerType::get(C->getContext(),
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TD.getTypeAllocSizeInBits(LoadTy));
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MapTy = PointerType::getUnqual(MapTy);
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} else
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return 0;
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C = FoldBitCast(C, MapTy, TD);
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if (Constant *Res = FoldReinterpretLoadFromConstPtr(C, TD))
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return FoldBitCast(Res, LoadTy, TD);
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return 0;
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}
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unsigned BytesLoaded = (IntType->getBitWidth() + 7) / 8;
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if (BytesLoaded > 32 || BytesLoaded == 0) return 0;
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GlobalValue *GVal;
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int64_t Offset;
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if (!IsConstantOffsetFromGlobal(C, GVal, Offset, TD))
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return 0;
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GlobalVariable *GV = dyn_cast<GlobalVariable>(GVal);
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if (!GV || !GV->isConstant() || !GV->hasDefinitiveInitializer() ||
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!GV->getInitializer()->getType()->isSized())
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return 0;
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// If we're loading off the beginning of the global, some bytes may be valid,
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// but we don't try to handle this.
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if (Offset < 0) return 0;
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// If we're not accessing anything in this constant, the result is undefined.
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if (uint64_t(Offset) >= TD.getTypeAllocSize(GV->getInitializer()->getType()))
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return UndefValue::get(IntType);
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unsigned char RawBytes[32] = {0};
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if (!ReadDataFromGlobal(GV->getInitializer(), Offset, RawBytes,
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BytesLoaded, TD))
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return 0;
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APInt ResultVal = APInt(IntType->getBitWidth(), RawBytes[BytesLoaded-1]);
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for (unsigned i = 1; i != BytesLoaded; ++i) {
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ResultVal <<= 8;
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ResultVal |= APInt(IntType->getBitWidth(), RawBytes[BytesLoaded-1-i]);
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}
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return ConstantInt::get(IntType->getContext(), ResultVal);
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}
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/// ConstantFoldLoadFromConstPtr - Return the value that a load from C would
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/// produce if it is constant and determinable. If this is not determinable,
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/// return null.
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Constant *llvm::ConstantFoldLoadFromConstPtr(Constant *C,
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const TargetData *TD) {
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// First, try the easy cases:
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if (GlobalVariable *GV = dyn_cast<GlobalVariable>(C))
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if (GV->isConstant() && GV->hasDefinitiveInitializer())
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return GV->getInitializer();
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// If the loaded value isn't a constant expr, we can't handle it.
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ConstantExpr *CE = dyn_cast<ConstantExpr>(C);
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if (!CE) return 0;
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if (CE->getOpcode() == Instruction::GetElementPtr) {
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if (GlobalVariable *GV = dyn_cast<GlobalVariable>(CE->getOperand(0)))
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if (GV->isConstant() && GV->hasDefinitiveInitializer())
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if (Constant *V =
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ConstantFoldLoadThroughGEPConstantExpr(GV->getInitializer(), CE))
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return V;
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}
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// Instead of loading constant c string, use corresponding integer value
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// directly if string length is small enough.
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std::string Str;
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if (TD && GetConstantStringInfo(CE, Str) && !Str.empty()) {
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unsigned StrLen = Str.length();
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const Type *Ty = cast<PointerType>(CE->getType())->getElementType();
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unsigned NumBits = Ty->getPrimitiveSizeInBits();
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// Replace LI with immediate integer store.
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if ((NumBits >> 3) == StrLen + 1) {
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APInt StrVal(NumBits, 0);
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APInt SingleChar(NumBits, 0);
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if (TD->isLittleEndian()) {
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for (signed i = StrLen-1; i >= 0; i--) {
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SingleChar = (uint64_t) Str[i] & UCHAR_MAX;
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StrVal = (StrVal << 8) | SingleChar;
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}
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} else {
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for (unsigned i = 0; i < StrLen; i++) {
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SingleChar = (uint64_t) Str[i] & UCHAR_MAX;
|
|
StrVal = (StrVal << 8) | SingleChar;
|
|
}
|
|
// Append NULL at the end.
|
|
SingleChar = 0;
|
|
StrVal = (StrVal << 8) | SingleChar;
|
|
}
|
|
return ConstantInt::get(CE->getContext(), StrVal);
|
|
}
|
|
}
|
|
|
|
// If this load comes from anywhere in a constant global, and if the global
|
|
// is all undef or zero, we know what it loads.
|
|
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(CE->getUnderlyingObject())){
|
|
if (GV->isConstant() && GV->hasDefinitiveInitializer()) {
|
|
const Type *ResTy = cast<PointerType>(C->getType())->getElementType();
|
|
if (GV->getInitializer()->isNullValue())
|
|
return Constant::getNullValue(ResTy);
|
|
if (isa<UndefValue>(GV->getInitializer()))
|
|
return UndefValue::get(ResTy);
|
|
}
|
|
}
|
|
|
|
// Try hard to fold loads from bitcasted strange and non-type-safe things. We
|
|
// currently don't do any of this for big endian systems. It can be
|
|
// generalized in the future if someone is interested.
|
|
if (TD && TD->isLittleEndian())
|
|
return FoldReinterpretLoadFromConstPtr(CE, *TD);
|
|
return 0;
|
|
}
|
|
|
|
static Constant *ConstantFoldLoadInst(const LoadInst *LI, const TargetData *TD){
|
|
if (LI->isVolatile()) return 0;
|
|
|
|
if (Constant *C = dyn_cast<Constant>(LI->getOperand(0)))
|
|
return ConstantFoldLoadFromConstPtr(C, TD);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/// SymbolicallyEvaluateBinop - One of Op0/Op1 is a constant expression.
|
|
/// Attempt to symbolically evaluate the result of a binary operator merging
|
|
/// these together. If target data info is available, it is provided as TD,
|
|
/// otherwise TD is null.
|
|
static Constant *SymbolicallyEvaluateBinop(unsigned Opc, Constant *Op0,
|
|
Constant *Op1, const TargetData *TD){
|
|
// SROA
|
|
|
|
// Fold (and 0xffffffff00000000, (shl x, 32)) -> shl.
|
|
// Fold (lshr (or X, Y), 32) -> (lshr [X/Y], 32) if one doesn't contribute
|
|
// bits.
|
|
|
|
|
|
// If the constant expr is something like &A[123] - &A[4].f, fold this into a
|
|
// constant. This happens frequently when iterating over a global array.
|
|
if (Opc == Instruction::Sub && TD) {
|
|
GlobalValue *GV1, *GV2;
|
|
int64_t Offs1, Offs2;
|
|
|
|
if (IsConstantOffsetFromGlobal(Op0, GV1, Offs1, *TD))
|
|
if (IsConstantOffsetFromGlobal(Op1, GV2, Offs2, *TD) &&
|
|
GV1 == GV2) {
|
|
// (&GV+C1) - (&GV+C2) -> C1-C2, pointer arithmetic cannot overflow.
|
|
return ConstantInt::get(Op0->getType(), Offs1-Offs2);
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/// CastGEPIndices - If array indices are not pointer-sized integers,
|
|
/// explicitly cast them so that they aren't implicitly casted by the
|
|
/// getelementptr.
|
|
static Constant *CastGEPIndices(Constant *const *Ops, unsigned NumOps,
|
|
const Type *ResultTy,
|
|
const TargetData *TD) {
|
|
if (!TD) return 0;
|
|
const Type *IntPtrTy = TD->getIntPtrType(ResultTy->getContext());
|
|
|
|
bool Any = false;
|
|
SmallVector<Constant*, 32> NewIdxs;
|
|
for (unsigned i = 1; i != NumOps; ++i) {
|
|
if ((i == 1 ||
|
|
!isa<StructType>(GetElementPtrInst::getIndexedType(Ops[0]->getType(),
|
|
reinterpret_cast<Value *const *>(Ops+1),
|
|
i-1))) &&
|
|
Ops[i]->getType() != IntPtrTy) {
|
|
Any = true;
|
|
NewIdxs.push_back(ConstantExpr::getCast(CastInst::getCastOpcode(Ops[i],
|
|
true,
|
|
IntPtrTy,
|
|
true),
|
|
Ops[i], IntPtrTy));
|
|
} else
|
|
NewIdxs.push_back(Ops[i]);
|
|
}
|
|
if (!Any) return 0;
|
|
|
|
Constant *C =
|
|
ConstantExpr::getGetElementPtr(Ops[0], &NewIdxs[0], NewIdxs.size());
|
|
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
|
|
if (Constant *Folded = ConstantFoldConstantExpression(CE, TD))
|
|
C = Folded;
|
|
return C;
|
|
}
|
|
|
|
/// SymbolicallyEvaluateGEP - If we can symbolically evaluate the specified GEP
|
|
/// constant expression, do so.
|
|
static Constant *SymbolicallyEvaluateGEP(Constant *const *Ops, unsigned NumOps,
|
|
const Type *ResultTy,
|
|
const TargetData *TD) {
|
|
Constant *Ptr = Ops[0];
|
|
if (!TD || !cast<PointerType>(Ptr->getType())->getElementType()->isSized())
|
|
return 0;
|
|
|
|
unsigned BitWidth =
|
|
TD->getTypeSizeInBits(TD->getIntPtrType(Ptr->getContext()));
|
|
APInt BasePtr(BitWidth, 0);
|
|
bool BaseIsInt = true;
|
|
if (!Ptr->isNullValue()) {
|
|
// If this is a inttoptr from a constant int, we can fold this as the base,
|
|
// otherwise we can't.
|
|
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr))
|
|
if (CE->getOpcode() == Instruction::IntToPtr)
|
|
if (ConstantInt *Base = dyn_cast<ConstantInt>(CE->getOperand(0))) {
|
|
BasePtr = Base->getValue();
|
|
BasePtr.zextOrTrunc(BitWidth);
|
|
}
|
|
|
|
if (BasePtr == 0)
|
|
BaseIsInt = false;
|
|
}
|
|
|
|
// If this is a constant expr gep that is effectively computing an
|
|
// "offsetof", fold it into 'cast int Size to T*' instead of 'gep 0, 0, 12'
|
|
for (unsigned i = 1; i != NumOps; ++i)
|
|
if (!isa<ConstantInt>(Ops[i]))
|
|
return 0;
|
|
|
|
APInt Offset = APInt(BitWidth,
|
|
TD->getIndexedOffset(Ptr->getType(),
|
|
(Value**)Ops+1, NumOps-1));
|
|
// If the base value for this address is a literal integer value, fold the
|
|
// getelementptr to the resulting integer value casted to the pointer type.
|
|
if (BaseIsInt) {
|
|
Constant *C = ConstantInt::get(Ptr->getContext(), Offset+BasePtr);
|
|
return ConstantExpr::getIntToPtr(C, ResultTy);
|
|
}
|
|
|
|
// Otherwise form a regular getelementptr. Recompute the indices so that
|
|
// we eliminate over-indexing of the notional static type array bounds.
|
|
// This makes it easy to determine if the getelementptr is "inbounds".
|
|
// Also, this helps GlobalOpt do SROA on GlobalVariables.
|
|
Ptr = cast<Constant>(Ptr->stripPointerCasts());
|
|
const Type *Ty = Ptr->getType();
|
|
SmallVector<Constant*, 32> NewIdxs;
|
|
do {
|
|
if (const SequentialType *ATy = dyn_cast<SequentialType>(Ty)) {
|
|
if (ATy->isPointerTy()) {
|
|
// The only pointer indexing we'll do is on the first index of the GEP.
|
|
if (!NewIdxs.empty())
|
|
break;
|
|
|
|
// Only handle pointers to sized types, not pointers to functions.
|
|
if (!ATy->getElementType()->isSized())
|
|
return 0;
|
|
}
|
|
|
|
// Determine which element of the array the offset points into.
|
|
APInt ElemSize(BitWidth, TD->getTypeAllocSize(ATy->getElementType()));
|
|
if (ElemSize == 0)
|
|
return 0;
|
|
APInt NewIdx = Offset.udiv(ElemSize);
|
|
Offset -= NewIdx * ElemSize;
|
|
NewIdxs.push_back(ConstantInt::get(TD->getIntPtrType(Ty->getContext()),
|
|
NewIdx));
|
|
Ty = ATy->getElementType();
|
|
} else if (const StructType *STy = dyn_cast<StructType>(Ty)) {
|
|
// Determine which field of the struct the offset points into. The
|
|
// getZExtValue is at least as safe as the StructLayout API because we
|
|
// know the offset is within the struct at this point.
|
|
const StructLayout &SL = *TD->getStructLayout(STy);
|
|
unsigned ElIdx = SL.getElementContainingOffset(Offset.getZExtValue());
|
|
NewIdxs.push_back(ConstantInt::get(Type::getInt32Ty(Ty->getContext()),
|
|
ElIdx));
|
|
Offset -= APInt(BitWidth, SL.getElementOffset(ElIdx));
|
|
Ty = STy->getTypeAtIndex(ElIdx);
|
|
} else {
|
|
// We've reached some non-indexable type.
|
|
break;
|
|
}
|
|
} while (Ty != cast<PointerType>(ResultTy)->getElementType());
|
|
|
|
// If we haven't used up the entire offset by descending the static
|
|
// type, then the offset is pointing into the middle of an indivisible
|
|
// member, so we can't simplify it.
|
|
if (Offset != 0)
|
|
return 0;
|
|
|
|
// Create a GEP.
|
|
Constant *C =
|
|
ConstantExpr::getGetElementPtr(Ptr, &NewIdxs[0], NewIdxs.size());
|
|
assert(cast<PointerType>(C->getType())->getElementType() == Ty &&
|
|
"Computed GetElementPtr has unexpected type!");
|
|
|
|
// If we ended up indexing a member with a type that doesn't match
|
|
// the type of what the original indices indexed, add a cast.
|
|
if (Ty != cast<PointerType>(ResultTy)->getElementType())
|
|
C = FoldBitCast(C, ResultTy, *TD);
|
|
|
|
return C;
|
|
}
|
|
|
|
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Constant Folding public APIs
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
|
|
/// ConstantFoldInstruction - Attempt to constant fold the specified
|
|
/// instruction. If successful, the constant result is returned, if not, null
|
|
/// is returned. Note that this function can only fail when attempting to fold
|
|
/// instructions like loads and stores, which have no constant expression form.
|
|
///
|
|
Constant *llvm::ConstantFoldInstruction(Instruction *I, const TargetData *TD) {
|
|
if (PHINode *PN = dyn_cast<PHINode>(I)) {
|
|
if (PN->getNumIncomingValues() == 0)
|
|
return UndefValue::get(PN->getType());
|
|
|
|
Constant *Result = dyn_cast<Constant>(PN->getIncomingValue(0));
|
|
if (Result == 0) return 0;
|
|
|
|
// Handle PHI nodes specially here...
|
|
for (unsigned i = 1, e = PN->getNumIncomingValues(); i != e; ++i)
|
|
if (PN->getIncomingValue(i) != Result && PN->getIncomingValue(i) != PN)
|
|
return 0; // Not all the same incoming constants...
|
|
|
|
// If we reach here, all incoming values are the same constant.
|
|
return Result;
|
|
}
|
|
|
|
// Scan the operand list, checking to see if they are all constants, if so,
|
|
// hand off to ConstantFoldInstOperands.
|
|
SmallVector<Constant*, 8> Ops;
|
|
for (User::op_iterator i = I->op_begin(), e = I->op_end(); i != e; ++i)
|
|
if (Constant *Op = dyn_cast<Constant>(*i))
|
|
Ops.push_back(Op);
|
|
else
|
|
return 0; // All operands not constant!
|
|
|
|
if (const CmpInst *CI = dyn_cast<CmpInst>(I))
|
|
return ConstantFoldCompareInstOperands(CI->getPredicate(), Ops[0], Ops[1],
|
|
TD);
|
|
|
|
if (const LoadInst *LI = dyn_cast<LoadInst>(I))
|
|
return ConstantFoldLoadInst(LI, TD);
|
|
|
|
return ConstantFoldInstOperands(I->getOpcode(), I->getType(),
|
|
Ops.data(), Ops.size(), TD);
|
|
}
|
|
|
|
/// ConstantFoldConstantExpression - Attempt to fold the constant expression
|
|
/// using the specified TargetData. If successful, the constant result is
|
|
/// result is returned, if not, null is returned.
|
|
Constant *llvm::ConstantFoldConstantExpression(const ConstantExpr *CE,
|
|
const TargetData *TD) {
|
|
SmallVector<Constant*, 8> Ops;
|
|
for (User::const_op_iterator i = CE->op_begin(), e = CE->op_end(); i != e; ++i) {
|
|
Constant *NewC = cast<Constant>(*i);
|
|
// Recursively fold the ConstantExpr's operands.
|
|
if (ConstantExpr *NewCE = dyn_cast<ConstantExpr>(NewC))
|
|
NewC = ConstantFoldConstantExpression(NewCE, TD);
|
|
Ops.push_back(NewC);
|
|
}
|
|
|
|
if (CE->isCompare())
|
|
return ConstantFoldCompareInstOperands(CE->getPredicate(), Ops[0], Ops[1],
|
|
TD);
|
|
return ConstantFoldInstOperands(CE->getOpcode(), CE->getType(),
|
|
Ops.data(), Ops.size(), TD);
|
|
}
|
|
|
|
/// ConstantFoldInstOperands - Attempt to constant fold an instruction with the
|
|
/// specified opcode and operands. If successful, the constant result is
|
|
/// returned, if not, null is returned. Note that this function can fail when
|
|
/// attempting to fold instructions like loads and stores, which have no
|
|
/// constant expression form.
|
|
///
|
|
/// TODO: This function neither utilizes nor preserves nsw/nuw/inbounds/etc
|
|
/// information, due to only being passed an opcode and operands. Constant
|
|
/// folding using this function strips this information.
|
|
///
|
|
Constant *llvm::ConstantFoldInstOperands(unsigned Opcode, const Type *DestTy,
|
|
Constant* const* Ops, unsigned NumOps,
|
|
const TargetData *TD) {
|
|
// Handle easy binops first.
|
|
if (Instruction::isBinaryOp(Opcode)) {
|
|
if (isa<ConstantExpr>(Ops[0]) || isa<ConstantExpr>(Ops[1]))
|
|
if (Constant *C = SymbolicallyEvaluateBinop(Opcode, Ops[0], Ops[1], TD))
|
|
return C;
|
|
|
|
return ConstantExpr::get(Opcode, Ops[0], Ops[1]);
|
|
}
|
|
|
|
switch (Opcode) {
|
|
default: return 0;
|
|
case Instruction::ICmp:
|
|
case Instruction::FCmp: assert(0 && "Invalid for compares");
|
|
case Instruction::Call:
|
|
if (Function *F = dyn_cast<Function>(Ops[0]))
|
|
if (canConstantFoldCallTo(F))
|
|
return ConstantFoldCall(F, Ops+1, NumOps-1);
|
|
return 0;
|
|
case Instruction::PtrToInt:
|
|
// If the input is a inttoptr, eliminate the pair. This requires knowing
|
|
// the width of a pointer, so it can't be done in ConstantExpr::getCast.
|
|
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[0])) {
|
|
if (TD && CE->getOpcode() == Instruction::IntToPtr) {
|
|
Constant *Input = CE->getOperand(0);
|
|
unsigned InWidth = Input->getType()->getScalarSizeInBits();
|
|
if (TD->getPointerSizeInBits() < InWidth) {
|
|
Constant *Mask =
|
|
ConstantInt::get(CE->getContext(), APInt::getLowBitsSet(InWidth,
|
|
TD->getPointerSizeInBits()));
|
|
Input = ConstantExpr::getAnd(Input, Mask);
|
|
}
|
|
// Do a zext or trunc to get to the dest size.
|
|
return ConstantExpr::getIntegerCast(Input, DestTy, false);
|
|
}
|
|
}
|
|
return ConstantExpr::getCast(Opcode, Ops[0], DestTy);
|
|
case Instruction::IntToPtr:
|
|
// If the input is a ptrtoint, turn the pair into a ptr to ptr bitcast if
|
|
// the int size is >= the ptr size. This requires knowing the width of a
|
|
// pointer, so it can't be done in ConstantExpr::getCast.
|
|
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[0]))
|
|
if (TD &&
|
|
TD->getPointerSizeInBits() <= CE->getType()->getScalarSizeInBits() &&
|
|
CE->getOpcode() == Instruction::PtrToInt)
|
|
return FoldBitCast(CE->getOperand(0), DestTy, *TD);
|
|
|
|
return ConstantExpr::getCast(Opcode, Ops[0], DestTy);
|
|
case Instruction::Trunc:
|
|
case Instruction::ZExt:
|
|
case Instruction::SExt:
|
|
case Instruction::FPTrunc:
|
|
case Instruction::FPExt:
|
|
case Instruction::UIToFP:
|
|
case Instruction::SIToFP:
|
|
case Instruction::FPToUI:
|
|
case Instruction::FPToSI:
|
|
return ConstantExpr::getCast(Opcode, Ops[0], DestTy);
|
|
case Instruction::BitCast:
|
|
if (TD)
|
|
return FoldBitCast(Ops[0], DestTy, *TD);
|
|
return ConstantExpr::getBitCast(Ops[0], DestTy);
|
|
case Instruction::Select:
|
|
return ConstantExpr::getSelect(Ops[0], Ops[1], Ops[2]);
|
|
case Instruction::ExtractElement:
|
|
return ConstantExpr::getExtractElement(Ops[0], Ops[1]);
|
|
case Instruction::InsertElement:
|
|
return ConstantExpr::getInsertElement(Ops[0], Ops[1], Ops[2]);
|
|
case Instruction::ShuffleVector:
|
|
return ConstantExpr::getShuffleVector(Ops[0], Ops[1], Ops[2]);
|
|
case Instruction::GetElementPtr:
|
|
if (Constant *C = CastGEPIndices(Ops, NumOps, DestTy, TD))
|
|
return C;
|
|
if (Constant *C = SymbolicallyEvaluateGEP(Ops, NumOps, DestTy, TD))
|
|
return C;
|
|
|
|
return ConstantExpr::getGetElementPtr(Ops[0], Ops+1, NumOps-1);
|
|
}
|
|
}
|
|
|
|
/// ConstantFoldCompareInstOperands - Attempt to constant fold a compare
|
|
/// instruction (icmp/fcmp) with the specified operands. If it fails, it
|
|
/// returns a constant expression of the specified operands.
|
|
///
|
|
Constant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate,
|
|
Constant *Ops0, Constant *Ops1,
|
|
const TargetData *TD) {
|
|
// fold: icmp (inttoptr x), null -> icmp x, 0
|
|
// fold: icmp (ptrtoint x), 0 -> icmp x, null
|
|
// fold: icmp (inttoptr x), (inttoptr y) -> icmp trunc/zext x, trunc/zext y
|
|
// fold: icmp (ptrtoint x), (ptrtoint y) -> icmp x, y
|
|
//
|
|
// ConstantExpr::getCompare cannot do this, because it doesn't have TD
|
|
// around to know if bit truncation is happening.
|
|
if (ConstantExpr *CE0 = dyn_cast<ConstantExpr>(Ops0)) {
|
|
if (TD && Ops1->isNullValue()) {
|
|
const Type *IntPtrTy = TD->getIntPtrType(CE0->getContext());
|
|
if (CE0->getOpcode() == Instruction::IntToPtr) {
|
|
// Convert the integer value to the right size to ensure we get the
|
|
// proper extension or truncation.
|
|
Constant *C = ConstantExpr::getIntegerCast(CE0->getOperand(0),
|
|
IntPtrTy, false);
|
|
Constant *Null = Constant::getNullValue(C->getType());
|
|
return ConstantFoldCompareInstOperands(Predicate, C, Null, TD);
|
|
}
|
|
|
|
// Only do this transformation if the int is intptrty in size, otherwise
|
|
// there is a truncation or extension that we aren't modeling.
|
|
if (CE0->getOpcode() == Instruction::PtrToInt &&
|
|
CE0->getType() == IntPtrTy) {
|
|
Constant *C = CE0->getOperand(0);
|
|
Constant *Null = Constant::getNullValue(C->getType());
|
|
return ConstantFoldCompareInstOperands(Predicate, C, Null, TD);
|
|
}
|
|
}
|
|
|
|
if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(Ops1)) {
|
|
if (TD && CE0->getOpcode() == CE1->getOpcode()) {
|
|
const Type *IntPtrTy = TD->getIntPtrType(CE0->getContext());
|
|
|
|
if (CE0->getOpcode() == Instruction::IntToPtr) {
|
|
// Convert the integer value to the right size to ensure we get the
|
|
// proper extension or truncation.
|
|
Constant *C0 = ConstantExpr::getIntegerCast(CE0->getOperand(0),
|
|
IntPtrTy, false);
|
|
Constant *C1 = ConstantExpr::getIntegerCast(CE1->getOperand(0),
|
|
IntPtrTy, false);
|
|
return ConstantFoldCompareInstOperands(Predicate, C0, C1, TD);
|
|
}
|
|
|
|
// Only do this transformation if the int is intptrty in size, otherwise
|
|
// there is a truncation or extension that we aren't modeling.
|
|
if ((CE0->getOpcode() == Instruction::PtrToInt &&
|
|
CE0->getType() == IntPtrTy &&
|
|
CE0->getOperand(0)->getType() == CE1->getOperand(0)->getType()))
|
|
return ConstantFoldCompareInstOperands(Predicate, CE0->getOperand(0),
|
|
CE1->getOperand(0), TD);
|
|
}
|
|
}
|
|
|
|
// icmp eq (or x, y), 0 -> (icmp eq x, 0) & (icmp eq y, 0)
|
|
// icmp ne (or x, y), 0 -> (icmp ne x, 0) | (icmp ne y, 0)
|
|
if ((Predicate == ICmpInst::ICMP_EQ || Predicate == ICmpInst::ICMP_NE) &&
|
|
CE0->getOpcode() == Instruction::Or && Ops1->isNullValue()) {
|
|
Constant *LHS =
|
|
ConstantFoldCompareInstOperands(Predicate, CE0->getOperand(0), Ops1,TD);
|
|
Constant *RHS =
|
|
ConstantFoldCompareInstOperands(Predicate, CE0->getOperand(1), Ops1,TD);
|
|
unsigned OpC =
|
|
Predicate == ICmpInst::ICMP_EQ ? Instruction::And : Instruction::Or;
|
|
Constant *Ops[] = { LHS, RHS };
|
|
return ConstantFoldInstOperands(OpC, LHS->getType(), Ops, 2, TD);
|
|
}
|
|
}
|
|
|
|
return ConstantExpr::getCompare(Predicate, Ops0, Ops1);
|
|
}
|
|
|
|
|
|
/// ConstantFoldLoadThroughGEPConstantExpr - Given a constant and a
|
|
/// getelementptr constantexpr, return the constant value being addressed by the
|
|
/// constant expression, or null if something is funny and we can't decide.
|
|
Constant *llvm::ConstantFoldLoadThroughGEPConstantExpr(Constant *C,
|
|
ConstantExpr *CE) {
|
|
if (CE->getOperand(1) != Constant::getNullValue(CE->getOperand(1)->getType()))
|
|
return 0; // Do not allow stepping over the value!
|
|
|
|
// Loop over all of the operands, tracking down which value we are
|
|
// addressing...
|
|
gep_type_iterator I = gep_type_begin(CE), E = gep_type_end(CE);
|
|
for (++I; I != E; ++I)
|
|
if (const StructType *STy = dyn_cast<StructType>(*I)) {
|
|
ConstantInt *CU = cast<ConstantInt>(I.getOperand());
|
|
assert(CU->getZExtValue() < STy->getNumElements() &&
|
|
"Struct index out of range!");
|
|
unsigned El = (unsigned)CU->getZExtValue();
|
|
if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) {
|
|
C = CS->getOperand(El);
|
|
} else if (isa<ConstantAggregateZero>(C)) {
|
|
C = Constant::getNullValue(STy->getElementType(El));
|
|
} else if (isa<UndefValue>(C)) {
|
|
C = UndefValue::get(STy->getElementType(El));
|
|
} else {
|
|
return 0;
|
|
}
|
|
} else if (ConstantInt *CI = dyn_cast<ConstantInt>(I.getOperand())) {
|
|
if (const ArrayType *ATy = dyn_cast<ArrayType>(*I)) {
|
|
if (CI->getZExtValue() >= ATy->getNumElements())
|
|
return 0;
|
|
if (ConstantArray *CA = dyn_cast<ConstantArray>(C))
|
|
C = CA->getOperand(CI->getZExtValue());
|
|
else if (isa<ConstantAggregateZero>(C))
|
|
C = Constant::getNullValue(ATy->getElementType());
|
|
else if (isa<UndefValue>(C))
|
|
C = UndefValue::get(ATy->getElementType());
|
|
else
|
|
return 0;
|
|
} else if (const VectorType *VTy = dyn_cast<VectorType>(*I)) {
|
|
if (CI->getZExtValue() >= VTy->getNumElements())
|
|
return 0;
|
|
if (ConstantVector *CP = dyn_cast<ConstantVector>(C))
|
|
C = CP->getOperand(CI->getZExtValue());
|
|
else if (isa<ConstantAggregateZero>(C))
|
|
C = Constant::getNullValue(VTy->getElementType());
|
|
else if (isa<UndefValue>(C))
|
|
C = UndefValue::get(VTy->getElementType());
|
|
else
|
|
return 0;
|
|
} else {
|
|
return 0;
|
|
}
|
|
} else {
|
|
return 0;
|
|
}
|
|
return C;
|
|
}
|
|
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Constant Folding for Calls
|
|
//
|
|
|
|
/// canConstantFoldCallTo - Return true if its even possible to fold a call to
|
|
/// the specified function.
|
|
bool
|
|
llvm::canConstantFoldCallTo(const Function *F) {
|
|
switch (F->getIntrinsicID()) {
|
|
case Intrinsic::sqrt:
|
|
case Intrinsic::powi:
|
|
case Intrinsic::bswap:
|
|
case Intrinsic::ctpop:
|
|
case Intrinsic::ctlz:
|
|
case Intrinsic::cttz:
|
|
case Intrinsic::uadd_with_overflow:
|
|
case Intrinsic::usub_with_overflow:
|
|
case Intrinsic::sadd_with_overflow:
|
|
case Intrinsic::ssub_with_overflow:
|
|
return true;
|
|
default:
|
|
return false;
|
|
case 0: break;
|
|
}
|
|
|
|
if (!F->hasName()) return false;
|
|
StringRef Name = F->getName();
|
|
|
|
// In these cases, the check of the length is required. We don't want to
|
|
// return true for a name like "cos\0blah" which strcmp would return equal to
|
|
// "cos", but has length 8.
|
|
switch (Name[0]) {
|
|
default: return false;
|
|
case 'a':
|
|
return Name == "acos" || Name == "asin" ||
|
|
Name == "atan" || Name == "atan2";
|
|
case 'c':
|
|
return Name == "cos" || Name == "ceil" || Name == "cosf" || Name == "cosh";
|
|
case 'e':
|
|
return Name == "exp";
|
|
case 'f':
|
|
return Name == "fabs" || Name == "fmod" || Name == "floor";
|
|
case 'l':
|
|
return Name == "log" || Name == "log10";
|
|
case 'p':
|
|
return Name == "pow";
|
|
case 's':
|
|
return Name == "sin" || Name == "sinh" || Name == "sqrt" ||
|
|
Name == "sinf" || Name == "sqrtf";
|
|
case 't':
|
|
return Name == "tan" || Name == "tanh";
|
|
}
|
|
}
|
|
|
|
static Constant *ConstantFoldFP(double (*NativeFP)(double), double V,
|
|
const Type *Ty) {
|
|
errno = 0;
|
|
V = NativeFP(V);
|
|
if (errno != 0) {
|
|
errno = 0;
|
|
return 0;
|
|
}
|
|
|
|
if (Ty->isFloatTy())
|
|
return ConstantFP::get(Ty->getContext(), APFloat((float)V));
|
|
if (Ty->isDoubleTy())
|
|
return ConstantFP::get(Ty->getContext(), APFloat(V));
|
|
llvm_unreachable("Can only constant fold float/double");
|
|
return 0; // dummy return to suppress warning
|
|
}
|
|
|
|
static Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double),
|
|
double V, double W, const Type *Ty) {
|
|
errno = 0;
|
|
V = NativeFP(V, W);
|
|
if (errno != 0) {
|
|
errno = 0;
|
|
return 0;
|
|
}
|
|
|
|
if (Ty->isFloatTy())
|
|
return ConstantFP::get(Ty->getContext(), APFloat((float)V));
|
|
if (Ty->isDoubleTy())
|
|
return ConstantFP::get(Ty->getContext(), APFloat(V));
|
|
llvm_unreachable("Can only constant fold float/double");
|
|
return 0; // dummy return to suppress warning
|
|
}
|
|
|
|
/// ConstantFoldCall - Attempt to constant fold a call to the specified function
|
|
/// with the specified arguments, returning null if unsuccessful.
|
|
Constant *
|
|
llvm::ConstantFoldCall(Function *F,
|
|
Constant *const *Operands, unsigned NumOperands) {
|
|
if (!F->hasName()) return 0;
|
|
StringRef Name = F->getName();
|
|
|
|
const Type *Ty = F->getReturnType();
|
|
if (NumOperands == 1) {
|
|
if (ConstantFP *Op = dyn_cast<ConstantFP>(Operands[0])) {
|
|
if (!Ty->isFloatTy() && !Ty->isDoubleTy())
|
|
return 0;
|
|
/// Currently APFloat versions of these functions do not exist, so we use
|
|
/// the host native double versions. Float versions are not called
|
|
/// directly but for all these it is true (float)(f((double)arg)) ==
|
|
/// f(arg). Long double not supported yet.
|
|
double V = Ty->isFloatTy() ? (double)Op->getValueAPF().convertToFloat() :
|
|
Op->getValueAPF().convertToDouble();
|
|
switch (Name[0]) {
|
|
case 'a':
|
|
if (Name == "acos")
|
|
return ConstantFoldFP(acos, V, Ty);
|
|
else if (Name == "asin")
|
|
return ConstantFoldFP(asin, V, Ty);
|
|
else if (Name == "atan")
|
|
return ConstantFoldFP(atan, V, Ty);
|
|
break;
|
|
case 'c':
|
|
if (Name == "ceil")
|
|
return ConstantFoldFP(ceil, V, Ty);
|
|
else if (Name == "cos")
|
|
return ConstantFoldFP(cos, V, Ty);
|
|
else if (Name == "cosh")
|
|
return ConstantFoldFP(cosh, V, Ty);
|
|
else if (Name == "cosf")
|
|
return ConstantFoldFP(cos, V, Ty);
|
|
break;
|
|
case 'e':
|
|
if (Name == "exp")
|
|
return ConstantFoldFP(exp, V, Ty);
|
|
break;
|
|
case 'f':
|
|
if (Name == "fabs")
|
|
return ConstantFoldFP(fabs, V, Ty);
|
|
else if (Name == "floor")
|
|
return ConstantFoldFP(floor, V, Ty);
|
|
break;
|
|
case 'l':
|
|
if (Name == "log" && V > 0)
|
|
return ConstantFoldFP(log, V, Ty);
|
|
else if (Name == "log10" && V > 0)
|
|
return ConstantFoldFP(log10, V, Ty);
|
|
else if (Name == "llvm.sqrt.f32" ||
|
|
Name == "llvm.sqrt.f64") {
|
|
if (V >= -0.0)
|
|
return ConstantFoldFP(sqrt, V, Ty);
|
|
else // Undefined
|
|
return Constant::getNullValue(Ty);
|
|
}
|
|
break;
|
|
case 's':
|
|
if (Name == "sin")
|
|
return ConstantFoldFP(sin, V, Ty);
|
|
else if (Name == "sinh")
|
|
return ConstantFoldFP(sinh, V, Ty);
|
|
else if (Name == "sqrt" && V >= 0)
|
|
return ConstantFoldFP(sqrt, V, Ty);
|
|
else if (Name == "sqrtf" && V >= 0)
|
|
return ConstantFoldFP(sqrt, V, Ty);
|
|
else if (Name == "sinf")
|
|
return ConstantFoldFP(sin, V, Ty);
|
|
break;
|
|
case 't':
|
|
if (Name == "tan")
|
|
return ConstantFoldFP(tan, V, Ty);
|
|
else if (Name == "tanh")
|
|
return ConstantFoldFP(tanh, V, Ty);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
if (ConstantInt *Op = dyn_cast<ConstantInt>(Operands[0])) {
|
|
if (Name.startswith("llvm.bswap"))
|
|
return ConstantInt::get(F->getContext(), Op->getValue().byteSwap());
|
|
else if (Name.startswith("llvm.ctpop"))
|
|
return ConstantInt::get(Ty, Op->getValue().countPopulation());
|
|
else if (Name.startswith("llvm.cttz"))
|
|
return ConstantInt::get(Ty, Op->getValue().countTrailingZeros());
|
|
else if (Name.startswith("llvm.ctlz"))
|
|
return ConstantInt::get(Ty, Op->getValue().countLeadingZeros());
|
|
return 0;
|
|
}
|
|
|
|
if (isa<UndefValue>(Operands[0])) {
|
|
if (Name.startswith("llvm.bswap"))
|
|
return Operands[0];
|
|
return 0;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
if (NumOperands == 2) {
|
|
if (ConstantFP *Op1 = dyn_cast<ConstantFP>(Operands[0])) {
|
|
if (!Ty->isFloatTy() && !Ty->isDoubleTy())
|
|
return 0;
|
|
double Op1V = Ty->isFloatTy() ?
|
|
(double)Op1->getValueAPF().convertToFloat() :
|
|
Op1->getValueAPF().convertToDouble();
|
|
if (ConstantFP *Op2 = dyn_cast<ConstantFP>(Operands[1])) {
|
|
if (Op2->getType() != Op1->getType())
|
|
return 0;
|
|
|
|
double Op2V = Ty->isFloatTy() ?
|
|
(double)Op2->getValueAPF().convertToFloat():
|
|
Op2->getValueAPF().convertToDouble();
|
|
|
|
if (Name == "pow")
|
|
return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty);
|
|
if (Name == "fmod")
|
|
return ConstantFoldBinaryFP(fmod, Op1V, Op2V, Ty);
|
|
if (Name == "atan2")
|
|
return ConstantFoldBinaryFP(atan2, Op1V, Op2V, Ty);
|
|
} else if (ConstantInt *Op2C = dyn_cast<ConstantInt>(Operands[1])) {
|
|
if (Name == "llvm.powi.f32")
|
|
return ConstantFP::get(F->getContext(),
|
|
APFloat((float)std::pow((float)Op1V,
|
|
(int)Op2C->getZExtValue())));
|
|
if (Name == "llvm.powi.f64")
|
|
return ConstantFP::get(F->getContext(),
|
|
APFloat((double)std::pow((double)Op1V,
|
|
(int)Op2C->getZExtValue())));
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
if (ConstantInt *Op1 = dyn_cast<ConstantInt>(Operands[0])) {
|
|
if (ConstantInt *Op2 = dyn_cast<ConstantInt>(Operands[1])) {
|
|
switch (F->getIntrinsicID()) {
|
|
default: break;
|
|
case Intrinsic::uadd_with_overflow: {
|
|
Constant *Res = ConstantExpr::getAdd(Op1, Op2); // result.
|
|
Constant *Ops[] = {
|
|
Res, ConstantExpr::getICmp(CmpInst::ICMP_ULT, Res, Op1) // overflow.
|
|
};
|
|
return ConstantStruct::get(F->getContext(), Ops, 2, false);
|
|
}
|
|
case Intrinsic::usub_with_overflow: {
|
|
Constant *Res = ConstantExpr::getSub(Op1, Op2); // result.
|
|
Constant *Ops[] = {
|
|
Res, ConstantExpr::getICmp(CmpInst::ICMP_UGT, Res, Op1) // overflow.
|
|
};
|
|
return ConstantStruct::get(F->getContext(), Ops, 2, false);
|
|
}
|
|
case Intrinsic::sadd_with_overflow: {
|
|
Constant *Res = ConstantExpr::getAdd(Op1, Op2); // result.
|
|
Constant *Overflow = ConstantExpr::getSelect(
|
|
ConstantExpr::getICmp(CmpInst::ICMP_SGT,
|
|
ConstantInt::get(Op1->getType(), 0), Op1),
|
|
ConstantExpr::getICmp(CmpInst::ICMP_SGT, Res, Op2),
|
|
ConstantExpr::getICmp(CmpInst::ICMP_SLT, Res, Op2)); // overflow.
|
|
|
|
Constant *Ops[] = { Res, Overflow };
|
|
return ConstantStruct::get(F->getContext(), Ops, 2, false);
|
|
}
|
|
case Intrinsic::ssub_with_overflow: {
|
|
Constant *Res = ConstantExpr::getSub(Op1, Op2); // result.
|
|
Constant *Overflow = ConstantExpr::getSelect(
|
|
ConstantExpr::getICmp(CmpInst::ICMP_SGT,
|
|
ConstantInt::get(Op2->getType(), 0), Op2),
|
|
ConstantExpr::getICmp(CmpInst::ICMP_SLT, Res, Op1),
|
|
ConstantExpr::getICmp(CmpInst::ICMP_SGT, Res, Op1)); // overflow.
|
|
|
|
Constant *Ops[] = { Res, Overflow };
|
|
return ConstantStruct::get(F->getContext(), Ops, 2, false);
|
|
}
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
return 0;
|
|
}
|
|
return 0;
|
|
}
|
|
|