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llvm-mirror/lib/IR/Operator.cpp
Sander de Smalen 11d1f1de44 [InstCombine] GEPOperator::accumulateConstantOffset does not support scalable vectors
Avoid transforming:

 %0 = bitcast i8* %base to <vscale x 16 x i8>*
 %1 = getelementptr <vscale x 16 x i8>, <vscale x 16 x i8>* %0, i64 1

into:

 %0 = getelementptr i8, i8* %base, i64 16
 %1 = bitcast i8* %0 to <vscale x 16 x i8>*

Reviewers: efriedma, ctetreau

Reviewed By: efriedma

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D76236
2020-03-18 14:58:46 +00:00

69 lines
2.5 KiB
C++

//===-- Operator.cpp - Implement the LLVM operators -----------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements the non-inline methods for the LLVM Operator classes.
//
//===----------------------------------------------------------------------===//
#include "llvm/IR/Operator.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/GetElementPtrTypeIterator.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Type.h"
#include "ConstantsContext.h"
namespace llvm {
Type *GEPOperator::getSourceElementType() const {
if (auto *I = dyn_cast<GetElementPtrInst>(this))
return I->getSourceElementType();
return cast<GetElementPtrConstantExpr>(this)->getSourceElementType();
}
Type *GEPOperator::getResultElementType() const {
if (auto *I = dyn_cast<GetElementPtrInst>(this))
return I->getResultElementType();
return cast<GetElementPtrConstantExpr>(this)->getResultElementType();
}
bool GEPOperator::accumulateConstantOffset(const DataLayout &DL,
APInt &Offset) const {
assert(Offset.getBitWidth() ==
DL.getIndexSizeInBits(getPointerAddressSpace()) &&
"The offset bit width does not match DL specification.");
for (gep_type_iterator GTI = gep_type_begin(this), GTE = gep_type_end(this);
GTI != GTE; ++GTI) {
ConstantInt *OpC = dyn_cast<ConstantInt>(GTI.getOperand());
if (!OpC)
return false;
if (OpC->isZero())
continue;
// Scalable vectors have are multiplied by a runtime constant.
if (auto *VecTy = dyn_cast<VectorType>(GTI.getIndexedType()))
if (VecTy->isScalable())
return false;
// Handle a struct index, which adds its field offset to the pointer.
if (StructType *STy = GTI.getStructTypeOrNull()) {
unsigned ElementIdx = OpC->getZExtValue();
const StructLayout *SL = DL.getStructLayout(STy);
Offset += APInt(Offset.getBitWidth(), SL->getElementOffset(ElementIdx));
continue;
}
// For array or vector indices, scale the index by the size of the type.
APInt Index = OpC->getValue().sextOrTrunc(Offset.getBitWidth());
Offset += Index * APInt(Offset.getBitWidth(),
DL.getTypeAllocSize(GTI.getIndexedType()));
}
return true;
}
}