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llvm-mirror/lib/IR/Operator.cpp
Eduard Burtescu c55147fcdc [opaque pointer types] [NFC] GEP: replace get(Pointer)ElementType uses with get{Source,Result}ElementType.
Summary:
GEPOperator: provide getResultElementType alongside getSourceElementType.
This is made possible by adding a result element type field to GetElementPtrConstantExpr, which GetElementPtrInst already has.

GEP: replace get(Pointer)ElementType uses with get{Source,Result}ElementType.

Reviewers: mjacob, dblaikie

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D16275

llvm-svn: 258145
2016-01-19 17:28:00 +00:00

51 lines
1.7 KiB
C++

#include "llvm/IR/Operator.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.getPointerSizeInBits(getPointerAddressSpace()) &&
"The offset must have exactly as many bits as our pointer.");
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;
// Handle a struct index, which adds its field offset to the pointer.
if (StructType *STy = dyn_cast<StructType>(*GTI)) {
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;
}
}