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Remove TargetBaseAlign. Keep alignment for stack adjustments.

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Summary:
TargetBaseAlign is no longer required since LSV checks if target allows misaligned accesses.
A constant defining a base alignment is still needed for stack accesses where alignment can be adjusted.

Reviewers: llvm-commits, jlebar

Subscribers: mzolotukhin, arsenm

Differential Revision: https://reviews.llvm.org/D22936

llvm-svn: 277038
This commit is contained in:
Alina Sbirlea
2016-07-28 21:26:40 +00:00
parent 56fdf0d97e
commit 7116eb6e16
1 changed files with 9 additions and 10 deletions
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19
llvm/lib/Transforms/Vectorize/LoadStoreVectorizer.cpp
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@@ -40,9 +40,8 @@ STATISTIC(NumScalarsVectorized, "Number of scalar accesses vectorized");
namespace {
// TODO: Remove this
static const unsigned TargetBaseAlign = 4;
// FIXME: Assuming stack alignment of 4 is always good enough
static const unsigned StackAdjustedAlignment = 4;
typedef SmallVector<Instruction *, 8> InstrList;
typedef MapVector<Value *, InstrList> InstrListMap;
@@ -798,8 +797,8 @@ bool Vectorizer::vectorizeStoreChain(
// so we can cheat and change it!
Value *V = GetUnderlyingObject(S0->getPointerOperand(), DL);
if (AllocaInst *AI = dyn_cast_or_null<AllocaInst>(V)) {
AI->setAlignment(TargetBaseAlign);
Alignment = TargetBaseAlign;
AI->setAlignment(StackAdjustedAlignment);
Alignment = StackAdjustedAlignment;
} else {
return false;
}
@@ -948,8 +947,8 @@ bool Vectorizer::vectorizeLoadChain(
// so we can cheat and change it!
Value *V = GetUnderlyingObject(L0->getPointerOperand(), DL);
if (AllocaInst *AI = dyn_cast_or_null<AllocaInst>(V)) {
AI->setAlignment(TargetBaseAlign);
Alignment = TargetBaseAlign;
AI->setAlignment(StackAdjustedAlignment);
Alignment = StackAdjustedAlignment;
} else {
return false;
}
@@ -1029,10 +1028,10 @@ bool Vectorizer::vectorizeLoadChain(
bool Vectorizer::accessIsMisaligned(unsigned SzInBytes, unsigned AddressSpace,
unsigned Alignment) {
if (Alignment % SzInBytes == 0)
return false;
bool Fast = false;
bool Allows = TTI.allowsMisalignedMemoryAccesses(SzInBytes * 8, AddressSpace,
Alignment, &Fast);
// TODO: Remove TargetBaseAlign
return !(Allows && Fast) && (Alignment % SzInBytes) != 0 &&
(Alignment % TargetBaseAlign) != 0;
return !Allows || !Fast;
}