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-rw-r--r--lib/Transforms/Scalar/ScalarReplAggregates.cpp61
1 files changed, 27 insertions, 34 deletions
diff --git a/lib/Transforms/Scalar/ScalarReplAggregates.cpp b/lib/Transforms/Scalar/ScalarReplAggregates.cpp
index e0674492f8..ec298e7316 100644
--- a/lib/Transforms/Scalar/ScalarReplAggregates.cpp
+++ b/lib/Transforms/Scalar/ScalarReplAggregates.cpp
@@ -1676,46 +1676,39 @@ void SROA::RewriteLoadUserOfWholeAlloca(LoadInst *LI, AllocaInst *AI,
}
/// HasPadding - Return true if the specified type has any structure or
-/// alignment padding, false otherwise.
+/// alignment padding in between the elements that would be split apart
+/// by SROA; return false otherwise.
static bool HasPadding(const Type *Ty, const TargetData &TD) {
- if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty))
- return HasPadding(ATy->getElementType(), TD);
-
- if (const VectorType *VTy = dyn_cast<VectorType>(Ty))
- return HasPadding(VTy->getElementType(), TD);
-
- if (const StructType *STy = dyn_cast<StructType>(Ty)) {
- const StructLayout *SL = TD.getStructLayout(STy);
- unsigned PrevFieldBitOffset = 0;
- for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
- unsigned FieldBitOffset = SL->getElementOffsetInBits(i);
-
- // Padding in sub-elements?
- if (HasPadding(STy->getElementType(i), TD))
- return true;
+ if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
+ Ty = ATy->getElementType();
+ return TD.getTypeSizeInBits(Ty) != TD.getTypeAllocSizeInBits(Ty);
+ }
- // Check to see if there is any padding between this element and the
- // previous one.
- if (i) {
- unsigned PrevFieldEnd =
+ // SROA currently handles only Arrays and Structs.
+ const StructType *STy = cast<StructType>(Ty);
+ const StructLayout *SL = TD.getStructLayout(STy);
+ unsigned PrevFieldBitOffset = 0;
+ for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
+ unsigned FieldBitOffset = SL->getElementOffsetInBits(i);
+
+ // Check to see if there is any padding between this element and the
+ // previous one.
+ if (i) {
+ unsigned PrevFieldEnd =
PrevFieldBitOffset+TD.getTypeSizeInBits(STy->getElementType(i-1));
- if (PrevFieldEnd < FieldBitOffset)
- return true;
- }
-
- PrevFieldBitOffset = FieldBitOffset;
- }
-
- // Check for tail padding.
- if (unsigned EltCount = STy->getNumElements()) {
- unsigned PrevFieldEnd = PrevFieldBitOffset +
- TD.getTypeSizeInBits(STy->getElementType(EltCount-1));
- if (PrevFieldEnd < SL->getSizeInBits())
+ if (PrevFieldEnd < FieldBitOffset)
return true;
}
+ PrevFieldBitOffset = FieldBitOffset;
}
-
- return TD.getTypeSizeInBits(Ty) != TD.getTypeAllocSizeInBits(Ty);
+ // Check for tail padding.
+ if (unsigned EltCount = STy->getNumElements()) {
+ unsigned PrevFieldEnd = PrevFieldBitOffset +
+ TD.getTypeSizeInBits(STy->getElementType(EltCount-1));
+ if (PrevFieldEnd < SL->getSizeInBits())
+ return true;
+ }
+ return false;
}
/// isSafeStructAllocaToScalarRepl - Check to see if the specified allocation of