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Simplify alignment handling in the record builder. 

llvm-svn: 78069
This commit is contained in:
Anders Carlsson 2009-08-04 16:29:15 +00:00
parent f222054df7
commit 19702bb054
1 changed files with 19 additions and 13 deletions
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32
clang/lib/CodeGen/CGRecordLayoutBuilder.cpp
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@ -117,22 +117,28 @@ bool CGRecordLayoutBuilder::LayoutField(const FieldDecl *D,
return true;
}
const llvm::Type *Ty = Types.ConvertTypeForMemRecursive(D->getType());
// Check if the field is aligned.
if (const AlignedAttr *PA = D->getAttr<AlignedAttr>()) {
unsigned FieldAlign = PA->getAlignment();
if (!Packed && getTypeAlignment(Ty) > FieldAlign)
return false;
}
assert(FieldOffset % 8 == 0 && "FieldOffset is not on a byte boundary!");
uint64_t FieldOffsetInBytes = FieldOffset / 8;
// Append padding if necessary.
AppendPadding(FieldOffsetInBytes, Ty);
const llvm::Type *Ty = Types.ConvertTypeForMemRecursive(D->getType());
unsigned TypeAlignment = getTypeAlignment(Ty);
// Round up the field offset to the alignment of the field type.
uint64_t AlignedNextFieldOffsetInBytes =
llvm::RoundUpToAlignment(NextFieldOffsetInBytes, TypeAlignment);
if (FieldOffsetInBytes < AlignedNextFieldOffsetInBytes) {
assert(!Packed && "Could not place field even with packed struct!");
return false;
}
if (AlignedNextFieldOffsetInBytes < FieldOffsetInBytes) {
// Even with alignment, the field offset is not at the right place,
// insert padding.
uint64_t PaddingInBytes = FieldOffsetInBytes - NextFieldOffsetInBytes;
AppendBytes(PaddingInBytes);
}
// Now append the field.
LLVMFields.push_back(LLVMFieldInfo(D, FieldTypes.size()));