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CodeGen: Cleanup CGRecordLowering::lowerUnion a little 

Remove some duplicated state, no functionality change intended.

llvm-svn: 219805
This commit is contained in:
David Majnemer 2014-10-15 16:36:11 +00:00
parent 473e7fdb08
commit 8476abe288
1 changed files with 7 additions and 7 deletions
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12
clang/lib/CodeGen/CGRecordLayoutBuilder.cpp
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@ -280,10 +280,6 @@ void CGRecordLowering::lowerUnion() {
CharUnits LayoutSize = Layout.getSize();
llvm::Type *StorageType = nullptr;
bool SeenNamedMember = false;
bool InitializingMemberIsNonZero = false;
// Compute zero-initializable status.
if (!D->field_empty() && !isZeroInitializable(*D->field_begin()))
IsZeroInitializable = IsZeroInitializableAsBase = false;
// Iterate through the fields setting bitFieldInfo and the Fields array. Also
// locate the "most appropriate" storage type. The heuristic for finding the
// storage type isn't necessary, the first (non-0-length-bitfield) field's
@ -301,6 +297,7 @@ void CGRecordLowering::lowerUnion() {
}
Fields[Field->getCanonicalDecl()] = 0;
llvm::Type *FieldType = getStorageType(Field);
// Compute zero-initializable status.
// This union might not be zero initialized: it may contain a pointer to
// data member which might have some exotic initialization sequence.
// If this is the case, then we aught not to try and come up with a "better"
@ -309,16 +306,19 @@ void CGRecordLowering::lowerUnion() {
if (!SeenNamedMember && Field->getDeclName()) {
SeenNamedMember = true;
if (!isZeroInitializable(Field)) {
InitializingMemberIsNonZero = true;
IsZeroInitializable = IsZeroInitializableAsBase = false;
StorageType = FieldType;
}
}
// Because our union isn't zero initializable, we won't be getting a better
// storage type.
if (!IsZeroInitializable)
continue;
// Conditionally update our storage type if we've got a new "better" one.
if (!StorageType ||
getAlignment(FieldType) > getAlignment(StorageType) ||
(getAlignment(FieldType) == getAlignment(StorageType) &&
getSize(FieldType) > getSize(StorageType)))
if (!InitializingMemberIsNonZero)
StorageType = FieldType;
}
// If we have no storage type just pad to the appropriate size and return.