Author: evancheng
Date: Mon Jan 28 03:49:51 2008
New Revision: 46450
URL: http://llvm.org/viewvc/llvm-project?rev=46450&view=rev
Log:
1. Only skip over zero sized bit fields which just affects layout, not all
zero-sized aggregates.
2. Do not pass zero sized struct and union parameters.
Modified:
llvm-gcc-4.2/trunk/gcc/llvm-abi.h
llvm-gcc-4.2/trunk/gcc/llvm-internal.h
llvm-gcc-4.2/trunk/gcc/llvm-types.cpp
Modified: llvm-gcc-4.2/trunk/gcc/llvm-abi.h
URL:
http://llvm.org/viewvc/llvm-project/llvm-gcc-4.2/trunk/gcc/llvm-abi.h?rev=46450&r1=46449&r2=46450&view=diff
==============================================================================
--- llvm-gcc-4.2/trunk/gcc/llvm-abi.h (original)
+++ llvm-gcc-4.2/trunk/gcc/llvm-abi.h Mon Jan 28 03:49:51 2008
@@ -120,6 +120,14 @@
}
}
+/// isZeroSizedStructOrUnion - Returns true if this is a struct or union
+/// which is zero bits wide.
+static bool isZeroSizedStructOrUnion(tree type) {
+ if (TREE_CODE(type) != RECORD_TYPE && TREE_CODE(type) != UNION_TYPE)
+ return false;
+ return int_size_in_bytes(type) == 0;
+}
+
// LLVM_SHOULD_PASS_AGGREGATE_USING_BYVAL_ATTR - Return true if this aggregate
// value should be passed by value, i.e. passing its address with the byval
// attribute bit set. The default is false.
@@ -212,6 +220,8 @@
/// their fields.
void HandleArgument(tree type, uint16_t *Attributes = NULL) {
const Type *Ty = ConvertType(type);
+ // Figure out if this field is zero bits wide, e.g. {} or [0 x int]. Do
+ // not include variable sized fields here.
std::vector<const Type*> Elts;
if (isPassedByInvisibleReference(type)) { // variable size -> by-ref.
C.HandleScalarArgument(PointerType::getUnqual(Ty), type);
@@ -225,8 +235,8 @@
*Attributes |= ParamAttr::ByVal;
} else if (LLVM_SHOULD_PASS_AGGREGATE_IN_INTEGER_REGS(type)) {
PassInIntegerRegisters(type, Ty);
- } else if (isAggregateOfSizeZero(type)) {
- // Zero sized aggregate, just drop it!
+ } else if (isZeroSizedStructOrUnion(type)) {
+ // Zero sized struct or union, just drop it!
;
} else if (TREE_CODE(type) == RECORD_TYPE) {
for (tree Field = TYPE_FIELDS(type); Field; Field = TREE_CHAIN(Field))
Modified: llvm-gcc-4.2/trunk/gcc/llvm-internal.h
URL:
http://llvm.org/viewvc/llvm-project/llvm-gcc-4.2/trunk/gcc/llvm-internal.h?rev=46450&r1=46449&r2=46450&view=diff
==============================================================================
--- llvm-gcc-4.2/trunk/gcc/llvm-internal.h (original)
+++ llvm-gcc-4.2/trunk/gcc/llvm-internal.h Mon Jan 28 03:49:51 2008
@@ -118,10 +118,6 @@
/// element added to match llvm struct type size and gcc struct type size.
bool isPaddingElement(const Type *T, unsigned N);
-/// isAggregateOfSizeZero - Returns true if this is an aggregate with size
zero.
-///
-bool isAggregateOfSizeZero(union tree_node*);
-
/// TypeConverter - Implement the converter from GCC types to LLVM types.
///
class TypeConverter {
Modified: llvm-gcc-4.2/trunk/gcc/llvm-types.cpp
URL:
http://llvm.org/viewvc/llvm-project/llvm-gcc-4.2/trunk/gcc/llvm-types.cpp?rev=46450&r1=46449&r2=46450&view=diff
==============================================================================
--- llvm-gcc-4.2/trunk/gcc/llvm-types.cpp (original)
+++ llvm-gcc-4.2/trunk/gcc/llvm-types.cpp Mon Jan 28 03:49:51 2008
@@ -1612,14 +1612,6 @@
}
-/// isAggregateOfSizeZero - Returns true if this is an aggregate with size
zero.
-///
-bool isAggregateOfSizeZero(tree type) {
- if (!isAggregateTreeType(type)) return false;
- return int_size_in_bytes(type) == 0;
-}
-
-
/// Mapping from type to type-used-as-base-class and back.
static DenseMap<tree, tree> BaseTypesMap;
@@ -2054,9 +2046,6 @@
unsigned FieldOffsetInBits = getFieldOffsetInBits(Field);
tree FieldType = getDeclaredType(Field);
- if (isAggregateOfSizeZero(FieldType))
- continue;
-
// If this is a bitfield, we may want to adjust the FieldOffsetInBits to
// produce safe code. In particular, bitfields will be loaded/stored as
// their *declared* type, not the smallest integer type that contains
@@ -2071,6 +2060,11 @@
// because the FieldOffsetInBits can be lower than it was in the
// previous iteration.
CurFieldNo = 0;
+
+ // Skip 'int:0', which just affects layout.
+ unsigned FieldSizeInBits = TREE_INT_CST_LOW(DECL_SIZE(Field));
+ if (FieldSizeInBits == 0)
+ continue;
}
// Figure out if this field is zero bits wide, e.g. {} or [0 x int]. Do
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