2012/2/27 Joseph S. Myers <jos...@codesourcery.com>:
> On Mon, 27 Feb 2012, Kai Tietz wrote:
>
>> For gcc_struct variant bitfields with different types get merged
>> together, but for ms_struct bitfields are getting merged together
>> only, if they have same type. As in those structures - I modified in
>> this patch - we have varying types for bitfields, this struct-layout
>> attribute is required.
>
> I think you need a comment in soft-fp.h explaining the issue (and in
> particular that it is about structures with consecutive (?) bit-fields
> with different declared types). Though I presume the attribute is
> harmless on other structures - so it might make sense to put it in
> single.h and double.h as well to make it clear that those structures too
> are expected to follow the same layout rules as those in extended.h and
> quad.h.
Ok. Done. Here is the patch for glibc only
ChangeLog glibc
2012-02-28 Kai Tietz <kti...@redhat.com>
* soft-fp/soft-fp.h (_FP_STRUCT_LAYOUT): If not defined,
define it as empty macro.
* soft-fp/quad.h: Mark bitfield-structures by _FP_STRUCT_LAYOUT.
* soft-fp/extended.h: Likewise.
* soft-fp/single.h: Likewise.
* soft-fp/double.h: Likewise.
Ok for apply?
Regards,
Kai
Index: soft-fp/extended.h
===================================================================
--- soft-fp/extended.h (revision 184486)
+++ soft-fp/extended.h (working copy)
@@ -64,7 +64,7 @@
union _FP_UNION_E
{
XFtype flt;
- struct
+ struct _FP_STRUCT_LAYOUT
{
#if __BYTE_ORDER == __BIG_ENDIAN
unsigned long pad1 : _FP_W_TYPE_SIZE;
@@ -263,7 +263,7 @@
union _FP_UNION_E
{
XFtype flt;
- struct {
+ struct _FP_STRUCT_LAYOUT {
#if __BYTE_ORDER == __BIG_ENDIAN
_FP_W_TYPE pad : (_FP_W_TYPE_SIZE - 1 - _FP_EXPBITS_E);
unsigned sign : 1;
Index: soft-fp/single.h
===================================================================
--- soft-fp/single.h (revision 184486)
+++ soft-fp/single.h (working copy)
@@ -58,7 +58,7 @@
union _FP_UNION_S
{
SFtype flt;
- struct {
+ struct _FP_STRUCT_LAYOUT {
#if __BYTE_ORDER == __BIG_ENDIAN
unsigned sign : 1;
unsigned exp : _FP_EXPBITS_S;
Index: soft-fp/double.h
===================================================================
--- soft-fp/double.h (revision 184486)
+++ soft-fp/double.h (working copy)
@@ -68,7 +68,7 @@
union _FP_UNION_D
{
DFtype flt;
- struct {
+ struct _FP_STRUCT_LAYOUT {
#if __BYTE_ORDER == __BIG_ENDIAN
unsigned sign : 1;
unsigned exp : _FP_EXPBITS_D;
@@ -167,7 +167,7 @@
union _FP_UNION_D
{
DFtype flt;
- struct {
+ struct _FP_STRUCT_LAYOUT {
#if __BYTE_ORDER == __BIG_ENDIAN
unsigned sign : 1;
unsigned exp : _FP_EXPBITS_D;
Index: soft-fp/quad.h
===================================================================
--- soft-fp/quad.h (revision 184486)
+++ soft-fp/quad.h (working copy)
@@ -67,7 +67,7 @@
union _FP_UNION_Q
{
TFtype flt;
- struct
+ struct _FP_STRUCT_LAYOUT
{
#if __BYTE_ORDER == __BIG_ENDIAN
unsigned sign : 1;
@@ -171,10 +171,11 @@
union _FP_UNION_Q
{
TFtype flt /* __attribute__((mode(TF))) */ ;
- struct {
+ struct _FP_STRUCT_LAYOUT {
_FP_W_TYPE a, b;
} longs;
- struct {
+ struct _FP_STRUCT_LAYOUT
+ {
#if __BYTE_ORDER == __BIG_ENDIAN
unsigned sign : 1;
unsigned exp : _FP_EXPBITS_Q;
Index: soft-fp/soft-fp.h
===================================================================
--- soft-fp/soft-fp.h (revision 184486)
+++ soft-fp/soft-fp.h (working copy)
@@ -85,6 +85,14 @@
#define FP_EX_DENORM 0
#endif
+/* For native windows targets struct-layout follows the ms-bitfields
+ layout. For unix-targets instead the gcc-struct-layout is used.
+ The difference between ms/gcc struct-layout is in consecutive bit-fields
+ with different declared types, which are getting packed different. */
+#ifndef _FP_STRUCT_LAYOUT
+#define _FP_STRUCT_LAYOUT
+#endif
+
#ifdef _FP_DECL_EX
#define FP_DECL_EX \
int _fex = 0; \
