Before, via pahole:
arm32, a 32-bit host which aligns uint64_t:
struct Property {
const char * name; /* 0 4 */
const PropertyInfo * info; /* 4 4 */
ptrdiff_t offset; /* 8 4 */
uint8_t bitnr; /* 12 1 */
/* XXX 3 bytes hole, try to pack */
uint64_t bitmask; /* 16 8 */
_Bool set_default; /* 24 1 */
/* XXX 7 bytes hole, try to pack */
union {
int64_t i; /* 32 8 */
uint64_t u; /* 32 8 */
} defval; /* 32 8 */
int arrayoffset; /* 40 4 */
const PropertyInfo * arrayinfo; /* 44 4 */
int arrayfieldsize; /* 48 4 */
const char * link_type; /* 52 4 */
/* size: 56, cachelines: 1, members: 11 */
/* sum members: 46, holes: 2, sum holes: 10 */
};
arm64, an arbitrary 64-bit host:
struct Property {
const char * name; /* 0 8 */
const PropertyInfo * info; /* 8 8 */
ptrdiff_t offset; /* 16 8 */
uint8_t bitnr; /* 24 1 */
/* XXX 7 bytes hole, try to pack */
uint64_t bitmask; /* 32 8 */
_Bool set_default; /* 40 1 */
/* XXX 7 bytes hole, try to pack */
union {
int64_t i; /* 48 8 */
uint64_t u; /* 48 8 */
} defval; /* 48 8 */
int arrayoffset; /* 56 4 */
/* XXX 4 bytes hole, try to pack */
const PropertyInfo * arrayinfo; /* 64 8 */
int arrayfieldsize; /* 72 4 */
/* XXX 4 bytes hole, try to pack */
const char * link_type; /* 80 8 */
/* size: 88, cachelines: 2, members: 11 */
/* sum members: 66, holes: 4, sum holes: 22 */
};
Afterward there are no holes in either structure.
For arm32, size 48, padding 2, saved 8 bytes.
For arm64, size 72, padding 6, saved 16 bytes.
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
include/hw/qdev-properties.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/include/hw/qdev-properties.h b/include/hw/qdev-properties.h
index 26ebd23068..1d154c1f23 100644
--- a/include/hw/qdev-properties.h
+++ b/include/hw/qdev-properties.h
@@ -16,17 +16,17 @@ struct Property {
const char *name;
const PropertyInfo *info;
ptrdiff_t offset;
- uint8_t bitnr;
+ const char *link_type;
uint64_t bitmask;
- bool set_default;
union {
int64_t i;
uint64_t u;
} defval;
- int arrayoffset;
const PropertyInfo *arrayinfo;
+ int arrayoffset;
int arrayfieldsize;
- const char *link_type;
+ uint8_t bitnr;
+ bool set_default;
};
struct PropertyInfo {
--
2.43.0
