joncampbell123/dosbox-x
1
0
Fork 0
mirror of https://github.com/joncampbell123/dosbox-x.git synced 2025-10-13 17:48:10 +08:00
Code Issues Packages Projects Releases Wiki Activity

Use offsetof to ensure MMX union packing is as expected

Browse Source
This commit is contained in:
Jonathan Campbell
2021-11-23 13:52:21 -08:00
parent b8ef06d410
commit affa499ce9
1 changed files with 7 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
include/mmx.h
View File

@@ -21,6 +21,8 @@
#if C_FPU
#include <stddef.h>
typedef union {
uint64_t q;
@@ -36,13 +38,17 @@ typedef union {
} sd;
static_assert(sizeof(sd) == 8, "MMX packing error");
struct {
struct uw_t {
uint16_t w0,w1,w2,w3;
} uw;
static_assert(sizeof(uw) == 8, "MMX packing error");
uint16_t uwa[4]; /* for PSHUFW */
static_assert(sizeof(uwa) == 8, "MMX packing error");
static_assert(offsetof(uw_t,w0) == 0, "MMX packing error");
static_assert(offsetof(uw_t,w1) == 2, "MMX packing error");
static_assert(offsetof(uw_t,w2) == 4, "MMX packing error");
static_assert(offsetof(uw_t,w3) == 6, "MMX packing error");
struct {
int16_t w0,w1,w2,w3;