gallium: Make pipe_viewport_state swizzle_x/y/z/w bit-fields 8 bits wide
Previously there were 20 padding bits after them, which would be left
uninitialized and preserved when writing to the swizzle members. This
could result in two equal viewport states spuriously being considered
different (because memcmp compared the padding bits as well).
Noticed while looking for something else with valgrind:
==801624== Conditional jump or move depends on uninitialised value(s)
==801624== at 0x10B86259: cso_set_viewport (cso_context.c:739)
==801624== by 0x10B862C7: cso_set_viewport_dims (cso_context.c:764)
==801624== by 0x1057E3A1: clear_with_quad (st_cb_clear.c:335)
==801624== by 0x1057E3A1: st_Clear (st_cb_clear.c:545)
==801624== [...]
==801624==
==801624== Conditional jump or move depends on uninitialised value(s)
==801624== at 0x10B885DE: cso_restore_viewport (cso_context.c:777)
==801624== by 0x10B885DE: cso_restore_state (cso_context.c:1710)
==801624== by 0x1057E4CB: clear_with_quad (st_cb_clear.c:364)
==801624== by 0x1057E4CB: st_Clear (st_cb_clear.c:545)
==801624== [...]
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6867>
diff --git a/src/gallium/include/pipe/p_state.h b/src/gallium/include/pipe/p_state.h
index 7acb79d..1d907bd 100644
--- a/src/gallium/include/pipe/p_state.h
+++ b/src/gallium/include/pipe/p_state.h
@@ -213,10 +213,10 @@
{
float scale[3];
float translate[3];
- enum pipe_viewport_swizzle swizzle_x:3;
- enum pipe_viewport_swizzle swizzle_y:3;
- enum pipe_viewport_swizzle swizzle_z:3;
- enum pipe_viewport_swizzle swizzle_w:3;
+ enum pipe_viewport_swizzle swizzle_x:8;
+ enum pipe_viewport_swizzle swizzle_y:8;
+ enum pipe_viewport_swizzle swizzle_z:8;
+ enum pipe_viewport_swizzle swizzle_w:8;
};
