gallium: fix more potential strict aliasing issues

In particular, gcc man page warns that
union a_union {
   int i;
   double d;
};

int f() {
   double d = 3.0;
   return ((union a_union *) &d)->i;
}

"might" not be ok (why not?), even though it doesn't seem to generate
any warnings. Hence don't use this and do the extra step to actually use
assignment to get the values in/out of the union.
This changes parts of 3456f9149b3009fcfce80054759d05883d3c4ee5.

1 files changed, 6 insertions, 4 deletions

diff --git a/src/gallium/drivers/r300/r300_state.c b/src/gallium/drivers/r300/r300_state.c
index 4ddbb357b6e..a83075df92f 100644
--- a/src/gallium/drivers/r300/r300_state.c
+++ b/src/gallium/drivers/r300/r300_state.c
@@ -151,9 +151,10 @@ static void r300_set_blend_color(struct pipe_context* pipe,
                                  const struct pipe_blend_color* color)
 {
     struct r300_context* r300 = r300_context(pipe);
+    union util_color uc;
 
-    util_pack_color(color->color, PIPE_FORMAT_A8R8G8B8_UNORM,
-            (union util_color *)&r300->blend_color_state->blend_color);
+    util_pack_color(color->color, PIPE_FORMAT_A8R8G8B8_UNORM, &uc);
+    r300->blend_color_state->blend_color = uc.ui;
 
     /* XXX if FP16 blending is enabled, we should use the FP16 format */
     r300->blend_color_state->blend_color_red_alpha =
@@ -513,6 +514,7 @@ static void*
     struct r300_context* r300 = r300_context(pipe);
     struct r300_sampler_state* sampler = CALLOC_STRUCT(r300_sampler_state);
     int lod_bias;
+    union util_color uc;
 
     sampler->filter0 |=
         (r300_translate_wrap(state->wrap_s) << R300_TX_WRAP_S_SHIFT) |
@@ -534,8 +536,8 @@ static void*
 
     sampler->filter1 |= r300_anisotropy(state->max_anisotropy);
 
-    util_pack_color(state->border_color, PIPE_FORMAT_A8R8G8B8_UNORM,
-                    (union util_color *)&sampler->border_color);
+    util_pack_color(state->border_color, PIPE_FORMAT_A8R8G8B8_UNORM, &uc);
+    sampler->border_color = uc.ui;
 
     /* R500-specific fixups and optimizations */
     if (r300_screen(r300->context.screen)->caps->is_r500) {