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d5d2fb5c4c
I recently discovered that the following code lead to valgrind errors:
struct isl_swizzle swizzle = ISL_SWIZZLE_IDENTITY;
VALGRIND_CHECK_MEM_IS_DEFINED(&swizzle, sizeof(swizzle));
which is surprising, because struct isl_swizzle is simply:
struct isl_swizzle {
enum isl_channel_select r:4;
enum isl_channel_select g:4;
enum isl_channel_select b:4;
enum isl_channel_select a:4;
};
and the above code initializes all of them with a C99 initializer.
Iván Briano reminded me that C99 initializers don't necessarily zero
padding. A quick inspection revealed that sizeof(struct isl_swizzle)
was 4 (rather than the expected 2). Ian Romanick suggested changing
it to uint16_t, since this is essentially dicing up an unsigned, and
that worked.
This patch marks enum isl_channel_select packed, changing its size
from 4 bytes to 1 byte. This then makes struct isl_swizzle 2 bytes,
with no bogus padding fields. This eliminates valgrind undefined
memory warnings.
These isl_swizzle values become part of our BLORP blit program keys,
which are then hashed. This undefined padding was being included in
the hashing, possibly leading to issues. I originally saw this error
when running KHR-GL45.texture_size_promotion.functional in iris under
valgrind.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
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| .. | ||
| blorp | ||
| common | ||
| compiler | ||
| dev | ||
| genxml | ||
| isl | ||
| perf | ||
| tools | ||
| vulkan | ||
| Android.blorp.mk | ||
| Android.common.mk | ||
| Android.compiler.mk | ||
| Android.dev.mk | ||
| Android.genxml.mk | ||
| Android.isl.mk | ||
| Android.mk | ||
| Android.perf.mk | ||
| Android.vulkan.mk | ||
| Makefile.perf.am | ||
| Makefile.sources | ||
| meson.build | ||