gallivm: correct channel shift logic on big endian

lp_build_fetch_rgba_soa fetches a texel from a texture.
Part of that process involves first gathering the element
together from memory into a packed format, and then breaking
out the individual color channels into separate, parallel
arrays.

The code fails to account for endianess when reading the packed
values.

This commit attempts to correct the problem by reversing the order
the packed values are read on big endian systems.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=100613
Cc: "17.2" "17.1" <mesa-stable@lists.freedesktop.org>
Signed-off-by: Ray Strode <rstrode@redhat.com>
Reviewed-by: Roland Scheidegger <sroland@vmware.com>
This commit is contained in:
Ray Strode 2017-08-23 16:32:42 -04:00 committed by Roland Scheidegger
parent c92fe8a8c5
commit 75cb6e3617

View file

@ -650,7 +650,13 @@ lp_build_fetch_rgba_soa(struct gallivm_state *gallivm,
for (i = 0; i < format_desc->nr_channels; i++) {
struct util_format_channel_description chan_desc = format_desc->channel[i];
unsigned blockbits = type.width;
unsigned vec_nr = chan_desc.shift / type.width;
unsigned vec_nr;
#ifdef PIPE_ARCH_BIG_ENDIAN
vec_nr = (format_desc->block.bits - (chan_desc.shift + chan_desc.size)) / type.width;
#else
vec_nr = chan_desc.shift / type.width;
#endif
chan_desc.shift %= type.width;
output[i] = lp_build_extract_soa_chan(&bld,