panfrost: protect alpha calculation from accessing non-existent component

We had a "Don't read out-of-bounds" sanity check for creating an alpha
when ATEST was needed, but that check happened only after we already
did a bi_extract(), which meant that the bi_extract could get into
trouble and assert() when there weren't enough components. Fixed by
re-arranging the calculation.

Signed-off-by: Eric R. Smith <eric.smith@collabora.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Erik Faye-Lund <erik.faye-lund>@collabora.com>
Cc: mesa-stable
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/28045>
This commit is contained in:
Eric R. Smith
2024-03-06 08:17:37 -04:00
committed by Marge Bot
parent a6f270c160
commit 0e1862a2ab

View File

@@ -837,15 +837,18 @@ bi_emit_fragment_out(bi_builder *b, nir_intrinsic_instr *instr)
nir_alu_type T = nir_intrinsic_src_type(instr);
bi_index rgba = bi_src_index(&instr->src[0]);
bi_index alpha = (T == nir_type_float16)
? bi_half(bi_extract(b, rgba, 1), true)
: (T == nir_type_float32) ? bi_extract(b, rgba, 3)
: bi_dontcare(b);
bi_index alpha;
/* Don't read out-of-bounds */
if (nir_src_num_components(instr->src[0]) < 4)
if (nir_src_num_components(instr->src[0]) < 4) {
/* Don't read out-of-bounds */
alpha = bi_imm_f32(1.0);
} else if (T == nir_type_float16) {
alpha = bi_half(bi_extract(b, rgba, 1), true);
} else if (T == nir_type_float32) {
alpha = bi_extract(b, rgba, 3);
} else {
alpha = bi_dontcare(b);
}
bi_emit_atest(b, alpha);
}