fdo-mirrors/mesa
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/mesa/mesa.git synced 2025-12-25 02:10:11 +01:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

nir/lower_int64: fix find_lsb(0)

Browse source 
If the high 32 bits were zero, this would be umin(find_lsb(lo), 31). This
evaluates to 31 if lo is also zero, instead of -1.

Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Fixes: 9293d8e64b ("nir: Add find_lsb lowering to nir_lower_int64.")
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/25409>
This commit is contained in:
Rhys Perry 2023-09-26 19:29:37 +01:00 • committed by Marge Bot
parent e90f9d8e21
commit bcdac65ca3
1 changed files with 4 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

5
src/compiler/nir/nir_lower_int64.c
View file

@ -713,8 +713,11 @@ lower_find_lsb64(nir_builder *b, nir_def *x)
/* Use umin so that -1 (no bits found) becomes larger (0xFFFFFFFF)
* than any actual bit position, so we return a found bit instead.
* This is similar to the ufind_msb lowering. If you need this lowering
* without uadd_sat, add code like in lower_ufind_msb64.
*/
return nir_umin(b, lo_lsb, nir_iadd_imm(b, hi_lsb, 32));
assert(!b->shader->options->lower_uadd_sat);
return nir_umin(b, lo_lsb, nir_uadd_sat(b, hi_lsb, nir_imm_int(b, 32)));
}
static nir_def *