nir_to_tgsi: Allow SSA defs to include swizzles, abs, and neg.

This will let some copy prop happen automatically, avoiding MOVs to temps.
Most importantly, though, it means that virgl won't see (unused channel)
swizzles from channels beyond the bounds of sysvals, which trigger shader
compile failures on the host.

softpipe shader-db:

total instructions in shared programs: 2946336 -> 2934777 (-0.39%)
instructions in affected programs: 374676 -> 363117 (-3.09%)
total temps in shared programs: 565552 -> 564139 (-0.25%)
temps in affected programs: 18138 -> 16725 (-7.79%)

Reviewed-by: Rob Clark <robdclark@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/12781>

diff --git a/src/gallium/auxiliary/nir/nir_to_tgsi.c b/src/gallium/auxiliary/nir/nir_to_tgsi.c
index 5a23c90..c307182 100644 (file)
--- a/src/gallium/auxiliary/nir/nir_to_tgsi.c
+++ b/src/gallium/auxiliary/nir/nir_to_tgsi.c
@@ -738,11 +738,7 @@ ntt_get_dest(struct ntt_compile *c, nir_dest *dest)
 static void
 ntt_store_def(struct ntt_compile *c, nir_ssa_def *def, struct ureg_src src)
 {
-   if (!src.Negate && !src.Absolute && !src.Indirect && !src.DimIndirect &&
-       src.SwizzleX == TGSI_SWIZZLE_X &&
-       (src.SwizzleY == TGSI_SWIZZLE_Y || def->num_components < 2) &&
-       (src.SwizzleZ == TGSI_SWIZZLE_Z || def->num_components < 3) &&
-       (src.SwizzleW == TGSI_SWIZZLE_W || def->num_components < 4)) {
+   if (!src.Indirect && !src.DimIndirect) {
       switch (src.File) {
       case TGSI_FILE_IMMEDIATE:
       case TGSI_FILE_INPUT: