Module: Mesa
Branch: main
Commit: 4a627af0e3670d409d8140c1f9ee1c7ac86b5ddf
URL:
http://cgit.freedesktop.org/mesa/mesa/commit/?id=4a627af0e3670d409d8140c1f9ee1c7ac86b5ddf
Author: antonino <antonino.manisca...@collabora.com>
Date: Thu Nov 2 18:03:41 2023 +0100
nir: don't take the derivative of the array index in `nir_lower_tex`
Previosuly when lowering to txd for sampler array the index would be
derived as well, therefore the resulting derivative would have been a
vec with one more component than what the txd instruction expects.
This patch truncates the coordinate vector in this case to make sure the
index is not derived.
Fixes: b154a4154b4 ("nir/lower_tex: rewrite tex/txb -> txd/txl before
saturating srcs")
Reviewed-by: Faith Ekstrand <faith.ekstr...@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/26012>
---
src/compiler/nir/nir_lower_tex.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/src/compiler/nir/nir_lower_tex.c b/src/compiler/nir/nir_lower_tex.c
index 83f3ebb5c9e..716c5dda7a8 100644
--- a/src/compiler/nir/nir_lower_tex.c
+++ b/src/compiler/nir/nir_lower_tex.c
@@ -872,10 +872,14 @@ lower_tex_to_txd(nir_builder *b, nir_tex_instr *tex)
txd->src[i].src = nir_src_for_ssa(tex->src[i].src.ssa);
txd->src[i].src_type = tex->src[i].src_type;
}
- int coord = nir_tex_instr_src_index(tex, nir_tex_src_coord);
- assert(coord >= 0);
- nir_def *dfdx = nir_fddx(b, tex->src[coord].src.ssa);
- nir_def *dfdy = nir_fddy(b, tex->src[coord].src.ssa);
+ int coord_idx = nir_tex_instr_src_index(tex, nir_tex_src_coord);
+ assert(coord_idx >= 0);
+ nir_def *coord = tex->src[coord_idx].src.ssa;
+ /* don't take the derivative of the array index */
+ if (tex->is_array)
+ coord = nir_channels(b, coord, nir_component_mask(coord->num_components
- 1));
+ nir_def *dfdx = nir_fddx(b, coord);
+ nir_def *dfdy = nir_fddy(b, coord);
txd->src[tex->num_srcs] = nir_tex_src_for_ssa(nir_tex_src_ddx, dfdx);
txd->src[tex->num_srcs + 1] = nir_tex_src_for_ssa(nir_tex_src_ddy, dfdy);
