From 7cd402c9c890b6f868299a79960bad5c70897f29 Mon Sep 17 00:00:00 2001
From: Boris Brezillon <boris.brezillon@collabora.com>
Date: Sat, 25 Sep 2021 14:08:58 +0200
Subject: [PATCH] nir/lower_blend: Shrink blended result if needed

Make sure the new and old sources have the same number of components,
otherwise the NIR validation pass complains.

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/13060>
---
 src/compiler/nir/nir_lower_blend.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/compiler/nir/nir_lower_blend.c b/src/compiler/nir/nir_lower_blend.c
index 659ecf9e70c..5e6a04f0ec7 100644
--- a/src/compiler/nir/nir_lower_blend.c
+++ b/src/compiler/nir/nir_lower_blend.c
@@ -374,6 +374,9 @@ nir_lower_blend_instr(nir_builder *b, nir_instr *instr, void *data)
    /* Apply a colormask */
    blended = nir_color_mask(b, options->rt[rt].colormask, blended, dst);
 
+   if (src_num_comps != 4)
+      blended = nir_channels(b, blended, BITFIELD_MASK(src_num_comps));
+
    /* Write out the final color instead of the input */
    nir_instr_rewrite_src_ssa(instr, &intr->src[1], blended);
    return true;