Mesa (staging/21.2): pan/bi: Don't set td in blend shaders

[GitLab Mirror]

Module: Mesa
Branch: staging/21.2
Commit: 277e0c45a9dae57c3288fb31282a9ddbea9f5a8c
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=277e0c45a9dae57c3288fb31282a9ddbea9f5a8c

Author: Alyssa Rosenzweig <alyssa at collabora.com>
Date:   Wed Aug 18 21:38:07 2021 +0000

pan/bi: Don't set td in blend shaders

This breaks screen-space derivatives in a shader that uses multiple
render targets, if the derivative calculation is scheduled after a BLEND
instruction calling into a blend shader.

Signed-off-by: Alyssa Rosenzweig <alyssa at collabora.com>
Cc: mesa-stable
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/12478>
(cherry picked from commit 710498e424e31ad4f308f52a03338ac30a70271b)

---

 .pick_status.json                            | 2 +-
 src/panfrost/bifrost/bi_helper_invocations.c | 5 +++--
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/.pick_status.json b/.pick_status.json
index 571571ee4d1..51b6a7da975 100644
--- a/.pick_status.json
+++ b/.pick_status.json
@@ -787,7 +787,7 @@
         "description": "pan/bi: Don't set td in blend shaders",
         "nominated": true,
         "nomination_type": 0,
-        "resolution": 0,
+        "resolution": 1,
         "main_sha": null,
         "because_sha": null
     },
diff --git a/src/panfrost/bifrost/bi_helper_invocations.c b/src/panfrost/bifrost/bi_helper_invocations.c
index a8d2c61c1e2..c9b5b4e3ebf 100644
--- a/src/panfrost/bifrost/bi_helper_invocations.c
+++ b/src/panfrost/bifrost/bi_helper_invocations.c
@@ -133,8 +133,9 @@ void
 bi_analyze_helper_terminate(bi_context *ctx)
 {
         /* Other shader stages do not have a notion of helper threads, so we
-         * can skip the analysis */
-        if (ctx->stage != MESA_SHADER_FRAGMENT)
+         * can skip the analysis. Don't run for blend shaders, either, since
+         * they run in the context of another shader that we don't see. */
+        if (ctx->stage != MESA_SHADER_FRAGMENT || ctx->inputs->is_blend)
                 return;
 
         /* Set blocks as directly requiring helpers, and if they do add them to