From 91f8e32a85fa31afc37bb1308927f5b890410854 Mon Sep 17 00:00:00 2001
From: Georg Lehmann <dadschoorse@gmail.com>
Date: Wed, 28 Aug 2024 19:03:53 +0200
Subject: [PATCH] nir/opt_sink: do not sink inverse_ballot out of loops
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Inverse_ballot result is undefined if the input is not dynamically uniform.
And sinking out of loops might make the input divergent.

Fixes: 18a0ff137ff ("nir: sink/move inverse_ballot like moves")

Reviewed-by: Daniel Schürmann <daniel@schuermann.dev>
Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30906>
---
 src/compiler/nir/nir_opt_sink.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/compiler/nir/nir_opt_sink.c b/src/compiler/nir/nir_opt_sink.c
index 8573b21e7a8..1ef33db5007 100644
--- a/src/compiler/nir/nir_opt_sink.c
+++ b/src/compiler/nir/nir_opt_sink.c
@@ -227,6 +227,7 @@ can_sink_out_of_loop(nir_intrinsic_instr *intrin)
     */
    return intrin->intrinsic != nir_intrinsic_load_ubo &&
           intrin->intrinsic != nir_intrinsic_load_ubo_vec4 &&
+          intrin->intrinsic != nir_intrinsic_inverse_ballot &&
           intrin->intrinsic != nir_intrinsic_load_ssbo;
 }