From f512965b0b3d70525424f100e534b8ac0a43a376 Mon Sep 17 00:00:00 2001 From: Iago Toral Quiroga Date: Wed, 13 Nov 2019 09:19:22 +0100 Subject: [PATCH] mesa/st: make sure we remove dead IO variables before handing NIR to backends MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Commit "1c2bf82d24a glsl: disable lower_fragdata_array() for NIR drivers" disabled the GLSL IR lowering that turned gl_FragData from an array into a collection of scalar outputs under the assumption that this was already being handled properly elsewhere, however there are some corner cases where NIR would fail to do this, leaving gl_FragData[] as an array variable. This can break backends that assume that all their outputs will be scalar and use the variable definitions from the shader to do their output setup, such as the case of V3D. At least one corner case was found in some Portal shaders from shader-db, where NIR would optimize out the full body of a fragment shader. In this scenario, the empty shader would keep the original array definition of gl_FragData[], causing the backend to assert. We need to do this late enough for it to be effective, since doing it in st_nir_preprocess does not fix the original problem. Closes: https://gitlab.freedesktop.org/mesa/mesa/issues/2091 Fixes: 1c2bf82d ("glsl: disable lower_fragdata_array() for NIR drivers") Reviewed-by: Marek Olšák --- src/mesa/state_tracker/st_glsl_to_nir.cpp | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/src/mesa/state_tracker/st_glsl_to_nir.cpp b/src/mesa/state_tracker/st_glsl_to_nir.cpp index 5aa47a42b2a..6cadf15d6df 100644 --- a/src/mesa/state_tracker/st_glsl_to_nir.cpp +++ b/src/mesa/state_tracker/st_glsl_to_nir.cpp @@ -493,7 +493,8 @@ st_glsl_to_nir_post_opts(struct st_context *st, struct gl_program *prog, st_nir_opts(nir); } - nir_variable_mode mask = nir_var_function_temp; + nir_variable_mode mask = (nir_variable_mode) + (nir_var_shader_in | nir_var_shader_out | nir_var_function_temp ); nir_remove_dead_variables(nir, mask); NIR_PASS_V(nir, nir_lower_atomics_to_ssbo, -- 2.30.2