[Mesa-dev] [PATCH 3/3] st/mesa: skip lower_output_reads when possible

[Nicolai Hähnle]

From: Nicolai Hähnle <nicolai.haehnle at amd.com>

---
 src/mesa/state_tracker/st_glsl_to_tgsi.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
index 8a247ea..7720edf 100644
--- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
@@ -6438,21 +6438,22 @@ get_mesa_program_tgsi(struct gl_context *ctx,
 
    v->have_sqrt = pscreen->get_shader_param(pscreen, ptarget,
                                             PIPE_SHADER_CAP_TGSI_SQRT_SUPPORTED);
    v->have_fma = pscreen->get_shader_param(pscreen, ptarget,
                                            PIPE_SHADER_CAP_TGSI_FMA_SUPPORTED);
 
    _mesa_generate_parameters_list_for_uniforms(shader_program, shader,
                                                prog->Parameters);
 
    /* Remove reads from output registers. */
-   lower_output_reads(shader->Stage, shader->ir);
+   if (!pscreen->get_param(pscreen, PIPE_CAP_TGSI_CAN_READ_OUTPUTS))
+      lower_output_reads(shader->Stage, shader->ir);
 
    /* Emit intermediate IR for main(). */
    visit_exec_list(shader->ir, v);
 
 #if 0
    /* Print out some information (for debugging purposes) used by the
     * optimization passes. */
    {
       int i;
       int *first_writes = rzalloc_array(v->mem_ctx, int, v->next_temp);
-- 
2.7.4