Mesa (master): anv/pipeline: lower constant initializers on output variables earlier

[Iago Toral Quiroga]

Module: Mesa
Branch: master
Commit: 99b57daf4a8289430728bec69f7dadfab457d990
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=99b57daf4a8289430728bec69f7dadfab457d990

Author: Iago Toral Quiroga <itoral at igalia.com>
Date:   Tue Jan 16 09:37:11 2018 +0100

anv/pipeline: lower constant initializers on output variables earlier

If a shader only writes to an output via a constant initializer we
need to lower it before we call nir_remove_dead_variables so that
this pass sees the stores from the initializer and doesn't kill the
output.

Fixes test failures in new work-in-progress CTS tests:
dEQP-VK.spirv_assembly.instruction.graphics.variable_init.output_vert
dEQP-VK.spirv_assembly.instruction.graphics.variable_init.output_frag

Reviewed-by: Jason Ekstrand <jason at jlekstrand.net>

---

 src/intel/vulkan/anv_pipeline.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/intel/vulkan/anv_pipeline.c b/src/intel/vulkan/anv_pipeline.c
index 48eefe828a..e16a7a1994 100644
--- a/src/intel/vulkan/anv_pipeline.c
+++ b/src/intel/vulkan/anv_pipeline.c
@@ -179,6 +179,11 @@ anv_shader_compile_to_nir(struct anv_pipeline *pipeline,
    assert(exec_list_length(&nir->functions) == 1);
    entry_point->name = ralloc_strdup(entry_point, "main");
 
+   /* Make sure we lower constant initializers on output variables so that
+    * nir_remove_dead_variables below sees the corresponding stores
+    */
+   NIR_PASS_V(nir, nir_lower_constant_initializers, nir_var_shader_out);
+
    NIR_PASS_V(nir, nir_remove_dead_variables,
               nir_var_shader_in | nir_var_shader_out | nir_var_system_value);