[Mesa-dev] [PATCH] st/glsl_to_nir: disable io lowering to temps for tess

[Timothy Arceri]

Lowering these to temps makes a big mess, and results in some
piglit test failures. Also the radeonsi backend (the only backend
to support tess) has support for indirects so there is no need to
lower them anyway.

Fixes the following piglit tests on radeonsi:

tests/spec/arb_tessellation_shader/execution/variable-indexing/tes-input-array-vec3-index-rd.shader_test
tests/spec/arb_tessellation_shader/execution/variable-indexing/tes-input-array-vec4-index-rd.shader_test
---
 src/mesa/state_tracker/st_glsl_to_nir.cpp | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/mesa/state_tracker/st_glsl_to_nir.cpp b/src/mesa/state_tracker/st_glsl_to_nir.cpp
index 99d620926a..6e3a1548f4 100644
--- a/src/mesa/state_tracker/st_glsl_to_nir.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_nir.cpp
@@ -490,9 +490,12 @@ st_nir_get_mesa_program(struct gl_context *ctx,
    set_st_program(prog, shader_program, nir);
    prog->nir = nir;
 
-   NIR_PASS_V(nir, nir_lower_io_to_temporaries,
-              nir_shader_get_entrypoint(nir),
-              true, true);
+   if (nir->info.stage != MESA_SHADER_TESS_CTRL &&
+       nir->info.stage != MESA_SHADER_TESS_EVAL) {
+      NIR_PASS_V(nir, nir_lower_io_to_temporaries,
+                 nir_shader_get_entrypoint(nir),
+                 true, true);
+   }
    NIR_PASS_V(nir, nir_lower_global_vars_to_local);
    NIR_PASS_V(nir, nir_split_var_copies);
    NIR_PASS_V(nir, nir_lower_var_copies);
@@ -665,7 +668,8 @@ st_finalize_nir(struct st_context *st, struct gl_program *prog,
 
    NIR_PASS_V(nir, nir_split_var_copies);
    NIR_PASS_V(nir, nir_lower_var_copies);
-   if (nir->info.stage != MESA_SHADER_TESS_CTRL)
+   if (nir->info.stage != MESA_SHADER_TESS_CTRL &&
+       nir->info.stage != MESA_SHADER_TESS_EVAL)
       NIR_PASS_V(nir, nir_lower_io_arrays_to_elements_no_indirects);
 
    if (nir->info.stage == MESA_SHADER_VERTEX) {
-- 
2.14.3