st/glsl_to_nir: add basic NIR opt loop helper

We need to be able to do these NIR opts in the state tracker
rather than the driver in order for the NIR linking opts to
be useful.

Reviewed-by: Nicolai Hähnle <[email protected]>

1 files changed, 31 insertions, 0 deletions

diff --git a/src/mesa/state_tracker/st_glsl_to_nir.cpp b/src/mesa/state_tracker/st_glsl_to_nir.cpp
index 4a772e65421..1b4f07111cf 100644
--- a/src/mesa/state_tracker/st_glsl_to_nir.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_nir.cpp
@@ -247,6 +247,37 @@ st_nir_assign_uniform_locations(struct gl_program *prog,
    *size = max;
 }
 
+static void
+st_nir_opts(nir_shader *nir)
+{
+   bool progress;
+   do {
+      progress = false;
+
+      NIR_PASS(progress, nir, nir_copy_prop);
+      NIR_PASS(progress, nir, nir_opt_remove_phis);
+      NIR_PASS(progress, nir, nir_opt_dce);
+      if (nir_opt_trivial_continues(nir)) {
+         progress = true;
+         NIR_PASS(progress, nir, nir_copy_prop);
+         NIR_PASS(progress, nir, nir_opt_dce);
+      }
+      NIR_PASS(progress, nir, nir_opt_if);
+      NIR_PASS(progress, nir, nir_opt_dead_cf);
+      NIR_PASS(progress, nir, nir_opt_cse);
+      NIR_PASS(progress, nir, nir_opt_peephole_select, 8);
+
+      NIR_PASS(progress, nir, nir_opt_algebraic);
+      NIR_PASS(progress, nir, nir_opt_constant_folding);
+
+      NIR_PASS(progress, nir, nir_opt_undef);
+      NIR_PASS(progress, nir, nir_opt_conditional_discard);
+      if (nir->options->max_unroll_iterations) {
+         NIR_PASS(progress, nir, nir_opt_loop_unroll, (nir_variable_mode)0);
+      }
+   } while (progress);
+}
+
 /* First third of converting glsl_to_nir.. this leaves things in a pre-
  * nir_lower_io state, so that shader variants can more easily insert/
  * replace variables, etc.