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 <nicolai.haehnle@amd.com>

diff --git a/src/mesa/state_tracker/st_glsl_to_nir.cpp b/src/mesa/state_tracker/st_glsl_to_nir.cpp
index 4a772e654210a48b96e1b4ac89392cd5607ae293..1b4f07111cf187a9bb955eb5c60bff6b48d05013 100644 (file)
--- 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.