Mesa (master): st/glsl_to_nir: add basic NIR opt loop helper

[Timothy Arceri]

Module: Mesa
Branch: master
Commit: bd98b8c74ef9d404f98b77519eaf327b938a150a
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=bd98b8c74ef9d404f98b77519eaf327b938a150a

Author: Timothy Arceri <tarceri at itsqueeze.com>
Date:   Tue Nov 14 10:13:58 2017 +1100

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 at amd.com>

---

 src/mesa/state_tracker/st_glsl_to_nir.cpp | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/src/mesa/state_tracker/st_glsl_to_nir.cpp b/src/mesa/state_tracker/st_glsl_to_nir.cpp
index 4a772e6542..1b4f07111c 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.