[Mesa-dev] [PATCH 09/23] nir: Return progress from nir_lower_clip_cull_distance_arrays().

[Matt Turner]

---
 src/compiler/nir/nir.h                             |  2 +-
 .../nir/nir_lower_clip_cull_distance_arrays.c      | 39 ++++++++++++++++------
 2 files changed, 30 insertions(+), 11 deletions(-)

diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
index 1c792f1..a0c57f4 100644
--- a/src/compiler/nir/nir.h
+++ b/src/compiler/nir/nir.h
@@ -2498,7 +2498,7 @@ bool nir_lower_idiv(nir_shader *shader);
 
 void nir_lower_clip_vs(nir_shader *shader, unsigned ucp_enables);
 void nir_lower_clip_fs(nir_shader *shader, unsigned ucp_enables);
-void nir_lower_clip_cull_distance_arrays(nir_shader *nir);
+bool nir_lower_clip_cull_distance_arrays(nir_shader *nir);
 
 void nir_lower_two_sided_color(nir_shader *shader);
 
diff --git a/src/compiler/nir/nir_lower_clip_cull_distance_arrays.c b/src/compiler/nir/nir_lower_clip_cull_distance_arrays.c
index 5a89edd..b255bc5 100644
--- a/src/compiler/nir/nir_lower_clip_cull_distance_arrays.c
+++ b/src/compiler/nir/nir_lower_clip_cull_distance_arrays.c
@@ -73,13 +73,13 @@ update_type(nir_variable *var, gl_shader_stage stage, unsigned length)
 /**
  * Rewrite any clip/cull distances to refer to the new combined array.
  */
-static void
+static bool
 rewrite_references(nir_instr *instr,
                    nir_variable *combined,
                    unsigned cull_offset)
 {
    if (instr->type != nir_instr_type_intrinsic)
-      return;
+      return false;
 
    nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
 
@@ -88,15 +88,15 @@ rewrite_references(nir_instr *instr,
 
    if (intrin->intrinsic != nir_intrinsic_load_var &&
        intrin->intrinsic != nir_intrinsic_store_var)
-      return;
+      return false;
 
    nir_deref_var *var_ref = intrin->variables[0];
    if (var_ref->var->data.mode != combined->data.mode)
-      return;
+      return false;
 
    if (var_ref->var->data.location != VARYING_SLOT_CLIP_DIST0 &&
        var_ref->var->data.location != VARYING_SLOT_CULL_DIST0)
-      return;
+      return false;
 
    /* Update types along the deref chain */
    const struct glsl_type *type = combined->type;
@@ -119,15 +119,18 @@ rewrite_references(nir_instr *instr,
    var_ref->var = combined;
 
    /* There's no need to update writemasks; it's a scalar array. */
+
+   return true;
 }
 
-static void
+static bool
 combine_clip_cull(nir_shader *nir,
                   struct exec_list *vars,
                   bool store_info)
 {
    nir_variable *cull = NULL;
    nir_variable *clip = NULL;
+   bool progress = false;
 
    nir_foreach_variable(var, vars) {
       if (var->data.location == VARYING_SLOT_CLIP_DIST0)
@@ -162,11 +165,21 @@ combine_clip_cull(nir_shader *nir,
          /* Rewrite CullDistance to reference the combined array */
          nir_foreach_function(function, nir) {
             if (function->impl) {
+               bool this_progress = false;
+
                nir_foreach_block(block, function->impl) {
                   nir_foreach_instr(instr, block) {
-                     rewrite_references(instr, clip, clip_array_size);
+                     this_progress |= rewrite_references(instr, clip,
+                                                         clip_array_size);
                   }
                }
+
+               if (this_progress) {
+                  nir_metadata_preserve(function->impl,
+                                        nir_metadata_block_index |
+                                        nir_metadata_dominance);
+               }
+               progress |= this_progress;
             }
          }
 
@@ -175,14 +188,20 @@ combine_clip_cull(nir_shader *nir,
          ralloc_free(cull);
       }
    }
+
+   return progress;
 }
 
-void
+bool
 nir_lower_clip_cull_distance_arrays(nir_shader *nir)
 {
+   bool progress = false;
+
    if (nir->stage <= MESA_SHADER_GEOMETRY)
-      combine_clip_cull(nir, &nir->outputs, true);
+      progress |= combine_clip_cull(nir, &nir->outputs, true);
 
    if (nir->stage > MESA_SHADER_VERTEX)
-      combine_clip_cull(nir, &nir->inputs, false);
+      progress |= combine_clip_cull(nir, &nir->inputs, false);
+
+   return progress;
 }
-- 
2.10.2