zink: use nir_shader_instructions_pass in lower_discard_if

Changes:
- nir_metadata_preserve(..., nir_metadata_dominance)
  is called only when pass makes progress
- nir_metadata_preserve(..., nir_metadata_all) is called when pass doesn't
  make progress

Signed-off-by: Marcin Ślusarz <marcin.slusarz@intel.com>
Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/12324>

diff --git a/src/gallium/drivers/zink/zink_compiler.c b/src/gallium/drivers/zink/zink_compiler.c
index 4cd2d28..19a2733 100644 (file)
--- a/src/gallium/drivers/zink/zink_compiler.c
+++ b/src/gallium/drivers/zink/zink_compiler.c
@@ -76,8 +76,13 @@ reads_work_dim(nir_shader *shader)
 }
 
 static bool
-lower_discard_if_instr(nir_intrinsic_instr *instr, nir_builder *b)
+lower_discard_if_instr(nir_builder *b, nir_instr *instr_, UNUSED void *cb_data)
 {
+   if (instr_->type != nir_instr_type_intrinsic)
+      return false;
+
+   nir_intrinsic_instr *instr = nir_instr_as_intrinsic(instr_);
+
    if (instr->intrinsic == nir_intrinsic_discard_if) {
       b->cursor = nir_before_instr(&instr->instr);
 
@@ -137,26 +142,10 @@ lower_discard_if_instr(nir_intrinsic_instr *instr, nir_builder *b)
 static bool
 lower_discard_if(nir_shader *shader)
 {
-   bool progress = false;
-
-   nir_foreach_function(function, shader) {
-      if (function->impl) {
-         nir_builder builder;
-         nir_builder_init(&builder, function->impl);
-         nir_foreach_block(block, function->impl) {
-            nir_foreach_instr_safe(instr, block) {
-               if (instr->type == nir_instr_type_intrinsic)
-                  progress |= lower_discard_if_instr(
-                                                  nir_instr_as_intrinsic(instr),
-                                                  &builder);
-            }
-         }
-
-         nir_metadata_preserve(function->impl, nir_metadata_dominance);
-      }
-   }
-
-   return progress;
+   return nir_shader_instructions_pass(shader,
+                                       lower_discard_if_instr,
+                                       nir_metadata_dominance,
+                                       NULL);
 }
 
 static bool