nir/repair_ssa: Refactor some use handling

We can mostly unify the instr-use and if-use handling, which is a lot more
concise.

Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>
Reviewed-by: Faith Ekstrand <faith.ekstrand@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/22343>

diff --git a/src/compiler/nir/nir_repair_ssa.c b/src/compiler/nir/nir_repair_ssa.c
index 3aae5fa9366a5cee1913c866ed2f79d7be1ff282..443fa894879ec414c06c1191ba5dc268a3432780 100644 (file)
--- a/src/compiler/nir/nir_repair_ssa.c
+++ b/src/compiler/nir/nir_repair_ssa.c
@@ -57,7 +57,9 @@ prep_build_phi(struct repair_ssa_state *state)
 static nir_block *
 get_src_block(nir_src *src)
 {
-   if (src->parent_instr->type == nir_instr_type_phi) {
+   if (src->is_if) {
+      return nir_cf_node_as_block(nir_cf_node_prev(&src->parent_if->cf_node));
+   } else if (src->parent_instr->type == nir_instr_type_phi) {
       return exec_node_data(nir_phi_src, src, src)->pred;
    } else {
       return src->parent_instr->block;
@@ -71,20 +73,12 @@ repair_ssa_def(nir_ssa_def *def, void *void_state)
 
    bool is_valid = true;
    nir_foreach_use_including_if(src, def) {
-      if (src->is_if) {
-         nir_block *block_before_if =
-            nir_cf_node_as_block(nir_cf_node_prev(&src->parent_if->cf_node));
-         if (nir_block_is_unreachable(block_before_if) ||
-             !nir_block_dominates(def->parent_instr->block, block_before_if)) {
-            is_valid = false;
-            break;
-         }
-      } else {
-         if (nir_block_is_unreachable(get_src_block(src)) ||
-             !nir_block_dominates(def->parent_instr->block, get_src_block(src))) {
-            is_valid = false;
-            break;
-         }
+      nir_block *src_block = get_src_block(src);
+
+      if (nir_block_is_unreachable(src_block) ||
+          !nir_block_dominates(def->parent_instr->block, src_block)) {
+         is_valid = false;
+         break;
       }
    }
 
@@ -102,31 +96,15 @@ repair_ssa_def(nir_ssa_def *def, void *void_state)
    nir_phi_builder_value_set_block_def(val, def->parent_instr->block, def);
 
    nir_foreach_use_including_if_safe(src, def) {
-      if (src->is_if) {
-         nir_block *block_before_if =
-            nir_cf_node_as_block(nir_cf_node_prev(&src->parent_if->cf_node));
-         if (block_before_if == def->parent_instr->block) {
-            assert(nir_phi_builder_value_get_block_def(val, block_before_if) == def);
-            continue;
-         }
-
-         nir_ssa_def *block_def =
-            nir_phi_builder_value_get_block_def(val, block_before_if);
-         if (block_def == def)
-            continue;
-
-         nir_if_rewrite_condition(src->parent_if, nir_src_for_ssa(block_def));
-         continue;
-      }
+      nir_block *block = get_src_block(src);
 
-      nir_block *src_block = get_src_block(src);
-      if (src_block == def->parent_instr->block) {
-         assert(nir_phi_builder_value_get_block_def(val, src_block) == def);
+      if (block == def->parent_instr->block) {
+         assert(nir_phi_builder_value_get_block_def(val, block) == def);
          continue;
       }
 
       nir_ssa_def *block_def =
-         nir_phi_builder_value_get_block_def(val, src_block);
+         nir_phi_builder_value_get_block_def(val, block);
       if (block_def == def)
          continue;
 
@@ -134,7 +112,8 @@ repair_ssa_def(nir_ssa_def *def, void *void_state)
        * isn't a cast, we need to wrap it in a cast so we don't loose any
        * deref information.
        */
-      if (def->parent_instr->type == nir_instr_type_deref &&
+      if (!src->is_if &&
+          def->parent_instr->type == nir_instr_type_deref &&
           src->parent_instr->type == nir_instr_type_deref &&
           nir_instr_as_deref(src->parent_instr)->deref_type != nir_deref_type_cast) {
          nir_deref_instr *cast =
@@ -154,7 +133,10 @@ repair_ssa_def(nir_ssa_def *def, void *void_state)
          block_def = &cast->dest.ssa;
       }
 
-      nir_instr_rewrite_src(src->parent_instr, src, nir_src_for_ssa(block_def));
+      if (src->is_if)
+         nir_if_rewrite_condition(src->parent_if, nir_src_for_ssa(block_def));
+      else
+         nir_instr_rewrite_src(src->parent_instr, src, nir_src_for_ssa(block_def));
    }
 
    return true;