[Mesa-dev] [RFC 1/5] nir/gcm: Compute the if-depth of each block

[Jason Ekstrand]

---
 src/compiler/nir/nir_opt_gcm.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/src/compiler/nir/nir_opt_gcm.c b/src/compiler/nir/nir_opt_gcm.c
index cff2315..72ddc54 100644
--- a/src/compiler/nir/nir_opt_gcm.c
+++ b/src/compiler/nir/nir_opt_gcm.c
@@ -38,6 +38,9 @@
  */
 
 struct gcm_block_info {
+   /* Number of if statements this block is inside */
+   unsigned if_depth;
+
    /* Number of loops this block is inside */
    unsigned loop_depth;
 
@@ -73,24 +76,28 @@ struct gcm_state {
 /* Recursively walks the CFG and builds the block_info structure */
 static void
 gcm_build_block_info(struct exec_list *cf_list, struct gcm_state *state,
-                     unsigned loop_depth)
+                     unsigned if_depth, unsigned loop_depth)
 {
    foreach_list_typed(nir_cf_node, node, node, cf_list) {
       switch (node->type) {
       case nir_cf_node_block: {
          nir_block *block = nir_cf_node_as_block(node);
+         state->blocks[block->index].if_depth = if_depth;
          state->blocks[block->index].loop_depth = loop_depth;
          break;
       }
       case nir_cf_node_if: {
          nir_if *if_stmt = nir_cf_node_as_if(node);
-         gcm_build_block_info(&if_stmt->then_list, state, loop_depth);
-         gcm_build_block_info(&if_stmt->else_list, state, loop_depth);
+         gcm_build_block_info(&if_stmt->then_list, state,
+                              if_depth + 1, loop_depth);
+         gcm_build_block_info(&if_stmt->else_list, state,
+                              if_depth + 1, loop_depth);
          break;
       }
       case nir_cf_node_loop: {
          nir_loop *loop = nir_cf_node_as_loop(node);
-         gcm_build_block_info(&loop->body, state, loop_depth + 1);
+         gcm_build_block_info(&loop->body, state,
+                              if_depth, loop_depth + 1);
          break;
       }
       default:
@@ -466,7 +473,7 @@ opt_gcm_impl(nir_function_impl *impl, bool value_number)
    nir_metadata_require(impl, nir_metadata_block_index |
                               nir_metadata_dominance);
 
-   gcm_build_block_info(&impl->body, &state, 0);
+   gcm_build_block_info(&impl->body, &state, 0, 0);
 
    nir_foreach_block(block, impl) {
       gcm_pin_instructions_block(block, &state);
-- 
2.5.0.400.gff86faf