[Mesa-dev] [PATCH 2/2] i965/cfg: Remove if_block/else_block.

[Matt Turner]

I used these in the SEL peephole, but they require extra tracking and
fix ups. The SEL peephole can pretty easily find the blocks it needs
without these.
---
 src/mesa/drivers/dri/i965/brw_cfg.cpp               | 15 +--------------
 src/mesa/drivers/dri/i965/brw_cfg.h                 |  8 --------
 src/mesa/drivers/dri/i965/brw_dead_control_flow.cpp |  8 --------
 3 files changed, 1 insertion(+), 30 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_cfg.cpp b/src/mesa/drivers/dri/i965/brw_cfg.cpp
index bb49a0a..02149e2 100644
--- a/src/mesa/drivers/dri/i965/brw_cfg.cpp
+++ b/src/mesa/drivers/dri/i965/brw_cfg.cpp
@@ -51,8 +51,7 @@ link(void *mem_ctx, bblock_t *block)
 }
 
 bblock_t::bblock_t(cfg_t *cfg) :
-   cfg(cfg), start_ip(0), end_ip(0), num(0),
-   if_block(NULL), else_block(NULL)
+   cfg(cfg), start_ip(0), end_ip(0), num(0)
 {
    instructions.make_empty();
    parents.make_empty();
@@ -136,7 +135,6 @@ bblock_t::combine_with(bblock_t *that)
    }
 
    this->end_ip = that->end_ip;
-   this->else_block = that->else_block;
    this->instructions.append_list(&that->instructions);
 
    this->cfg->remove_block(that);
@@ -238,17 +236,6 @@ cfg_t::cfg_t(exec_list *instructions)
          assert(cur_if->end()->opcode == BRW_OPCODE_IF);
          assert(!cur_else || cur_else->end()->opcode == BRW_OPCODE_ELSE);
 
-         cur_if->if_block = cur_if;
-         cur_if->else_block = cur_else;
-
-	 if (cur_else) {
-            cur_else->if_block = cur_if;
-            cur_else->else_block = cur_else;
-         }
-
-         cur->if_block = cur_if;
-         cur->else_block = cur_else;
-
 	 /* Pop the stack so we're in the previous if/else/endif */
 	 cur_if = pop_stack(&if_stack);
 	 cur_else = pop_stack(&else_stack);
diff --git a/src/mesa/drivers/dri/i965/brw_cfg.h b/src/mesa/drivers/dri/i965/brw_cfg.h
index 388d29e..48bca9f 100644
--- a/src/mesa/drivers/dri/i965/brw_cfg.h
+++ b/src/mesa/drivers/dri/i965/brw_cfg.h
@@ -89,14 +89,6 @@ struct bblock_t {
    struct exec_list parents;
    struct exec_list children;
    int num;
-
-   /* If the current basic block ends in an IF or ELSE instruction, these will
-    * point to the basic blocks containing the other associated instruction.
-    *
-    * Otherwise they are NULL.
-    */
-   struct bblock_t *if_block;
-   struct bblock_t *else_block;
 };
 
 static inline struct backend_instruction *
diff --git a/src/mesa/drivers/dri/i965/brw_dead_control_flow.cpp b/src/mesa/drivers/dri/i965/brw_dead_control_flow.cpp
index 4c9d7b9..03f838d 100644
--- a/src/mesa/drivers/dri/i965/brw_dead_control_flow.cpp
+++ b/src/mesa/drivers/dri/i965/brw_dead_control_flow.cpp
@@ -85,7 +85,6 @@ dead_control_flow_eliminate(backend_visitor *v)
          }
 
          if (else_inst) {
-            else_block->if_block->else_block = NULL;
             else_inst->remove(else_block);
          }
 
@@ -102,13 +101,6 @@ dead_control_flow_eliminate(backend_visitor *v)
          if (earlier_block && earlier_block->can_combine_with(later_block)) {
             earlier_block->combine_with(later_block);
 
-            foreach_block (block, v->cfg) {
-               if (block->if_block == later_block)
-                  block->if_block = earlier_block;
-               if (block->else_block == later_block)
-                  block->else_block = earlier_block;
-            }
-
             /* If ENDIF was in its own block, then we've now deleted it and
              * merged the two surrounding blocks, the latter of which the
              * __next block pointer was pointing to.
-- 
2.0.4