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authorIan Romanick <[email protected]>2016-02-24 19:39:49 -0800
committerIan Romanick <[email protected]>2016-02-26 16:51:27 -0800
commit5bfb3027834602841a62907929bb7795068fd44e (patch)
tree37e3fd1eed4d940d805d7271e36548abde822566
parent2513a20240e77a9a0a453d9789c64a656852c929 (diff)
i965/cfg: Split out dead control flow paths to simplify both paths
v2: Fix some bad indentation. Suggested by Curro. Signed-off-by: Ian Romanick <[email protected]> Reviewed-by: Francisco Jerez <[email protected]>
-rw-r--r--src/mesa/drivers/dri/i965/brw_dead_control_flow.cpp93
1 files changed, 38 insertions, 55 deletions
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 856357239a4..345149287ed 100644
--- a/src/mesa/drivers/dri/i965/brw_dead_control_flow.cpp
+++ b/src/mesa/drivers/dri/i965/brw_dead_control_flow.cpp
@@ -48,67 +48,50 @@ dead_control_flow_eliminate(backend_shader *s)
/* ENDIF instructions, by definition, can only be found at the start of
* basic blocks.
*/
- if (inst->opcode == BRW_OPCODE_ENDIF) {
- bool found = false;
- bblock_t *if_block = NULL, *else_block = NULL, *endif_block = block;
- backend_instruction *endif_inst = inst;
-
- backend_instruction *if_inst = NULL, *else_inst = NULL;
- if (prev_inst->opcode == BRW_OPCODE_ELSE) {
- else_inst = prev_inst;
- else_block = endif_block->prev();
- found = true;
-
- /* Don't remove the ENDIF if we didn't find a dead IF. */
- endif_inst = NULL;
- }
-
- if (prev_inst->opcode == BRW_OPCODE_IF) {
- if_inst = prev_inst;
- if_block = prev_block;
- found = true;
- }
-
- if (found) {
- bblock_t *earlier_block = NULL, *later_block = NULL;
+ if (inst->opcode == BRW_OPCODE_ENDIF &&
+ prev_inst->opcode == BRW_OPCODE_ELSE) {
+ bblock_t *const else_block = prev_block;
+ backend_instruction *const else_inst = prev_inst;
- if (if_inst) {
- if (if_block->start_ip == if_block->end_ip) {
- earlier_block = if_block->prev();
- } else {
- earlier_block = if_block;
- }
- if_inst->remove(if_block);
- }
+ else_inst->remove(else_block);
+ progress = true;
+ } else if (inst->opcode == BRW_OPCODE_ENDIF &&
+ prev_inst->opcode == BRW_OPCODE_IF) {
+ bblock_t *const endif_block = block;
+ bblock_t *const if_block = prev_block;
+ backend_instruction *const endif_inst = inst;
+ backend_instruction *const if_inst = prev_inst;
- if (else_inst) {
- else_inst->remove(else_block);
- }
+ bblock_t *earlier_block = NULL, *later_block = NULL;
- if (endif_inst) {
- if (endif_block->start_ip == endif_block->end_ip) {
- later_block = endif_block->next();
- } else {
- later_block = endif_block;
- }
- endif_inst->remove(endif_block);
- }
+ if (if_block->start_ip == if_block->end_ip) {
+ earlier_block = if_block->prev();
+ } else {
+ earlier_block = if_block;
+ }
+ if_inst->remove(if_block);
- assert((earlier_block == NULL) == (later_block == NULL));
- if (earlier_block && earlier_block->can_combine_with(later_block)) {
- earlier_block->combine_with(later_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.
- */
- if (endif_block != later_block) {
- __next = earlier_block->next();
- }
+ if (endif_block->start_ip == endif_block->end_ip) {
+ later_block = endif_block->next();
+ } else {
+ later_block = endif_block;
+ }
+ endif_inst->remove(endif_block);
+
+ assert((earlier_block == NULL) == (later_block == NULL));
+ if (earlier_block && earlier_block->can_combine_with(later_block)) {
+ earlier_block->combine_with(later_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.
+ */
+ if (endif_block != later_block) {
+ __next = earlier_block->next();
}
-
- progress = true;
}
+
+ progress = true;
} else if (inst->opcode == BRW_OPCODE_ELSE &&
prev_inst->opcode == BRW_OPCODE_IF) {
bblock_t *const else_block = block;