diff mbox series

[5/5] kill redundant stores (local)

Message ID 20210410223044.86100-6-luc.vanoostenryck@gmail.com (mailing list archive)
State Mainlined, archived
Headers show
Series kill more dead stores | expand

Commit Message

Luc Van Oostenryck April 10, 2021, 10:30 p.m. UTC 
A store is called 'redundant' when the corresponding location
already contains the value that will be stored.

This patch removes such stores in the case where the memops
which make them redundant is in the same basic block.

Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
---
 memops.c                                  | 5 +++++
 validation/memops/kill-redundant-store0.c | 1 -
 2 files changed, 5 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/memops.c b/memops.c
index 44d90754d279..f734f6eb7398 100644
--- a/memops.c
+++ b/memops.c
@@ -213,6 +213,11 @@  static bool try_to_kill_store(pseudo_t pseudo, struct instruction *insn,
 		/* possible partial dominance? */
 		if (dominance < 0)
 			return false;
+		if (insn->target == dom->target && insn->bb == dom->bb) {
+			// found a memop which makes the store redundant
+			kill_instruction_force(insn);
+			return false;
+		}
 		if (dom->opcode == OP_LOAD)
 			return false;
 		if (dom->is_volatile)
diff --git a/validation/memops/kill-redundant-store0.c b/validation/memops/kill-redundant-store0.c
index e911166dd953..8819938fe763 100644
--- a/validation/memops/kill-redundant-store0.c
+++ b/validation/memops/kill-redundant-store0.c
@@ -7,7 +7,6 @@  void foo(int *ptr)
 /*
  * check-name: kill-redundant-store0
  * check-command: test-linearize -Wno-decl $file
- * check-known-to-fail
  *
  * check-output-ignore
  * check-output-excludes: store