diff mbox series

[6/9] unop: simplify ~(x + C) --> ~C - x

Message ID 20201023163939.58359-7-luc.vanoostenryck@gmail.com (mailing list archive)
State Mainlined, archived
Headers show
Series basic unop simplifications | expand

Commit Message

Luc Van Oostenryck Oct. 23, 2020, 4:39 p.m. UTC 
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
---
 simplify.c                              | 7 +++++++
 validation/optim/simplify-not-add-cte.c | 1 -
 2 files changed, 7 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/simplify.c b/simplify.c
index 8f6b821dcf8c..63431b3d00b1 100644
--- a/simplify.c
+++ b/simplify.c
@@ -1463,6 +1463,13 @@  static int simplify_unop(struct instruction *insn)
 
 	case OP_NOT:
 		switch (DEF_OPCODE(def, src)) {
+		case OP_ADD:
+			if (!constant(def->src2))
+				break;
+			insn->opcode = OP_SUB;	// ~(x + C) --> ~C - x
+			src = eval_unop(OP_NOT, insn->size, def->src2);
+			use_pseudo(insn, def->src1, &insn->src2);
+			return replace_pseudo(insn, &insn->src1, src);
 		case OP_NOT:		// ~(~x) --> x
 			return replace_with_pseudo(insn, def->src);
 		}
diff --git a/validation/optim/simplify-not-add-cte.c b/validation/optim/simplify-not-add-cte.c
index cf7fe2f27258..6594012b5077 100644
--- a/validation/optim/simplify-not-add-cte.c
+++ b/validation/optim/simplify-not-add-cte.c
@@ -5,7 +5,6 @@  int foo(int x) { return ~(x + C) == (~C - x); }
 /*
  * check-name: simplify-not-add-cte
  * check-command: test-linearize -Wno-decl $file
- * check-known-to-fail
  *
  * check-output-ignore
  * check-output-contains: ret\\..*\\$1