diff mbox series

[8/9] unop: simplify ~(x ^ C) --> x ^ ~C

Message ID 20201023163939.58359-9-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                              | 6 ++++++
 validation/optim/simplify-not-xor-cte.c | 1 -
 2 files changed, 6 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/simplify.c b/simplify.c
index 8173777652af..1b6e1cc2313b 100644
--- a/simplify.c
+++ b/simplify.c
@@ -1478,6 +1478,12 @@  static int simplify_unop(struct instruction *insn)
 			insn->opcode = OP_ADD;	// ~(C - x) --> x + ~C
 			insn->src2 = eval_unop(OP_NOT, insn->size, def->src1);
 			return replace_pseudo(insn, &insn->src1, def->src2);
+		case OP_XOR:
+			if (!constant(def->src2))
+				break;
+			insn->opcode = OP_XOR;	// ~(x ^ C) --> x ^ ~C
+			insn->src2 = eval_unop(OP_NOT, insn->size, def->src2);
+			return replace_pseudo(insn, &insn->src1, def->src1);
 		}
 		break;
 	case OP_NEG:
diff --git a/validation/optim/simplify-not-xor-cte.c b/validation/optim/simplify-not-xor-cte.c
index d3046f208fce..c3c803b30250 100644
--- a/validation/optim/simplify-not-xor-cte.c
+++ b/validation/optim/simplify-not-xor-cte.c
@@ -5,7 +5,6 @@  int foo(int x) { return ~(x ^ C) == (x ^ ~C); }
 /*
  * check-name: simplify-not-xor-cte
  * check-command: test-linearize -Wno-decl $file
- * check-known-to-fail
  *
  * check-output-ignore
  * check-output-contains: ret\\..*\\$1