2 files changed, 5 insertions, 2 deletions
diff --git a/simplify.c b/simplify.c
index fb63aa9b..db2fba7f 100644
--- a/simplify.c
+++ b/simplify.c
@@ -607,9 +607,13 @@ static int simplify_seteq_setne(struct instruction *insn, long long value)
 		remove_usage(old, &insn->src1);
 		return REPEAT_CSE;
 
+	case OP_SEXT:
+		if (value && (def->orig_type->bit_size == 1))
+			break;
+		/* Fall through */
 	case OP_ZEXT:
 		// Convert:
-		//	zext.m	%s <- (1) %a
+		//	*ext.m	%s <- (1) %a
 		//	setne.1 %r <- %s, $0
 		// into:
 		//	setne.1 %s <- %a, $0
diff --git a/validation/optim/bool-sext-test.c b/validation/optim/bool-sext-test.c
index 0ca3dea9..bd85e06e 100644
--- a/validation/optim/bool-sext-test.c
+++ b/validation/optim/bool-sext-test.c
@@ -6,7 +6,6 @@ _Bool nes1(  signed char a) { return a != 1; }
 /*
  * check-name: bool-sext-test
  * check-command: test-linearize -Wno-decl $file
- * check-known-to-fail
  *
  * check-output-ignore
  * check-output-excludes: sext\\.