2 files changed, 10 insertions, 1 deletions
diff --git a/simplify.c b/simplify.c
index 1ac000e5..2549860e 100644
--- a/simplify.c
+++ b/simplify.c
@@ -1008,6 +1008,16 @@ static int simplify_cast(struct instruction *insn)
 			return replace_pseudo(insn, &insn->src1, def->src);
 		}
 		break;
+	case OP_ZEXT:
+	case OP_SEXT:
+		switch (insn->opcode) {
+		case OP_TRUNC:
+			osize = def->orig_type->bit_size;
+			if (size == osize)
+				return replace_with_pseudo(insn, def->src);
+			break;
+		}
+		break;
 	}
 
 	return 0;
diff --git a/validation/optim/ext-trunc-same.c b/validation/optim/ext-trunc-same.c
index 634fdb87..2bfcf030 100644
--- a/validation/optim/ext-trunc-same.c
+++ b/validation/optim/ext-trunc-same.c
@@ -11,7 +11,6 @@ short ueq(unsigned short x)
 /*
  * check-name: ext-trunc-same
  * check-command: test-linearize -Wno-decl $file
- * check-known-to-fail
  *
  * check-output-ignore
  * check-output-excludes: trunc\\.