From b8709501f944cb6421c6b4c447acfe8870c4ccc1 Mon Sep 17 00:00:00 2001
From: Quentin Carbonneaux <quentin.carbonneaux@yale.edu>
Date: Mon, 18 Apr 2016 13:25:32 -0400
Subject: [PATCH] do not rewrite overwritten slots in memopt

---
 mem.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/mem.c b/mem.c
index b94f0a7..c59d7fe 100644
--- a/mem.c
+++ b/mem.c
@@ -43,6 +43,8 @@ memopt(Fn *fn)
 		/* specific to NAlign == 3 */
 		assert(rtype(i->to) == RTmp);
 		t = &fn->tmp[i->to.val];
+		if (t->ndef != 1)
+			goto Skip;
 		k = -1;
 		s = -1;
 		for (u=t->use; u != &t->use[t->nuse]; u++) {