1 files changed, 4 insertions, 1 deletions
diff --git a/optmem.c b/optmem.c
index 9e8d1c6..1c137b7 100644
--- a/optmem.c
+++ b/optmem.c
@@ -184,8 +184,8 @@ void
 mem2reg(struct function *fn)
 {
    static struct bitset ssealed[4];
-   struct block *blk = fn->entry;
    struct ssabuilder sb = { .nblk = fn->nblk };
+   struct block *blk;
 
    sb.pendingphis = xcalloc(fn->nblk * sizeof *sb.pendingphis);
    if (fn->nblk <= 64 * arraylength(ssealed)) {
@@ -195,6 +195,9 @@ mem2reg(struct function *fn)
       sb.sealed = xcalloc(BSSIZE(fn->nblk) * sizeof *sb.sealed);
    }
 
+   sortrpo(fn);
+   blk = fn->entry;
+
    do {
       for (int i = 0; i < blk->ins.n; ++i) {
          struct use *use, *uend;