mem2reg: fix deltrivialphis bug

4 files changed, 64 insertions, 10 deletions

diff --git a/cfg.c b/cfg.c
new file mode 100644
index 0000000..73c7559
--- /dev/null
+++ b/cfg.c
@@ -0,0 +1,43 @@
+#include "ir.h"
+
+static void
+porec(struct block ***rpo, struct block *b)
+{
+   if (wasvisited(b)) return;
+   markvisited(b);
+   if (b->s2) porec(rpo, b->s2);
+   if (b->s1) porec(rpo, b->s1);
+   *--*rpo = b;
+}
+
+void
+sortrpo(struct function *fn)
+{
+   static struct block **rpobuf;
+   struct block **rpoend, **rpo;
+   int i, ndead;
+
+   xbgrow(&rpobuf, fn->nblk);
+   rpo = rpoend = rpobuf + fn->nblk,
+
+   startbbvisit();
+   fn->entry->id = 0;
+   markvisited(fn->entry);
+   if (fn->entry->s1) porec(&rpo, fn->entry->s1);
+   if (fn->entry->s2) porec(&rpo, fn->entry->s2);
+   *--rpo = fn->entry;
+   ndead = rpo - rpobuf;
+   for (i = 1, ++rpo; rpo < rpoend; ++rpo, ++i) {
+      rpo[-1]->lnext = rpo[0];
+      rpo[0]->lprev = rpo[-1];
+      rpo[0]->id = i;
+   }
+   fn->entry->lprev = rpo[-1];
+   rpo[-1]->lnext = fn->entry;
+   for (rpo = rpobuf; ndead > 0; --ndead) {
+      (*rpo)->lnext = (*rpo)->lprev = NULL;
+      freeblk(fn, *rpo);
+   }
+}
+
+/* vim:set ts=3 sw=3 expandtab: */
diff --git a/ir.c b/ir.c
index b1045b1..834ff45 100644
--- a/ir.c
+++ b/ir.c
@@ -288,7 +288,7 @@ newinstr(void)
       assert(ninstr < arraylength(instrtab));
       t = ninstr++;
    }
-   if (instrnuse[t] > arraylength(*instrusebuf))
+   if (instruse[t] != instrusebuf[t])
       xbfree(instruse[t]);
    instruse[t] = instrusebuf[t];
    instrnuse[t] = 0;
@@ -298,8 +298,9 @@ newinstr(void)
 void
 adduse(struct block *ublk, int ui, union ref r) {
    struct use user = { ublk, ui };
+
    if (r.t != RTMP) return;
-   if (instrnuse[r.i] < arraylength(*instrusebuf)) {
+   if (instrnuse[r.i] < arraylength(instrusebuf[r.i])) {
       instruse[r.i][instrnuse[r.i]++] = user;
    } else if (instrnuse[r.i] == arraylength(*instrusebuf)) {
       struct use *use = NULL;
@@ -416,8 +417,10 @@ replcuses(union ref from, union ref to)
 void
 deluses(int ins)
 {
-   if (instrnuse[ins] > 2)
+   if (instruse[ins] != instrusebuf[ins]) {
       xbfree(instruse[ins]);
+      instruse[ins] = instrusebuf[ins];
+   }
    instrnuse[ins] = 0;
 }
 
diff --git a/optmem.c b/optmem.c
index 00be3a0..9e8d1c6 100644
--- a/optmem.c
+++ b/optmem.c
@@ -43,17 +43,15 @@ deltrivialphis(struct ssabuilder *sb, struct block *blk, union ref phiref)
 
    assert(instrtab[phiref.i].op == Ophi);
 
-   if (phiref.i == 4)
-      efmt("");
-
    for (int i = 0; i < blk->npred; ++i) {
-      if (args[i].bits == same.bits || args[i].bits == phiref.bits)
+      if (args[i].bits == same.bits || args[i].bits == phiref.bits) {
          continue; /* unique value or self-reference */
-      if (same.bits != 0) {
+      } if (same.bits != 0) {
          return phiref; /* non-trivial */
       }
       same = args[i];
    }
+
    if (same.bits == 0)
       same = UNDREF; /* the phi is unreachable or in the start block */
 
@@ -78,6 +76,7 @@ Redo:
          union ref vphi2 = deltrivialphis(sb, use->blk, it);
          if (vphi2.bits != it.bits) {
             /* deletion happened so phiref use may have changed */
+            if (same.bits == it.bits) same.bits = vphi2.bits;
             goto Redo;
          }
       }
@@ -106,6 +105,7 @@ writevar(struct ssabuilder *sb, int var, struct block *blk, union ref val)
    if (!(pcurdefs = imap_get(&sb->curdefs, var))) {
       pcurdefs = imap_set(&sb->curdefs, var, xcalloc(sb->nblk * sizeof(union ref)));
    }
+   if (val.t == RTMP) assert(instrtab[val.i].op != Onop);
    (*pcurdefs)[blk->id] = val;
 }
 
@@ -144,6 +144,7 @@ trysealrec(struct ssabuilder *sb, struct block *blk)
 {
    vec_of(struct pendingphi) *pending;
 
+Recur:
    if (bstest(sb->sealed, blk->id)) return 1;
    if (blk->id > sb->lastvisit) return 0;
    markvisited(blk);
@@ -160,8 +161,14 @@ trysealrec(struct ssabuilder *sb, struct block *blk)
                  mkref(RTMP, pending->p[i].phi));
    }
    vfree(pending);
-   if (blk->s1) trysealrec(sb, blk->s1);
-   if (blk->s2) trysealrec(sb, blk->s2);
+   if (blk->s1 && !blk->s2) {
+      blk = blk->s1;
+      goto Recur;
+   } else if (blk->s1 && blk->s2) {
+      trysealrec(sb, blk->s1);
+      blk = blk->s2;
+      goto Recur;
+   }
    return 1;
 }
 
diff --git a/regalloc.c b/regalloc.c
index 2a878d0..1018e7c 100644
--- a/regalloc.c
+++ b/regalloc.c
@@ -33,6 +33,7 @@ readvar(struct bitset *defined, enum irclass cls, int var, struct block *blk)
    union ref val;
 
    if (bstest(defined, var)) return mkref(RTMP, var);
+   assert(cls && "?");
 
    /* memoed definition */
    if (xbcap(curdefs) > blk->id && xbcap(curdefs[blk->id]) > var && curdefs[blk->id][var])