diff options
| -rw-r--r-- | fold.c | 50 |
1 files changed, 27 insertions, 23 deletions
diff --git a/fold.c b/fold.c index dde3114..2c72999 100644 --- a/fold.c +++ b/fold.c @@ -65,23 +65,29 @@ update(int t, int m, Fn *fn) } } +static int +deadedge(int s, int d) +{ + Edge *e; + + e = edge[s]; + if (e[0].dest == d && !e[0].dead) + return 0; + if (e[1].dest == d && !e[1].dead) + return 0; + return 1; +} + static void visitphi(Phi *p, int n, Fn *fn) { - int v, m, dead; + int v; uint a; v = Top; - for (a=0; a<p->narg; a++) { - m = p->blk[a]->id; - dead = 1; - if (edge[m][0].dest == n) - dead &= edge[m][0].dead; - if (edge[m][1].dest == n) - dead &= edge[m][1].dead; - if (!dead) + for (a=0; a<p->narg; a++) + if (!deadedge(p->blk[a]->id, n)) v = latmerge(v, latval(p->arg[a])); - } update(p->to.val, v, fn); } @@ -160,17 +166,14 @@ initedge(Edge *e, Blk *s) } static int -renref(Ref *r, Fn *fn) +renref(Ref *r) { + int l; + if (rtype(*r) == RTmp) - switch (val[r->val]) { - case Top: - err("temporary %%%s is ill-defined", - fn->tmp[r->val].name); - case Bot: - break; - default: - *r = CON(val[r->val]); + if ((l=val[r->val]) != Bot) { + assert(l != Top); + *r = CON(l); return 1; } return 0; @@ -281,16 +284,17 @@ fold(Fn *fn) *pp = p->link; else { for (a=0; a<p->narg; a++) - renref(&p->arg[a], fn); + if (!deadedge(p->blk[a]->id, b->id)) + renref(&p->arg[a]); pp = &p->link; } for (i=b->ins; i-b->ins < b->nins; i++) - if (renref(&i->to, fn)) + if (renref(&i->to)) *i = (Ins){.op = ONop}; else for (n=0; n<2; n++) - renref(&i->arg[n], fn); - renref(&b->jmp.arg, fn); + renref(&i->arg[n]); + renref(&b->jmp.arg); if (b->jmp.type == JJnz && rtype(b->jmp.arg) == RCon) { b->jmp.type = JJmp; if (czero(&fn->con[b->jmp.arg.val], 0)) |