diff options
| -rw-r--r-- | all.h | 3 | ||||
| -rw-r--r-- | main.c | 1 | ||||
| -rw-r--r-- | ssa.c | 21 |
3 files changed, 19 insertions, 6 deletions
diff --git a/all.h b/all.h index ae39145..fc26a61 100644 --- a/all.h +++ b/all.h @@ -248,7 +248,7 @@ struct Use { UIns, UJmp, } type; - int bid; + uint bid; union { Ins *ins; Phi *phi; @@ -279,6 +279,7 @@ struct Alias { struct Tmp { char name[NString]; + uint bid; /* id of a defining block */ Use *use; uint ndef, nuse; uint cost; diff --git a/main.c b/main.c index 033ed9c..99ab330 100644 --- a/main.c +++ b/main.c @@ -65,6 +65,7 @@ func(Fn *fn) fillpreds(fn); filluse(fn); memopt(fn); + filluse(fn); ssa(fn); filluse(fn); ssacheck(fn); diff --git a/ssa.c b/ssa.c index 7ae8117..c098438 100644 --- a/ssa.c +++ b/ssa.c @@ -47,6 +47,7 @@ filluse(Fn *fn) /* todo, is this the correct file? */ tmp = fn->tmp; for (t=Tmp0; t<fn->ntmp; t++) { + tmp[t].bid = -1u; tmp[t].ndef = 0; tmp[t].nuse = 0; tmp[t].cls = 0; @@ -59,6 +60,7 @@ filluse(Fn *fn) for (p=b->phi; p; p=p->link) { assert(rtype(p->to) == RTmp); tp = p->to.val; + tmp[tp].bid = b->id; tmp[tp].ndef++; tmp[tp].cls = p->cls; tp = phicls(tp, fn->tmp); @@ -84,6 +86,7 @@ filluse(Fn *fn) w = WFull; t = i->to.val; tmp[t].width = w; + tmp[t].bid = b->id; tmp[t].ndef++; tmp[t].cls = i->cls; } @@ -111,9 +114,10 @@ phiins(Fn *fn) Blk *a, *b, **blist, **be, **bp; Ins *i; Phi *p; + Use *use; Ref r; - int t, nt; - uint n; + int t, nt, ok; + uint n, defb; short k; bsinit(u, fn->nblk); @@ -125,8 +129,15 @@ phiins(Fn *fn) fn->tmp[t].visit = 0; if (fn->tmp[t].phi != 0) continue; - if (fn->tmp[t].ndef == 1) - continue; + if (fn->tmp[t].ndef == 1) { + ok = 1; + defb = fn->tmp[t].bid; + use = fn->tmp[t].use; + for (n=fn->tmp[t].nuse; n--; use++) + ok &= use->bid == defb; + if (ok || defb == fn->start->id) + continue; + } bszero(u); k = -1; bp = be; @@ -293,7 +304,7 @@ renblk(Blk *b, Name **stk, Fn *fn) renblk(s, stk, fn); } -/* require rpo and ndef */ +/* require rpo and use */ void ssa(Fn *fn) { |