diff options
| -rw-r--r-- | fold.c | 97 |
1 files changed, 57 insertions, 40 deletions
diff --git a/fold.c b/fold.c index 34b6165..b7bc201 100644 --- a/fold.c +++ b/fold.c @@ -19,9 +19,14 @@ static Use **usewrk; static uint nuse; static int -czero(Con *c) +czero(Con *c, int w) { - return c->type == CBits && c->bits.i == 0; + if (c->type != CBits) + return 0; + if (w) + return !c->bits.i; + else + return !(c->bits.i & 0xffffffff); } static int @@ -67,21 +72,25 @@ update(int t, int v, Fn *fn) vgrow(&usewrk, ++nuse); usewrk[nuse-1] = &tmp->use[u]; } + val[t] = v; } } static void visitphi(Phi *p, int n, Fn *fn) { - int v, dead; + int v, m, dead; uint a; v = Top; for (a=0; a<p->narg; a++) { - if (edge[n][0].dest == p->blk[a]->id) - dead = edge[n][0].dead; + m = p->blk[a]->id; + if (edge[m][0].dest == n) + dead = edge[m][0].dead; + else if (edge[m][1].dest == n) + dead = edge[m][1].dead; else - dead = edge[n][1].dead; + die("invalid phi argument"); if (!dead) v = latmerge(v, latval(p->arg[a])); } @@ -109,7 +118,7 @@ visitins(Ins *i, Fn *fn) v = opfold(i->op, i->cls, &fn->con[l], &fn->con[r], fn); } else v = Bot; - assert(v != Top); + /* fprintf(stderr, "\nvisiting %s (%p)", opdesc[i->op].name, (void *)i); */ update(i->to.val, v, fn); } @@ -126,7 +135,7 @@ visitjmp(Blk *b, int n, Fn *fn) edge[n][0].work = &edge[n][1]; flowrk = &edge[n][0]; } - else if (czero(&fn->con[l])) { + else if (czero(&fn->con[l], 0)) { assert(edge[n][0].dead); edge[n][1].work = flowrk; flowrk = &edge[n][1]; @@ -163,7 +172,7 @@ initedge(Edge *e, Blk *s) void fold(Fn *fn) { - Edge *e; + Edge *e, start; Use *u; Blk *b; Phi *p; @@ -174,26 +183,16 @@ fold(Fn *fn) edge = emalloc(fn->nblk * sizeof edge[0]); usewrk = vnew(0, sizeof usewrk[0]); - for (b=fn->start; b; b=b->link) { - for (p=b->phi; p; p=p->link) - val[p->to.val] = Top; - for (i=b->ins; i-b->ins < b->nins; i++) - if (rtype(i->to) == RTmp) { - if (opdesc[i->op].cfold) - val[i->to.val] = Top; - else - val[i->to.val] = Bot; - } - } + for (n=0; n<fn->ntmp; n++) + val[n] = Top; for (n=0; n<fn->nblk; n++) { b = fn->rpo[n]; b->visit = 0; initedge(&edge[n][0], b->s1); initedge(&edge[n][1], b->s2); } - assert(fn->start->id == 0); - edge[0][0].work = &edge[0][1]; - flowrk = &edge[0][0]; + initedge(&start, fn->start); + flowrk = &start; nuse = 0; /* 1. find out constants and dead cfg edges */ @@ -225,15 +224,16 @@ fold(Fn *fn) visitphi(u->u.phi, u->bid, fn); continue; } + n = u->bid; + b = fn->rpo[n]; if (b->visit == 0) continue; - n = u->bid; switch (u->type) { case UIns: visitins(u->u.ins, fn); break; case UJmp: - visitjmp(fn->rpo[n], n, fn); + visitjmp(b, n, fn); break; default: die("unreachable"); @@ -243,6 +243,20 @@ fold(Fn *fn) break; } + if (debug['F']) { + fprintf(stderr, "\n> SCCP findings:\n"); + for (n=Tmp0; n<fn->ntmp; n++) { + fprintf(stderr, "%10s: ", fn->tmp[n].name); + if (val[n] == Top) + fprintf(stderr, "Top"); + else if (val[n] == Bot) + fprintf(stderr, "Bot"); + else + printref(CON(val[n]), fn, stderr); + fprintf(stderr, "\n"); + } + } + /* 2. trim dead code, replace constants */ free(val); @@ -265,10 +279,8 @@ foldint(Con *res, int op, int w, Con *cl, Con *cr) lab = 0; l.s = cl->bits.i; - r.s = cl->bits.i; - switch (op) { - case OAdd: - x = l.u + r.u; + r.s = cr->bits.i; + if (op == OAdd) { if (cl->type == CAddr) { if (cr->type == CAddr) err("undefined addition (addr + addr)"); @@ -276,9 +288,8 @@ foldint(Con *res, int op, int w, Con *cl, Con *cr) } else if (cr->type == CAddr) lab = cr->label; - break; - case OSub: - x = l.u - r.u; + } + else if (op == OSub) { if (cl->type == CAddr) { if (cr->type != CAddr) lab = cl->label; @@ -287,7 +298,12 @@ foldint(Con *res, int op, int w, Con *cl, Con *cr) } else if (cr->type == CAddr) err("undefined substraction (num - addr)"); - break; + } + else if (cl->type == CAddr || cr->type == CAddr) + err("invalid address operand for '%s'", opdesc[op].name); + switch (op) { + case OAdd: x = l.u + r.u; break; + case OSub: x = l.u - r.u; break; case ODiv: x = l.s / r.s; break; case ORem: x = l.s % r.s; break; case OUDiv: x = l.u / r.u; break; @@ -367,6 +383,7 @@ foldint(Con *res, int op, int w, Con *cl, Con *cr) die("unreachable"); } *res = (Con){lab ? CAddr : CBits, .bits={.i=x}}; + res->bits.i = x; if (lab) strcpy(res->label, lab); } @@ -377,6 +394,8 @@ foldflt(Con *res, int op, int w, Con *cl, Con *cr) float xs, ls, rs; double xd, ld, rd; + if (cl->type != CBits || cr->type != CBits) + err("invalid address operand for '%s'", opdesc[op].name); if (w) { ld = cl->bits.d; rd = cr->bits.d; @@ -387,7 +406,7 @@ foldflt(Con *res, int op, int w, Con *cl, Con *cr) case OMul: xd = ld * rd; break; case OSitof: xd = cl->bits.i; break; case OExts: xd = cl->bits.s; break; - case OCast: xd = cl->bits.d; break; + case OCast: xd = ld; break; default: die("unreachable"); } *res = (Con){CBits, .bits={.d=xd}, .flt=2}; @@ -401,7 +420,7 @@ foldflt(Con *res, int op, int w, Con *cl, Con *cr) case OMul: xs = ls * rs; break; case OSitof: xs = cl->bits.i; break; case OTruncd: xs = cl->bits.d; break; - case OCast: xs = cl->bits.s; break; + case OCast: xs = ls; break; default: die("unreachable"); } *res = (Con){CBits, .bits={.s=xs}, .flt=1}; @@ -415,21 +434,19 @@ opfold(int op, int cls, Con *cl, Con *cr, Fn *fn) Con c; if ((op == ODiv || op == OUDiv - || op == ORem || op == OURem) && czero(cr)) + || op == ORem || op == OURem) && czero(cr, KWIDE(cls))) err("null divisor in '%s'", opdesc[op].name); if (cls == Kw || cls == Kl) foldint(&c, op, cls == Kl, cl, cr); - else { - if (cl->type != CBits || cr->type != CBits) - err("invalid address operand for '%s'", opdesc[op].name); + else foldflt(&c, op, cls == Kd, cl, cr); - } if (c.type == CBits) nc = getcon(c.bits.i, fn).val; else { nc = fn->ncon; vgrow(&fn->con, ++fn->ncon); } + assert(!(cls == Ks || cls == Kd) || c.flt); fn->con[nc] = c; return nc; } |