commit 03083f653dabf85522f6e9580cdc0e450b6432c6
parent f2b2256ebee7e402aa6a8f02b4bf885b217c6494
Author: Quentin Carbonneaux <quentin.carbonneaux@yale.edu>
Date: Thu, 7 Apr 2016 14:20:47 -0400
adjustments in sccp
Diffstat:
| M | fold.c | | | 97 | ++++++++++++++++++++++++++++++++++++++++++++++--------------------------------- |
1 file changed, 57 insertions(+), 40 deletions(-)
diff --git 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;
}
