#include "gc.h"
void
cgen(Node *n, Node *nn)
{
Node *l, *r;
Prog *p1;
Node nod, nod1, nod2, nod3, nod4;
int o;
long v, curs;
if(debug['g']) {
prtree(nn, "cgen lhs");
prtree(n, "cgen");
}
if(n == Z || n->type == T)
return;
if(typesuv[n->type->etype]) {
sugen(n, nn, n->type->width);
return;
}
l = n->left;
r = n->right;
o = n->op;
if(n->addable >= INDEXED) {
if(nn == Z) {
switch(o) {
default:
nullwarn(Z, Z);
break;
case OINDEX:
nullwarn(l, r);
break;
}
return;
}
gmove(n, nn);
return;
}
curs = cursafe;
if(n->complex >= FNX)
if(l->complex >= FNX)
if(r != Z && r->complex >= FNX)
switch(o) {
default:
regret(&nod, r);
cgen(r, &nod);
regsalloc(&nod1, r);
gopcode(OAS, &nod, Z, &nod1);
regfree(&nod);
nod = *n;
nod.right = &nod1;
cgen(&nod, nn);
return;
case OFUNC:
case OCOMMA:
case OANDAND:
case OOROR:
case OCOND:
case ODOT:
break;
}
switch(o) {
default:
diag(n, "unknown op in cgen: %O", o);
break;
case OAS:
if(l->op == OBIT)
goto bitas;
if(l->addable >= INDEXED && l->complex < FNX) {
if(nn != Z || r->addable < INDEXED) {
if(r->complex >= FNX && nn == Z)
regret(&nod, r);
else
regalloc(&nod, r, nn);
cgen(r, &nod);
gmove(&nod, l);
if(nn != Z)
gmove(&nod, nn);
regfree(&nod);
} else
gmove(r, l);
break;
}
if(l->complex >= r->complex) {
reglcgen(&nod1, l, Z);
if(r->addable >= INDEXED) {
gmove(r, &nod1);
if(nn != Z)
gmove(r, nn);
regfree(&nod1);
break;
}
regalloc(&nod, r, nn);
cgen(r, &nod);
} else {
regalloc(&nod, r, nn);
cgen(r, &nod);
reglcgen(&nod1, l, Z);
}
gmove(&nod, &nod1);
regfree(&nod);
regfree(&nod1);
break;
bitas:
n = l->left;
regalloc(&nod, r, nn);
if(l->complex >= r->complex) {
reglcgen(&nod1, n, Z);
cgen(r, &nod);
} else {
cgen(r, &nod);
reglcgen(&nod1, n, Z);
}
regalloc(&nod2, n, Z);
gopcode(OAS, &nod1, Z, &nod2);
bitstore(l, &nod, &nod1, &nod2, nn);
break;
case OBIT:
if(nn == Z) {
nullwarn(l, Z);
break;
}
bitload(n, &nod, Z, Z, nn);
gopcode(OAS, &nod, Z, nn);
regfree(&nod);
break;
case OADD:
case OSUB:
case OAND:
case OOR:
case OXOR:
case OLSHR:
case OASHL:
case OASHR:
/*
* immediate operands
*/
if(nn != Z)
if(r->op == OCONST)
if(!typefd[n->type->etype]) {
cgen(l, nn);
if(r->vconst == 0)
if(o != OAND)
break;
if(nn != Z)
gopcode(o, r, Z, nn);
break;
}
case OLMUL:
case OLDIV:
case OLMOD:
case OMUL:
case ODIV:
case OMOD:
if(nn == Z) {
nullwarn(l, r);
break;
}
if(o == OMUL || o == OLMUL) {
if(mulcon(n, nn))
break;
}
if(l->complex >= r->complex) {
regalloc(&nod, l, nn);
cgen(l, &nod);
regalloc(&nod1, r, Z);
cgen(r, &nod1);
gopcode(o, &nod1, Z, &nod);
} else {
regalloc(&nod, r, nn);
cgen(r, &nod);
regalloc(&nod1, l, Z);
cgen(l, &nod1);
gopcode(o, &nod, &nod1, &nod);
}
gopcode(OAS, &nod, Z, nn);
regfree(&nod);
regfree(&nod1);
break;
case OASLSHR:
case OASASHL:
case OASASHR:
case OASAND:
case OASADD:
case OASSUB:
case OASXOR:
case OASOR:
if(l->op == OBIT)
goto asbitop;
if(r->op == OCONST)
if(!typefd[r->type->etype])
if(!typefd[n->type->etype]) {
if(l->addable < INDEXED)
reglcgen(&nod2, l, Z);
else
nod2 = *l;
regalloc(&nod, r, nn);
gopcode(OAS, &nod2, Z, &nod);
gopcode(o, r, Z, &nod);
gopcode(OAS, &nod, Z, &nod2);
regfree(&nod);
if(l->addable < INDEXED)
regfree(&nod2);
break;
}
case OASLMUL:
case OASLDIV:
case OASLMOD:
case OASMUL:
case OASDIV:
case OASMOD:
if(l->op == OBIT)
goto asbitop;
if(l->complex >= r->complex) {
if(l->addable < INDEXED)
reglcgen(&nod2, l, Z);
else
nod2 = *l;
regalloc(&nod1, r, Z);
cgen(r, &nod1);
} else {
regalloc(&nod1, r, Z);
cgen(r, &nod1);
if(l->addable < INDEXED)
reglcgen(&nod2, l, Z);
else
nod2 = *l;
}
regalloc(&nod, n, nn);
gmove(&nod2, &nod);
gopcode(o, &nod1, Z, &nod);
gmove(&nod, &nod2);
if(nn != Z)
gopcode(OAS, &nod, Z, nn);
regfree(&nod);
regfree(&nod1);
if(l->addable < INDEXED)
regfree(&nod2);
break;
asbitop:
regalloc(&nod4, n, nn);
if(l->complex >= r->complex) {
bitload(l, &nod, &nod1, &nod2, &nod4);
regalloc(&nod3, r, Z);
cgen(r, &nod3);
} else {
regalloc(&nod3, r, Z);
cgen(r, &nod3);
bitload(l, &nod, &nod1, &nod2, &nod4);
}
gmove(&nod, &nod4);
gopcode(o, &nod3, Z, &nod4);
regfree(&nod3);
gmove(&nod4, &nod);
regfree(&nod4);
bitstore(l, &nod, &nod1, &nod2, nn);
break;
case OADDR:
if(nn == Z) {
nullwarn(l, Z);
break;
}
lcgen(l, nn);
break;
case OFUNC:
if(l->complex >= FNX) {
if(l->op != OIND)
diag(n, "bad function call");
regret(&nod, l->left);
cgen(l->left, &nod);
regsalloc(&nod1, l->left);
gopcode(OAS, &nod, Z, &nod1);
regfree(&nod);
nod = *n;
nod.left = &nod2;
nod2 = *l;
nod2.left = &nod1;
nod2.complex = 1;
cgen(&nod, nn);
return;
}
o = reg[REGARG];
gargs(r, &nod, &nod1);
if(l->addable < INDEXED) {
reglcgen(&nod, l, Z);
gopcode(OFUNC, Z, Z, &nod);
regfree(&nod);
} else
gopcode(OFUNC, Z, Z, l);
if(REGARG)
if(o != reg[REGARG])
reg[REGARG]--;
if(nn != Z) {
regret(&nod, n);
gopcode(OAS, &nod, Z, nn);
regfree(&nod);
}
break;
case OIND:
if(nn == Z) {
nullwarn(l, Z);
break;
}
regialloc(&nod, n, nn);
r = l;
while(r->op == OADD)
r = r->right;
if(sconst(r)) {
v = r->vconst;
r->vconst = 0;
cgen(l, &nod);
nod.xoffset += v;
r->vconst = v;
} else
cgen(l, &nod);
regind(&nod, n);
gopcode(OAS, &nod, Z, nn);
regfree(&nod);
break;
case OEQ:
case ONE:
case OLE:
case OLT:
case OGE:
case OGT:
case OLO:
case OLS:
case OHI:
case OHS:
if(nn == Z) {
nullwarn(l, r);
break;
}
boolgen(n, 1, nn);
break;
case OANDAND:
case OOROR:
boolgen(n, 1, nn);
if(nn == Z)
patch(p, pc);
break;
case ONOT:
if(nn == Z) {
nullwarn(l, Z);
break;
}
boolgen(n, 1, nn);
break;
case OCOMMA:
cgen(l, Z);
cgen(r, nn);
break;
case OCAST:
if(nn == Z) {
nullwarn(l, Z);
break;
}
/*
* convert from types l->n->nn
*/
if(nocast(l->type, n->type)) {
if(nocast(n->type, nn->type)) {
cgen(l, nn);
break;
}
}
regalloc(&nod, l, nn);
cgen(l, &nod);
regalloc(&nod1, n, &nod);
gopcode(OAS, &nod, Z, &nod1);
gopcode(OAS, &nod1, Z, nn);
regfree(&nod1);
regfree(&nod);
break;
case ODOT:
sugen(l, nodrat, l->type->width);
if(nn != Z) {
warn(n, "non-interruptable temporary");
nod = *nodrat;
if(!r || r->op != OCONST) {
diag(n, "DOT and no offset");
break;
}
nod.xoffset += (long)r->vconst;
nod.type = n->type;
cgen(&nod, nn);
}
break;
case OCOND:
bcgen(l, 1);
p1 = p;
cgen(r->left, nn);
gbranch(OGOTO);
patch(p1, pc);
p1 = p;
cgen(r->right, nn);
patch(p1, pc);
break;
case OPOSTINC:
case OPOSTDEC:
v = 1;
if(l->type->etype == TIND)
v = l->type->link->width;
if(o == OPOSTDEC)
v = -v;
if(l->op == OBIT)
goto bitinc;
if(nn == Z)
goto pre;
if(l->addable < INDEXED)
reglcgen(&nod2, l, Z);
else
nod2 = *l;
regalloc(&nod, l, nn);
gopcode(OAS, &nod2, Z, &nod);
regalloc(&nod1, l, Z);
if(typefd[l->type->etype]) {
regalloc(&nod3, l, Z);
if(v < 0) {
gopcode(OAS, nodfconst(-v), Z, &nod3);
gopcode(OSUB, &nod3, &nod, &nod1);
} else {
gopcode(OAS, nodfconst(v), Z, &nod3);
gopcode(OADD, &nod3, &nod, &nod1);
}
regfree(&nod3);
} else
gopcode(OADD, nodconst(v), &nod, &nod1);
gopcode(OAS, &nod1, Z, &nod2);
regfree(&nod);
regfree(&nod1);
if(l->addable < INDEXED)
regfree(&nod2);
break;
case OPREINC:
case OPREDEC:
v = 1;
if(l->type->etype == TIND)
v = l->type->link->width;
if(o == OPREDEC)
v = -v;
if(l->op == OBIT)
goto bitinc;
pre:
if(l->addable < INDEXED)
reglcgen(&nod2, l, Z);
else
nod2 = *l;
regalloc(&nod, l, nn);
gopcode(OAS, &nod2, Z, &nod);
if(typefd[l->type->etype]) {
regalloc(&nod3, l, Z);
if(v < 0) {
gopcode(OAS, nodfconst(-v), Z, &nod3);
gopcode(OSUB, &nod3, Z, &nod);
} else {
gopcode(OAS, nodfconst(v), Z, &nod3);
gopcode(OADD, &nod3, Z, &nod);
}
regfree(&nod3);
} else
gopcode(OADD, nodconst(v), Z, &nod);
gopcode(OAS, &nod, Z, &nod2);
if(nn && l->op == ONAME) /* in x=++i, emit USED(i) */
gins(ANOP, l, Z);
regfree(&nod);
if(l->addable < INDEXED)
regfree(&nod2);
break;
bitinc:
if(nn != Z && (o == OPOSTINC || o == OPOSTDEC)) {
bitload(l, &nod, &nod1, &nod2, Z);
gopcode(OAS, &nod, Z, nn);
gopcode(OADD, nodconst(v), Z, &nod);
bitstore(l, &nod, &nod1, &nod2, Z);
break;
}
bitload(l, &nod, &nod1, &nod2, nn);
gopcode(OADD, nodconst(v), Z, &nod);
bitstore(l, &nod, &nod1, &nod2, nn);
break;
}
cursafe = curs;
}
void
reglcgen(Node *t, Node *n, Node *nn)
{
Node *r;
long v;
regialloc(t, n, nn);
if(n->op == OIND) {
r = n->left;
while(r->op == OADD)
r = r->right;
if(sconst(r)) {
v = r->vconst;
r->vconst = 0;
lcgen(n, t);
t->xoffset += v;
r->vconst = v;
regind(t, n);
return;
}
}
lcgen(n, t);
regind(t, n);
}
void
lcgen(Node *n, Node *nn)
{
Prog *p1;
Node nod;
if(debug['g']) {
prtree(nn, "lcgen lhs");
prtree(n, "lcgen");
}
if(n == Z || n->type == T)
return;
if(nn == Z) {
nn = &nod;
regalloc(&nod, n, Z);
}
switch(n->op) {
default:
if(n->addable < INDEXED) {
diag(n, "unknown op in lcgen: %O", n->op);
break;
}
nod = *n;
nod.op = OADDR;
nod.left = n;
nod.right = Z;
nod.type = types[TIND];
gopcode(OAS, &nod, Z, nn);
break;
case OCOMMA:
cgen(n->left, n->left);
lcgen(n->right, nn);
break;
case OIND:
cgen(n->left, nn);
break;
case OCOND:
bcgen(n->left, 1);
p1 = p;
lcgen(n->right->left, nn);
gbranch(OGOTO);
patch(p1, pc);
p1 = p;
lcgen(n->right->right, nn);
patch(p1, pc);
break;
}
}
void
bcgen(Node *n, int true)
{
if(n->type == T)
gbranch(OGOTO);
else
boolgen(n, true, Z);
}
void
boolgen(Node *n, int true, Node *nn)
{
int o;
Prog *p1, *p2;
Node *l, *r, nod, nod1;
long curs;
if(debug['g']) {
prtree(nn, "boolgen lhs");
prtree(n, "boolgen");
}
curs = cursafe;
l = n->left;
r = n->right;
switch(n->op) {
default:
regalloc(&nod, n, nn);
cgen(n, &nod);
if(nn == Z || typefd[n->type->etype]) {
o = ONE;
if(true)
o = comrel[relindex(o)];
if(typefd[n->type->etype]) {
nodreg(&nod1, n, NREG+FREGZERO);
gopcode(o, &nod, &nod1, Z);
} else
gopcode(o, &nod, Z, Z);
regfree(&nod);
goto com;
}
if(true)
gopcode(OCOND, &nod, nodconst(0), &nod);
else
gopcode(OCOND, nodconst(1), &nod, &nod);
gopcode(OAS, &nod, Z, nn);
regfree(&nod);
break;
case OCONST:
o = vconst(n);
if(!true)
o = !o;
gbranch(OGOTO);
if(o) {
p1 = p;
gbranch(OGOTO);
patch(p1, pc);
}
goto com;
case OCOMMA:
cgen(l, Z);
boolgen(r, true, nn);
break;
case ONOT:
boolgen(l, !true, nn);
break;
case OCOND:
bcgen(l, 1);
p1 = p;
bcgen(r->left, true);
p2 = p;
gbranch(OGOTO);
patch(p1, pc);
p1 = p;
bcgen(r->right, !true);
patch(p2, pc);
p2 = p;
gbranch(OGOTO);
patch(p1, pc);
patch(p2, pc);
goto com;
case OANDAND:
if(!true)
goto caseor;
caseand:
bcgen(l, true);
p1 = p;
bcgen(r, !true);
p2 = p;
patch(p1, pc);
gbranch(OGOTO);
patch(p2, pc);
goto com;
case OOROR:
if(!true)
goto caseand;
caseor:
bcgen(l, !true);
p1 = p;
bcgen(r, !true);
p2 = p;
gbranch(OGOTO);
patch(p1, pc);
patch(p2, pc);
goto com;
case OEQ:
case ONE:
case OLE:
case OLT:
case OGE:
case OGT:
case OHI:
case OHS:
case OLO:
case OLS:
o = n->op;
if(true)
o = comrel[relindex(o)];
if(l->complex >= FNX && r->complex >= FNX) {
regret(&nod, r);
cgen(r, &nod);
regsalloc(&nod1, r);
gopcode(OAS, &nod, Z, &nod1);
regfree(&nod);
nod = *n;
nod.right = &nod1;
boolgen(&nod, true, nn);
break;
}
if(nn != Z && !typefd[l->type->etype]) {
if(l->complex >= r->complex) {
regalloc(&nod1, l, nn);
cgen(l, &nod1);
regalloc(&nod, r, Z);
cgen(r, &nod);
} else {
regalloc(&nod, r, nn);
cgen(r, &nod);
regalloc(&nod1, l, Z);
cgen(l, &nod1);
}
switch(o) {
case OEQ:
gopcode(OSUB, &nod1, &nod, &nod);
gopcode(OCOND, &nod, nodconst(0), &nod);
break;
case ONE:
gopcode(OSUB, &nod1, &nod, &nod);
gopcode(OCOND, nodconst(1), &nod, &nod);
break;
case OLE:
gopcode(OCOMMA, &nod1, &nod, &nod);
break;
case OGT:
gopcode(OCOMMA, &nod1, &nod, &nod);
gopcode(OXOR, nodconst(1), &nod, &nod);
break;
case OLT:
gopcode(OCOMMA, &nod, &nod1, &nod);
gopcode(OXOR, nodconst(1), &nod, &nod);
break;
case OGE:
gopcode(OCOMMA, &nod, &nod1, &nod);
break;
case OLS:
gopcode(OCOND, &nod1, &nod, &nod);
break;
case OHI:
gopcode(OCOND, &nod1, &nod, &nod);
gopcode(OXOR, nodconst(1), &nod, &nod);
break;
case OLO:
gopcode(OCOND, &nod, &nod1, &nod);
gopcode(OXOR, nodconst(1), &nod, &nod);
break;
case OHS:
gopcode(OCOND, &nod, &nod1, &nod);
break;
}
gopcode(OAS, &nod, Z, nn);
regfree(&nod);
regfree(&nod1);
break;
}
if(sconst(l)) {
switch(o) {
default:
if(l->vconst != 0)
break;
case OGT:
case OHI:
case OLE:
case OLS:
regalloc(&nod, r, nn);
cgen(r, &nod);
gopcode(o, l, &nod, Z);
regfree(&nod);
goto com;
}
}
if(sconst(r)) {
switch(o) {
default:
if(r->vconst != 0)
break;
case OGE:
case OHS:
case OLT:
case OLO:
regalloc(&nod, l, nn);
cgen(l, &nod);
gopcode(o, &nod, r, Z);
regfree(&nod);
goto com;
}
}
if(l->complex >= r->complex) {
regalloc(&nod1, l, nn);
cgen(l, &nod1);
regalloc(&nod, r, Z);
cgen(r, &nod);
} else {
regalloc(&nod, r, nn);
cgen(r, &nod);
regalloc(&nod1, l, Z);
cgen(l, &nod1);
}
gopcode(o, &nod1, &nod, Z);
regfree(&nod);
regfree(&nod1);
com:
if(nn != Z) {
p1 = p;
gopcode(OAS, nodconst(1), Z, nn);
gbranch(OGOTO);
p2 = p;
patch(p1, pc);
gopcode(OAS, nodconst(0), Z, nn);
patch(p2, pc);
}
break;
}
cursafe = curs;
}
void
sugen(Node *n, Node *nn, long w)
{
Prog *p1;
Node nod0, nod1, nod2, nod3, nod4, *l, *r;
Type *t;
long pc1;
int i, m, c;
if(n == Z || n->type == T)
return;
if(debug['g']) {
prtree(nn, "sugen lhs");
prtree(n, "sugen");
}
if(nn == nodrat)
if(w > nrathole)
nrathole = w;
switch(n->op) {
case OIND:
if(nn == Z) {
nullwarn(n->left, Z);
break;
}
default:
goto copy;
case OCONST:
if(n->type && typev[n->type->etype]) {
if(nn == Z) {
nullwarn(n->left, Z);
break;
}
t = nn->type;
nn->type = types[TLONG];
reglcgen(&nod1, nn, Z);
nn->type = t;
if(align(0, types[TCHAR], Aarg1)) /* isbigendian */
gopcode(OAS, nod32const(n->vconst>>32), Z, &nod1);
else
gopcode(OAS, nod32const(n->vconst), Z, &nod1);
nod1.xoffset += SZ_LONG;
if(align(0, types[TCHAR], Aarg1)) /* isbigendian */
gopcode(OAS, nod32const(n->vconst), Z, &nod1);
else
gopcode(OAS, nod32const(n->vconst>>32), Z, &nod1);
regfree(&nod1);
break;
}
goto copy;
case ODOT:
l = n->left;
sugen(l, nodrat, l->type->width);
if(nn != Z) {
warn(n, "non-interruptable temporary");
nod1 = *nodrat;
r = n->right;
if(!r || r->op != OCONST) {
diag(n, "DOT and no offset");
break;
}
nod1.xoffset += (long)r->vconst;
nod1.type = n->type;
sugen(&nod1, nn, w);
}
break;
case OSTRUCT:
/*
* rewrite so lhs has no fn call
*/
if(nn != Z && nn->complex >= FNX) {
nod1 = *n;
nod1.type = typ(TIND, n->type);
regret(&nod2, &nod1);
lcgen(nn, &nod2);
regsalloc(&nod0, &nod1);
gopcode(OAS, &nod2, Z, &nod0);
regfree(&nod2);
nod1 = *n;
nod1.op = OIND;
nod1.left = &nod0;
nod1.right = Z;
nod1.complex = 1;
sugen(n, &nod1, w);
return;
}
r = n->left;
for(t = n->type->link; t != T; t = t->down) {
l = r;
if(r->op == OLIST) {
l = r->left;
r = r->right;
}
if(nn == Z) {
cgen(l, nn);
continue;
}
/*
* hand craft *(&nn + o) = l
*/
nod0 = znode;
nod0.op = OAS;
nod0.type = t;
nod0.left = &nod1;
nod0.right = l;
nod1 = znode;
nod1.op = OIND;
nod1.type = t;
nod1.left = &nod2;
nod2 = znode;
nod2.op = OADD;
nod2.type = typ(TIND, t);
nod2.left = &nod3;
nod2.right = &nod4;
nod3 = znode;
nod3.op = OADDR;
nod3.type = nod2.type;
nod3.left = nn;
nod4 = znode;
nod4.op = OCONST;
nod4.type = nod2.type;
nod4.vconst = t->offset;
ccom(&nod0);
acom(&nod0);
xcom(&nod0);
nod0.addable = 0;
cgen(&nod0, Z);
}
break;
case OAS:
if(nn == Z) {
if(n->addable < INDEXED)
sugen(n->right, n->left, w);
break;
}
sugen(n->right, nodrat, w);
warn(n, "non-interruptable temporary");
sugen(nodrat, n->left, w);
sugen(nodrat, nn, w);
break;
case OFUNC:
if(nn == Z) {
sugen(n, nodrat, w);
break;
}
if(nn->op != OIND) {
nn = new1(OADDR, nn, Z);
nn->type = types[TIND];
nn->addable = 0;
} else
nn = nn->left;
n = new(OFUNC, n->left, new(OLIST, nn, n->right));
n->type = types[TVOID];
n->left->type = types[TVOID];
cgen(n, Z);
break;
case OCOND:
bcgen(n->left, 1);
p1 = p;
sugen(n->right->left, nn, w);
gbranch(OGOTO);
patch(p1, pc);
p1 = p;
sugen(n->right->right, nn, w);
patch(p1, pc);
break;
case OCOMMA:
cgen(n->left, Z);
sugen(n->right, nn, w);
break;
}
return;
copy:
if(nn == Z)
return;
if(n->complex >= FNX && nn->complex >= FNX) {
t = nn->type;
nn->type = types[TLONG];
regialloc(&nod1, nn, Z);
lcgen(nn, &nod1);
regsalloc(&nod2, nn);
nn->type = t;
gopcode(OAS, &nod1, Z, &nod2);
regfree(&nod1);
nod2.type = typ(TIND, t);
nod1 = nod2;
nod1.op = OIND;
nod1.left = &nod2;
nod1.right = Z;
nod1.complex = 1;
nod1.type = t;
sugen(n, &nod1, w);
return;
}
if(n->complex > nn->complex) {
t = n->type;
n->type = types[TLONG];
reglcgen(&nod1, n, Z);
n->type = t;
t = nn->type;
nn->type = types[TLONG];
reglcgen(&nod2, nn, Z);
nn->type = t;
} else {
t = nn->type;
nn->type = types[TLONG];
reglcgen(&nod2, nn, Z);
nn->type = t;
t = n->type;
n->type = types[TLONG];
reglcgen(&nod1, n, Z);
n->type = t;
}
w /= SZ_LONG;
if(w <= 5) {
layout(&nod1, &nod2, w, 0, Z);
goto out;
}
/*
* minimize space for unrolling loop
* 3,4,5 times. (6 or more is never minimum)
* if small structure, try 2 also.
*/
c = 0; /* set */
m = 100;
i = 3;
if(w <= 15)
i = 2;
for(; i<=5; i++)
if(i + w%i <= m) {
c = i;
m = c + w%c;
}
regalloc(&nod3, ®node, Z);
layout(&nod1, &nod2, w%c, w/c, &nod3);
pc1 = pc;
layout(&nod1, &nod2, c, 0, Z);
gopcode(OSUB, nodconst(1), Z, &nod3);
nod1.op = OREGISTER;
gopcode(OADD, nodconst(c*SZ_LONG), Z, &nod1);
nod2.op = OREGISTER;
gopcode(OADD, nodconst(c*SZ_LONG), Z, &nod2);
gopcode(OEQ, &nod3, Z, Z);
p->as = ABGTZ;
patch(p, pc1);
regfree(&nod3);
out:
regfree(&nod1);
regfree(&nod2);
}
void
layout(Node *f, Node *t, int c, int cv, Node *cn)
{
Node t1, t2;
while(c > 3) {
layout(f, t, 2, 0, Z);
c -= 2;
}
regalloc(&t1, ®node, Z);
regalloc(&t2, ®node, Z);
t1.type = types[TLONG];
t2.type = types[TLONG];
if(c > 0) {
gopcode(OAS, f, Z, &t1);
f->xoffset += SZ_LONG;
}
if(cn != Z)
gopcode(OAS, nodconst(cv), Z, cn);
if(c > 1) {
gopcode(OAS, f, Z, &t2);
f->xoffset += SZ_LONG;
}
if(c > 0) {
gopcode(OAS, &t1, Z, t);
t->xoffset += SZ_LONG;
}
if(c > 2) {
gopcode(OAS, f, Z, &t1);
f->xoffset += SZ_LONG;
}
if(c > 1) {
gopcode(OAS, &t2, Z, t);
t->xoffset += SZ_LONG;
}
if(c > 2) {
gopcode(OAS, &t1, Z, t);
t->xoffset += SZ_LONG;
}
regfree(&t1);
regfree(&t2);
}
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