void
walkswitch(Node *sw)
{
/*
* reorder the body into (OLIST, cases, statements)
* cases have OGOTO into statements.
* both have inserted OBREAK statements
*/
if(sw->ntest == N) {
sw->ntest = nodbool(1);
typecheck(&sw->ntest, Erv);
}
if(sw->ntest->op == OTYPESW) {
typeswitch(sw);
//dump("sw", sw);
return;
}
exprswitch(sw);
}
void
walkswitch(Node *sw)
{
/*
* reorder the body into (OLIST, cases, statements)
* cases have OGOTO into statements.
* both have inserted OBREAK statements
*/
if(sw->ntest == N) {
sw->ntest = nodbool(1);
typecheck(&sw->ntest, Erv);
}
if(sw->ntest->op == OTYPESW) {
typeswitch(sw);
//dump("sw", sw);
return;
}
exprswitch(sw);
// Discard old AST elements after a walk. They can confuse racewealk.
sw->ntest = nil;
sw->list = nil;
}
/*
* normal (expression) switch.
* rebulid case statements into if .. goto
*/
static void
exprswitch(Node *sw)
{
Node *def;
NodeList *cas;
Node *a;
Case *c0, *c, *c1;
Type *t;
int arg, ncase;
casebody(sw, N);
arg = Snorm;
if(isconst(sw->ntest, CTBOOL)) {
arg = Strue;
if(sw->ntest->val.u.bval == 0)
arg = Sfalse;
}
walkexpr(&sw->ntest, &sw->ninit);
t = sw->type;
if(t == T)
return;
/*
* convert the switch into OIF statements
*/
exprname = N;
cas = nil;
if(arg != Strue && arg != Sfalse) {
exprname = temp(sw->ntest->type);
cas = list1(nod(OAS, exprname, sw->ntest));
typechecklist(cas, Etop);
} else {
exprname = nodbool(arg == Strue);
}
c0 = mkcaselist(sw, arg);
if(c0 != C && c0->type == Tdefault) {
def = c0->node->right;
c0 = c0->link;
} else {
def = nod(OBREAK, N, N);
}
loop:
if(c0 == C) {
cas = list(cas, def);
sw->nbody = concat(cas, sw->nbody);
sw->list = nil;
walkstmtlist(sw->nbody);
return;
}
// deal with the variables one-at-a-time
if(!okforcmp[t->etype] || c0->type != Texprconst) {
a = exprbsw(c0, 1, arg);
cas = list(cas, a);
c0 = c0->link;
goto loop;
}
// do binary search on run of constants
ncase = 1;
for(c=c0; c->link!=C; c=c->link) {
if(c->link->type != Texprconst)
break;
ncase++;
}
// break the chain at the count
c1 = c->link;
c->link = C;
// sort and compile constants
c0 = csort(c0, exprcmp);
a = exprbsw(c0, ncase, arg);
cas = list(cas, a);
c0 = c1;
goto loop;
}
void
walkrange(Node *n)
{
Node *ohv1, *hv1, *hv2; // hidden (old) val 1, 2
Node *ha, *hit; // hidden aggregate, iterator
Node *hn, *hp; // hidden len, pointer
Node *hb; // hidden bool
Node *a, *v1, *v2; // not hidden aggregate, val 1, 2
Node *fn, *tmp;
NodeList *body, *init;
Type *th, *t;
int lno;
t = n->type;
init = nil;
a = n->right;
lno = setlineno(a);
if(t->etype == TSTRING && !eqtype(t, types[TSTRING])) {
a = nod(OCONV, n->right, N);
a->type = types[TSTRING];
}
v1 = n->list->n;
v2 = N;
if(n->list->next)
v2 = n->list->next->n;
hv2 = N;
if(v2 == N && t->etype == TARRAY) {
// will have just one reference to argument.
// no need to make a potentially expensive copy.
ha = a;
} else {
ha = temp(a->type);
init = list(init, nod(OAS, ha, a));
}
switch(t->etype) {
default:
fatal("walkrange");
case TARRAY:
hv1 = temp(types[TINT]);
hn = temp(types[TINT]);
hp = nil;
init = list(init, nod(OAS, hv1, N));
init = list(init, nod(OAS, hn, nod(OLEN, ha, N)));
if(v2) {
hp = temp(ptrto(n->type->type));
tmp = nod(OINDEX, ha, nodintconst(0));
tmp->etype = 1; // no bounds check
init = list(init, nod(OAS, hp, nod(OADDR, tmp, N)));
}
n->ntest = nod(OLT, hv1, hn);
n->nincr = nod(OASOP, hv1, nodintconst(1));
n->nincr->etype = OADD;
if(v2 == N)
body = list1(nod(OAS, v1, hv1));
else {
a = nod(OAS2, N, N);
a->list = list(list1(v1), v2);
a->rlist = list(list1(hv1), nod(OIND, hp, N));
body = list1(a);
tmp = nod(OADD, hp, nodintconst(t->type->width));
tmp->type = hp->type;
tmp->typecheck = 1;
tmp->right->type = types[tptr];
tmp->right->typecheck = 1;
body = list(body, nod(OAS, hp, tmp));
}
break;
case TMAP:
th = typ(TARRAY);
th->type = ptrto(types[TUINT8]);
// see ../../pkg/runtime/hashmap.h:/hash_iter
// Size in words.
th->bound = 5 + 4*3 + 4*4/widthptr;
hit = temp(th);
fn = syslook("mapiterinit", 1);
argtype(fn, t->down);
argtype(fn, t->type);
argtype(fn, th);
init = list(init, mkcall1(fn, T, nil, typename(t), ha, nod(OADDR, hit, N)));
n->ntest = nod(ONE, nod(OINDEX, hit, nodintconst(0)), nodnil());
fn = syslook("mapiternext", 1);
argtype(fn, th);
n->nincr = mkcall1(fn, T, nil, nod(OADDR, hit, N));
if(v2 == N) {
fn = syslook("mapiter1", 1);
argtype(fn, th);
argtype(fn, t->down);
a = nod(OAS, v1, mkcall1(fn, t->down, nil, nod(OADDR, hit, N)));
} else {
fn = syslook("mapiter2", 1);
argtype(fn, th);
argtype(fn, t->down);
argtype(fn, t->type);
a = nod(OAS2, N, N);
a->list = list(list1(v1), v2);
a->rlist = list1(mkcall1(fn, getoutargx(fn->type), nil, nod(OADDR, hit, N)));
}
body = list1(a);
break;
case TCHAN:
hv1 = temp(t->type);
hb = temp(types[TBOOL]);
n->ntest = nod(ONE, hb, nodbool(0));
a = nod(OAS2RECV, N, N);
a->typecheck = 1;
a->list = list(list1(hv1), hb);
a->rlist = list1(nod(ORECV, ha, N));
n->ntest->ninit = list1(a);
body = list1(nod(OAS, v1, hv1));
break;
case TSTRING:
ohv1 = temp(types[TINT]);
hv1 = temp(types[TINT]);
init = list(init, nod(OAS, hv1, N));
if(v2 == N)
a = nod(OAS, hv1, mkcall("stringiter", types[TINT], nil, ha, hv1));
else {
hv2 = temp(runetype);
a = nod(OAS2, N, N);
a->list = list(list1(hv1), hv2);
fn = syslook("stringiter2", 0);
a->rlist = list1(mkcall1(fn, getoutargx(fn->type), nil, ha, hv1));
}
n->ntest = nod(ONE, hv1, nodintconst(0));
n->ntest->ninit = list(list1(nod(OAS, ohv1, hv1)), a);
body = list1(nod(OAS, v1, ohv1));
if(v2 != N)
body = list(body, nod(OAS, v2, hv2));
break;
}
n->op = OFOR;
typechecklist(init, Etop);
n->ninit = concat(n->ninit, init);
typechecklist(n->ntest->ninit, Etop);
typecheck(&n->ntest, Erv);
typecheck(&n->nincr, Etop);
typechecklist(body, Etop);
n->nbody = concat(body, n->nbody);
walkstmt(&n);
lineno = lno;
}
/*
* generate:
* res = n;
* simplifies and calls gmove.
*/
void
cgen(Node *n, Node *res)
{
Node *nl, *nr, *r;
Node n1, n2;
int a, f;
Prog *p1, *p2, *p3;
Addr addr;
if(debug['g']) {
dump("\ncgen-n", n);
dump("cgen-res", res);
}
if(n == N || n->type == T)
goto ret;
if(res == N || res->type == T)
fatal("cgen: res nil");
while(n->op == OCONVNOP)
n = n->left;
// inline slices
if(cgen_inline(n, res))
goto ret;
if(n->ullman >= UINF) {
if(n->op == OINDREG)
fatal("cgen: this is going to misscompile");
if(res->ullman >= UINF) {
tempname(&n1, n->type);
cgen(n, &n1);
cgen(&n1, res);
goto ret;
}
}
if(isfat(n->type)) {
sgen(n, res, n->type->width);
goto ret;
}
if(!res->addable) {
if(n->ullman > res->ullman) {
regalloc(&n1, n->type, res);
cgen(n, &n1);
if(n1.ullman > res->ullman) {
dump("n1", &n1);
dump("res", res);
fatal("loop in cgen");
}
cgen(&n1, res);
regfree(&n1);
goto ret;
}
if(res->ullman >= UINF)
goto gen;
if(complexop(n, res)) {
complexgen(n, res);
goto ret;
}
f = 1; // gen thru register
switch(n->op) {
case OLITERAL:
if(smallintconst(n))
f = 0;
break;
case OREGISTER:
f = 0;
break;
}
if(!iscomplex[n->type->etype]) {
a = optoas(OAS, res->type);
if(sudoaddable(a, res, &addr)) {
if(f) {
regalloc(&n2, res->type, N);
cgen(n, &n2);
p1 = gins(a, &n2, N);
regfree(&n2);
} else
p1 = gins(a, n, N);
p1->to = addr;
if(debug['g'])
print("%P [ignore previous line]\n", p1);
sudoclean();
goto ret;
}
}
gen:
igen(res, &n1, N);
cgen(n, &n1);
regfree(&n1);
goto ret;
}
// update addressability for string, slice
// can't do in walk because n->left->addable
// changes if n->left is an escaping local variable.
switch(n->op) {
case OLEN:
if(isslice(n->left->type) || istype(n->left->type, TSTRING))
n->addable = n->left->addable;
break;
case OCAP:
if(isslice(n->left->type))
n->addable = n->left->addable;
break;
}
if(complexop(n, res)) {
complexgen(n, res);
goto ret;
}
if(n->addable) {
gmove(n, res);
goto ret;
}
nl = n->left;
nr = n->right;
if(nl != N && nl->ullman >= UINF)
if(nr != N && nr->ullman >= UINF) {
tempname(&n1, nl->type);
cgen(nl, &n1);
n2 = *n;
n2.left = &n1;
cgen(&n2, res);
goto ret;
}
if(!iscomplex[n->type->etype]) {
a = optoas(OAS, n->type);
if(sudoaddable(a, n, &addr)) {
if(res->op == OREGISTER) {
p1 = gins(a, N, res);
p1->from = addr;
} else {
regalloc(&n2, n->type, N);
p1 = gins(a, N, &n2);
p1->from = addr;
gins(a, &n2, res);
regfree(&n2);
}
sudoclean();
goto ret;
}
}
switch(n->op) {
default:
dump("cgen", n);
fatal("cgen: unknown op %N", n);
break;
// these call bgen to get a bool value
case OOROR:
case OANDAND:
case OEQ:
case ONE:
case OLT:
case OLE:
case OGE:
case OGT:
case ONOT:
p1 = gbranch(AJMP, T);
p2 = pc;
gmove(nodbool(1), res);
p3 = gbranch(AJMP, T);
patch(p1, pc);
bgen(n, 1, p2);
gmove(nodbool(0), res);
patch(p3, pc);
goto ret;
case OPLUS:
cgen(nl, res);
goto ret;
// unary
case OCOM:
a = optoas(OXOR, nl->type);
regalloc(&n1, nl->type, N);
cgen(nl, &n1);
nodconst(&n2, nl->type, -1);
gins(a, &n2, &n1);
gmove(&n1, res);
regfree(&n1);
goto ret;
case OMINUS:
if(isfloat[nl->type->etype]) {
nr = nodintconst(-1);
convlit(&nr, n->type);
a = optoas(OMUL, nl->type);
goto sbop;
}
a = optoas(n->op, nl->type);
goto uop;
// symmetric binary
case OAND:
case OOR:
case OXOR:
case OADD:
case OMUL:
a = optoas(n->op, nl->type);
if(a != AIMULB)
goto sbop;
cgen_bmul(n->op, nl, nr, res);
break;
// asymmetric binary
case OSUB:
a = optoas(n->op, nl->type);
goto abop;
case OCONV:
regalloc(&n1, nl->type, res);
regalloc(&n2, n->type, &n1);
cgen(nl, &n1);
// if we do the conversion n1 -> n2 here
// reusing the register, then gmove won't
// have to allocate its own register.
gmove(&n1, &n2);
gmove(&n2, res);
regfree(&n2);
regfree(&n1);
break;
case ODOT:
case ODOTPTR:
case OINDEX:
case OIND:
case ONAME: // PHEAP or PPARAMREF var
igen(n, &n1, res);
gmove(&n1, res);
regfree(&n1);
break;
case OLEN:
if(istype(nl->type, TMAP) || istype(nl->type, TCHAN)) {
// map and chan have len in the first 32-bit word.
// a zero pointer means zero length
regalloc(&n1, types[tptr], res);
cgen(nl, &n1);
nodconst(&n2, types[tptr], 0);
gins(optoas(OCMP, types[tptr]), &n1, &n2);
p1 = gbranch(optoas(OEQ, types[tptr]), T);
n2 = n1;
n2.op = OINDREG;
n2.type = types[TINT32];
gmove(&n2, &n1);
patch(p1, pc);
gmove(&n1, res);
regfree(&n1);
break;
}
if(istype(nl->type, TSTRING) || isslice(nl->type)) {
// both slice and string have len one pointer into the struct.
// a zero pointer means zero length
regalloc(&n1, types[tptr], res);
agen(nl, &n1);
n1.op = OINDREG;
n1.type = types[TUINT32];
n1.xoffset = Array_nel;
gmove(&n1, res);
regfree(&n1);
break;
}
fatal("cgen: OLEN: unknown type %lT", nl->type);
break;
case OCAP:
if(istype(nl->type, TCHAN)) {
// chan has cap in the second 32-bit word.
// a zero pointer means zero length
regalloc(&n1, types[tptr], res);
cgen(nl, &n1);
nodconst(&n2, types[tptr], 0);
gins(optoas(OCMP, types[tptr]), &n1, &n2);
p1 = gbranch(optoas(OEQ, types[tptr]), T);
n2 = n1;
n2.op = OINDREG;
n2.xoffset = 4;
n2.type = types[TINT32];
gmove(&n2, &n1);
patch(p1, pc);
gmove(&n1, res);
regfree(&n1);
break;
}
if(isslice(nl->type)) {
regalloc(&n1, types[tptr], res);
agen(nl, &n1);
n1.op = OINDREG;
n1.type = types[TUINT32];
n1.xoffset = Array_cap;
gmove(&n1, res);
regfree(&n1);
break;
}
fatal("cgen: OCAP: unknown type %lT", nl->type);
break;
case OADDR:
agen(nl, res);
break;
case OCALLMETH:
cgen_callmeth(n, 0);
cgen_callret(n, res);
break;
case OCALLINTER:
cgen_callinter(n, res, 0);
cgen_callret(n, res);
break;
case OCALLFUNC:
cgen_call(n, 0);
cgen_callret(n, res);
break;
case OMOD:
case ODIV:
if(isfloat[n->type->etype]) {
a = optoas(n->op, nl->type);
goto abop;
}
cgen_div(n->op, nl, nr, res);
break;
case OLSH:
case ORSH:
cgen_shift(n->op, nl, nr, res);
break;
}
goto ret;
sbop: // symmetric binary
if(nl->ullman < nr->ullman) {
r = nl;
nl = nr;
nr = r;
}
abop: // asymmetric binary
if(nl->ullman >= nr->ullman) {
regalloc(&n1, nl->type, res);
cgen(nl, &n1);
if(sudoaddable(a, nr, &addr)) {
p1 = gins(a, N, &n1);
p1->from = addr;
gmove(&n1, res);
sudoclean();
regfree(&n1);
goto ret;
}
regalloc(&n2, nr->type, N);
cgen(nr, &n2);
} else {
regalloc(&n2, nr->type, N);
cgen(nr, &n2);
regalloc(&n1, nl->type, res);
cgen(nl, &n1);
}
gins(a, &n2, &n1);
gmove(&n1, res);
regfree(&n1);
regfree(&n2);
goto ret;
uop: // unary
regalloc(&n1, nl->type, res);
cgen(nl, &n1);
gins(a, N, &n1);
gmove(&n1, res);
regfree(&n1);
goto ret;
ret:
;
}