ref: ca68760317b98797cdd7b0464390b04bb1fd8f23
dir: /cc2/target/qbe/cgen.c/
static char sccsid[] = "@(#) ./cc2/arch/qbe/cgen.c";
#include <assert.h>
#include <stdlib.h>
#include <cstd.h>
#include "arch.h"
#include "../../../inc/scc.h"
#include "../../cc2.h"
enum sflags {
ISTMP = 1,
ISCONS = 2
};
static char opasmw[] = {
[OADD] = ASADDW,
[OSUB] = ASSUBW,
[OMUL] = ASMULW,
[OMOD] = ASMODW,
[ODIV] = ASDIVW,
[OSHL] = ASSHLW,
[OSHR] = ASSHRW,
[OLT] = ASLTW,
[OGT] = ASGTW,
[OLE] = ASLEW,
[OGE] = ASGEW,
[OEQ] = ASEQW,
[ONE] = ASNEW,
[OBAND] = ASBANDW,
[OBOR] = ASBORW,
[OBXOR] = ASBXORW,
};
static char opasml[] = {
[OADD] = ASADDL,
[OSUB] = ASSUBL,
[OMUL] = ASMULL,
[OMOD] = ASMODL,
[ODIV] = ASDIVL,
[OSHL] = ASSHLL,
[OSHR] = ASSHRL,
[OLT] = ASLTL,
[OGT] = ASGTL,
[OLE] = ASLEL,
[OGE] = ASGEL,
[OEQ] = ASEQL,
[ONE] = ASNEL,
[OBAND] = ASBANDL,
[OBOR] = ASBORL,
[OBXOR] = ASBXORL,
};
static char opasms[] = {
[OADD] = ASADDS,
[OSUB] = ASSUBS,
[OMUL] = ASMULS,
[ODIV] = ASDIVS,
[OLT] = ASLTS,
[OGT] = ASGTS,
[OLE] = ASLES,
[OGE] = ASGES,
[OEQ] = ASEQS,
[ONE] = ASNES,
};
static char opasmd[] = {
[OADD] = ASADDD,
[OSUB] = ASSUBD,
[OMUL] = ASMULD,
[ODIV] = ASDIVD,
[OLT] = ASLTD,
[OGT] = ASGTD,
[OLE] = ASLED,
[OGE] = ASGED,
[OEQ] = ASEQD,
[ONE] = ASNED,
};
extern Type int32type, uint32type, ptrtype;
static Node *
tmpnode(Node *np, Type *tp)
{
char flags;
Symbol *sym;
if (!np)
np = node(OTMP);
sym = getsym(TMPSYM);
sym->type = np->type = *tp;
flags = tp->flags & ~(PARF|INITF);
sym->type.flags = np->type.flags = flags;
sym->kind = STMP;
np->left = np->right = NULL;
np->u.sym = sym;
np->op = OTMP;
np->flags |= ISTMP;
return np;
}
static Node *
load(Type *tp, Node *np, Node *new)
{
int op;
int flags = tp->flags;
if (flags & (AGGRF|FUNF)) {
*new = *np;
return new;
}
switch (tp->size) {
case 1:
op = ASLDSB;
break;
case 2:
op = ASLDSH;
break;
case 4:
op = (flags & FLOATF) ? ASLDS : ASLDSW;
break;
case 8:
op = (flags & FLOATF) ? ASLDD : ASLDL;
break;
default:
abort();
}
/*
* unsigned version of operations are always +1 the
* signed version
*/
if ((flags & (INTF|SIGNF)) == INTF && tp->size < 8)
++op;
code(op, tmpnode(new, tp), np, NULL);
return new;
}
static Node *rhs(Node *np, Node *new);
static Node *
cast(Type *td, Node *ns, Node *nd)
{
Type *ts;
Node aux1, aux2;
int op, d_isint, s_isint;
ts = &ns->type;
d_isint = (td->flags & INTF) != 0;
s_isint = (ts->flags & INTF) != 0;
if (d_isint && s_isint) {
if (td->size <= ts->size) {
*nd = *ns;
return nd;
}
assert(td->size == 4 || td->size == 8);
switch (ts->size) {
case 1:
op = (td->size == 4) ? ASEXTBW : ASEXTBL;
break;
case 2:
op = (td->size == 4) ? ASEXTHW : ASEXTHL;
break;
case 4:
op = ASEXTWL;
break;
default:
abort();
}
/*
* unsigned version of operations are always +1 the
* signed version
*/
op += (ts->flags & SIGNF) == 0;
} else if (d_isint) {
/* conversion from float to int */
switch (ts->size) {
case 4:
op = (td->size == 8) ? ASSTOL : ASSTOW;
break;
case 8:
op = (td->size == 8) ? ASDTOL : ASDTOW;
break;
default:
abort();
}
/* TODO: Add signess */
} else if (s_isint) {
/* conversion from int to float */
switch (ts->size) {
case 1:
case 2:
ts = (ts->flags&SIGNF) ? &int32type : &uint32type;
ns = cast(ts, ns, tmpnode(&aux2, ts));
case 4:
op = (td->size == 8) ? ASSWTOD : ASSWTOS;
break;
case 8:
op = (td->size == 8) ? ASSLTOD : ASSLTOS;
break;
default:
abort();
}
/* TODO: Add signess */
} else {
/* conversion from float to float */
op = (td->size == 4) ? ASEXTS : ASTRUNCD;
}
code(op, tmpnode(nd, td), ns, NULL);
return nd;
}
static Node *
call(Node *np, Node *fun, Node *ret)
{
int n, op;
Type *tp;
Node aux, **q, *p, *pars[NR_FUNPARAM];
for (n = 0, p = np->right; p; p = p->right)
pars[n++] = rhs(p->left, node(OTMP));
tp = &np->type;
code(ASCALL, tmpnode(ret, tp), fun, NULL);
for (q = pars; q < &pars[n]; ++q) {
op = (q == &pars[n-1]) ? ASPARE : ASPAR;
tmpnode(&aux, &(*q)->type);
code(op, NULL, *q, &aux);
}
code((np->op == OCALL) ? ASCALLE : ASCALLEX, NULL, NULL, NULL);
return ret;
}
static Node *
assign(Type *tp, Node *to, Node *from)
{
int op;
switch (tp->size) {
case 1:
op = ASSTB;
break;
case 2:
op = ASSTH;
break;
case 4:
op = (tp->flags & FLOATF) ? ASSTS : ASSTW;
break;
case 8:
op = (tp->flags & FLOATF) ? ASSTD : ASSTL;
break;
default:
op = ASSTM;
break;
}
code(op, to, from, NULL);
return from;
}
static Node *
copy(Type *tp, Node *to, Node *from)
{
int op;
switch (tp->size) {
case 1:
op = ASCOPYB;
break;
case 2:
op = ASCOPYH;
break;
case 4:
op = (tp->flags & FLOATF) ? ASCOPYS : ASCOPYW;
break;
case 8:
op = (tp->flags & FLOATF) ? ASCOPYD : ASCOPYL;
break;
default:
/* TODO: Need to handle the general case */
abort();
}
code(op, to, from, NULL);
return from;
}
/* TODO: Do field() transformation in sethi */
static Node *
field(Node *np, Node *ret, int islhs)
{
Node base, node, off, add, *addr;
TUINT offset = np->right->u.sym->u.off;
addr = rhs(np->left, &base);
if (offset != 0) {
node.op = OADD;
node.type = ptrtype;
node.left = addr;
node.right = constnode(&off, offset, &ptrtype);
addr = rhs(&node, &add);
}
if (islhs)
*ret = *addr;
else
load(&np->type, addr, ret);
return ret;
}
static Node *
lhs(Node *np, Node *new)
{
switch (np->op) {
case OMEM:
case OAUTO:
*new = *np;
return new;
case OPTR:
return rhs(np->left, new);
case OFIELD:
return field(np, new, 1);
default:
abort();
}
}
static void
bool(Node *np, Symbol *true, Symbol *false)
{
Node *l = np->left, *r = np->right;
Node ret, ifyes, ifno;
Symbol *label;
switch (np->op) {
case ONEG:
bool(l, false, true);
break;
case OAND:
label = newlabel();
bool(l, label, false);
setlabel(label);
bool(r, true, false);
break;
case OOR:
label = newlabel();
bool(l, true, label);
setlabel(label);
bool(r, true, false);
break;
default:
label2node(&ifyes, true);
label2node(&ifno, false);
code(ASBRANCH, rhs(np, &ret), &ifyes, &ifno);
break;
}
}
static Node *
ternary(Node *np, Node *ret)
{
Node ifyes, ifno, phi, *colon, aux1, aux2, aux3;
tmpnode(ret, &np->type);
label2node(&ifyes, NULL);
label2node(&ifno, NULL);
label2node(&phi, NULL);
colon = np->right;
code(ASBRANCH, rhs(np->left, &aux1), &ifyes, &ifno);
setlabel(ifyes.u.sym);
copy(&ret->type, ret, rhs(colon->left, &aux2));
code(ASJMP, NULL, &phi, NULL);
setlabel(ifno.u.sym);
copy(&ret->type, ret, rhs(colon->right, &aux3));
setlabel(phi.u.sym);
return ret;
}
static Node *
function(void)
{
Node aux;
Symbol *p;
/* allocate stack space for parameters */
for (p = locals; p && (p->type.flags & PARF) != 0; p = p->next)
code(ASALLOC, label2node(&aux, p), NULL, NULL);
/* allocate stack space for local variables) */
for ( ; p && p->id != TMPSYM; p = p->next) {
if (p->kind != SAUTO)
continue;
code(ASALLOC, label2node(&aux, p), NULL, NULL);
}
/* store formal parameters in parameters */
for (p = locals; p; p = p->next) {
if ((p->type.flags & PARF) == 0)
break;
code(ASFORM, label2node(&aux, p), NULL, NULL);
}
return NULL;
}
static void
swtch_if(Node *idx)
{
Node aux1, aux2, *np;
Symbol *deflabel = NULL;
for (;;) {
np = delstmt();
setlabel(np->label);
switch (np->op) {
case OESWITCH:
if (!deflabel)
deflabel = np->u.sym;
aux1.op = OJMP;
aux1.label = NULL;
aux1.u.sym = deflabel;
cgen(&aux1);
return;
case OCASE:
aux1 = *np;
aux1.op = OBRANCH;
aux1.label = NULL;
aux1.left = &aux2;
aux2.op = OEQ;
aux2.type = idx->type;
aux2.left = np->left;
aux2.right = idx;
cgen(&aux1);
break;
case ODEFAULT:
deflabel = np->u.sym;
break;
default:
abort();
}
}
}
static Node *
rhs(Node *np, Node *ret)
{
Node aux1, aux2, *phi, *l = np->left, *r = np->right;
Type *tp;
int off, op;
char *tbl;
Symbol *true, *false;
tp = &np->type;
switch (np->op) {
case OBFUN:
return function();
case ONOP:
case OBLOOP:
case OELOOP:
case OEFUN:
return NULL;
case OTMP:
case OCONST:
*ret = *np;
return np;
case OMEM:
case OAUTO:
return load(tp, np, ret);
case ONEG:
case OAND:
case OOR:
true = newlabel();
false = newlabel();
phi = label2node(&aux1, NULL);
tmpnode(ret, &int32type);
bool(np, true, false);
setlabel(true);
code(ASCOPYW, ret, constnode(&aux2, 1, &int32type), NULL);
code(ASJMP, NULL, phi, NULL);
setlabel(false);
code(ASCOPYW, ret, constnode(&aux2, 0, &int32type), NULL);
setlabel(phi->u.sym);
return ret;
case OMOD:
case OSHR:
assert(tp->flags & INTF);
case ODIV:
case OLT:
case OGT:
case OLE:
case OGE:
/*
* unsigned version of operations are always +1 the
* signed version
*/
off = (tp->flags & SIGNF) == 0;
goto binary;
case OSHL:
case OBAND:
case OBOR:
case OBXOR:
assert(tp->flags & INTF);
case OADD:
case OSUB:
case OMUL:
case OEQ:
case ONE:
off = 0;
binary:
if (l->complex >= r->complex) {
rhs(l, &aux1);
rhs(r, &aux2);
} else {
rhs(r, &aux2);
rhs(l, &aux1);
}
switch (tp->size) {
case 4:
tbl = (tp->flags & FLOATF) ? opasms : opasmw;
break;
case 8:
tbl = (tp->flags & FLOATF) ? opasmd : opasml;
break;
default:
abort();
}
op = tbl[np->op] + off;
tmpnode(ret, tp);
code(op, ret, &aux1, &aux2);
return ret;
case OCALL:
case OCALLE:
if (l->op == OPTR)
l = rhs(l, &aux1);
return call(np, l, ret);
case OCAST:
return cast(tp, rhs(l, &aux1), ret);
case OASSIG:
/* TODO: Do this transformations in sethi */
switch (np->u.subop) {
case OINC:
op = OADD;
goto post_oper;
case ODEC:
op = OSUB;
post_oper:
aux1.op = op;
aux1.left = rhs(l, ret);
aux1.right = r;
aux1.type = np->type;
rhs(&aux1, &aux2);
lhs(l, &aux1);
assign(tp, &aux1, &aux2);
break;
default:
aux2.type = np->type;
aux2.op = np->u.subop;
aux2.right = np->right;
aux2.left = np->left;
r = rhs(&aux2, &aux1);
Node aux3;
if (l->op == OCAST) {
aux3.type = l->left->type;
aux3.op = OCAST;
aux3.left = r;
aux3.right = NULL;
r = &aux3;
l = l->left;
}
case 0:
/* TODO: see what is the most difficult */
lhs(l, &aux2);
rhs(r, ret);
return assign(tp, &aux2, ret);
}
return ret;
case OASK:
return ternary(np, ret);
case OCOMMA:
rhs(l, &aux1);
return rhs(r, ret);
case OPTR:
return load(tp, rhs(l, &aux1), ret);
case OADDR:
lhs(l, ret);
ret->type = *tp;
return ret;
case OFIELD:
return field(np, ret, 0);
case OBUILTIN:
switch (np->u.subop) {
case BVA_START:
l = rhs(l, &aux1);
code(ASVSTAR, NULL, l, NULL);
return NULL;
case BVA_END:
return NULL;
case BVA_ARG:
l = rhs(l, &aux1);
code(ASVARG, tmpnode(ret, tp), l, NULL);
return ret;
case BVA_COPY:
/* TODO */
default:
abort();
}
default:
abort();
}
abort();
}
Node *
cgen(Node *np)
{
Node aux, *p, *next;
setlabel(np->label);
switch (np->op) {
case OJMP:
label2node(&aux, np->u.sym);
code(ASJMP, NULL, &aux, NULL);
break;
case OBRANCH:
next = np->next;
if (!next->label)
next->label = newlabel();
bool(np->left, np->u.sym, next->label);
break;
case ORET:
p = (np->left) ? rhs(np->left, &aux) : NULL;
code(ASRET, NULL, p, NULL);
break;
case OBSWITCH:
p = rhs(np->left, &aux);
swtch_if(p);
break;
default:
rhs(np, &aux);
break;
}
return NULL;
}
/*
* This is strongly influenced by
* http://plan9.bell-labs.com/sys/doc/compiler.ps (/sys/doc/compiler.ps)
* calculate addresability as follows
* AUTO => 11 value+fp
* REG => 11 reg
* STATIC => 11 (value)
* CONST => 11 $value
* These values of addressability are not used in the code generation.
* They are only used to calculate the Sethi-Ullman numbers. Since
* QBE is AMD64 targered we could do a better job there, and try to
* detect some of the complex addressing modes of these processors.
*/
Node *
sethi(Node *np)
{
Node *lp, *rp;
if (!np)
return np;
np->complex = 0;
np->address = 0;
lp = np->left;
rp = np->right;
switch (np->op) {
case OAUTO:
case OREG:
case OMEM:
case OCONST:
np->address = 11;
break;
case OCPL:
assert(np->type.flags & INTF);
np->op = OBXOR;
rp = constnode(NULL, ~(TUINT) 0, &np->type);
goto binary;
case OSNEG:
np->op = OSUB;
rp = lp;
lp = constnode(NULL, 0, &np->type);
if ((np->type.flags & INTF) == 0)
lp->u.f = 0.0;
default:
binary:
lp = sethi(lp);
rp = sethi(rp);
break;
}
np->left = lp;
np->right = rp;
if (np->address > 10)
return np;
if (lp)
np->complex = lp->complex;
if (rp) {
int d = np->complex - rp->complex;
if (d == 0)
++np->complex;
else if (d < 0)
np->complex = rp->complex;
}
if (np->complex == 0)
++np->complex;
return np;
}