harvey/sys/src/cmd/qc/swt.c

/*
 * This file is part of the UCB release of Plan 9. It is subject to the license
 * terms in the LICENSE file found in the top-level directory of this
 * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
 * part of the UCB release of Plan 9, including this file, may be copied,
 * modified, propagated, or distributed except according to the terms contained
 * in the LICENSE file.
 */

#include "gc.h"

static int	doubleflag;

void
swit1(C1 *q, int nc, int32_t def, Node *n)
{
	Node tn;
	
	regalloc(&tn, &regnode, Z);
	swit2(q, nc, def, n, &tn);
	regfree(&tn);
}

void
swit2(C1 *q, int nc, int32_t def, Node *n, Node *tn)
{
	C1 *r;
	int i;
	Prog *sp;

	if(nc < 5) {
		for(i=0; i<nc; i++) {
			if(sval(q->val)) {
				gopcode(OEQ, n, Z, nodconst(q->val));
			} else {
				gopcode(OSUB, nodconst(q->val), n, tn);
				gopcode(OEQ, tn, Z, nodconst(0));
			}
			patch(p, q->label);
			q++;
		}
		gbranch(OGOTO);
		patch(p, def);
		return;
	}
	i = nc / 2;
	r = q+i;
	if(sval(r->val)) {
		gopcode(OGT, n, Z, nodconst(r->val));
		sp = p;
	} else {
		gopcode(OSUB, nodconst(r->val), n, tn);
		gopcode(OGT, tn, Z, nodconst(0));
		sp = p;
	}
	gbranch(OGOTO);
	p->as = ABEQ;
	patch(p, r->label);
	swit2(q, i, def, n, tn);

	patch(sp, pc);
	swit2(r+1, nc-i-1, def, n, tn);
}

void
bitload(Node *b, Node *n1, Node *n2, Node *n3, Node *nn)
{
	int sh;
	int32_t v;
	Node *l;

	/*
	 * n1 gets adjusted/masked value
	 * n2 gets address of cell
	 * n3 gets contents of cell
	 */
	l = b->left;
	if(n2 != Z) {
		regalloc(n1, l, nn);
		reglcgen(n2, l, Z);
		regalloc(n3, l, Z);
		gopcode(OAS, n2, Z, n3);
		gopcode(OAS, n3, Z, n1);
	} else {
		regalloc(n1, l, nn);
		cgen(l, n1);
	}
	if(b->type->shift == 0 && typeu[b->type->etype]) {
		v = ~0 + (1L << b->type->nbits);
		gopcode(OAND, nodconst(v), Z, n1);
	} else {
		sh = 32 - b->type->shift - b->type->nbits;
		if(sh > 0)
			gopcode(OASHL, nodconst(sh), Z, n1);
		sh += b->type->shift;
		if(sh > 0)
			if(typeu[b->type->etype])
				gopcode(OLSHR, nodconst(sh), Z, n1);
			else
				gopcode(OASHR, nodconst(sh), Z, n1);
	}
}

void
bitstore(Node *b, Node *n1, Node *n2, Node *n3, Node *nn)
{
	int32_t v;
	Node nod, *l;
	int sh;

	/*
	 * n1 has adjusted/masked value
	 * n2 has address of cell
	 * n3 has contents of cell
	 */
	l = b->left;
	regalloc(&nod, l, Z);
	v = ~0 + (1L << b->type->nbits);
	gopcode(OAND, nodconst(v), Z, n1);
	gopcode(OAS, n1, Z, &nod);
	if(nn != Z)
		gopcode(OAS, n1, Z, nn);
	sh = b->type->shift;
	if(sh > 0)
		gopcode(OASHL, nodconst(sh), Z, &nod);
	v <<= sh;
	gopcode(OAND, nodconst(~v), Z, n3);
	gopcode(OOR, n3, Z, &nod);
	gopcode(OAS, &nod, Z, n2);

	regfree(&nod);
	regfree(n1);
	regfree(n2);
	regfree(n3);
}

int32_t
outstring(char *s, int32_t n)
{
	int32_t r;

	if(suppress)
		return nstring;
	r = nstring;
	while(n) {
		string[mnstring] = *s++;
		mnstring++;
		nstring++;
		if(mnstring >= NSNAME) {
			gpseudo(ADATA, symstring, nodconst(0L));
			p->from.offset += nstring - NSNAME;
			p->reg = NSNAME;
			p->to.type = D_SCONST;
			memmove(p->to.sval, string, NSNAME);
			mnstring = 0;
		}
		n--;
	}
	return r;
}

int
mulcon(Node *n, Node *nn)
{
	Node *l, *r, nod1, nod2;
	Multab *m;
	int32_t v;
	int o;
	char code[sizeof(m->code)+2], *p;

	if(typefd[n->type->etype])
		return 0;
	l = n->left;
	r = n->right;
	if(l->op == OCONST) {
		l = r;
		r = n->left;
	}
	if(r->op != OCONST)
		return 0;
	v = convvtox(r->vconst, n->type->etype);
	if(v != r->vconst) {
		if(debug['M'])
			print("%L multiply conv: %lld\n", n->lineno, r->vconst);
		return 0;
	}
	m = mulcon0(n, v);
	if(!m) {
		if(debug['M'])
			print("%L multiply table: %lld\n", n->lineno, r->vconst);
		return 0;
	}

	memmove(code, m->code, sizeof(m->code));
	code[sizeof(m->code)] = 0;

	p = code;
	if(p[1] == 'i')
		p += 2;
	regalloc(&nod1, n, nn);
	cgen(l, &nod1);
	if(v < 0)
		gopcode(ONEG, &nod1, Z, &nod1);
	regalloc(&nod2, n, Z);

loop:
	switch(*p) {
	case 0:
		regfree(&nod2);
		gopcode(OAS, &nod1, Z, nn);
		regfree(&nod1);
		return 1;
	case '+':
		o = OADD;
		goto addsub;
	case '-':
		o = OSUB;
	addsub:	/* number is r,n,l */
		v = p[1] - '0';
		r = &nod1;
		if(v&4)
			r = &nod2;
		n = &nod1;
		if(v&2)
			n = &nod2;
		l = &nod1;
		if(v&1)
			l = &nod2;
		gopcode(o, l, n, r);
		break;
	default: /* op is shiftcount, number is r,l */
		v = p[1] - '0';
		r = &nod1;
		if(v&2)
			r = &nod2;
		l = &nod1;
		if(v&1)
			l = &nod2;
		v = *p - 'a';
		if(v < 0 || v >= 32) {
			diag(n, "mulcon unknown op: %c%c", p[0], p[1]);
			break;
		}
		gopcode(OASHL, nodconst(v), l, r);
		break;
	}
	p += 2;
	goto loop;
}

void
gextern(Sym *s, Node *a, int32_t o, int32_t w)
{
	if(a->op == OCONST && typev[a->type->etype]) {
		if(align(0, types[TCHAR], Aarg1))	/* isbigendian */
			gpseudo(ADATA, s, nod32const(a->vconst>>32));
		else
			gpseudo(ADATA, s, nod32const(a->vconst));
		p->from.offset += o;
		p->reg = 4;
		if(align(0, types[TCHAR], Aarg1))	/* isbigendian */
			gpseudo(ADATA, s, nod32const(a->vconst));
		else
			gpseudo(ADATA, s, nod32const(a->vconst>>32));
		p->from.offset += o + 4;
		p->reg = 4;
		return;
	}
	gpseudo(ADATA, s, a);
	p->from.offset += o;
	p->reg = w;
	if(p->to.type == D_OREG)
		p->to.type = D_CONST;
}

void	zname(Biobuf*, Sym*, int);
char*	zaddr(char*, Adr*, int);
void	zwrite(Biobuf*, Prog*, int, int);
void	outhist(Biobuf*);

void
outcode(void)
{
	struct { Sym *sym; int16_t type; } h[NSYM];
	Prog *p;
	Sym *s;
	int sf, st, t, sym;

	if(debug['S']) {
		for(p = firstp; p != P; p = p->link)
			if(p->as != ADATA && p->as != AGLOBL)
				pc--;
		for(p = firstp; p != P; p = p->link) {
			print("%P\n", p);
			if(p->as != ADATA && p->as != AGLOBL)
				pc++;
		}
	}
	outhist(&outbuf);
	for(sym=0; sym<NSYM; sym++) {
		h[sym].sym = S;
		h[sym].type = 0;
	}
	sym = 1;
	for(p = firstp; p != P; p = p->link) {
	jackpot:
		sf = 0;
		s = p->from.sym;
		while(s != S) {
			sf = s->sym;
			if(sf < 0 || sf >= NSYM)
				sf = 0;
			t = p->from.name;
			if(h[sf].type == t)
			if(h[sf].sym == s)
				break;
			s->sym = sym;
			zname(&outbuf, s, t);
			h[sym].sym = s;
			h[sym].type = t;
			sf = sym;
			sym++;
			if(sym >= NSYM)
				sym = 1;
			break;
		}
		st = 0;
		s = p->to.sym;
		while(s != S) {
			st = s->sym;
			if(st < 0 || st >= NSYM)
				st = 0;
			t = p->to.name;
			if(h[st].type == t)
			if(h[st].sym == s)
				break;
			s->sym = sym;
			zname(&outbuf, s, t);
			h[sym].sym = s;
			h[sym].type = t;
			st = sym;
			sym++;
			if(sym >= NSYM)
				sym = 1;
			if(st == sf)
				goto jackpot;
			break;
		}
		zwrite(&outbuf, p, sf, st);
	}
	firstp = P;
	lastp = P;
}

void
zwrite(Biobuf *b, Prog *p, int sf, int st)
{
	char bf[100], *bp;
	int32_t l;

	bf[0] = p->as;
	bf[1] = p->as>>8;
	bf[2] = p->reg;
	if(p->from3.type != D_NONE)
		bf[2] |= 0x40;
	l = p->lineno;
	bf[3] = l;
	bf[4] = l>>8;
	bf[5] = l>>16;
	bf[6] = l>>24;
	bp = zaddr(bf+7, &p->from, sf);
	if(bf[2] & 0x40)
		bp = zaddr(bp, &p->from3, 0);
	bp = zaddr(bp, &p->to, st);
	Bwrite(b, bf, bp-bf);
}

void
outhist(Biobuf *b)
{
	Hist *h;
	char *p, *q, *op, c;
	Prog pg;
	int n;

	pg = zprog;
	pg.as = AHISTORY;
	c = pathchar();
	for(h = hist; h != H; h = h->link) {
		p = h->name;
		op = 0;
		/* on windows skip drive specifier in pathname */
		if(systemtype(Windows) && p && p[1] == ':'){
			p += 2;
			c = *p;
		}
		if(p && p[0] != c && h->offset == 0 && pathname){
			/* on windows skip drive specifier in pathname */
			if(systemtype(Windows) && pathname[1] == ':') {
				op = p;
				p = pathname+2;
				c = *p;
			} else if(pathname[0] == c){
				op = p;
				p = pathname;
			}
		}
		while(p) {
			q = utfrune(p, c);
			if(q) {
				n = q-p;
				if(n == 0){
					n = 1;	/* leading "/" */
					*p = '/';	/* don't emit "\" on windows */
				}
				q++;
			} else {
				n = strlen(p);
				q = 0;
			}
			if(n) {
				Bputc(b, ANAME);
				Bputc(b, ANAME>>8);
				Bputc(b, D_FILE);
				Bputc(b, 1);
				Bputc(b, '<');
				Bwrite(b, p, n);
				Bputc(b, 0);
			}
			p = q;
			if(p == 0 && op) {
				p = op;
				op = 0;
			}
		}
		pg.lineno = h->line;
		pg.to.type = zprog.to.type;
		pg.to.offset = h->offset;
		if(h->offset)
			pg.to.type = D_CONST;

		zwrite(b, &pg, 0, 0);
	}
}

void
zname(Biobuf *b, Sym *s, int t)
{
	char *n, bf[8];
	uint32_t sig;

	n = s->name;
	if(debug['T'] && t == D_EXTERN && s->sig != SIGDONE && s->type != types[TENUM] && s != symrathole){
		sig = sign(s);
		bf[0] = ASIGNAME;
		bf[1] = ASIGNAME>>8;
		bf[2] = sig;
		bf[3] = sig>>8;
		bf[4] = sig>>16;
		bf[5] = sig>>24;
		bf[6] = t;
		bf[7] = s->sym;
		Bwrite(b, bf, 8);
		s->sig = SIGDONE;
	}
	else{
		bf[0] = ANAME;
		bf[1] = ANAME>>8;
		bf[2] = t;	/* type */
		bf[3] = s->sym;	/* sym */
		Bwrite(b, bf, 4);
	}
	Bwrite(b, n, strlen(n)+1);
}

char*
zaddr(char *bp, Adr *a, int s)
{
	int32_t l;
	Ieee e;

	bp[0] = a->type;
	bp[1] = a->reg;
	bp[2] = s;
	bp[3] = a->name;
	bp += 4;
	switch(a->type) {
	default:
		diag(Z, "unknown type %d in zaddr", a->type);

	case D_NONE:
	case D_REG:
	case D_FREG:
	case D_CREG:
		break;

	case D_OREG:
	case D_CONST:
	case D_BRANCH:
		l = a->offset;
		bp[0] = l;
		bp[1] = l>>8;
		bp[2] = l>>16;
		bp[3] = l>>24;
		bp += 4;
		break;

	case D_SCONST:
		memmove(bp, a->sval, NSNAME);
		bp += NSNAME;
		break;

	case D_FCONST:
		ieeedtod(&e, a->dval);
		l = e.l;
		bp[0] = l;
		bp[1] = l>>8;
		bp[2] = l>>16;
		bp[3] = l>>24;
		bp += 4;
		l = e.h;
		bp[0] = l;
		bp[1] = l>>8;
		bp[2] = l>>16;
		bp[3] = l>>24;
		bp += 4;
		break;
	}
	return bp;
}

static int
doubled(Type *t)
{
	Type *v;

	if(debug['4'])
		return 0;
	if(t->nbits != 0)
		return 0;
	switch(t->etype){
	case TDOUBLE:
		return 1;

	case TARRAY:
		for(v=t; v->etype==TARRAY; v=v->link)
			;
		return v->etype == TDOUBLE;

	case TSTRUCT:
	case TUNION:
		for(v = t->link; v != T; v = v->down)
			if(doubled(v))
				return 1;
		break;
	}
	return 0;
}

int32_t
align(int32_t i, Type *t, int op)
{
	int32_t o;
	Type *v;
	int w, pc;

	o = i;
	w = 1;
	pc = 0;
	switch(op) {
	default:
		diag(Z, "unknown align opcode %d", op);
		break;

	case Asu2:	/* padding at end of a struct */
		w = doubled(t)? SZ_DOUBLE: SZ_LONG;
		if(packflg)
			w = packflg;
		break;

	case Ael1:	/* initial align of struct element (also automatic) */
		for(v=t; v->etype==TARRAY; v=v->link)
			;
		w = ewidth[v->etype];
		if(w <= 0 || w >= SZ_LONG){
			if(doubled(v)){
				w = SZ_DOUBLE;
				doubleflag = 1;
			}else
				w = SZ_LONG;
		}
		if(packflg)
			w = packflg;
		break;

	case Ael2:	/* width of a struct element */
		o += t->width;
		break;

	case Aarg0:	/* initial passbyptr argument in arg list */
		if(typesuv[t->etype]) {
			o = align(o, types[TIND], Aarg1);
			o = align(o, types[TIND], Aarg2);
		}
		break;

	case Aarg1:	/* initial align of parameter */
		w = ewidth[t->etype];
		if(w <= 0 || w >= SZ_LONG) {
			if(doubled(t)){
				w = SZ_DOUBLE;
				pc = SZ_LONG;		/* alignment must account for pc */
				hasdoubled = 1;
			}else
				w = SZ_LONG;
			break;
		}
		o += SZ_LONG - w;	/* big endian adjustment */
		w = 1;
		break;

	case Aarg2:	/* width of a parameter */
		o += t->width;
		w = SZ_LONG;
		if(doubled(t)){
			pc = SZ_LONG;
			hasdoubled = 1;
		}
		break;

	case Aaut3:	/* total align of automatic */
		doubleflag = 0;
		o = align(o, t, Ael1);
		o = align(o, t, Ael2);
		hasdoubled |= doubleflag;
		break;
	}
	o = round(o+pc, w)-pc;
	if(debug['A'])
		print("align %s %ld %T = %ld\n", bnames[op], i, t, o);
	return o;
}

int32_t
maxround(int32_t max, int32_t v)
{
	int w;

	w = SZ_LONG;
	if((debug['8'] || hasdoubled) && !debug['4'])
		w = SZ_DOUBLE;
	v = round(v, w);
	if(v > max)
		return v;
	return max;
}