20060303

1 files changed, 613 insertions, 0 deletions

diff --git a/utils/5c/sgen.c b/utils/5c/sgen.c
new file mode 100644
index 00000000..b20865d9
--- /dev/null
+++ b/utils/5c/sgen.c
@@ -0,0 +1,613 @@
+#include "gc.h"
+
+void
+codgen(Node *n, Node *nn)
+{
+	Prog *sp;
+	Node *n1, nod, nod1;
+
+	cursafe = 0;
+	curarg = 0;
+	maxargsafe = 0;
+
+	/*
+	 * isolate name
+	 */
+	for(n1 = nn;; n1 = n1->left) {
+		if(n1 == Z) {
+			diag(nn, "cant find function name");
+			return;
+		}
+		if(n1->op == ONAME)
+			break;
+	}
+	nearln = nn->lineno;
+	gpseudo(ATEXT, n1->sym, nodconst(stkoff));
+	sp = p;
+
+	/*
+	 * isolate first argument
+	 */
+	if(REGARG >= 0) {
+		if(typesuv[thisfn->link->etype]) {
+			nod1 = *nodret->left;
+			nodreg(&nod, &nod1, REGARG);
+			gopcode(OAS, &nod, Z, &nod1);
+		} else
+		if(firstarg && typechlp[firstargtype->etype]) {
+			nod1 = *nodret->left;
+			nod1.sym = firstarg;
+			nod1.type = firstargtype;
+			nod1.xoffset = align(0, firstargtype, Aarg1);
+			nod1.etype = firstargtype->etype;
+			nodreg(&nod, &nod1, REGARG);
+			gopcode(OAS, &nod, Z, &nod1);
+		}
+	}
+
+	retok = 0;
+	gen(n);
+	if(!retok)
+		if(thisfn->link->etype != TVOID)
+			warn(Z, "no return at end of function: %s", n1->sym->name);
+	noretval(3);
+	gbranch(ORETURN);
+
+	if(!debug['N'] || debug['R'] || debug['P'])
+		regopt(sp);
+
+	sp->to.offset += maxargsafe;
+}
+
+void
+supgen(Node *n)
+{
+	long spc;
+	Prog *sp;
+
+	if(n == Z)
+		return;
+	suppress++;
+	spc = pc;
+	sp = lastp;
+	gen(n);
+	lastp = sp;
+	pc = spc;
+	sp->link = nil;
+	suppress--;
+}
+
+void
+gen(Node *n)
+{
+	Node *l, nod;
+	Prog *sp, *spc, *spb;
+	Case *cn;
+	long sbc, scc;
+	int o, f;
+
+loop:
+	if(n == Z)
+		return;
+	nearln = n->lineno;
+	o = n->op;
+	if(debug['G'])
+		if(o != OLIST)
+			print("%L %O\n", nearln, o);
+
+	retok = 0;
+	switch(o) {
+
+	default:
+		complex(n);
+		cgen(n, Z, 0);
+		break;
+
+	case OLIST:
+		gen(n->left);
+
+	rloop:
+		n = n->right;
+		goto loop;
+
+	case ORETURN:
+		retok = 1;
+		complex(n);
+		if(n->type == T)
+			break;
+		l = n->left;
+		if(l == Z) {
+			noretval(3);
+			gbranch(ORETURN);
+			break;
+		}
+		if(typesuv[n->type->etype]) {
+			sugen(l, nodret, n->type->width);
+			noretval(3);
+			gbranch(ORETURN);
+			break;
+		}
+		regret(&nod, n);
+		cgen(l, &nod, 0);
+		regfree(&nod);
+		if(typefd[n->type->etype])
+			noretval(1);
+		else
+			noretval(2);
+		gbranch(ORETURN);
+		break;
+
+	case OLABEL:
+		l = n->left;
+		if(l) {
+			l->pc = pc;
+			if(l->label)
+				patch(l->label, pc);
+		}
+		gbranch(OGOTO);	/* prevent self reference in reg */
+		patch(p, pc);
+		goto rloop;
+
+	case OGOTO:
+		retok = 1;
+		n = n->left;
+		if(n == Z)
+			return;
+		if(n->complex == 0) {
+			diag(Z, "label undefined: %s", n->sym->name);
+			return;
+		}
+		if(suppress)
+			return;
+		gbranch(OGOTO);
+		if(n->pc) {
+			patch(p, n->pc);
+			return;
+		}
+		if(n->label)
+			patch(n->label, pc-1);
+		n->label = p;
+		return;
+
+	case OCASE:
+		l = n->left;
+		if(cases == C)
+			diag(n, "case/default outside a switch");
+		if(l == Z) {
+			cas();
+			cases->val = 0;
+			cases->def = 1;
+			cases->label = pc;
+			goto rloop;
+		}
+		complex(l);
+		if(l->type == T)
+			goto rloop;
+		if(l->op == OCONST)
+		if(typechl[l->type->etype]) {
+			cas();
+			cases->val = l->vconst;
+			cases->def = 0;
+			cases->label = pc;
+			goto rloop;
+		}
+		diag(n, "case expression must be integer constant");
+		goto rloop;
+
+	case OSWITCH:
+		l = n->left;
+		complex(l);
+		if(l->type == T)
+			break;
+		if(!typechl[l->type->etype]) {
+			diag(n, "switch expression must be integer");
+			break;
+		}
+
+		gbranch(OGOTO);		/* entry */
+		sp = p;
+
+		cn = cases;
+		cases = C;
+		cas();
+
+		sbc = breakpc;
+		breakpc = pc;
+		gbranch(OGOTO);
+		spb = p;
+
+		gen(n->right);
+		gbranch(OGOTO);
+		patch(p, breakpc);
+
+		patch(sp, pc);
+		regalloc(&nod, l, Z);
+		nod.type = types[TLONG];
+		cgen(l, &nod, 0);
+		doswit(&nod);
+		regfree(&nod);
+		patch(spb, pc);
+
+		cases = cn;
+		breakpc = sbc;
+		break;
+
+	case OWHILE:
+	case ODWHILE:
+		l = n->left;
+		gbranch(OGOTO);		/* entry */
+		sp = p;
+
+		scc = continpc;
+		continpc = pc;
+		gbranch(OGOTO);
+		spc = p;
+
+		sbc = breakpc;
+		breakpc = pc;
+		gbranch(OGOTO);
+		spb = p;
+
+		patch(spc, pc);
+		if(n->op == OWHILE)
+			patch(sp, pc);
+		bcomplex(l, Z);		/* test */
+		patch(p, breakpc);
+
+		if(n->op == ODWHILE)
+			patch(sp, pc);
+		gen(n->right);		/* body */
+		gbranch(OGOTO);
+		patch(p, continpc);
+
+		patch(spb, pc);
+		continpc = scc;
+		breakpc = sbc;
+		break;
+
+	case OFOR:
+		l = n->left;
+		gen(l->right->left);	/* init */
+		gbranch(OGOTO);		/* entry */
+		sp = p;
+
+		scc = continpc;
+		continpc = pc;
+		gbranch(OGOTO);
+		spc = p;
+
+		sbc = breakpc;
+		breakpc = pc;
+		gbranch(OGOTO);
+		spb = p;
+
+		patch(spc, pc);
+		gen(l->right->right);	/* inc */
+		patch(sp, pc);	
+		if(l->left != Z) {	/* test */
+			bcomplex(l->left, Z);
+			patch(p, breakpc);
+		}
+		gen(n->right);		/* body */
+		gbranch(OGOTO);
+		patch(p, continpc);
+
+		patch(spb, pc);
+		continpc = scc;
+		breakpc = sbc;
+		break;
+
+	case OCONTINUE:
+		if(continpc < 0) {
+			diag(n, "continue not in a loop");
+			break;
+		}
+		gbranch(OGOTO);
+		patch(p, continpc);
+		break;
+
+	case OBREAK:
+		if(breakpc < 0) {
+			diag(n, "break not in a loop");
+			break;
+		}
+		gbranch(OGOTO);
+		patch(p, breakpc);
+		break;
+
+	case OIF:
+		l = n->left;
+		if(bcomplex(l, n->right)) {
+			if(typefd[l->type->etype])
+				f = !l->fconst;
+			else
+				f = !l->vconst;
+			if(debug['c'])
+				print("%L const if %s\n", nearln, f ? "false" : "true");
+			if(f) {
+				supgen(n->right->left);
+				gen(n->right->right);
+			}
+			else {
+				gen(n->right->left);
+				supgen(n->right->right);
+			}
+		}
+		else {
+			sp = p;
+			if(n->right->left != Z)
+				gen(n->right->left);
+			if(n->right->right != Z) {
+				gbranch(OGOTO);
+				patch(sp, pc);
+				sp = p;
+				gen(n->right->right);
+			}
+			patch(sp, pc);
+		}
+		break;
+
+	case OSET:
+	case OUSED:
+		usedset(n->left, o);
+		break;
+	}
+}
+
+void
+usedset(Node *n, int o)
+{
+	if(n->op == OLIST) {
+		usedset(n->left, o);
+		usedset(n->right, o);
+		return;
+	}
+	complex(n);
+	switch(n->op) {
+	case OADDR:	/* volatile */
+		gins(ANOP, n, Z);
+		break;
+	case ONAME:
+		if(o == OSET)
+			gins(ANOP, Z, n);
+		else
+			gins(ANOP, n, Z);
+		break;
+	}
+}
+
+void
+noretval(int n)
+{
+
+	if(n & 1) {
+		gins(ANOP, Z, Z);
+		p->to.type = D_REG;
+		p->to.reg = REGRET;
+	}
+	if(n & 2) {
+		gins(ANOP, Z, Z);
+		p->to.type = D_FREG;
+		p->to.reg = FREGRET;
+	}
+}
+
+/*
+ *	calculate addressability as follows
+ *		CONST ==> 20		$value
+ *		NAME ==> 10		name
+ *		REGISTER ==> 11		register
+ *		INDREG ==> 12		*[(reg)+offset]
+ *		&10 ==> 2		$name
+ *		ADD(2, 20) ==> 2	$name+offset
+ *		ADD(3, 20) ==> 3	$(reg)+offset
+ *		&12 ==> 3		$(reg)+offset
+ *		*11 ==> 11		??
+ *		*2 ==> 10		name
+ *		*3 ==> 12		*(reg)+offset
+ *	calculate complexity (number of registers)
+ */
+void
+xcom(Node *n)
+{
+	Node *l, *r;
+	int t;
+
+	if(n == Z)
+		return;
+	l = n->left;
+	r = n->right;
+	n->addable = 0;
+	n->complex = 0;
+	switch(n->op) {
+	case OCONST:
+		n->addable = 20;
+		return;
+
+	case OREGISTER:
+		n->addable = 11;
+		return;
+
+	case OINDREG:
+		n->addable = 12;
+		return;
+
+	case ONAME:
+		n->addable = 10;
+		return;
+
+	case OADDR:
+		xcom(l);
+		if(l->addable == 10)
+			n->addable = 2;
+		if(l->addable == 12)
+			n->addable = 3;
+		break;
+
+	case OIND:
+		xcom(l);
+		if(l->addable == 11)
+			n->addable = 12;
+		if(l->addable == 3)
+			n->addable = 12;
+		if(l->addable == 2)
+			n->addable = 10;
+		break;
+
+	case OADD:
+		xcom(l);
+		xcom(r);
+		if(l->addable == 20) {
+			if(r->addable == 2)
+				n->addable = 2;
+			if(r->addable == 3)
+				n->addable = 3;
+		}
+		if(r->addable == 20) {
+			if(l->addable == 2)
+				n->addable = 2;
+			if(l->addable == 3)
+				n->addable = 3;
+		}
+		break;
+
+	case OASLMUL:
+	case OASMUL:
+		xcom(l);
+		xcom(r);
+		t = vlog(r);
+		if(t >= 0) {
+			n->op = OASASHL;
+			r->vconst = t;
+			r->type = types[TINT];
+		}
+		break;
+
+	case OMUL:
+	case OLMUL:
+		xcom(l);
+		xcom(r);
+		t = vlog(r);
+		if(t >= 0) {
+			n->op = OASHL;
+			r->vconst = t;
+			r->type = types[TINT];
+		}
+		t = vlog(l);
+		if(t >= 0) {
+			n->op = OASHL;
+			n->left = r;
+			n->right = l;
+			r = l;
+			l = n->left;
+			r->vconst = t;
+			r->type = types[TINT];
+		}
+		break;
+
+	case OASLDIV:
+		xcom(l);
+		xcom(r);
+		t = vlog(r);
+		if(t >= 0) {
+			n->op = OASLSHR;
+			r->vconst = t;
+			r->type = types[TINT];
+		}
+		break;
+
+	case OLDIV:
+		xcom(l);
+		xcom(r);
+		t = vlog(r);
+		if(t >= 0) {
+			n->op = OLSHR;
+			r->vconst = t;
+			r->type = types[TINT];
+		}
+		break;
+
+	case OASLMOD:
+		xcom(l);
+		xcom(r);
+		t = vlog(r);
+		if(t >= 0) {
+			n->op = OASAND;
+			r->vconst--;
+		}
+		break;
+
+	case OLMOD:
+		xcom(l);
+		xcom(r);
+		t = vlog(r);
+		if(t >= 0) {
+			n->op = OAND;
+			r->vconst--;
+		}
+		break;
+
+	default:
+		if(l != Z)
+			xcom(l);
+		if(r != Z)
+			xcom(r);
+		break;
+	}
+	if(n->addable >= 10)
+		return;
+
+	if(l != Z)
+		n->complex = l->complex;
+	if(r != Z) {
+		if(r->complex == n->complex)
+			n->complex = r->complex+1;
+		else
+		if(r->complex > n->complex)
+			n->complex = r->complex;
+	}
+	if(n->complex == 0)
+		n->complex++;
+
+	if(com64(n))
+		return;
+
+	switch(n->op) {
+	case OFUNC:
+		n->complex = FNX;
+		break;
+
+	case OADD:
+	case OXOR:
+	case OAND:
+	case OOR:
+	case OEQ:
+	case ONE:
+		/*
+		 * immediate operators, make const on right
+		 */
+		if(l->op == OCONST) {
+			n->left = r;
+			n->right = l;
+		}
+		break;
+	}
+}
+
+int
+bcomplex(Node *n, Node *c)
+{
+
+	complex(n);
+	if(n->type != T)
+	if(tcompat(n, T, n->type, tnot))
+		n->type = T;
+	if(n->type != T) {
+		if(c != Z && n->op == OCONST && deadheads(c))
+			return 1;
+		bool64(n);
+		boolgen(n, 1, Z);
+	} else
+		gbranch(OGOTO);
+	return 0;
+}