Import sources from 2011-03-30 iso image

1 files changed, 227 insertions, 0 deletions

diff --git a/sys/src/cmd/vc/sgen.c b/sys/src/cmd/vc/sgen.c
new file mode 100755
index 000000000..6e70748b7
--- /dev/null
+++ b/sys/src/cmd/vc/sgen.c
@@ -0,0 +1,227 @@
+#include "gc.h"
+
+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(l);
+		if(t >= 0) {
+			n->left = r;
+			n->right = l;
+			l = r;
+			r = n->right;
+		}
+		t = vlog(r);
+		if(t >= 0) {
+			n->op = OASHL;
+			r->vconst = t;
+			r->type = types[TINT];
+			simplifyshift(n);
+		}
+		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];
+			simplifyshift(n);
+		}
+		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;
+
+	case OLSHR:
+	case OASHL:
+	case OASHR:
+		xcom(l);
+		xcom(r);
+		simplifyshift(n);
+		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;
+	}
+}
+