avoid register computing len(x), cap(x)

for slice or string x.

R=ken
OCL=32249
CL=32249

src/cmd/5g/cgen.c

@@ -91,6 +91,20 @@ cgen(Node *n, Node *res)
 		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(n->addable) {
 		gmove(n, res);
 		goto ret;

src/cmd/5g/gsubr.c

@@ -628,23 +628,23 @@ gmove(Node *f, Node *t)
 //	case CASE(TINT32, TINT64):	// sign extend int32
 //	case CASE(TINT32, TUINT64):
 //		fatal("gmove TINT32,INT64 not implemented");
-//// 		split64(t, &tlo, &thi);
-//// 		nodreg(&flo, tlo.type, D_AX);
-//// 		nodreg(&fhi, thi.type, D_DX);
-//// 		gmove(f, &flo);
-//// 		gins(ACDQ, N, N);
-//// 		gins(AMOVL, &flo, &tlo);
-//// 		gins(AMOVL, &fhi, &thi);
-//// 		splitclean();
+////		split64(t, &tlo, &thi);
+////		nodreg(&flo, tlo.type, D_AX);
+////		nodreg(&fhi, thi.type, D_DX);
+////		gmove(f, &flo);
+////		gins(ACDQ, N, N);
+////		gins(AMOVL, &flo, &tlo);
+////		gins(AMOVL, &fhi, &thi);
+////		splitclean();
 //		return;
 
 //	case CASE(TUINT32, TINT64):	// zero extend uint32
 //	case CASE(TUINT32, TUINT64):
 //		fatal("gmove TUINT32,INT64 not implemented");
-//// 		split64(t, &tlo, &thi);
-//// 		gmove(f, &tlo);
-//// 		gins(AMOVL, ncon(0), &thi);
-//// 		splitclean();
+////		split64(t, &tlo, &thi);
+////		gmove(f, &tlo);
+////		gins(AMOVL, ncon(0), &thi);
+////		splitclean();
 //		return;
 
 //	/*
@@ -813,23 +813,23 @@ gmove(Node *f, Node *t)
 //	case CASE(TINT64, TFLOAT32):
 //	case CASE(TINT64, TFLOAT64):
 //		fatal("gmove TINT,TFLOAT not implemented");
-//// 		if(t->op != OREGISTER)
-//// 			goto hard;
-//// 		if(f->op == OREGISTER) {
-//// 			cvt = f->type;
-//// 			goto hardmem;
-//// 		}
-//// 		switch(ft) {
-//// 		case TINT16:
-//// 			a = AFMOVW;
-//// 			break;
-//// 		case TINT32:
-//// 			a = AFMOVL;
-//// 			break;
-//// 		default:
-//// 			a = AFMOVV;
-//// 			break;
-//// 		}
+////		if(t->op != OREGISTER)
+////			goto hard;
+////		if(f->op == OREGISTER) {
+////			cvt = f->type;
+////			goto hardmem;
+////		}
+////		switch(ft) {
+////		case TINT16:
+////			a = AFMOVW;
+////			break;
+////		case TINT32:
+////			a = AFMOVL;
+////			break;
+////		default:
+////			a = AFMOVV;
+////			break;
+////		}
 //		break;
 
 //	case CASE(TINT8, TFLOAT32):
@@ -1186,6 +1186,18 @@ naddr(Node *n, Addr *a)
 		}
 		break;
 
+	case OLEN:
+		// len of string or slice
+		naddr(n->left, a);
+		a->offset += Array_nel;
+		break;
+
+	case OCAP:
+		// cap of string or slice
+		naddr(n->left, a);
+		a->offset += Array_cap;
+		break;
+
 	case OADDR:
 		naddr(n->left, a);
 		if(a->type == D_OREG) {

src/cmd/6g/cgen.c

@@ -102,6 +102,20 @@ cgen(Node *n, Node *res)
 		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(n->addable) {
 		gmove(n, res);
 		goto ret;

src/cmd/6g/gsubr.c

@@ -417,6 +417,8 @@ int
 ismem(Node *n)
 {
 	switch(n->op) {
+	case OLEN:
+	case OCAP:
 	case OINDREG:
 	case ONAME:
 	case OPARAM:
@@ -1012,6 +1014,18 @@ naddr(Node *n, Addr *a)
 			}
 		fatal("naddr: OADDR\n");
 
+	case OLEN:
+		// len of string or slice
+		naddr(n->left, a);
+		a->offset += Array_nel;
+		break;
+
+	case OCAP:
+		// cap of string or slice
+		naddr(n->left, a);
+		a->offset += Array_cap;
+		break;
+
 //	case OADD:
 //		if(n->right->op == OLITERAL) {
 //			v = n->right->vconst;

src/cmd/8g/cgen.c

@@ -83,6 +83,20 @@ cgen(Node *n, Node *res)
 		return;
 	}
 
+	// 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 both are addressable, move
 	if(n->addable && res->addable) {
 		gmove(n, res);

src/cmd/8g/gsubr.c

@@ -959,6 +959,8 @@ int
 ismem(Node *n)
 {
 	switch(n->op) {
+	case OLEN:
+	case OCAP:
 	case OINDREG:
 	case ONAME:
 	case OPARAM:
@@ -1762,6 +1764,18 @@ naddr(Node *n, Addr *a)
 			}
 		fatal("naddr: OADDR\n");
 
+	case OLEN:
+		// len of string or slice
+		naddr(n->left, a);
+		a->offset += Array_nel;
+		break;
+
+	case OCAP:
+		// cap of string or slice
+		naddr(n->left, a);
+		a->offset += Array_cap;
+		break;
+
 //	case OADD:
 //		if(n->right->op == OLITERAL) {
 //			v = n->right->vconst;