gc: remove &[10]int -> []int conversion

Fixes #829.

R=ken2
CC=golang-dev
https://golang.org/cl/2124044

src/cmd/gc/go.h

@@ -262,7 +262,7 @@ struct	Node
 	Sym*	sym;		// various
 	int32	vargen;		// unique name for OTYPE/ONAME
 	int32	lineno;
-	int32   endlineno;
+	int32	endlineno;
 	vlong	xoffset;
 	int32	ostk;
 	int32	iota;
@@ -358,7 +358,7 @@ enum
 	OCLOSURE,
 	OCMPIFACE, OCMPSTR,
 	OCOMPLIT, OMAPLIT, OSTRUCTLIT, OARRAYLIT,
-	OCONV, OCONVIFACE, OCONVNOP, OCONVSLICE,
+	OCONV, OCONVIFACE, OCONVNOP,
 	OCOPY,
 	ODCL, ODCLFUNC, ODCLFIELD, ODCLCONST, ODCLTYPE,
 	ODOT, ODOTPTR, ODOTMETH, ODOTINTER, OXDOT,

src/cmd/gc/print.c

@@ -55,7 +55,6 @@ exprfmt(Fmt *f, Node *n, int prec)
 	case OCALL:
 	case OCONV:
 	case OCONVNOP:
-	case OCONVSLICE:
 	case OMAKESLICE:
 	case ORUNESTR:
 	case OADDR:
@@ -319,9 +318,12 @@ exprfmt(Fmt *f, Node *n, int prec)
 		break;
 
 	case OSLICE:
+	case OSLICESTR:
+	case OSLICEARR:
 		exprfmt(f, n->left, 7);
 		fmtprint(f, "[");
-		exprfmt(f, n->right->left, 0);
+		if(n->right->left != N)
+			exprfmt(f, n->right->left, 0);
 		fmtprint(f, ":");
 		if(n->right->right != N)
 			exprfmt(f, n->right->right, 0);
@@ -361,7 +363,6 @@ exprfmt(Fmt *f, Node *n, int prec)
 	case OCONV:
 	case OCONVIFACE:
 	case OCONVNOP:
-	case OCONVSLICE:
 	case OARRAYBYTESTR:
 	case ORUNESTR:
 		if(n->type == T || n->type->sym == S)

src/cmd/gc/sinit.c

@@ -401,7 +401,7 @@ slicelit(int ctxt, Node *n, Node *var, NodeList **init)
 		arraylit(ctxt, 2, n, vstat, init);
 
 		// copy static to slice
-		a = nod(OADDR, vstat, N);
+		a = nod(OSLICE, vstat, nod(OKEY, N, N));
 		a = nod(OAS, var, a);
 		typecheck(&a, Etop);
 		a->dodata = 2;
@@ -459,7 +459,7 @@ slicelit(int ctxt, Node *n, Node *var, NodeList **init)
 	}
 
 	// make slice out of heap (5)
-	a = nod(OAS, var, vauto);
+	a = nod(OAS, var, nod(OSLICE, vauto, nod(OKEY, N, N)));
 	typecheck(&a, Etop);
 	walkexpr(&a, init);
 	*init = list(*init, a);
@@ -864,8 +864,18 @@ gen_as_init(Node *n)
 	default:
 		goto no;
 
-	case OCONVSLICE:
-		goto slice;
+	case OCONVNOP:
+		nr = nr->left;
+		if(nr == N || nr->op != OSLICEARR)
+			goto no;
+		// fall through
+	
+	case OSLICEARR:
+		if(nr->right->op == OKEY && nr->right->left == N && nr->right->right == N) {
+			nr = nr->left;
+			goto slice;
+		}
+		goto no;
 
 	case OLITERAL:
 		break;
@@ -914,7 +924,7 @@ yes:
 
 slice:
 	gused(N); // in case the data is the dest of a goto
-	nr = n->right->left;
+	nl = nr;
 	if(nr == N || nr->op != OADDR)
 		goto no;
 	nr = nr->left;
@@ -926,7 +936,7 @@ slice:
 		goto no;
 
 	nam.xoffset += Array_array;
-	gdata(&nam, n->right->left, types[tptr]->width);
+	gdata(&nam, nl, types[tptr]->width);
 
 	nam.xoffset += Array_nel-Array_array;
 	nodconst(&nod1, types[TINT32], nr->type->bound);

src/cmd/gc/subr.c

@@ -1924,13 +1924,6 @@ assignop(Type *src, Type *dst, char **why)
 	// 7. Any typed value can be assigned to the blank identifier.
 	if(dst->etype == TBLANK)
 		return OCONVNOP;
-	
-	// 8. Array to slice.
-	// TODO(rsc): Not for long.
-	if(!src->sym || !dst->sym)
-	if(isptr[src->etype] && isfixedarray(src->type) && isslice(dst))
-	if(eqtype(src->type->type, dst->type))
-		return OCONVSLICE;
 
 	return 0;
 }

src/cmd/gc/typecheck.c

@@ -648,19 +648,16 @@ reswitch:
 		defaultlit(&n->right->left, T);
 		defaultlit(&n->right->right, T);
 		if(isfixedarray(n->left->type)) {
-			// Insert explicit & before fixed array
-			// so that back end knows to move to heap.
 			n->left = nod(OADDR, n->left, N);
 			typecheck(&n->left, top);
 		}
-		implicitstar(&n->left);
 		if(n->right->left != N) {
 			if((t = n->right->left->type) == T)
 				goto error;
 			if(!isint[t->etype]) {
 				yyerror("invalid slice index %#N (type %T)", n->right->left, t);
 				goto error;
-		}
+			}
 		}
 		if(n->right->right != N) {
 			if((t = n->right->right->type) == T)
@@ -678,9 +675,9 @@ reswitch:
 			n->op = OSLICESTR;
 			goto ret;
 		}
-		if(isfixedarray(t)) {
+		if(isptr[t->etype] && isfixedarray(t->type)) {
 			n->type = typ(TARRAY);
-			n->type->type = t->type;
+			n->type->type = t->type->type;
 			n->type->bound = -1;
 			dowidth(n->type);
 			n->op = OSLICEARR;
@@ -1269,7 +1266,7 @@ implicitstar(Node **nn)
 	Type *t;
 	Node *n;
 
-	// insert implicit * if needed
+	// insert implicit * if needed for fixed array
 	n = *nn;
 	t = n->type;
 	if(t == T || !isptr[t->etype])

src/cmd/gc/walk.c

@@ -1124,35 +1124,23 @@ walkexpr(Node **np, NodeList **init)
 		// slicearray(old *any, uint64 nel, lb uint64, hb uint64, width uint64) (ary []any)
 		t = n->type;
 		fn = syslook("slicearray", 1);
-		argtype(fn, n->left->type);	// any-1
+		argtype(fn, n->left->type->type);	// any-1
 		argtype(fn, t->type);			// any-2
 		if(n->right->left == N)
 			l = nodintconst(0);
 		else
 			l = conv(n->right->left, types[TUINT64]);
 		if(n->right->right == N)
-			r = nodintconst(n->left->type->bound);
+			r = nodintconst(n->left->type->type->bound);
 		else
 			r = conv(n->right->right, types[TUINT64]);
 		n = mkcall1(fn, t, init,
-			nod(OADDR, n->left, N), nodintconst(n->left->type->bound),
+			n->left, nodintconst(n->left->type->type->bound),
 			l,
 			r,
 			nodintconst(t->type->width));
 		goto ret;
 
-	case OCONVSLICE:
-		// slicearray(old *any, uint64 nel, lb uint64, hb uint64, width uint64) (ary []any)
-		fn = syslook("slicearray", 1);
-		argtype(fn, n->left->type->type);		// any-1
-		argtype(fn, n->type->type);			// any-2
-		n = mkcall1(fn, n->type, init, n->left,
-			nodintconst(n->left->type->type->bound),
-			nodintconst(0),
-			nodintconst(n->left->type->type->bound),
-			nodintconst(n->type->type->width));
-		goto ret;
-
 	case OADDR:;
 		Node *nvar, *nstar;
 
@@ -2140,12 +2128,17 @@ static void
 heapmoves(void)
 {
 	NodeList *nn;
-
+	int32 lno;
+	
+	lno = lineno;
+	lineno = curfn->lineno;
 	nn = paramstoheap(getthis(curfn->type), 0);
 	nn = concat(nn, paramstoheap(getinarg(curfn->type), 0));
 	nn = concat(nn, paramstoheap(getoutarg(curfn->type), 1));
 	curfn->enter = concat(curfn->enter, nn);
+	lineno = curfn->endlineno;
 	curfn->exit = returnsfromheap(getoutarg(curfn->type));
+	lineno = lno;
 }
 
 static Node*