static initialization of slices

R=r
OCL=29016
CL=29016

src/cmd/6g/gen.c

@@ -701,8 +701,6 @@ clearfat(Node *nl)
 int
 getlit(Node *lit)
 {
-	int l;
-
 	if(smallintconst(lit))
 		return mpgetfix(lit->val.u.xval);
 	return -1;
@@ -748,7 +746,7 @@ no:
 int
 gen_as_init(Node *nr, Node *nl)
 {
-	Node nam;
+	Node nam, nod1;
 	Prog *p;
 
 	if(!initflag)
@@ -762,6 +760,32 @@ gen_as_init(Node *nr, Node *nl)
 		return 1;
 	}
 
+	if(nr->op == OCOMPSLICE) {
+		// create a slice pointing to an array
+		if(!stataddr(&nam, nl)) {
+			dump("stataddr", nl);
+			goto no;
+		}
+
+		p = gins(ADATA, &nam, nr->left);
+		p->from.scale = types[tptr]->width;
+		p->to.index = p->to.type;
+		p->to.type = D_ADDR;
+//print("%P\n", p);
+
+		nodconst(&nod1, types[TINT32], nr->left->type->bound);
+		p = gins(ADATA, &nam, &nod1);
+		p->from.scale = types[TINT32]->width;
+		p->from.offset += types[tptr]->width;
+//print("%P\n", p);
+
+		p = gins(ADATA, &nam, &nod1);
+		p->from.scale = types[TINT32]->width;
+		p->from.offset += types[tptr]->width+types[TINT32]->width;
+
+		goto yes;
+	}
+
 	if(nr->type == T ||
 	   !eqtype(nl->type, nr->type))
 		goto no;

src/cmd/gc/dcl.c

@@ -1360,7 +1360,7 @@ initlin(Node* n)
 		   n->right->right->op != OLIST ||
 		   n->right->right->left->op != OAS ||
 		   n->right->right->right->op != OAS ||
-		   memcmp(n->left->sym->name, "mapassign1", 10) != 0)
+		   strcmp(n->left->sym->name, "mapassign1") != 0)
 			dump("o=call", n);
 		n->ninit = N;
 		xxx = list(xxx, n);
@@ -1385,7 +1385,7 @@ inittmp(Node *n)
 	if(n->op == ONAME)
 	if(n->sym != S)
 	if(n->class == PAUTO)
-	if(memcmp(n->sym->name, "!tmpname", 8) == 0)
+	if(strcmp(n->sym->name, "!tmpname!") == 0)
 		return 1;
 	return 0;
 }
@@ -1409,12 +1409,59 @@ indsametmp(Node *n1, Node *n2)
 	return 0;
 }
 
+Node*
+slicerewrite(Node *n)
+{
+	Iter param;
+	Node *a, *wid, *nel;
+	Type *t;
+	int b;
+
+	if(n == N || n->op != OCALL || !isslice(n->type) ||
+	   n->left == N || n->left->sym == S ||
+	   strcmp(n->left->sym->name, "newarray") != 0)
+		goto no;
+
+	// call to newarray - find width and nel
+	wid = N;
+	nel = N;
+	a = listfirst(&param, &n->right);
+	while(a != N) {
+		if(a->op == OAS &&
+		   a->left != N && a->right != N &&
+		   a->left->op == OINDREG && a->right->op == OLITERAL &&
+		   a->left->sym != S) {
+			if(strcmp(a->left->sym->name, "nel") == 0)
+				nel = a->right;
+			if(strcmp(a->left->sym->name, "width") == 0)
+				wid = a->right;
+		}
+		a = listnext(&param);
+	}
+	if(wid == N || nel == N)
+		goto no;
+
+	b = mpgetfix(nel->val.u.xval);
+	if(b == 0)
+		goto no;
+
+	t = shallow(n->type);
+	t->bound = b;
+	a = staticname(t);
+	a = nod(OCOMPSLICE, a, N);
+	a->type = n->type;
+	return a;
+
+no:
+	return N;
+}
+
 int
 initsub(Node *n, Node *nam)
 {
-	Iter iter;
-	Node *r;
-	int any, i;
+	Iter iter, param;
+	Node *r, *w;
+	int any;
 
 	any = 0;
 	r = listfirst(&iter, &xxx);
@@ -1427,7 +1474,13 @@ initsub(Node *n, Node *nam)
 			case ONAME:
 				if(sametmp(r->left, nam)) {
 					any = 1;
+					w = slicerewrite(r->right);
 					r->left = n;
+					if(w != N) {
+						n = w->left;	// from now on use fixed array
+						r->right = w;
+						break;
+					}
 				}
 				break;
 			case ODOT:
@@ -1454,27 +1507,18 @@ initsub(Node *n, Node *nam)
 			break;
 		case OCALL:
 			// call to mapassign1
-			// look through all three parameters
-			for(i=0; i<2; i++) {
-				r = r->right;
-				if(r == N || r->op != OLIST)
-					break;
-				if(sametmp(r->left->right, nam)) {
-					any = 1;
-					r->left->right = n;
-				}
-				if(indsametmp(r->left->right, nam)) {
-					any = 1;
-					r->left->left->right = n;
-				}
-				if(sametmp(r->right->right, nam)) {
+			// look through the parameters
+			w = listfirst(&param, &r->right);
+			while(w != N) {
+				if(sametmp(w->right, nam)) {
 					any = 1;
-					r->right->right = n;
+					w->right = n;
 				}
-				if(indsametmp(r->right->right, nam)) {
+				if(indsametmp(w->right, nam)) {
 					any = 1;
-					r->right->left->right = n;
+					w->right->left = n;
 				}
+				w = listnext(&param);
 			}
 			break;
 		}

src/cmd/gc/go.h

@@ -325,7 +325,7 @@ enum
 	ONOT, OCOM, OPLUS, OMINUS, OSEND, ORECV,
 	OLITERAL, OREGISTER, OINDREG,
 	OKEY, OPARAM,
-	OCOMPOS,
+	OCOMPOS, OCOMPSLICE, OCOMPMAP,
 	OCONV,
 	ODOTTYPE, OTYPESW,
 	OBAD,
@@ -565,10 +565,11 @@ EXTERN	Dcl*	externdcl;
 EXTERN	Dcl*	exportlist;
 EXTERN	Dcl*	signatlist;
 EXTERN	Dcl*	typelist;
-EXTERN	int	dclcontext;	// PEXTERN/PAUTO
+EXTERN	int	dclcontext;		// PEXTERN/PAUTO
 EXTERN	int	importflag;
 EXTERN	int	inimportsys;
 EXTERN	int	initflag;		// compiling the init fn
+EXTERN	int	statuniqgen;		// name generator for static temps
 
 EXTERN	uint32	iota;
 EXTERN	Node*	lastconst;
@@ -748,6 +749,7 @@ Node*	syslook(char*, int);
 Node*	treecopy(Node*);
 int	isselect(Node*);
 void	tempname(Node*, Type*);
+Node*	staticname(Type*);
 int	iscomposite(Type*);
 Node*	callnew(Type*);
 

src/cmd/gc/subr.c

@@ -666,6 +666,8 @@ opnames[] =
 	[OCMP]		= "CMP",
 	[OFALL]		= "FALL",
 	[OCOMPOS]	= "COMPOS",
+	[OCOMPSLICE]	= "COMPSLICE",
+	[OCOMPMAP]	= "COMPMAP",
 	[ODOTTYPE]	= "DOTTYPE",
 	[OCONV]		= "CONV",
 	[OCOM]		= "COM",
@@ -2389,6 +2391,18 @@ tempname(Node *n, Type *t)
 	n->xoffset = -stksize;
 }
 
+Node*
+staticname(Type *t)
+{
+	Node *n;
+
+	snprint(namebuf, sizeof(namebuf), "statictmp_%.4d·%s", statuniqgen, filename);
+	statuniqgen++;
+	n = newname(lookup(namebuf));
+	addvar(n, t, PEXTERN);
+	return n;
+}
+
 void
 setmaxarg(Type *t)
 {

src/cmd/gc/walk.c

@@ -581,6 +581,10 @@ loop:
 		walkconv(n);
 		goto ret;
 
+	case OCOMPMAP:
+	case OCOMPSLICE:
+		goto ret;
+
 	case OCOMPOS:
 		t = n->type;
 		if(t == T)