8c: handle 64-bit switch value

Cases must still be 32-bit values, but one thing at a time.

R=ality, ken2, ken
CC=golang-dev
https://golang.org/cl/5485063

src/cmd/8c/swt.c

@@ -36,12 +36,40 @@ swit1(C1 *q, int nc, int32 def, Node *n)
 	C1 *r;
 	int i;
 	Prog *sp;
+	Node n1, nreg, ncon;
+
+	if(typev[n->type->etype]) {
+		if(n->op != ONAME || n->sym != nodsafe->sym) {
+			regsalloc(&nreg, n);
+			nreg.type = types[TVLONG];
+			cgen(n, &nreg);
+			swit1(q, nc, def, &nreg);
+			return;
+		}
+	} else {
+		if(n->op != OREGISTER) {
+			regalloc(&nreg, n, Z);
+			nreg.type = types[TLONG];
+			cgen(n, &nreg);
+			swit1(q, nc, def, &nreg);
+			regfree(&nreg);
+			return;
+		}
+	}
 
 	if(nc < 5) {
 		for(i=0; i<nc; i++) {
 			if(debug['W'])
 				print("case = %.8ux\n", q->val);
-			gopcode(OEQ, n->type, n, nodconst(q->val));
+			if(n->type && typev[n->type->etype]) {
+				memset(&n1, 0, sizeof n1);
+				n1.op = OEQ;
+				n1.left = n;
+				ncon = *nodconst(q->val);
+				n1.right = &ncon;
+				boolgen(&n1, 1, Z);
+			} else
+				gopcode(OEQ, n->type, n, nodconst(q->val));
 			patch(p, q->label);
 			q++;
 		}
@@ -53,10 +81,22 @@ swit1(C1 *q, int nc, int32 def, Node *n)
 	r = q+i;
 	if(debug['W'])
 		print("case > %.8ux\n", r->val);
-	gopcode(OGT, n->type, n, nodconst(r->val));
-	sp = p;
-	gbranch(OGOTO);
-	p->as = AJEQ;
+	if(n->type && typev[n->type->etype]) {
+		memset(&n1, 0, sizeof n1);
+		n1.op = OGT;
+		n1.left = n;
+		ncon = *nodconst(r->val);
+		n1.right = &ncon;
+		boolgen(&n1, 1, Z);
+		sp = p;
+		n1.op = OEQ;
+		boolgen(&n1, 1, Z);
+	} else {
+		gopcode(OGT, n->type, n, nodconst(r->val));
+		sp = p;
+		gbranch(OGOTO);
+		p->as = AJEQ;
+	}
 	patch(p, r->label);
 	swit1(q, i, def, n);
 

src/cmd/cc/pgen.c

@@ -293,7 +293,7 @@ loop:
 		complex(l);
 		if(l->type == T)
 			break;
-		if(!typeword[l->type->etype] || l->type->etype == TIND) {
+		if(!typechlvp[l->type->etype] || l->type->etype == TIND) {
 			diag(n, "switch expression must be integer");
 			break;
 		}
@@ -320,15 +320,7 @@ loop:
 		}
 
 		patch(sp, pc);
-		regalloc(&nod, l, Z);
-		/* always signed */
-		if(typev[l->type->etype])
-			nod.type = types[TVLONG];
-		else
-			nod.type = types[TLONG];
-		cgen(l, &nod);
-		doswit(&nod);
-		regfree(&nod);
+		doswit(l);
 		patch(spb, pc);
 
 		cases = cn;