+ case ODIV:
+ case OMOD:
+ if(nn != Z)
+ if((t = vlog(r)) >= 0) {
+ /* signed div/mod by constant power of 2 */
+ cgen(l, nn);
+ gopcode(OGE, nodconst(0), nn, Z);
+ p1 = p;
+ if(o == ODIV) {
+ gopcode(OADD, nodconst((1<<t)-1), Z, nn);
+ patch(p1, pc);
+ gopcode(OASHR, nodconst(t), Z, nn);
+ } else {
+ gopcode(ONEG, nn, Z, nn);
+ gopcode(OAND, nodconst((1<<t)-1), Z, nn);
+ gopcode(ONEG, nn, Z, nn);
+ gbranch(OGOTO);
+ patch(p1, pc);
+ p1 = p;
+ gopcode(OAND, nodconst((1<<t)-1), Z, nn);
+ patch(p1, pc);
+ }
+ break;
+ }
+ goto muldiv;
+
+ case OXOR:
+#ifdef NOTYET
+ if(nn != Z)
+ if(r->op == OCONST && r->vconst == -1){
+ cgen(l, nn);
+ gopcode(OCOM, nn, Z, nn);
+ break;
+ }
+#endif
+