+ char tmp[128];
+ snprintf(buf, len, "class: %s", req->cls->name);
+
+ if(arch_register_req_is(req, limited)) {
+ unsigned n_regs = req->cls->n_regs;
+ unsigned i;
+
+ strncat(buf, " limited:", len);
+ for(i = 0; i < n_regs; ++i) {
+ if(rbitset_is_set(req->limited, i)) {
+ const arch_register_t *reg = &req->cls->regs[i];
+ strncat(buf, " ", len);
+ strncat(buf, reg->name, len);
+ }
+ }
+ }
+
+ if(arch_register_req_is(req, should_be_same)) {
+ const unsigned other = req->other_same;
+ int i;
+
+ ir_snprintf(tmp, sizeof(tmp), " same to:");
+ for (i = 0; 1U << i <= other; ++i) {
+ if (other & (1U << i)) {
+ ir_snprintf(tmp, sizeof(tmp), " %+F", get_irn_n(skip_Proj_const(node), i));
+ strncat(buf, tmp, len);
+ }
+ }
+ }
+
+ if (arch_register_req_is(req, must_be_different)) {
+ const unsigned other = req->other_different;
+ int i;
+
+ ir_snprintf(tmp, sizeof(tmp), " different from:");
+ for (i = 0; 1U << i <= other; ++i) {
+ if (other & (1U << i)) {
+ ir_snprintf(tmp, sizeof(tmp), " %+F", get_irn_n(skip_Proj_const(node), i));
+ strncat(buf, tmp, len);
+ }
+ }
+ }
+
+ if (arch_register_req_is(req, ignore)) {
+ strncat(buf, " ignore", len);
+ }
+ if (arch_register_req_is(req, produces_sp)) {
+ strncat(buf, " produces_sp", len);
+ }
+
+ return buf;