+/**
+ * Makes every conflict on the given register transitive. In other words,
+ * every register that conflicts with r will now conflict with every other
+ * register conflicting with r.
+ *
+ * This can simplify code for setting up multiple register classes
+ * which are aggregates of some base hardware registers, compared to
+ * explicitly using ra_add_reg_conflict.
+ */
+void
+ra_make_reg_conflicts_transitive(struct ra_regs *regs, unsigned int r)
+{
+ struct ra_reg *reg = ®s->regs[r];
+ BITSET_WORD tmp;
+ int c;
+
+ BITSET_FOREACH_SET(c, tmp, reg->conflicts, regs->count) {
+ struct ra_reg *other = ®s->regs[c];
+ for (unsigned i = 0; i < BITSET_WORDS(regs->count); i++)
+ other->conflicts[i] |= reg->conflicts[i];
+ }
+}
+