+ if (subregs_of_mode)
+ htab_empty (subregs_of_mode);
+ else
+ subregs_of_mode = htab_create (100, som_hash, som_eq, free);
+}
+
+void
+record_subregs_of_mode (rtx subreg)
+{
+ struct subregs_of_mode_node dummy, *node;
+ enum machine_mode mode;
+ unsigned int regno;
+ void **slot;
+
+ if (!REG_P (SUBREG_REG (subreg)))
+ return;
+
+ regno = REGNO (SUBREG_REG (subreg));
+ mode = GET_MODE (subreg);
+
+ if (regno < FIRST_PSEUDO_REGISTER)
+ return;
+
+ dummy.block = regno & -8;
+ slot = htab_find_slot_with_hash (subregs_of_mode, &dummy,
+ dummy.block, INSERT);
+ node = *slot;
+ if (node == NULL)
+ {
+ node = XCNEW (struct subregs_of_mode_node);
+ node->block = regno & -8;
+ *slot = node;
+ }
+
+ node->modes[mode] |= 1 << (regno & 7);