+/* A wrapper around add_dependence_1, to add a dependence of CON on
+ PRO, with type DEP_TYPE. This function implements special handling
+ for REG_DEP_CONTROL dependencies. For these, we optionally promote
+ the type to REG_DEP_ANTI if we can determine that predication is
+ impossible; otherwise we add additional true dependencies on the
+ INSN_COND_DEPS list of the jump (which PRO must be). */
+void
+add_dependence (rtx con, rtx pro, enum reg_note dep_type)
+{
+ if (dep_type == REG_DEP_CONTROL
+ && !(current_sched_info->flags & DO_PREDICATION))
+ dep_type = REG_DEP_ANTI;
+
+ /* A REG_DEP_CONTROL dependence may be eliminated through predication,
+ so we must also make the insn dependent on the setter of the
+ condition. */
+ if (dep_type == REG_DEP_CONTROL)
+ {
+ rtx real_pro = pro;
+ rtx other = real_insn_for_shadow (real_pro);
+ rtx cond;
+
+ if (other != NULL_RTX)
+ real_pro = other;
+ cond = sched_get_reverse_condition_uncached (real_pro);
+ /* Verify that the insn does not use a different value in
+ the condition register than the one that was present at
+ the jump. */
+ if (cond == NULL_RTX)
+ dep_type = REG_DEP_ANTI;
+ else if (INSN_CACHED_COND (real_pro) == const_true_rtx)
+ {
+ HARD_REG_SET uses;
+ CLEAR_HARD_REG_SET (uses);
+ note_uses (&PATTERN (con), record_hard_reg_uses, &uses);
+ if (TEST_HARD_REG_BIT (uses, REGNO (XEXP (cond, 0))))
+ dep_type = REG_DEP_ANTI;
+ }
+ if (dep_type == REG_DEP_CONTROL)
+ {
+ if (sched_verbose >= 5)
+ fprintf (sched_dump, "making DEP_CONTROL for %d\n",
+ INSN_UID (real_pro));
+ add_dependence_list (con, INSN_COND_DEPS (real_pro), 0,
+ REG_DEP_TRUE);
+ }
+ }
+
+ add_dependence_1 (con, pro, dep_type);
+}
+