+add_deps_for_risky_insns (rtx head, rtx tail)
+{
+ rtx insn, prev;
+ int classification;
+ rtx last_jump = NULL_RTX;
+ rtx next_tail = NEXT_INSN (tail);
+ basic_block last_block = NULL, bb;
+
+ for (insn = head; insn != next_tail; insn = NEXT_INSN (insn))
+ {
+ add_delay_dependencies (insn);
+ if (control_flow_insn_p (insn))
+ {
+ bb = BLOCK_FOR_INSN (insn);
+ bb->aux = last_block;
+ last_block = bb;
+ /* Ensure blocks stay in the same order. */
+ if (last_jump)
+ add_dependence (insn, last_jump, REG_DEP_ANTI);
+ last_jump = insn;
+ }
+ else if (INSN_P (insn) && last_jump != NULL_RTX)
+ {
+ classification = haifa_classify_insn (insn);
+ prev = last_jump;
+
+ switch (classification)
+ {
+ case PFREE_CANDIDATE:
+ if (flag_schedule_speculative_load)
+ {
+ bb = earliest_block_with_similiar_load (last_block, insn);
+ if (bb)
+ {
+ bb = (basic_block) bb->aux;
+ if (!bb)
+ break;
+ prev = BB_END (bb);
+ }
+ }
+ /* Fall through. */
+ case TRAP_RISKY:
+ case IRISKY:
+ case PRISKY_CANDIDATE:
+ /* ??? We could implement better checking PRISKY_CANDIDATEs
+ analogous to sched-rgn.c. */
+ /* We can not change the mode of the backward
+ dependency because REG_DEP_ANTI has the lowest
+ rank. */
+ if (! sched_insns_conditions_mutex_p (insn, prev))
+ {
+ if ((current_sched_info->flags & DO_SPECULATION)
+ && (spec_info->mask & BEGIN_CONTROL))
+ {
+ dep_def _dep, *dep = &_dep;
+
+ init_dep (dep, prev, insn, REG_DEP_ANTI);
+
+ if (current_sched_info->flags & USE_DEPS_LIST)
+ {
+ DEP_STATUS (dep) = set_dep_weak (DEP_ANTI, BEGIN_CONTROL,
+ MAX_DEP_WEAK);
+
+ }
+ sd_add_or_update_dep (dep, false);
+ }
+ else
+ add_dependence (insn, prev, REG_DEP_CONTROL);
+ }
+
+ break;
+
+ default:
+ break;
+ }
+ }
+ }
+ /* Maintain the invariant that bb->aux is clear after use. */
+ while (last_block)
+ {
+ bb = (basic_block) last_block->aux;
+ last_block->aux = NULL;
+ last_block = bb;
+ }
+}
+
+/* Schedule a single extended basic block, defined by the boundaries
+ HEAD and TAIL.
+
+ We change our expectations about scheduler behaviour depending on
+ whether MODULO_SCHEDULING is true. If it is, we expect that the
+ caller has already called set_modulo_params and created delay pairs
+ as appropriate. If the modulo schedule failed, we return
+ NULL_RTX. */
+
+basic_block
+schedule_ebb (rtx head, rtx tail, bool modulo_scheduling)