[PATCH 4/4] sched1: model: ICE on infinite loops in predecessor promotion (Not for Merge)

[Vineet Gupta]

This is just a testing hack in case someone runs into infinite loops
with model schedule change. I did run into quite a few during the course
of development and instead of sched trace files eating up the disk,
better to ICE and abort.

gcc/ChangeLog:

        * haifa-sched.cc (model_promote_predecessors): Add infinite
        looping checks.

Signed-off-by: Vineet Gupta <vine...@rivosinc.com>
---
 gcc/haifa-sched.cc | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/gcc/haifa-sched.cc b/gcc/haifa-sched.cc
index 67f99ce00339..471f7c686e9d 100644
--- a/gcc/haifa-sched.cc
+++ b/gcc/haifa-sched.cc
@@ -3714,6 +3714,18 @@ model_promote_predecessors (struct model_insn_info *insn)
   struct model_insn_info *pro, *first, *leaf_true_dep = NULL;
   sd_iterator_def sd_it;
   dep_t dep;
+  int lockup_local_count = 0;
+  static int lockup_inter_insn, lockup_inter_count;
+
+  if (lockup_inter_insn == insn->insn->u2.insn_uid)
+    {
+      gcc_assert (lockup_inter_count++ < 1000);
+    }
+  else
+    {
+       lockup_inter_insn = insn->insn->u2.insn_uid;
+       lockup_inter_count = 0;
+    }
 
   if (sched_verbose >= 7)
     fprintf (sched_dump, ";;\t+--- priority of %d = %d, priority of",
@@ -3765,6 +3777,7 @@ model_promote_predecessors (struct model_insn_info *insn)
                }
            }
        }
+      gcc_assert (++lockup_local_count < 10000);
       if (!first)
        break;
       insn = first;
-- 
2.43.0