The following avoids recording BB dependences for debug stmt uses.
Bootstrap and regtest running on x86_64-unknown-linux-gnu.
It's unlikely a dependence is just because of debug stmts so
actual compare-debug issues are very unlikely. Still spotted
while investigating a CI regression mail (for an obsolete broken
patch ...)
* tree-ssa-tail-merge.cc (same_succ_hash): Skip debug
stmts.
---
gcc/tree-ssa-tail-merge.cc | 3 +++
1 file changed, 3 insertions(+)
diff --git a/gcc/tree-ssa-tail-merge.cc b/gcc/tree-ssa-tail-merge.cc
index f4e6ae6e8a2..c8b4a79294d 100644
--- a/gcc/tree-ssa-tail-merge.cc
+++ b/gcc/tree-ssa-tail-merge.cc
@@ -474,6 +474,9 @@ same_succ_hash (const same_succ *e)
!gsi_end_p (gsi); gsi_next_nondebug (&gsi))
{
stmt = gsi_stmt (gsi);
+ if (is_gimple_debug (stmt))
+ continue;
+
stmt_update_dep_bb (stmt);
if (stmt_local_def (stmt))
continue;
--
2.35.3
