[gcc r14-9004] Do not record dependences from debug stmts in tail merging

[gcc r14-9004] Do not record dependences from debug stmts in tail merging

[Richard Biener]

https://gcc.gnu.org/g:ab5fb0f99313a7d1204a82c5aeb6748d98c7fb0f

commit r14-9004-gab5fb0f99313a7d1204a82c5aeb6748d98c7fb0f
Author: Richard Biener <rguenther@suse.de>
Date:   Thu Feb 15 10:52:09 2024 +0100

    Do not record dependences from debug stmts in tail merging
    
    The following avoids recording BB dependences for debug stmt uses.
    
            * tree-ssa-tail-merge.cc (same_succ_hash): Skip debug
            stmts.

Diff:
---
 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 f4e6ae6e8a2a..c8b4a79294d7 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;