[gcc r16-3160] forwprop: Fix non-call exceptions some more with copy prop for aggregates [PR121494]

[Andrew Pinski via Gcc-cvs]

https://gcc.gnu.org/g:2fe432175ef135037dea210002881a093f328779

commit r16-3160-g2fe432175ef135037dea210002881a093f328779
Author: Andrew Pinski <andrew.pin...@oss.qualcomm.com>
Date:   Mon Aug 11 20:47:30 2025 +0000

    forwprop: Fix non-call exceptions some more with copy prop for aggregates 
[PR121494]
    
    Note this conflicts with my not yet approved patch for copy prop for 
aggregates into
    function arguments (I will get back to that soon).
    
    So the problem here is that I assumed if:
    *a = decl1;
    would not cause an exception that:
    decl2 = *a;
    would cause not cause one too.
    
    I was wrong, in some cases where the Ada front-end marks `*a` in the store
    as TREE_THIS_NOTRAP (due to knowing never be null or some other cases).
    So that means when we prop decl1 into the statement storing decl2, we need 
to
    mark that statement as possible to cleanup for eh.
    
    Bootstraped and tested on x86_64-linux-gnu.
    Also tested on x86_64-linux-gnu with a hack to force generate LC constant 
decls in the gimplifier.
    
            PR tree-optimization/121494
    gcc/ChangeLog:
    
            * tree-ssa-forwprop.cc (optimize_agr_copyprop): Mark the bb of the 
use
            stmt if needed for eh cleanup.
    
    Signed-off-by: Andrew Pinski <andrew.pin...@oss.qualcomm.com>

Diff:
---
 gcc/tree-ssa-forwprop.cc | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/gcc/tree-ssa-forwprop.cc b/gcc/tree-ssa-forwprop.cc
index 1cde5f85150e..4237a2013bad 100644
--- a/gcc/tree-ssa-forwprop.cc
+++ b/gcc/tree-ssa-forwprop.cc
@@ -1487,6 +1487,7 @@ optimize_agr_copyprop (gimple_stmt_iterator *gsip)
          fprintf (dump_file, "after previous\n  ");
          print_gimple_stmt (dump_file, stmt, 0, dump_flags);
        }
+      gimple *orig_stmt = use_stmt;
       gimple_stmt_iterator gsi = gsi_for_stmt (use_stmt);
       gimple_assign_set_rhs_from_tree (&gsi, unshare_expr (src));
       update_stmt (use_stmt);
@@ -1496,6 +1497,10 @@ optimize_agr_copyprop (gimple_stmt_iterator *gsip)
          fprintf (dump_file, "into\n  ");
          print_gimple_stmt (dump_file, use_stmt, 0, dump_flags);
        }
+
+      /* Mark the bb for eh cleanup if needed.  */
+      if (maybe_clean_or_replace_eh_stmt (orig_stmt, use_stmt))
+       bitmap_set_bit (to_purge, gimple_bb (stmt)->index);
       statistics_counter_event (cfun, "copy prop for aggregate", 1);
       changed = true;
     }