[gcc r12-8109] ipa/104303 - revert overly conservative DCE change

[gcc r12-8109] ipa/104303 - revert overly conservative DCE change

[Richard Biener]

https://gcc.gnu.org/g:7c7e78e9c460991349065572e32cac49b20d0432

commit r12-8109-g7c7e78e9c460991349065572e32cac49b20d0432
Author: Richard Biener <rguenther@suse.de>
Date:   Tue Apr 12 16:40:11 2022 +0200

    ipa/104303 - revert overly conservative DCE change
    
    The following reverts the DCE change back to the original behavior
    which should be handled well during the propagation stage.  That
    should fix the failures Thomas Schwinge is reporting.
    
    2022-04-12  Richard Biener  <rguenther@suse.de>
    
            PR ipa/104303
            * tree-ssa-dce.cc (mark_stmt_if_obviously_necessary): Do not
            include local escaped memory as obviously necessary stores.

Diff:
---
 gcc/tree-ssa-dce.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gcc/tree-ssa-dce.cc b/gcc/tree-ssa-dce.cc
index 34ce8abe33a..2067b711d5b 100644
--- a/gcc/tree-ssa-dce.cc
+++ b/gcc/tree-ssa-dce.cc
@@ -315,7 +315,7 @@ mark_stmt_if_obviously_necessary (gimple *stmt, bool aggressive)
     }
 
   if ((gimple_vdef (stmt) && keep_all_vdefs_p ())
-      || stmt_may_clobber_global_p (stmt, true))
+      || stmt_may_clobber_global_p (stmt, false))
     {
       mark_stmt_necessary (stmt, true);
       return;