[gcc r11-8747] Don't process lookups for debug statements in Ranger.

[gcc r11-8747] Don't process lookups for debug statements in Ranger.

[Andrew Macleod]

https://gcc.gnu.org/g:263a7e20c88a35bdfaebfac3c9abb313c5867590

commit r11-8747-g263a7e20c88a35bdfaebfac3c9abb313c5867590
Author: Andrew MacLeod <amacleod@redhat.com>
Date:   Tue Jun 8 09:43:17 2021 -0400

    Don't process lookups for debug statements in Ranger.
    
    Although PR 100781 is not an issue in GCC11, its possible that a similar
    situation may arise.  The identical fix cannot be easily introduced.
    With EVRP always running in hybrid mode, there is no need for ranger to
    spawn a lookup for a debug statement in this release.
    
            * gimple-range.cc (gimple_ranger::range_of_expr): Treat debug statments
            as contextless queries to avoid additional lookups.

Diff:
---
 gcc/gimple-range.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gcc/gimple-range.cc b/gcc/gimple-range.cc
index 6158a754dd6..fd7fa5e3dbb 100644
--- a/gcc/gimple-range.cc
+++ b/gcc/gimple-range.cc
@@ -945,7 +945,7 @@ gimple_ranger::range_of_expr (irange &r, tree expr, gimple *stmt)
     return get_tree_range (r, expr);
 
   // If there is no statement, just get the global value.
-  if (!stmt)
+  if (!stmt || is_gimple_debug (stmt))
     {
       if (!m_cache.get_global_range (r, expr))
         r = gimple_range_global (expr);