[gcc r12-4209] Ranger: More efficient zero/nonzero check.

[Andrew Macleod]

https://gcc.gnu.org/g:4b8ca6c6177b2bd948c1cb2a116955b942751559

commit r12-4209-g4b8ca6c6177b2bd948c1cb2a116955b942751559
Author: Andrew MacLeod <amacleod@redhat.com>
Date:   Mon Sep 27 18:53:54 2021 -0400

    Ranger: More efficient zero/nonzero check.
    
    A recent change introduced a frequent check for zero and non-zero which has
    caused a lot of extra temporary trees to be created.  Make the check more
    efficent as it is always a pointer and thus unsigned.
    
            * gimple-range-cache.cc (non_null_ref::adjust_range): Check for
            zero and non-zero more efficently.

Diff:
---
 gcc/gimple-range-cache.cc | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/gcc/gimple-range-cache.cc b/gcc/gimple-range-cache.cc
index 61043d3f375..91dd5a5c087 100644
--- a/gcc/gimple-range-cache.cc
+++ b/gcc/gimple-range-cache.cc
@@ -98,9 +98,10 @@ non_null_ref::adjust_range (irange &r, tree name, basic_block bb,
     return false;
 
   // We only care about the null / non-null property of pointers.
-  if (!POINTER_TYPE_P (TREE_TYPE (name)) || r.zero_p () || r.nonzero_p ())
+  if (!POINTER_TYPE_P (TREE_TYPE (name)))
+    return false;
+  if (r.undefined_p () || r.lower_bound () != 0 || r.upper_bound () == 0)
     return false;
-
   // Check if pointers have any non-null dereferences.
   if (non_null_deref_p (name, bb, search_dom))
     {