[gcc r14-1496] analyzer: regions in different memory spaces can't alias

[gcc r14-1496] analyzer: regions in different memory spaces can't alias

[David Malcolm]

https://gcc.gnu.org/g:b8a916726e7f4b8871ac9dd75b66d26d1adf4798

commit r14-1496-gb8a916726e7f4b8871ac9dd75b66d26d1adf4798
Author: David Malcolm <dmalcolm@redhat.com>
Date:   Fri Jun 2 09:28:30 2023 -0400

    analyzer: regions in different memory spaces can't alias
    
    gcc/analyzer/ChangeLog:
            * store.cc (store::eval_alias_1): Regions in different memory
            spaces can't alias.
    
    Signed-off-by: David Malcolm <dmalcolm@redhat.com>

Diff:
---
 gcc/analyzer/store.cc | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/gcc/analyzer/store.cc b/gcc/analyzer/store.cc
index e8c927b9fe9..4d1de825e79 100644
--- a/gcc/analyzer/store.cc
+++ b/gcc/analyzer/store.cc
@@ -2710,6 +2710,18 @@ tristate
 store::eval_alias_1 (const region *base_reg_a,
 		     const region *base_reg_b) const
 {
+  /* If they're in different memory spaces, they can't alias.  */
+  {
+    enum memory_space memspace_a = base_reg_a->get_memory_space ();
+    if (memspace_a != MEMSPACE_UNKNOWN)
+      {
+	enum memory_space memspace_b = base_reg_b->get_memory_space ();
+	if (memspace_b != MEMSPACE_UNKNOWN
+	    && memspace_a != memspace_b)
+	  return tristate::TS_FALSE;
+      }
+  }
+
   if (const symbolic_region *sym_reg_a
       = base_reg_a->dyn_cast_symbolic_region ())
     {