[gcc r12-6672] tree-optimization/103987 - guard DSE modref query

[gcc r12-6672] tree-optimization/103987 - guard DSE modref query

[Richard Biener]

https://gcc.gnu.org/g:3ed40db0f12994e64434dc2e0590ba1da7ba5f60

commit r12-6672-g3ed40db0f12994e64434dc2e0590ba1da7ba5f60
Author: Richard Biener <rguenther@suse.de>
Date:   Tue Jan 18 13:26:22 2022 +0100

    tree-optimization/103987 - guard DSE modref query
    
    This adds a missing guard for a pointer to the DSE modref query,
    otherwise we can end up invoking APIs desired to only work on
    pointers on non-pointers when there are mismatches between declared
    and actual arguments of functions in the program.
    
    2022-01-18  Richard Biener  <rguenther@suse.de>
    
            PR tree-optimization/103987
            * tree-ssa-dse.cc (dse_optimize_call): Properly guard modref
            query with a pointer check.
    
            * gcc.dg/torture/pr103987.c: New testcase.

Diff:
---
 gcc/testsuite/gcc.dg/torture/pr103987.c | 13 +++++++++++++
 gcc/tree-ssa-dse.cc                     |  7 +++++--
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/gcc/testsuite/gcc.dg/torture/pr103987.c b/gcc/testsuite/gcc.dg/torture/pr103987.c
new file mode 100644
index 00000000000..6bfc76881a1
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr103987.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+
+void foo();
+
+void bar(int i)
+{
+  foo (i);
+}
+
+void foo(int *p)
+{
+  *p = 0;
+}
diff --git a/gcc/tree-ssa-dse.cc b/gcc/tree-ssa-dse.cc
index ed73bee932a..47997df2125 100644
--- a/gcc/tree-ssa-dse.cc
+++ b/gcc/tree-ssa-dse.cc
@@ -43,6 +43,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "cgraph.h"
 #include "ipa-modref-tree.h"
 #include "ipa-modref.h"
+#include "target.h"
 
 /* This file implements dead store elimination.
 
@@ -1190,10 +1191,12 @@ dse_optimize_call (gimple_stmt_iterator *gsi, sbitmap live_bytes)
 	{
 	  tree arg = access_node.get_call_arg (stmt);
 
-	  if (!arg)
+	  if (!arg || !POINTER_TYPE_P (TREE_TYPE (arg)))
 	    return false;
 
-	  if (integer_zerop (arg) && flag_delete_null_pointer_checks)
+	  if (integer_zerop (arg)
+	      && !targetm.addr_space.zero_address_valid
+		    (TYPE_ADDR_SPACE (TREE_TYPE (arg))))
 	    continue;
 
 	  ao_ref ref;