tree-vrp.c (infer_value_range): Ignore asm statements when looking for memory accesses for...

./:	* tree-vrp.c (infer_value_range): Ignore asm statements when
	looking for memory accesses for -fdelete-null-pointer-checks.
testsuite/:
	* gcc.target/i386/20080723-1.c: New test.

From-SVN: r138107

gcc/ChangeLog

+2008-07-23  Ian Lance Taylor  <iant@google.com>
+
+	* tree-vrp.c (infer_value_range): Ignore asm statements when
+	looking for memory accesses for -fdelete-null-pointer-checks.
+
 2008-07-24  Ben Elliston  <bje@au.ibm.com>
 
 	* config/spu/spu-c.c (__vector_keyword): New variable.

gcc/testsuite/ChangeLog

+2008-07-23  Ian Lance Taylor  <iant@google.com>
+
+	* gcc.target/i386/20080723-1.c: New test.
+
 2008-07-24  Ben Elliston  <bje@au.ibm.com>
 
 	* gcc.target/spu/vector.c: New test.

gcc/testsuite/gcc.target/i386/20080723-1.c

+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+extern void abort (void);
+extern void exit (int);
+
+static inline __attribute__((always_inline))
+void
+prefetch (void *x)
+{
+  asm volatile("prefetcht0 %0" : : "m" (*(unsigned long *)x));
+}
+
+struct hlist_head
+{
+  struct hlist_node *first;
+};
+
+struct hlist_node
+{
+  struct hlist_node *next;
+  unsigned long i_ino;
+};
+
+struct hlist_node * find_inode_fast(struct hlist_head *head, unsigned long ino)
+{
+  struct hlist_node *node;
+
+  for (node = head->first;
+       node && (prefetch (node->next), 1);
+       node = node->next)
+    {
+      if (node->i_ino == ino)
+	break;
+    }
+  return node ? node : 0;
+}
+
+struct hlist_node g2;
+struct hlist_node g1 = { &g2 };
+struct hlist_head h = { &g1 };
+
+int
+main()
+{
+  if (find_inode_fast (&h, 1) != 0)
+    abort ();
+  exit (0);
+}

gcc/tree-vrp.c

@@ -3456,7 +3456,9 @@ infer_value_range (tree stmt, tree op, enum tree_code *comp_code_p, tree *val_p)
 
   /* We can only assume that a pointer dereference will yield
      non-NULL if -fdelete-null-pointer-checks is enabled.  */
-  if (flag_delete_null_pointer_checks && POINTER_TYPE_P (TREE_TYPE (op)))
+  if (flag_delete_null_pointer_checks
+      && POINTER_TYPE_P (TREE_TYPE (op))
+      && TREE_CODE (stmt) != ASM_EXPR)
     {
       unsigned num_uses, num_loads, num_stores;