[PATCH] Fix tree-ssa-strlen.c ICE (PR tree-optimization/71707)

[Jakub Jelinek]

Hi!

I thought for ADDR_EXPRs we couldn't reach this, but we actually can, when
there is an SSA_NAME with POINTER_PLUS_EXPR of ADDR_EXPR and constant.

The following patch handles it.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2016-06-30  Jakub Jelinek  <ja...@redhat.com>

        PR tree-optimization/71707
        * tree-ssa-strlen.c (get_stridx_plus_constant): Handle already present
        strinfo even for ADDR_EXPR ptr.

        * gcc.dg/strlenopt-29.c: New test.

--- gcc/tree-ssa-strlen.c.jj    2016-06-29 16:10:27.000000000 +0200
+++ gcc/tree-ssa-strlen.c       2016-06-30 10:28:30.605430361 +0200
@@ -677,8 +677,14 @@ get_stridx_plus_constant (strinfo *bases
        {
          if (r == 0)
            {
-             gcc_assert (TREE_CODE (ptr) == SSA_NAME);
-             ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] = si->idx;
+             if (TREE_CODE (ptr) == SSA_NAME)
+               ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] = si->idx;
+             else
+               {
+                 int *pidx = addr_stridxptr (TREE_OPERAND (ptr, 0));
+                 if (pidx != NULL && *pidx == 0)
+                   *pidx = si->idx;
+               }
              return si->idx;
            }
          break;
--- gcc/testsuite/gcc.dg/strlenopt-29.c.jj      2016-06-30 10:36:34.673371348 
+0200
+++ gcc/testsuite/gcc.dg/strlenopt-29.c 2016-06-30 10:38:21.731032244 +0200
@@ -0,0 +1,27 @@
+/* PR tree-optimization/71707 */
+/* { dg-do run } */
+/* { dg-options "-O2 -fdump-tree-strlen" } */
+
+#include "strlenopt.h"
+
+char a[32];
+size_t b;
+
+__attribute__((noinline, noclone)) char *
+foo (void)
+{
+  char *p = memcpy (a, "a", 2) + 1;
+  memcpy (&a[1], "b", 2);
+  b = strlen (a) + strlen (&a[1]) + strlen (p);
+  return p;
+}
+
+int
+main ()
+{
+  if (foo () != &a[1] || b != 4)
+    abort ();
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump-times "strlen \\(" 0 "strlen" } } */

        Jakub