[Bug fortran/77678] ICE in fold_read_from_constant_string, at fold-const.c:13706

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77678

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |accepts-invalid

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
I have a patch for the ICE.

Index: gcc/expr.c
===================================================================
--- gcc/expr.c  (revision 240342)
+++ gcc/expr.c  (working copy)
@@ -10274,7 +10257,8 @@ expand_expr_real_1 (tree exp, rtx target
                                            fold_convert_loc (loc, sizetype,
                                                              low_bound));

-               if (compare_tree_int (index1, TREE_STRING_LENGTH (init)) < 0)
+               if (tree_fits_uhwi_p (index1)
+                   && compare_tree_int (index1, TREE_STRING_LENGTH (init)) <
0)
                  {
                    tree type = TREE_TYPE (TREE_TYPE (init));
                    machine_mode mode = TYPE_MODE (type);