https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71448
--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
I wrote so far
--- fold-const.c.jj1 2016-06-06 19:39:40.000000000 +0200
+++ fold-const.c 2016-06-08 09:56:56.830326277 +0200
@@ -8527,9 +8527,9 @@ fold_comparison (location_t loc, enum tr
if ((offset0 == offset1
|| (offset0 && offset1
&& operand_equal_p (offset0, offset1, 0)))
- && (code == EQ_EXPR
- || code == NE_EXPR
- || (indirect_base0 && DECL_P (base0))
+ && (equality_code
+ || (indirect_base0
+ && (DECL_P (base0) || TREE_CODE (base0) == STRING_CST))
|| POINTER_TYPE_OVERFLOW_UNDEFINED))
{
@@ -8568,7 +8568,9 @@ fold_comparison (location_t loc, enum tr
6.5.6/8 and /9 with respect to the signed ptrdiff_t. */
else if (bitpos0 == bitpos1
&& (equality_code
- || (indirect_base0 && DECL_P (base0))
+ || (indirect_base0
+ && (DECL_P (base0)
+ || TREE_CODE (base0) == STRING_CST))
|| POINTER_TYPE_OVERFLOW_UNDEFINED))
{
/* By converting to signed sizetype we cover middle-end pointer
for this which works fine, but you're right CONSTANT_CLASS_P (base0) might be
better.
