This avoids setting the TREE_OVERFLOW bit on DECL_FIELD_OFFSET for
the shifted bounds field.
If DECL_FIELD_OFFSET of array-field is always a constant we could
as well use
DECL_FIELD_OFFSET (bounds_field)
= size_int (-int_byte_position (array_field));
also I notice that DECL_OFFSET_ALIGN is now bogus for bounds_field.
DECL_FIELD_OFFSET no longer has the desired zero bits. Shouldn't we
instead set DECL_FIELD_OFFSET to -DECL_OFFSET_ALIGN and adjust
DECL_FIELD_BIT_OFFSET accordingly?
Well, with the above questions and suggestions I'd rather leave it
to you deciding whether you like the below hack or want to rework
the function a bit.
Fixes
=== gnat tests ===
Running target unix/
FAIL: gnat.dg/align_max.adb execution test
FAIL: gnat.dg/thin_pointer2.adb execution test
FAIL: gnat.dg/unc_memfree.adb execution test
Running target unix//-m32
FAIL: gnat.dg/align_max.adb execution test
FAIL: gnat.dg/thin_pointer2.adb execution test
FAIL: gnat.dg/unc_memfree.adb execution test
Richard.
2011-09-02 Richard Guenther <rguent...@suse.de>
ada/
* gcc-interface/utils.c (shift_unc_components_for_thin_pointers):
Drop overflow bit on negative offsets.
Index: trunk/gcc/ada/gcc-interface/utils.c
===================================================================
*** trunk.orig/gcc/ada/gcc-interface/utils.c 2011-09-05 13:01:59.000000000
+0200
--- trunk/gcc/ada/gcc-interface/utils.c 2011-09-05 13:56:37.000000000 +0200
*************** shift_unc_components_for_thin_pointers (
*** 3411,3416 ****
--- 3414,3425 ----
DECL_FIELD_OFFSET (bounds_field)
= size_binop (MINUS_EXPR, size_zero_node, byte_position (array_field));
+ if (TREE_CODE (DECL_FIELD_OFFSET (bounds_field)) == INTEGER_CST
+ && TREE_OVERFLOW (DECL_FIELD_OFFSET (bounds_field)))
+ DECL_FIELD_OFFSET (bounds_field)
+ = build_int_cst_wide (sizetype,
+ TREE_INT_CST_LOW (DECL_FIELD_OFFSET (bounds_field)),
+ TREE_INT_CST_HIGH (DECL_FIELD_OFFSET
(bounds_field)));
DECL_FIELD_OFFSET (array_field) = size_zero_node;
DECL_FIELD_BIT_OFFSET (array_field) = bitsize_zero_node;
