[Bug c++/86763] [7/8 Regression] Wrong code comparing member of copy of a 237 byte object with nontrivial default constructor on x86-64 arch

2018-08-17 Thread rguenth at gcc dot gnu.org 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86763

--- Comment #13 from Richard Biener  ---
Author: rguenth
Date: Fri Aug 17 11:51:48 2018
New Revision: 263617

URL: https://gcc.gnu.org/viewcvs?rev=263617=gcc=rev
Log:
2018-08-17  Richard Biener  

Backport from mainline
2018-08-02  Richard Biener  

PR c++/86763
* class.c (layout_class_type): Copy TYPE_TYPELESS_STORAGE
to the CLASSTYPE_AS_BASE.

* g++.dg/torture/pr86763.C: New testcase.

Added:
branches/gcc-8-branch/gcc/testsuite/g++.dg/torture/pr86763.C
Modified:
branches/gcc-8-branch/gcc/cp/ChangeLog
branches/gcc-8-branch/gcc/cp/class.c
branches/gcc-8-branch/gcc/testsuite/ChangeLog

[Bug c++/86763] [7/8 Regression] Wrong code comparing member of copy of a 237 byte object with nontrivial default constructor on x86-64 arch

2018-08-06 Thread curlypaul924 at gmail dot com 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86763

--- Comment #12 from Paul Brannan  ---
(In reply to Richard Biener from comment #9)
> The following seems to work, will test.
> 
> Index: gcc/cp/class.c
> ===
> --- gcc/cp/class.c  (revision 263209)
> +++ gcc/cp/class.c  (working copy)
> @@ -6243,6 +6243,7 @@ layout_class_type (tree t, tree *virtual
>   bitsize_int (BITS_PER_UNIT)));
>SET_TYPE_ALIGN (base_t, rli->record_align);
>TYPE_USER_ALIGN (base_t) = TYPE_USER_ALIGN (t);
> +  TYPE_TYPELESS_STORAGE (base_t) = TYPE_TYPELESS_STORAGE (t);
>  
>/* Copy the non-static data members of T. This will include its
>  direct non-virtual bases & vtable.  */

This patch fixes the failure in my original (non-reduced test case).

[Bug c++/86763] [7/8 Regression] Wrong code comparing member of copy of a 237 byte object with nontrivial default constructor on x86-64 arch

2018-08-02 Thread rguenth at gcc dot gnu.org 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86763

Richard Biener  changed:

   What|Removed |Added

  Known to work||9.0
Summary|[7/8/9 Regression] Wrong|[7/8 Regression] Wrong code
   |code comparing member of|comparing member of copy of
   |copy of a 237 byte object   |a 237 byte object with
   |with nontrivial default |nontrivial default
   |constructor on x86-64 arch  |constructor on x86-64 arch

--- Comment #11 from Richard Biener  ---
Fixed on trunk sofar.