[Bug target/61296] Excessive alignment in ix86_data_alignment

["hjl.tools at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61296

H.J. Lu <hjl.tools at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |kirill.yukhin at intel dot com

--- Comment #14 from H.J. Lu <hjl.tools at gmail dot com> ---
I got

[hjl@gnu-6 pr61296]$ cat a.c
struct foo
{
  char i[128];
};

struct foo x = { 1 };
[hjl@gnu-6 pr61296]$ make a.s
/export/build/gnu/gcc-misc/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc-misc/build-x86_64-linux/gcc/ -O3 -mavx2 -S a.c
[hjl@gnu-6 pr61296]$ cat a.s
    .file    "a.c"
    .globl    x
    .data
    .align 64
    .type    x, @object
    .size    x, 128
x:
    .byte    1
    .zero    127
    .ident    "GCC: (GNU) 5.0.0 20141216 (experimental)"
    .section    .note.GNU-stack,"",@progbits
[hjl@gnu-6 pr61296]$ 

Which older GCC expects 64-byte alignment here?  We should limit
DATA_ALIGNMENT to the maximum alignment actually expected by the
older GCC, which I believe is 32 byte, and have an option to limit
DATA_ALIGNMENT to MAX (ABI alignment, natural alignment).