[Bug target/50498] New: __sync_bool_compare_and_swap_16 isn't supported for x86_64

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50498

             Bug #: 50498
           Summary: __sync_bool_compare_and_swap_16 isn't supported for
                    x86_64
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: hjl.to...@gmail.com
                CC: ubiz...@gmail.com
            Target: x86_64


[hjl@gnu-6 tmp]$ gcc -S -O2 y.c
[hjl@gnu-6 tmp]$ cat y.s
    .file    "y.c"
    .text
    .p2align 4,,15
    .globl    f8
    .type    f8, @function
f8:
.LFB0:
    .cfi_startproc
    xorl    %eax, %eax
    movl    $1, %edx
    lock cmpxchgq    %rdx, -8(%rsp)
    ret
    .cfi_endproc
.LFE0:
    .size    f8, .-f8
    .p2align 4,,15
    .globl    f16
    .type    f16, @function
f16:
.LFB1:
    .cfi_startproc
    subq    $24, %rsp
    .cfi_def_cfa_offset 32
    movl    $1, %ecx
    xorl    %r8d, %r8d
    movq    %rsp, %rdi
    xorl    %esi, %esi
    xorl    %edx, %edx
    call    __sync_bool_compare_and_swap_16
    addq    $24, %rsp
    .cfi_def_cfa_offset 8
    ret
    .cfi_endproc
.LFE1:
    .size    f16, .-f16
    .ident    "GCC: (GNU) 4.6.0 20110603 (Red Hat 4.6.0-10)"
    .section    .note.GNU-stack,"",@progbits
[hjl@gnu-6 tmp]$ gcc -S -O2 y.c -m32
[hjl@gnu-6 tmp]$ cat y.s
    .file    "y.c"
    .text
    .p2align 4,,15
    .globl    f8
    .type    f8, @function
f8:
.LFB0:
    .cfi_startproc
    pushl    %ebx
    .cfi_def_cfa_offset 8
    .cfi_offset 3, -8
    xorl    %eax, %eax
    subl    $16, %esp
    .cfi_def_cfa_offset 24
    xorl    %edx, %edx
    movl    $1, %ebx
    xorl    %ecx, %ecx
    lock cmpxchg8b    8(%esp)
    addl    $16, %esp
    .cfi_def_cfa_offset 8
    popl    %ebx
    .cfi_def_cfa_offset 4
    .cfi_restore 3
    ret
    .cfi_endproc
.LFE0:
    .size    f8, .-f8
    .ident    "GCC: (GNU) 4.6.0 20110603 (Red Hat 4.6.0-10)"
    .section    .note.GNU-stack,"",@progbits
[hjl@gnu-6 tmp]$ 

I am using cmpxchg16b for __sync_bool_compare_and_swap_16.