[Bug target/57624] New: BZHI instrinsic is missing

["sgunderson at bigfoot dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57624

            Bug ID: 57624
           Summary: BZHI instrinsic is missing
           Product: gcc
           Version: 4.8.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: sgunderson at bigfoot dot com

Hi,

The GCC documentation
(http://gcc.gnu.org/onlinedocs/gcc/X86-Built_002din-Functions.html) claims
there should be such an intrinsic, added in gcc 4.7:

     unsigned long long _bzhi_u64 (unsigned long long, unsigned long long)

Yet, with gcc 4.8.1 (Debian 4.8.1-2), nothing of the sort exists:

sesse@gruessi:~$ gcc-4.8 -Wall -O2 -mbmi2 -c bzhi-test.c
bzhi-test.c: In function âfuncâ:
bzhi-test.c:5:2: warning: implicit declaration of function â_bzhi_u64â
[-Wimplicit-function-declaration]
  return _bzhi_u64(x, y);
  ^

A function call is generated instead, which was obviously not what I intended.
:-)

I thought this was maybe just a documentation error, but
__builtin_ia32_bzhi_u64 also does not exist.