Richard Biener <rguenth at gcc dot> changed:

           What    |Removed                     |Added
             Target|                            |x86_64-*-*
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2016-09-22
                 CC|                            |matz at gcc dot
     Ever confirmed|0                           |1

--- Comment #1 from Richard Biener <rguenth at gcc dot> ---
First of all you need to make sure to have recent glibc installed to benefit
the vectorized math routines therein.  Otherwise we cannot vectorize std::log.

Second, I think the if (i == 0) needs loop splitting (patch pending, author
If you re-write the loop to

  if (s != 0)
    a[i] = b[i] * c[i];
  for (unsigned i = 1; i < s; ++i)
    a[i] = (b[i] + c[i]) * c[i-1] * std::log(i);

then GCC will be able to vectorize it.  Confirmed because of that issue.

Reply via email to