[Bug middle-end/49363] [feature request] multiple target attribute (and runtime dispatching based on cpuid)

["vincenzo.innocente at cern dot ch" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49363

--- Comment #2 from vincenzo Innocente <vincenzo.innocente at cern dot ch> 2011-06-11 05:58:46 UTC ---
These new developments sound interesting. Hope somebody is working on it and
will publish a testable version soon.
On the other hand I was thinking more of exploiting auto-vectorization for
which having multiple copy of the very same code looks to me not necessary and
error prone, Something for instance along these line
float  __attribute__ ((__target__ ("sse2","sse3","avx","fma"))) 
sum0(float const * __restrict__ x, 
           float const * __restrict__ y, float const * __restrict__ z) {
  float sum=0;
  for (int i=0; i!=1024; ++i)
    sum += z[i]+x[i]*y[i];
  return sum;
}

If my understanding of the proposal is correct I will have to copy-paste this
function four times, one for each target.