This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: Big differences on SpecFP results for gcc and icc
- From: David Edelsohn <dje at watson dot ibm dot com>
- To: Daniel Berlin <dberlin at dberlin dot org>, Uros Bizjak <uros at kss-loka dot si>, gcc at gcc dot gnu dot org, Scott Robert Ladd <scott dot ladd at coyotegulch dot com>
- Date: Sun, 12 Jun 2005 15:36:33 -0400
- Subject: Re: Big differences on SpecFP results for gcc and icc
- References: <42ABFE7C.5040804@kss-loka.si> <1118583184.8107.98.camel@linux.site>
We have investigated these benchmarks for PowerPC. The high-level
analysis is:
>>>>> Daniel Berlin writes:
>> An interesting examples are:
>> -177.mesa (this is a c test), where icc is almost 40% faster
FP to Int conversion.
Dan> SSE Vectorization, I believe.
>> -178.galgel, where icc is again 40% faster
Dan> This is because of a better fortran *library*, not compiler.
Dan> IIRC, it's all in matmul.
Agreed, Fortran90 arrays and matmul.
>> -179.art, where llvm is more than 1.5x faster than both gcc and icc
Dan> taken care of on struct-reorg.
Agreed, art hack on struct-reorg branch.
>> -187.facerec, where icc is 100% faster than gcc
Dan> No idea.
Fortran90 arrays.
>> -189.lucas, where icc is 60% faster
Dan> No idea, though i'd imagine its the same issue.
Fortran90 arrays and FP to Int conversion.
David