[Bug target/29852] New: x86_64: SSE version missing for fmod{d,s,x}f3

burnus at gcc dot gnu dot org gcc-bugzilla@gcc.gnu.org
Wed Nov 15 20:46:00 GMT 2006


The is currently no SSE version in x86_64 for fmod.

fmod{d,s,x}f3 intriniscs are constrainted by:
 "TARGET_USE_FANCY_MATH_387
  && (!(TARGET_SSE2 && TARGET_SSE_MATH) || TARGET_MIX_SSE_I387)"

The need for these intriniscs can be seen in the Polyhedron Fortran performance
test "ac". As soon as gfortran started to used fmod the execution time for the
program "ac" almost trippled under x86_64 as libcall to the math library is
done. For the performance, see:
http://www.suse.de/~gcctest/c++bench/polyhedron/polyhedron-summary.txt-ac-3.png
at http://www.suse.de/~gcctest/c++bench/polyhedron/

See mailing list thread which starts with
http://gcc.gnu.org/ml/fortran/2006-11/msg00333.html
the actually interesting thread starts, however, with:
http://gcc.gnu.org/ml/fortran/2006-11/msg00353.html


-- 
           Summary: x86_64: SSE version missing for fmod{d,s,x}f3
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: enhancement
          Priority: P3
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: burnus at gcc dot gnu dot org
  GCC host triplet: x86_64-unknown-linux-gnu
GCC target triplet: x86_64-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29852



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