ImageMagic with Webp

[Jos Chrispijn]

   After I installed ImageMagic port, I got stuck at the installation of
   Webp:

   ===>  Building for webp-0.4.1
   Making all in src
   Making all in dec
   Making all in enc
   Making all in dsp
     CC     libwebpdspdecode_sse2_la-lossless_sse2.lo
   lossless_sse2.c: In function 'ConvertBGRAToBGR':
   lossless_sse2.c:403: note: use -flax-vector-conversions to permit
   conversions between vectors with differing element types or numbers of
   subparts
   lossless_sse2.c:403: error: incompatible type for argument 1 of
   '__builtin_ia32_psrlqi128'
   lossless_sse2.c:404: error: incompatible type for argument 1 of
   '__builtin_ia32_psrlqi128'
   *** [libwebpdspdecode_sse2_la-lossless_sse2.lo] Error code 1
   1 error
   *** [all-recursive] Error code 1
   1 error
   *** [all-recursive] Error code 1
   1 error
   ===> Compilation failed unexpectedly.
   Try to set MAKE_JOBS_UNSAFE=yes and rebuild before reporting the
   failure to
   the maintainer.
   *** [do-build] Error code 1
   Stop in /usr/ports/graphics/webp.
   *** [install] Error code 1
   Stop in /usr/ports/graphics/webp.
   *** [reinstall] Error code 1
   Stop in /usr/ports/graphics/webp.

   --- end of text --

   Can you tell me how to solve?

   Thanks,
   Jos Chrispijn