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< IUSE="doc fltk gif glut gsl hdf5 jpeg octave python qt4 wxwindows"
---
> IUSE="doc fltk gif glut gsl hdf5 jpeg octave openmp python qt4 wxwindows"
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< 	if ! version_is_at_least "4.3.0" "$(gcc-version)"; then
< 		eerror "You need >=gcc-4.3.0 to compile this package"
< 		die "Wrong gcc version"
---
> 	if ( use openmp ) then
> 	   if ( $(tc-getCC)$ == *gcc* ) then
> 	      if ( $(gcc-major-version)$(gcc-minor-version) -lt 43 ) then
> 		  eerror "You are using gcc and OpenMP is only available with gcc >= 4.2 "
> 		  eerror "mathgl requires at least gcc >= 4.3"
> 		  eerror "If you want to use gcc you also need to enable the openmp useflag for gcc"
> 		  die "wrong compiler version"
> 	      elif ( ! built_with_use sys-devel/gcc openmp ) then
> 		  eerror "You are using gcc, gcc needs to be build with the openmp useflag"
> 		  die "Wrong configuration for gcc"
> 	      fi
> 	    fi
> 	    einfo "You are not using gcc"
> 	    einfo "You should ensure that your compiler is providing support for openmp"
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> 	epatch "${FILESDIR}"/${P}-openmp.patch
> 	cp "${FILESDIR}/ax_openmp.m4" "${S}/config/"
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> 		$(use_enable openmp) \