Re: What is libg2c.a? And why do I have to link to it?
Mikael> I have a autoconf test that fails if i don't give -lg2c as
Mikael> extra link flags. Without g2c there are undefined references
Mikael> to e_wsfe, z_abs, c_sqrt, etc. Is not g2c an internal gcc
Mikael> thing?
dnl this fails for lapack
AC_CHECK_LIB(m, pow)
AC_CHECK_LIB(blas,ddot_)
AC_CHECK_LIB(lapack,sspsv_)
dnl this succeeds for lapack
AC_CHECK_LIB(m, pow)
AC_CHECK_LIB(blas,ddot_)
AC_CHECK_LIB(lapack,sspsv_,,,-lg2c)
The blas and lapack libraries are originally written in Fortran, I
believe. Thus gcc needs the Fortran compatibility library g2c when
linking them. (The g in the name stands for g77, not very obvious
unfortunately)
--
Ian Zimmerman, Oakland, California, U.S.A.
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