Re: x86 cpu capabilites detection routine to be commited

Prakash Punnoor wrote:

>What I want is that the configure script detects MMX (and other SIMD) by
>checking whether the compiler (with given use flags) sets the
>corresponding defines; eg. if the compiler sets __MMX__.
>  
>
I just wrote this up real quick, put this in mmxtest.m4 in either . or
m4/ and run aclocal -I . or -I m4 before running autoconf.  For a
reference check out your /usr/share/aclocal files for examples.

    dnl MMX_TEST([ACTION-IF-FOUND [, ACTION-IF-NOT-FOUND]])
    dnl
    AC_DEFUN([MMX_TEST], [dnl
        AC_MSG_CHECKING([for __MMX__ macro])

        ac_save_CFLAGS="$CFLAGS"
        CFLAGS="$CFLAGS -mmmx"
        AC_TRY_COMPILE([
           #ifndef __MMX__
           # error __MMX__ define missing when using -mmmx CFLAG
           #endif
        ],, ac_have_mmx=yes, ac_have_mmx=no)

        if test x$ac_have_mmx = xyes; then
           AC_MSG_RESULT([yes])
           ifelse([$2], , :, [$2])
        else
           AC_MSG_RESULT([no])
           ifelse([$3], , :, [$3])
        fi
    ])


/james

-- 
James Tomaschke
Snr. Software Engineer
InfoSemiconductor, Inc.