[Vm-dev] Portability problems: compiler flags

[Igor Stasenko]

On 25 January 2011 03:26, Aleksej Saushev <asau at inbox.ru> wrote:
>
>  Hello!
>
> Squeak uses highly unportable flag "-mno-fused-madd".
> It isn't present in many systems, even those using GCC,
> since many systems use older compilers.
>
> Also, why do you build fdlibm? It is old stuff that works not so well,
> we have better libm. Is there a way to use our libm?
>
I asked  same question few weeks ago.
Check mailing list archive for discussion.
In short: differrent libm implementations work differently and some
have bad support of IEEE standard.

>
> No "-mno-fused-madd" in our compiler.
>
> --- unix/plugins/FloatMathPlugin/config.cmake.orig      2011-01-25 04:56:17.000000000 +0300
> +++ unix/plugins/FloatMathPlugin/config.cmake   2011-01-25 05:15:59.000000000 +0300
> @@ -10,7 +10,7 @@
>  # GCC optimizations break fdlibm so disable them for now.
>
>  IF (CMAKE_COMPILER_IS_GNUCC)
> -  SET (LIBM_CFLAGS "${CMAKE_C_FLAGS} -O0 -mno-fused-madd")
> +  SET (LIBM_CFLAGS "${CMAKE_C_FLAGS}")
>  ELSE ()
>   SET (LIBM_CFLAGS "${CMAKE_C_FLAGS}")
>  ENDIF ()
>
>
>
> --
> HE CE3OH...
>



-- 
Best regards,
Igor Stasenko AKA sig.