[oe] liboil softfloat fix questions

[Khem Raj]

On Thu, Sep 25, 2008 at 12:31 AM, Koen Kooi <k.kooi at student.utwente.nl> wrote:
> Hi,
>
> I noticed liboil got patched:
>
> +if test x"${ENABLE_SOFTFLOAT}" = "xyes"; then
> +      VFP_CFLAGS="$VFP_CFLAGS -mfloat-abi=softfp"
> +else
> +      VFP_CFLAGS="$VFP_CFLAGS -mfpu=vfp"
>
> That looks a bit wrong to me, since for EABI you'd want '-mfloat-abi=softfp
> -mfpu=vfp' to make it use the VFP coprocessor using softfloat calling
> conventions[1] and plain '-mfloat-abi=softfp' to do softfloat, and with OABI
> you don't want to pass '-mfloat-abi=softfp'
> To make it even more complicated, on armv7a[2] you want to pass -mfpu=neon
> -mfloat-abi=softfp. If you look at the output of gcc -S you'll see that EABI
> won't use an FPU unless you pass in -mfloat-abi=softfp *and* -mfpu=<FPU>.

yes thats right

>
> AFAICT OE passes all the needed magic already in TARGET_CCFLAGS, so it seems
> that this entire construct can be removed.
>
> Robert, could you beat the cacao people with a cluebat so they get their
> stuff right?
>
> regards,
>
> Koen
>
> [1] There are more permutations, but let's focus on the one OE is currently
> using
> [2] On cortex-a8 the VFP isn't pipelined, so double precision math is twice
> as slow compared to ARM11 cores, the NEON unit is pipelined, but can only do
> single-precision. '

should get better with cortex-a9

So don't be surprised if your new omap3 nokia tablet
> performs FP math slower than your n810.

>
>
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