Re: [PATCH 1/2] powerpc: split the math emulation into two parts

[Kumar Gala <galak@kernel.crashing.org>]

On Jul 16, 2013, at 6:57 AM, Kevin Hao wrote:

> For some SoC (such as the FSL BookE) even though there does have
> a hardware FPU, but not all floating point instructions are
> implemented. Unfortunately some versions of gcc do use these
> unimplemented instructions. Then we have to enable the math emulation
> to workaround this issue. It seems a little redundant to have the
> support to emulate all the floating point instructions in this case.
> So split the math emulation into two parts. One is for the SoC which
> doesn't have FPU at all and the other for the SoC which does have the
> hardware FPU and only need some special floating point instructions to
> be emulated.
>=20
> Signed-off-by: Kevin Hao <haokexin@gmail.com>
> ---
> arch/powerpc/Kconfig           | 20 ++++++++++++++++++++
> arch/powerpc/math-emu/Makefile | 24 ++++++++++++------------
> arch/powerpc/math-emu/math.c   | 20 ++++++++++++++------
> 3 files changed, 46 insertions(+), 18 deletions(-)

why make the split, what harm is there in just turning on the full =
emulation code to handle the unimplemented cases?

who says what some other implementation doesn't need something that you =
have in CONFIG_MATH_EMULATION_FULL?

Is the kernel code size really an issue?

- k=