[PATCH, rs6000, libgcc] Implement temporary solution for __divkc3 and __mulkc3

[Segher Boessenkool]

On Mon, Jul 11, 2016 at 02:38:50PM -0500, Bill Schmidt wrote:
> It was recently brought to my attention that glibc needs access to complex
> multiply and divide for IEEE-128 floating-point in GCC 6.2 in order to move
> ahead with the library implementation work.  This patch enables this support
> using only target-specific changes to avoid any possible effect on other
> targets.  This is not the correct long-term approach, and I am working on a
> patch that instead makes use of the common infrastructure.  The plan is to
> use the current patch for GCC 6, and replace it with the other approach in
> GCC 7 shortly.
> 
> Thus this patch copies the common code for complex multiply and divide out
> of libgcc2.c into separate Power-specific files, and specializes it for
> the KC type.  It adds a couple of straightforward tests to verify that the
> approach works.  I've tested the code generated for these tests on a POWER9
> simulator as well as a POWER8 machine.
> 
> Bootstrapped and tested on powerpc64le-unknown-linux-gnu with no regressions.
> I've also asked the glibc team to verify that this serves their requirements.
> Is this ok for trunk, and for gcc-6-branch after a short burn-in period?

Okay for both.  Ugly :-)


Segher