RFR: Only include fpu_control.h on 32-bit x86

[David Holmes]

On 12/04/2017 9:46 AM, Mikael Vidstedt wrote:
>
> os_linux_x86_.cpp has some code to set/update/tickle the fpu control word. The code makes use of functions from the fpu_control.h header, but is only used on 32-bit x86. musl doesn’t have the fpu_control.h header file.

So musl doesn't support 32-bit x86?

> This change adds a conditional include guard to only include the fpu_control.h on 32-bit x86 (!AMD64), which matches the guards used in the places further down in the file where the functionality is actually used.
>
> http://cr.openjdk.java.net/~mikael/webrevs/portola/fpucontrol/webrev.00/hotspot/webrev/

Using a consistent guard makes a lot of sense.

I wonder if we even need this FPU control word stuff these days ...

Thanks,
David

> Cheers,
> Mikael
>