[PATCH] Add a new macro to mask a float

[Joseph Myers]

On Tue, 28 Jun 2016, Tulio Magno Quites Machado Filho wrote:

> Defining a new macro allows architectures to provide more efficient
> implementations than using a GET_FLOAT_WORD/SET_FLOAT_WORD pair.
> As an example, POWER8 is able to mask the float directly in the VSX
> without copying the data to a GPR and copying it back.
> 
> This patch introduces the new macro MASK_FLOAT.  The generic
> implementation remains unchanged.

I think this would better be implemented as a compiler optimization that 
recognizes the pattern of masking a float value.

Note that language runtimes sometimes include code derived from fdlibm (to 
ensure system-independent results rather than results depending on system 
libm), so the optimization wouldn't be purely for building glibc.

-- 
Joseph S. Myers
joseph@codesourcery.com