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Re: [RFC][PATCH 0/2] aarch64: Add optimized ASIMD versions of sinf/cosf

Joseph Myers wrote:
> On Tue, 13 Jun 2017, Szabolcs Nagy wrote:
> > the c implementation is generic
> > (sometimes the instruction scheduling is suboptimal and
> > i found that union based bithacks don't always give good
> > code but those are issues we can work on the gcc side)
> Indeed, I've told powerpc people trying to add powerpc-specific versions 
> of those union-based macros to do the optimization on the compiler side.  
> Exactly the same applies to AArch64 - there are lots of copies of 
> fdlibm-based code and similar union-based code in different projects, 
> making compilers optimize better will help more than just glibc.

Agreed. I recently committed an AArch64 fix for int<->FP moves
(, so the
particular issue Szabolcs mentions is fixed.  I've got several other
improvements inspired by non-optimal sequences in math functions
in review or development.  It's fairly trivial to get GCC generate the
expected code, so there is no excuse for using assembly code.


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