[PATCH] AArch64: Add support for roundeven[f]

[Joseph Myers]

On Tue, 8 Jun 2021, Szabolcs Nagy via Libc-alpha wrote:

> The 06/03/2021 14:51, Wilco Dijkstra via Libc-alpha wrote:
> > 
> > Add inline assembler versions of the roundeven functions.
> > 
> > Passes GLIBC regress. OK for commit?
> 
> i checked if we can do this via builtins, but
> 
> - __builtin_roundeven is only available since gcc-10
> - gcc as of now is not able to inline it as single instruction.

It can inline it on x86_64 (with -msse4.1 or later), but it only has the 
instruction patterns for x86 and not other architectures at present.  
Effectively this is one bug per architecture with relevant instructions 
that aren't used at present.

-- 
Joseph S. Myers
joseph@codesourcery.com