Re: cortex / arm-hardfloat-linux-gnueabi (was Re: armelfp: new architecture name for an armel variant)

[Paul Brook <paul@codesourcery.com>]

> As Konstantinos explained, this is something of the order of 6 moves
> around from integer to float and back again for a relatively simple
> function like sinf() which takes one floating point argument and
> returns one. vmov rN, sN has a penalty of around 20 cycles. Nothing is
> being done here, it stalls the entire pipeline until it is complete.
> You can't schedule around it. And it does this 6 times.

This is nonsense, as I already explained[1].
The hard-float ABI version of sinf actually has more unavoidable stalls than 
the soft-float ABI.

Paul

[1] http://lists.debian.org/debian-arm/2010/07/msg00147.html.