On 29/03/2022 00:38, Richard Henderson wrote:
On 3/28/22 14:14, matheus.fe...@eldorado.org.br wrote:
From: Matheus Ferst <matheus.fe...@eldorado.org.br>
This RFC is a first attempt at implementing the 128-bit integer
conversion routines in softfloat, as required by the xscv[su]qqp and
xscvqp[su]qz instructions of PowerISA v3.1.
Instead of using int128.h, int-to-float routines receive the 128-bit
numbers through a pair of 64-bit values, and float-to-int conversions
use a pointer to return the lower half of the result.
We only need the parts128 methods, but since the difference to parts64
ones seemed minor, I included both in this patch.
RFC:
- Should we use struct Int128 instead of 64-bit value pairs?
I think so. We have it, and it makes the interface more obvious.
- I've not tested the float64 methods since the PPC instructions only
use the quad-precision routines. Should we keep them in the final
version?
Let's not add anything that we don't have a need for.
It may eventually be needed by RISC-V RV128, but we can add it then.
r~
Thanks for your comments and review. I'll send an alternative version of
this RFC using Int128.
--
Matheus K. Ferst
Instituto de Pesquisas ELDORADO <http://www.eldorado.org.br/>
Analista de Software
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