在 2022/12/29 上午1:30, Richard Henderson 写道:
On 12/27/22 18:34, gaosong wrote:
The manual says "The lower 64 bits of each vector register overlap
with the floating point register of the same number. In other words
When the basic floating-point instruction is executed to update the
floating-point register, the low 64 bits of the corresponding LSX
register
are also updated to the same value."
So If we don't use the fpr_t. we should:
1 Update LSX low 64 bits after floating point instruction translation;
2 Update floating-point registers after LSX instruction translation.
Should we do this or have I misunderstood?
You should use fpr_t, you should not use cpu_fpr[].
This is the same as aarch64, for instance.
A related question though: does the manual mention whether the fpu
instructions only modify the lower 64 bits, or do the high 64-bits
become zeroed, nanboxed, or unspecified?
Only modify the lower 64bits, the high 64-bits is unpecified.
Thanks.
Song Gao
I strongly suggest that you introduce wrappers to load/store fpr
values from their env slots. I would name them similarly to
gpr_{src,dst}, gen_set_gpr.
Got it.
r~
