Subject: Re: copyin() to fetch instructions for FPU.
To: Toru Nishimura <nisimura@itc.aist-nara.ac.jp>
From: Ignatios Souvatzis <ignatios@cs.uni-bonn.de>
List: port-mips
Date: 04/01/2000 16:21:53
On Sat, Apr 01, 2000 at 06:30:30PM +0900, Toru Nishimura wrote:
> I'm wondering whether it'd make any difference if all of copyin() operations
> are replaced with appropriate fuiword() and brothers;
> 
>         lw      v1, _C_LABEL(curpcb)
>         la      v0, _C_LABEL(fswberr)
>         blt     a0, zero, _C_LABEL(fswberr)
>         sw      v0, U_PCB_ONFAULT(v1)
>         lw      v0, 0(a0)                       # fetch word
>         j       ra
>         sw      zero, U_PCB_ONFAULT(v1)
> 
> They consume only 7 instructions to execute and most of cases won't
> post any exception to fetch.

Be careful. The 32bit versions have a bogus definition of error returns.

Regards,
	-is

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