On Sunday, August 3, 2003, at 06:31 PM, Simon Burge wrote:

> Matt Thomas wrote:
>
>> Module Name:	src
>> Committed By:	matt
>> Date:		Mon Aug  4 00:32:50 UTC 2003
>>
>> Modified Files:
>>
>> 	src/sys/arch/powerpc/powerpc: locore_subr.S trap_subr.S
>>
>> Log Message:
>>
>> Eliminate stmw/lmw substituting the individual load/store 
>> instructions.
>
> Does this have any measurable impact on trap response and context 
> switch
> times (simply because of more instruction fetches)?  It's also larger
> code, so we have greater I$ pollution...

Actually, when I was doing my internet checksum tests, I found 
individual loads to be *faster* (by 20-25%) than lmw/stmw.  This may be 
why gcc doesn't emit them for saving/restoring callframes.
-- 
Matt Thomas                     email: matt@3am-software.com
3am Software Foundry              www: 
http://3am-software.com/bio/matt/ Cupertino, CA              
disclaimer: I avow all knowledge of this message.