[PATCH] s390: performance fix for tc pipeline recycle on z10

Wolfgang Gellerich gelleric@linux.vnet.ibm.com
Tue Dec 16 09:10:00 GMT 2008


Andreas Krebbel wrote:
> Hi Wolfgang,
>
>   
>> 2008-12-11  Wolfgang Gellerich  <gellerich@de.ibm.com>
>>
>> 	* config/s390/s390.c (s390_swap_cmp): New function.
>> 	(s390_non_addr_reg_read_p): New function.
>> 	(s390_z10_optimize_cmp): New function.
>> 	(s390_reorg): Added call to s390_optimize_cmp.
>> 	* config/s390/s390.md (nop1): New insn.
>>     
>
> Thanks!
>
> I've applied your patch to mainline with a few minor changes.
> E.g. I've removed several superfluous brackets in if conditions.
>
> Bye,
>
> -Andreas-
>   
Hi Andreas,

Many thanks. Concerning the brackets: I consider them as "defensive
programming style". A project I was with some years ago had plenty of
problems related to ill-formed expressions mixing comparisons, bitwise 
and logical
operations in a way that finally caused unexpected effects. Since then,
I prefer having one pair of brackets too much, in particular since they
get removed very early in the translation process.

Regards, Wolfgang

-- 
---
Dr. Wolfgang Gellerich
IBM Deutschland Entwicklung GmbH
Schönaicher Strasse 220
71032 Böblingen, Germany
Tel. +49 / 7031 / 162598
gellerich@de.ibm.com

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