[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


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