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Re: inline asm constraints for conditions
- From: David Edelsohn <dje at watson dot ibm dot com>
- To: Gabriel Paubert <paubert at iram dot es>
- Cc: Richard Henderson <rth at redhat dot com>, David Howells <dhowells at redhat dot com>, gcc at gcc dot gnu dot org
- Date: Mon, 29 Sep 2003 14:23:34 -0400
- Subject: Re: inline asm constraints for conditions
>>>>> Gabriel Paubert writes:
Gabriel> One thing I've done in a few cases when testing several flags in PPC
Gabriel> assembly is moving the flags to CR with an mtcrf instruction and
Gabriel> then use bt/bf on the corresponding bit. This eliminates quite a few
Gabriel> testing instructions and allows to prepare the CR field(s) well in
Gabriel> advance. GCC does not do anything remotely similar AFAICT.
Gabriel> Is this kind of technique what you have in mind?
Yes, this is what I was describing.
David