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Re: impact of -minsert-sched-nops
- From: David Edelsohn <dje at watson dot ibm dot com>
- To: Jack Howarth <howarth at bromo dot med dot uc dot edu>
- Cc: gcc at gcc dot gnu dot org
- Date: Mon, 24 Nov 2003 14:42:54 -0500
- Subject: Re: impact of -minsert-sched-nops
- References: <200311241926.OAA40832@bromo.msbb.uc.edu>
>>>>> Jack Howarth writes:
Jack> Does anyone know what the impact is of using -minsert-sched-nops
Jack> on a non-Power4 processor? That is if I compile some fortran with
Jack> -minsert-sched-nops on g77 for use on a G5, will the same code work
Jack> properly on a G4 as well? Thanks in advance for any clarifications.
Yes, the NOPs have no effect on G4 processors. It's the normal
PowerPC NOP instruction.
However, targeting G5 may generate some other new instructions.
If one does not specify G5 processor, then GCC does not know what
instructions need special group. Catch-22, unfortunately.
David