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Re: branch delay slots

From: Richard Sandiford <rsandifo at nildram dot co dot uk>
To: Boris Boesler <baembel at gmx dot de>
Cc: Ian Lance Taylor <iant at google dot com>, GCC <gcc at gcc dot gnu dot org>
Date: Wed, 12 Dec 2007 18:13:00 +0000
Subject: Re: branch delay slots
References: <0375011D-0C51-4101-801E-5AC4217DB0DC@gmx.de> <m3k5nkaqhq.fsf@localhost.localdomain> <D9D08030-371A-4FD4-925B-5AEFED4C6BF7@gmx.de>

Boris Boesler <baembel@gmx.de> writes:
>   Ok, I think I found it: GCC leaves control-flow operations as they  
> are, if it can not place other operations in branch delay slots  
> (represented as SEQUENCEs in GCC); or in other words: GCC does not  
> represent empty delay slots.
>
>   Is this correct?

Yeah.  See e.g. the way the MIPS port deals with this.  The jump and
call patterns add a nop to the asm string when final_sequence is null.

Richard

References:
- branch delay slots
  - From: Boris Boesler
- Re: branch delay slots
  - From: Ian Lance Taylor
- Re: branch delay slots
  - From: Boris Boesler

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