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Re: ABI voilation

From: Tim Prince <tprince at computer dot org>
To: kanishk rastogi <kanishk dot 85 at gmail dot com>
Cc: gcc-help at gcc dot gnu dot org
Date: Mon, 08 Oct 2007 05:43:02 -0700
Subject: Re: ABI voilation
References: <9ee2fe770710072302s1d2f819ci6272529738339d72@mail.gmail.com>

kanishk rastogi wrote:
> hi all,
> I wanted to know if when i specify -O[0-3] flag to gcc does gcc
> optimize the code even violating ABI for that specific arch.
> If yes can i specify gcc not to violate the ABI ....
> I am mostly concerned witht he ABI specification which tells how to
> call another function..
> 

Only the -Os changes the value of -mpreferred-stack-boundary, breaking
the ability to support vectorization or other alignment dependent code
in the callee. That change can be over-ridden e.g. by -Os
-mpreferred-stack-boundary=4.  Evidently, this is a target dependent
question.  For example, double alignment is maintained by -Os for some
targets but not others.

Follow-Ups:
- Re: ABI voilation
  - From: Andrew Haley

References:
- ABI voilation
  - From: kanishk rastogi

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