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Re: Endian swapping with C code on ARM

From: Robert Dewar <dewar at gnat dot com>
To: Giovanni Bajo <giovannibajo at libero dot it>
Cc: gcc at gcc dot gnu dot org
Date: Fri, 09 Jul 2004 11:26:14 -0400
Subject: Re: Endian swapping with C code on ARM
References: <20040709004757.088F34F3D0@ws7-6.us4.outblaze.com> <1089365023.8278.9.camel@pc960.cambridge.arm.com> <40EEAB2C.40500@gnat.com> <ccmc82$h4l$1@sea.gmane.org>

Giovanni Bajo wrote:

Robert Dewar wrote:

Wouldn't it be a good idea to have a built-in for endian
swapping. Many architectures have specialized instructions
or effective sequences for this common operation.

Agreed. A builtin and some magic to recognize common shift/or sequences to do
that manually, so that it can optimized to the builtin.


I am a bit dubious about "common shift/or sequences", since there
are many equivalent ways to code this manually. I rather dislike
fragile code that conforms to some particular pattern "knowing"
that the compiler will recognize it.

References:
- Endian swapping with C code on ARM
  - From: chicken george
- Re: Endian swapping with C code on ARM
  - From: Richard Earnshaw
- Re: Endian swapping with C code on ARM
  - From: Robert Dewar
- Re: Endian swapping with C code on ARM
  - From: Giovanni Bajo

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