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Re: arm-elf-gcc memcpy builtin?

From: Grant Edwards <grante at visi dot com>
To: Richard dot Earnshaw at arm dot com
Cc: crossgcc at sources dot redhat dot com
Date: Tue, 5 Nov 2002 09:47:50 -0600
Subject: Re: arm-elf-gcc memcpy builtin?
References: <20021104140430.A29172@visi.com> <200211051010.gA5AAO821676@pc960.cambridge.arm.com>

On Tue, Nov 05, 2002 at 10:10:24AM +0000, Richard Earnshaw wrote:

> > Does the ARM back end not know how to do a built-in memcpy?
> > 
> > $ arm-elf-gcc -v
> > Reading specs from /usr/local/lib/gcc-lib/arm-elf/2.95.2/specs
> > gcc version 2.95.2 19991024 (release)
> 
> The built-in memcpy will only be used if both the memory areas are word 
> aligned and the transfer is less than 65 bytes.  It doesn't have to be a 
> multiple of 4 bytes transferred.

Ah.  Most of the memcpy() calls I'm worried about have
alignments that can't be determined at compile time, so I guess
I'm out of luck.

The next option is to re-write the memcpy function in assembly
and tweak every last bit of performance out of it I can.

-- 
Grant Edwards
grante@visi.com

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Follow-Ups:
- Re: arm-elf-gcc memcpy builtin?
  - From: Joel Sherrill
- Re: arm-elf-gcc memcpy builtin?
  - From: William A. Gatliff

References:
- arm-elf-gcc memcpy builtin?
  - From: Grant Edwards
- Re: arm-elf-gcc memcpy builtin?
  - From: Richard Earnshaw

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