Re: genesi and open rd

[Martin Guy <martinwguy@gmail.com>]

On 2/8/10, Bill Gatliff <bgat@billgatliff.com> wrote:
> OT, but has anyone looked at what gains can be had by rebuilding
>  packages with, say, A8 or other optimizations for processors that
>  support them?
Well, it has a VFP FPU, so floating point apps will run N times
faster, and GCC optimizes some kinds of integer loops into SIMD
instructions for the NEON, beside the different instruction timing
info and pipeline description for better instruction scheduling.

The easiest way to try this is to make fake versions of gcc and put
them at the start of the PATH:

mkdir ~/cortex
cat > ~/cortex/gcc << EOF
#! /bin/sh

exec gcc-4.3-crunch -mcpu=cortex-a8 -mfpu=vfp -mfloat-abi=softfp "$@"
EOF
chmod 755 ~/cortex/gcc
ln -s gcc ~/cortex/cc
ln -s gcc ~/cortex/gcc-4.3
ln -s gcc ~/cortex/arm-linux-gnueabi-gcc

and fool the build system into using them

PATH=~/cortex:$PATH dpkg-buildpackage -rfakeroot -B

I'd be interested to know what difference it makes to non-FP applications

   M