Hi,
I spent the last few weeks testing different compilers and here's the
summary:
gcc 4.2.1: lacks armv7 and NEON support
gcc csl 2007q3 (4.2.1 based): working armv7 and working NEON
gcc 4.2.2: lacks armv7 and NEON support
gcc csl 2008q1 (4.2.3 based): working armv7, broken NEON[1]
gcc 4.3.0: working armv7, broken NEON[2]
So if you want to use NEON properly (-mpfu=neon -ftree-vectorize -
mfloat-abi=softfp) you should get the 2007q3 toolchain.
I'm keeping my eyes out for the pending gcc 4.3.1 release, since the
vectorizer is rumoured to work a lot better compared to 4.2.x
versions.
regards,
Koen
[1] http://www.codesourcery.com/archives/arm-gnu/msg01892.html
[2] it ICEs when passed -mfpu=neon