On Fri, 2010-09-17 at 18:21 +0800, Yao Qi wrote:
Michael Hope wrote:
It's only part of the puzzle, but I run speed benchmarks as part of the continious build: http://ex.seabright.co.nz/helpers/buildlog http://ex.seabright.co.nz/helpers/benchcompare http://ex.seabright.co.nz/build/gcc-linaro-4.5-2010.09-1/logs/armv7l-maveric...
I've just modified this to build different variants as well. ffmpeg now builds as supplied (-O2 and others), with -Os, with hand-written assembler turned off, and with -mfpu=neon. corebench builds in -O2 and -Os.
Here are some options we may have to use in our benchmarks, {-Os,-O2} -fno-common -mthumb --mfloat-abi={hard,soft} -mfpu=neon
IIRC, hardfp will increase the code size to some extent.
hard-float should show a significant code size saving over pure soft-float for anything with floating point code as the compiler will be able to use single instructions for many operations rather than library calls.
R.