Success!
Some working magic seems to be this:
gcc -s -o particle1 \
-O3 \
-march=k8 \
-mfpmath=sse \
-finline-limit=100000 \
--param large-function-insns=1000000 \
--param inline-unit-growth=1000000 \
--param sra-field-structure-ratio=0 \
particle1.c -lm
although it looks like -Os gives an additional improvement.
This (with GCC 4.1) reduces code volume to about 16k from a previous
near 1M, and reduces runtime by a factor of about 2700, as compared to
just -O3.
Further improvements welcome.
I'd also suggest adding a section to the GCC documentation on "how to
use GCC as a back-end to another compiler" which gives some typical
magic options like the above that would be useful in circumstances
like these.
--
Barak A. Pearlmutter <barak@xxxxxxxxxx>
Hamilton Institute & Dept Comp Sci, NUI Maynooth, Co. Kildare, Ireland
http://www.bcl.hamilton.ie/~barak/
