On 07/03/12 12:46, Mathias Gaunard wrote:
On 07/03/2012 06:22 PM, Roland Bock wrote:
Can somebody try with a different compiler? Or is this test complete nonsense for some reason?
With GCC 4.7.0, no optimization
Roland: real 4.87 user 4.36 sys 0.20
Eric: Exhausts all my ram (8 GB) after 24.27 seconds
With -O3
Roland: real 1.28 user 0.95 sys 0.18
Eric: Exhausts all my ram (8 GB) after 25.07 seconds
I'm surprised that with more optimization (-O3) less compile time is taken (1.28 < 4.87). The gcc 4.7 docs here: http://gcc.gnu.org/onlinedocs/gcc-4.7.1/gcc/Optimize- Options.html#Optimize-Options claim: Optimizing compilation takes somewhat more time, and a lot more memory for a large function. Anyone know why, in this particular case, -O3 is faster than with no optimization? -regards, Larry