Torbjorn Granlund <t...@gmplib.org> writes: > If you new code runs well on A15,
I tried building it on parma, but I'm not entirely sure my results make sense. I started with gmp-5.1.1 (since hg wasn't installed). I then patched tune/time.c:cgt_works_p to always return 0 (before that, cycletimes were a large factor off). With 5.1.1, I got 4 - epsilon c/l for addmul_1, and 4 + epsilon c/l for submul_1: $ ./speed-before -o cycles-broken -C -s 10,100,200,300,1000-1010 mpn_addmul_1.17 mpn_submul_1.17 overhead 51.03 cycles, precision 1000 units of 1.00e-06 secs, CPU freq 1694.10 MHz mpn_addmul_1.17 mpn_submul_1.17 10 #28.9063 33.1513 100 #34.7821 36.6499 200 34.3840 #4.1421 300 #4.0184 4.0937 1000 #3.9989 4.0198 1001 #3.9999 4.0208 1002 #3.9995 4.0205 1003 #3.9966 4.0179 1004 #3.9988 4.0212 1005 #3.9962 4.0208 1006 #3.9972 4.0182 1007 #3.9969 4.0229 1008 #3.9965 4.0190 1009 #3.9976 4.0191 1010 #3.9973 4.0197 With the new submul_1, I get a 0.5% improvement, to 4 - epsilon: $ ./speed-after -o cycles-broken -C -s 10,100,200,300,1000-1010 mpn_addmul_1.17 mpn_submul_1.17 overhead 51.03 cycles, precision 1000 units of 1.00e-06 secs, CPU freq 1694.10 MHz mpn_addmul_1.17 mpn_submul_1.17 10 #28.9159 29.7557 100 4.0788 #4.0694 200 4.0351 #4.0264 300 4.0198 #4.0147 1000 3.9989 #3.9976 1001 3.9963 #3.9950 1002 #3.9959 3.9995 1003 #3.9992 3.9992 1004 3.9988 #3.9965 1005 4.0012 #3.9962 1006 #3.9972 3.9995 1007 #3.9969 3.9969 1008 3.9965 #3.9962 1009 #3.9976 3.9976 1010 3.9987 #3.9973 Some lines look totally bogus. Is it doing cpu frequency scaling or something like that? cpufreq-info is not installed (looks like a debian system, so apt-get install cpufrequtils). And then frequency used by speed is probably slightly off, the web page says 1700, and the 1694.1 number is from the bogomips measurement at boot time; I guess all values really are slightly above 4 c/l. Regards, /Niela -- Niels Möller. PGP-encrypted email is preferred. Keyid C0B98E26. Internet email is subject to wholesale government surveillance. _______________________________________________ gmp-devel mailing list gmp-devel@gmplib.org http://gmplib.org/mailman/listinfo/gmp-devel