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*To*: mathgroup*From*: stevec (Steve Christensen)*Date*: Wed, 15 Mar 89 10:55:30 CST

>From att!twitch!rvk at uxc.cso.uiuc.edu Subject: Mathematica and libm? The following item was seen in a netnews group, and might be of some interest to people in your area. I coded the program, and get essentially the same results. while I don't know whether the explanation supplied is correct or not, I am wondering how something like this might affect packages like Mathematica. ------------------------------------------------------------ If you use libm (especially trancendental functions sin(), cos(), ln(), exp() etc..) you can get nearly a 10* speedup by using the clumsy code inlining facility provided by Sun's C complier. For example (on Sun 3/60, SunOS 4.0.1) The following code: #include <math.h> main() { register int i; register double x, y; for(i = 0, x = 0; i < 100000; i++, x += 2*M_PI/100000.0) y = cos(x); } Compiled with: cc -O -f68881 -o cos cos.c -lm Runs in: real 0m30.16s user 0m24.56s sys 0m0.58s Compiled with (but how incredibly *UGLY*): cc -O -f68881 -o cos cos.c /usr/lib/f68881/libm.il Runs in: real 0m4.33s user 0m3.65s sys 0m0.20s REASON: Although Sun went to the trouble of making the assembly inline file /usr/lib/f68881/libm.il, and a 68881 version of the maths library, they *DID NOT* make assembly versions of the maths functions to put into the maths library! (and similarly for the FPA)