From: fuer@nessie.gud.siemens.co.at (Gerhard Fuernkranz) Subject: Re: [Q] GCC compiler - floating point operation. Date: Tue, 6 Jul 1993 07:41:32 GMT
Taek-Soo Kim (tkim@uws2.ecs.umass.edu) wrote:
:
: Hi,
:
: I just got the linux and X window ported to my PC and has been testing the
: running time of PC (486SX25 with 8 MB). I have wrote a simple loop which will
^^^^ That's your problem.
486SX has no built in floating point unit,
therefore all FPU instructions are emulated
by software. Buy a 486DX if you want good
floating point performance.
: count the number of loops executed in C language. I have two version of it,
: one which counts in integer and the other in double.
:
: After the compilation I compared the running time with DECstation 2100.
: In case of integer version, PC was about 1.5 times faster but the double
: version was about 40 times slower than DECstation 2100. The compile option
: I have tried on linux was "-O6 -m486".
: