Fortran vs. C for numerical work (SUMMARY)

Jim Giles jlg at lanl.gov
Fri Nov 30 04:52:25 AEST 1990


>From article <1990Nov29.040910.7400 at kithrup.COM>, by sef at kithrup.COM (Sean Eric Fagan):
> [...]
> Uhm... you don't have to, I don't think.  A Cyber had only one type of
> multiply instruction, but if the exponent were 0, it did an integer
> multiplication.  I believe Cray's do the same thing.

No.  The Crays have an integer multiply unit for addresses.  This mult
takes 4 clocks.  Memory access costs 14 or 17 clocks depending on the
model of machine you have.

J. Giles



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