[comp.unix.cray] Cray YMP instruction timings?

bernhold@qtp.ufl.edu (David E. Bernholdt) (12/18/90)

First a specific question, then a general one:

1) How long does it take (clock cycles) to execute each for the
following in scalar mode on a YMP?
	integer compare
	integer addition
	integer multiplication
	single precision multiplication

2) Aside from bothering you kind folks again, where can I find similar
information about other operations?

Thanks in advance.
-- 
David Bernholdt			bernhold@qtp.ufl.edu
Quantum Theory Project		bernhold@ufpine.bitnet
University of Florida
Gainesville, FL  32611		904/392 6365

djh@xipe.osc.edu (David Heisterberg) (12/18/90)

In article <1212@red.qtp.ufl.edu> bernhold@qtp.ufl.edu (David E. Bernholdt) writes:
>1) How long does it take (clock cycles) to execute each for the
>following in scalar mode on a YMP?
>	integer compare
>	integer addition
>	integer multiplication
>	single precision multiplication

There's no integer compare, just use subtract.  48 bit integer
multiplication is done in the floating multiplier (no conversion penalty,
as there is for reciprocal).

The following is from the Symbolic Machine Instructions Reference (SR-0085B):

address add/sub   (32 bit)       2    12ns
address multiply  (32 bit)       5    30ns

scalar/vector integer add/sub    3/3  18/18ns
scalar/vector logical            1/2   6/12ns
scalar/vector shift              3/3  18/18ns
scalar/vector population/parity  7/4  42/24ns
scalar leading zero              6    36ns

floating add/sub                 7  [ 6 for XMP!]  42ns
floating multiply                8  [ 7 for XMP!]  48ns
floating reciprocal             15  [14 for XMP!]  90ns

Dave, you can probably order SR-0085 from OSC.
--
David J. Heisterberg		djh@osc.edu		And you all know
The Ohio Supercomputer Center	djh@ohstpy.bitnet	security Is mortals'
Columbus, Ohio  43212		ohstpy::djh		chiefest enemy.