Cray YMP instruction timings?
David Heisterberg
djh at xipe.osc.edu
Wed Dec 19 01:21:27 AEST 1990
In article <1212 at red.qtp.ufl.edu> bernhold at 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 at osc.edu And you all know
The Ohio Supercomputer Center djh at ohstpy.bitnet security Is mortals'
Columbus, Ohio 43212 ohstpy::djh chiefest enemy.
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