🚀 go-pugleaf

In posting results for the Convex C220, Marv neglected to mention that
these results are SCALAR only, with vectorization and parallelization
inhibited.  In fact, the inner loop in this benchmark is quite amenable
to vectorization and parallelization:


Script started on Thu May 23 12:46:35 199
hurst [32]cc -ds -O3 -o bobstone bobstone.c
            Optimization by Loop for Routine main

Line     Iter.   Reordering            Optimizing / Special            Exec.
Num.     Var.    Transformation         Transformation                  Mode 
-----------------------------------------------------------------------------
  13     i       Scalar                                                       
  16     loc     PARA/VECTOR                                            SVZ   

Line     Iter.   Analysis
Num.     Var.             
-----------------------------------------------------------------------------
  13     i       Inner loop has induction value with varying base or step
  16     loc     Parallel outer strip mine loop
hurst [33]uptime
 12:47pm  up 1 day, 19:38,  3 users,  load average: 0.01, 0.35, 0.96
hurst [34]/bin/time bobstone
Total time (sys+user)       :	1.66  (bobstones)
Page faults (min/maj)       :	5/69
Blocks in input/output      :	0/0
Context switches (vol/invol):	178/16
        0.7 real        1.4 user        0.1 sys 
script done on Thu May 23 12:47:15 199

Note that the wall clock time is less than the CPU time, since the
CPU cycles were distributed across multiple heads.  Hurst is a C240,
with four processors, and was lightly loaded at the time.  The speedup
from parallel execution was only a bit more than 2X, not uncommon for
loops which are both vectorized and executed in parallel.  The speedup
would likely only approach 4X for much larger trip counts for the loc
loop.

Please note that the above is the result of exactly five minutes of
compile-execute-analysis.  Thus I fall into the same trap I often
complain about...generating benchmark numbers without any meaningful
analysis of the results  8-{.

Kirby Collins
Strategic Planner
Convex Computer