Naive number questions

Bryce Kampjes bryce at kampjes2.demon.co.uk
Tue Nov 2 23:15:34 UTC 2004


John M McIntosh writes:
 > b) The Java solution just uses 64 bit integers, which on some platforms  
 > might have hardware support.
 > Now if the Java folks could give us oh say a few % of the money they  
 > spent on Java, say a few tens of million, then we too
 > could develop a faster Squeak VM. Besides it is a JIT and those  
 > millions produce native instructions.

I benchmarked just the inner loop to avoid the big integer problems.
I get 8 seconds interpreted and 1.5 seconds compiling with Exupery.

Knowing how sloppy Exupery's generated code is Java isn't that hard
a target to compete with.

Squeak needs to tag check, detag, add, overflow check, then retag
each instruction. Given the current object format that's at least
8 instructions. Java can probably manage with 2 assuming it checks
for overflow. Exupery generates 10. Exupery is also storing
temporaries in the MethodContext rather than registers.

2 instructions could be achieved with sufficient effort. Probably less
than John's tens of millions.

Bryce



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