Re: [tcljava-dev] Performance results for new TJC compiler

[Mo D. <md...@un...>]

Hello all

I have recently implemented the "compiled locals" feature from the
C version of Tcl in the TJC compiler. This feature makes use
of an array of variable objects known at compile time instead of
using a hashtable to store the variable objects. This means that
a TJC compiled proc will now consume less memory and will execute
more quickly in many cases. Here are the highlights showing
performance improvements found when comparing TJC compiled
code before and after the "compiled locals" enhancement. These
times are all in ms, they come from the tclbench test
suite found in tcljava/tests/tclbench in the CVS.

Tcl Bench test name			Pre-locals	W-locals
invoke_1_to_10				3585		1873
invoke_1_to_10_loop			51770		18320
invoke_empty				42		20
bench_set_different_scalars		26		10
bench_set_same_scalar			10		6
bench_set_global_import			18		12
bench_set_array_variable_keys		70		28
bench_set_array_and_scalar_names	52		38
bench_incr_array_constant_50		100		50
data-create-array			5668		1652

These results show that the "compiled locals" feature has
resulted in a significant performance improvement for many
common cases.

cheers
Mo DeJong