[tcljava-dev] [PATCH] Performance improvement

[Shawn B. <sh...@qc...>]

I ran the JavaWorld article's Tcl scripts and got similar (but slightly 
slower) results
for the four tests (JDK 1.3.1, Jacl CVS 1.3).

Using a Profiler, I found a hot spot in Expression.java.
The code attempts to see if the parsed value is an integer (or double).
Unfortunately, it is passing non-numbers into strtod which is throwing
an expensive RuntimeException.

The attached fix was straightforward and borrows from the Tcl C code.

The performance improvement is significant:

Test 1 - For loop counting from 1 to 1,000,000
Before: 180 seconds
After:   50 seconds

Test 2 - Compare 1,000,000 integers for equality
Before:  368 seconds
After:    94 seconds

-- 
Shawn Boyce
QCOM, Inc.   
Quality Software is Our Business
http://www.qcominc.com