Execution time from the profile includes sub-functions.
For example, the tcd_t1_decode function calls the t1_decode_cblks function multiple times. The execution time for tcd_t1_decode includes the time for every call to t1_decode_cblks. The t1_decode_cblk function was responsible for most of the execution time (121 out of 128 seconds). Almost all of this time in this function is split between three other functions t1_dec_sigpass (51 seconds), t1_dec_refpass (36 seconds), and t1_dec_cInpass (35 seconds). Each of these functions make millions of calls to only a few other functions. The profiler was written very simply. The profiler consists of a single CProfiler class in C++. The constructor records the start time using a high resolution timer. The destructor calculates the elapsed time and updates a collection of counters. Declaring a variable of the CProfiler class is all that's required to capture the execution time and call count. The constructor accepts a single argument, which is used as a unique identifier. Results are grouped by this identifier. The name of the function was used at the unique identifier. After running the simulation a static method is called to dump the statistics. The most expensive part of the coding was adding CProfiler variables to the start of each function. No attempt was made to subtract out the time spent in sub-routines. No attempt was made to subtract out the impact of the CProfiler class itself. The CProfiler class will not be submitted to the OpenJPEG source code. Comments in their Google group suggest they prefer to limit the source code to C and are not interested in using C++ objects. Sheet Spotter _____ From: lee.sai...@gmail.com [mailto:lee.sai...@gmail.com] On Behalf Of Ponzu Sent: September 26, 2010 10:03 AM To: Sheet Spotter Cc: Robin Cornelius; opensource-dev Subject: Re: [opensource-dev] Openjpeg/KDU the cold hard metrics Does the execution time *include* the time of sub-functions called, or does it *exclude*? On Sun, Sep 26, 2010 at 3:02 AM, Sheet Spotter <sheet.spot...@gmail.com> wrote: I created a crude profiling tool to determine where to focus on improving the performance of OpenJPEG v2.
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