Timing and Profiling

I have usually used the TSC (TSCL+TSCH) register for high resolution profiling.  This register works identically on both c64x+ and c66x.

The following wiki has the example code: http://processors.wiki.ti.com/index.php/Porting_GPP_code_to_DSP_and_Codec_Engine#Benchmark_Code_on_DSP_using_the_Time_Stamp_Counter_.28TSC.29

Since TSCL rolls over every ~4 billion cycles, most code does not require using TSCH so you can save some overhead by not reading TSCH.

If you have a larger body of code, the compiler can help instrument the code using the entry/exit hook compiler flags.  Please see section 2.16 of the compiler documentation which is in: C:\Program Files\Texas Instruments\ccsv5\tools\compiler\c6000\doc\spru187S.pdf.

TSCL/H are definitely the best way to go.  After it's initialized, it works basically the same as clock()

For clock() specifically, make sure you enable the clock on CCS (I believe it is an option under the 'Run' toolbar in the Debug perspective) -- otherwise, clock() will always return 0

I myself never figured out how to profile, sorry on that point.

I don't know what your 3rd point is trying to ask, but skeletal debug has very very little impact on performance but increases debuggability greatly (you can see at least function names instead of absolutely nothing at all)

There are also the Timestamp routines, but these basically serve the same purpose as the TSC registers -- but the value read by Timestamp is shared by all cores (I believe) whereas the TSC registers differ between cores (i.e. the time on 1 core might not be the same as the other)

I just tried the following example using the compiler that comes with ccs v5.0.3. 

The file tscl_demo.c contains:

#include <c6x.h>
#include <stdio.h>

void main() {
  TSCL = 1;
  printf ("Value of TSCL: %d\n", TSCL);
}

The compiler command and output:

C:\Temp>"c:\Program Files\Texas Instruments\ccsv5\tools\compiler\c6000\bin\cl6x.exe" -mv6600 --verbose -c tscl_demo.c -I "c:\Program Files\Texas Instruments\ccsv5\tools\compiler\c6000\include"
TMS320C6x C/C++ Compiler                v7.2.1
Tools Copyright (c) 1996-2011 Texas Instruments Incorporated
   "tscl_demo.c"   ==> main