vtune

I am using Intel VTune Amplifier XE 2011 to analyze the performance of my program. I want to be able to view the source code in the analysis results, and the documentation says I need to provide the symbol information. Unfortunately, it does not state how to generate that symbol information when compiling my program. In the Windows version of VTune all I had to do was provide the ".pdb" file that Microsoft Visual Studio would generate. Is there a similar kind of file I can create using g++ to provide this symbol information? JimR gcc -g <your stuff> should be all that's necessary. However I

I was writing some templated code to benchmark a numeric algorithm using both floats and doubles, in order to compare against a GPU implementation. I discovered that my floating point code was slower and after investigating using Vtune Amplifier from Intel I discovered that g++ was generating extra x86 instructions (cvtps2pd/cvtpd2ps and unpcklps/unpcklpd) to convert some intermediate results from float to double and then back again. The performance degradation is almost 10% for this application. After compiling with the flag -Wdouble-promotion (which BTW is not included with -Wall or -Wextra)

I have a profiling issue - imagine I have the following code... void main() { well_written_function(); badly_written_function(); } void well_written_function() { for (a small number) { highly_optimised_subroutine(); } } void badly_written_function() { for (a wastefully and unnecessarily large number) { highly_optimised_subroutine(); } } void highly_optimised_subroutine() { // lots of code } If I run this under vtune (or other profilers) it is very hard to spot that anything is wrong. All the hotspots will appear in the section marked "// lots of code" which is already optimised. The badly

I am adding usage of a small library to a large existing piece of software and would like to analyze (in finder detail than just in&out rdtsc() or gettimeofday calls) the overhead and it's attribution of the small library. Using things like rdtsc() I can get a sense of the latency that calling my libraries functions have, but I cannot do latency attribution unless I am also able to see whether branches are not being predicted well, caching isnt working properly, etc..I looked into PAPI as I imagined looking at a certain hardware events going into and out of a routine in my library within the