On Sun, 21 Jul 2013 01:20:25 -0400 Nat Tuck <[email protected]> wrote: > I've pushed a modified pocl that is able to compile kernels > significantly faster by only linking in OpenCL functions that the > kernel actually uses: > > https://code.launchpad.net/~nat-ferrus/pocl/pocl > > On some simple test cases, I'm seeing the "pocl-workgroup" script run > in 0.5 seconds instead of 10 seconds. Running "make check" with my > branch takes about half the time as with stock pocl (25 minutes > rather than 45 minutes). My branch is failing 4 tests, which also > speeds up the total test time, but most of that speedup is in faster > compiles on successful tests.
That speedup does sound great! Could you comment a bit on the internals how this works? At pocl build-time rebuild-index.pl generates an indexed version of the kerel.bc library? What is the format of this, or are all the kernel library functions kept in separate files? If the latter, what are the functions.list and functions.index needed for? Why put this in the lib/kernel/x86_64 directory? It doesn't seem x86_64-specific. At least ARM and PPC would benefit directly from this, why not TCE too? This sounds essentially as a "dead-code-elimination" done a priori. Since I'm trying to get rid of the scripts, I wonder if this could not be done without the need for extra helper scripts? Did you trace the performance - what exactly did consume the time with the monolitihic kenrel.bc library? I remember trying a DCE as the first pass to opt in pocl-workgroup, but it having no effect on execution time. Thanks for your input - kernel compilation time has always been the stumbling block for pocl, now that might change :) kalle ------------------------------------------------------------------------------ See everything from the browser to the database with AppDynamics Get end-to-end visibility with application monitoring from AppDynamics Isolate bottlenecks and diagnose root cause in seconds. Start your free trial of AppDynamics Pro today! http://pubads.g.doubleclick.net/gampad/clk?id=48808831&iu=/4140/ostg.clktrk _______________________________________________ pocl-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/pocl-devel
