search for: expensive_loop

Hi, Under linux a large portion of the profiling these days happens with perf, but there's no support for it from LLVM's JITs. For a while perf could associate address+size to symbols by writing a /tmp/perf-$pid.map file: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/tools/perf/Documentation/jit-interface.txt A year or so perf also gained the ability to actually

...clean, but I think in a good enough state for you to estimate complexity. What do you think? I've below included some example output to show what's going on. Regards, Andres A random example (source c file also attached): # generate some IR, with debug info clang -ggdb -S -c -emit-llvm expensive_loop.c -o tmp/expensive_loop.ll # record profile ('-k1; is the clocksource, -g hierarchical) perf record -g -k 1 lli -jit-kind=mcjit /tmp/expensive_loop.ll 1 # enrich profile with JIT information emitted due to patch perf inject --jit -i perf.data -o perf.jit.data # and show information perf report...

...//reviews.llvm.org/D44892 I'd greatly appreciate reviews! > What do you think? I've below included some example output to show > what's going on. > > A random example (source c file also attached): > # generate some IR, with debug info > clang -ggdb -S -c -emit-llvm expensive_loop.c -o tmp/expensive_loop.ll > # record profile ('-k1; is the clocksource, -g hierarchical) > perf record -g -k 1 lli -jit-kind=mcjit /tmp/expensive_loop.ll 1 > # enrich profile with JIT information emitted due to patch > perf inject --jit -i perf.data -o perf.jit.data > # and show...

Having something like this available in tree would definitely be useful. For simplicity, why don't we start with support for the second style? This is the long term useful one and would be a good starting point for getting the code in tree. Can you give a pointer to the patch so that I can assess the rough complexity? If it's simple enough, I'd be happy to help get it reviewed