Hello,
My name is Rantao Chen and i am a student at the University of Maryland. I am
currently doing some research for a professor to do Basic Block profiling using
LLVM. I have set up the environment correctly and built the profile_rt.so shared
library, but i am having some problems using the LLVM profiling tools.
I run "opt -insert-function-profiling -insert-block-profiling input.bc -o
output.bc" and an output file generates correctly.
I have disassembled the output file and i can see that profiling code has been
added.
I then run "llvm-prof -A output.bc -o llvmprof.out".
For some reason, nothing gets written to llvmprof.out; instead everything is
written to the terminal window. At the very top, i get a message saying
"function counts are not available" and every basic block has an execution count
of 0.
Am i doing something wrong or am i missing an option flag somewhere? If
anyone could offer any help or suggestions on why this is happening and/or
how to get basic block profiling working, i would greatly appreciate it.
Thanks in advance.
-Rantao Chen