[LLVMdev] Path profiling command

[Andreas Neustifter]

Hi All!

I was involved in the LLVM profiling business during late 2009 and
early 2010 but I was not working on the path profiling but the
"regular" profiling code. So I'm only guessing in case there is not
other answer.

On 9 May 2011 20:19, Andrew Trick <atrick at apple.com> wrote:
>
> On May 9, 2011, at 3:36 AM, Linh Ho Tran wrote:
>
> [...]
>
> The error message from llvm-prof is:  llvm-prof: Unkknown packet #5
>
> Could you explain me the error message?
>
> Are there errors in the command chain?
>
> What is the format of file  llvmprof.out? Is it possible to read
> llvmprof.out from command llvm-prof by ignoring step 5?
>
> What is the purpose of command in step 5?

Most of the LLVM profiling uses a binary format to dump the data, this
dump consists of several blocks with block headers, those headers
define the content of the block. To me it seem (again speculating
here) that there is a block header in this dump that is not recognised
by llvm-prof.

Ensure that the version of llvm-prof is from the same build as the
version of opt that you are using to instrument the code. If those
versions match then code is most likely broken.

Cheers, Andi