What if I want to get a count of how many times a particular instruction is called?

[philtomson]

I'd like to count the number of times a particular multiply-accummulate instruction is called (specifically vfmadd231ps) in an executable. Is this possible? If so, how would one go about it?

[gamozolabs]

That's somewhat tricky. Right now the best way would be to have that information in the cannoli server (like load a json file with the addresses you want to instrument that have the appropriate opcodes). I could maybe send the instruction bytes up so they could be inspected at lift time!

[philtomson]

I could maybe send the instruction bytes up so they could be inspected at lift time!

that would be useful.

[stsquad]

You can use the existing execlog plugin for a rough and ready count (I'm doing cvtss2sd as I don't have a test case using vfmadd handy):

$ ./qemu-x86_64 -plugin ./contrib/plugins/libexeclog.so,ifilter="cvtss2sd" -d plugin -D cvt.log ./tests/tcg/x86_64-linux-user/float_madds
...
$ cat cvt.log | cut -d "," -f 4,5 | sort | uniq -c
    380  "cvtss2sd %xmm0, %xmm0"
   1520  "cvtss2sd %xmm0, %xmm1"
    760  "cvtss2sd %xmm1, %xmm1"
    376  "cvtss2sd %xmm2, %xmm2"