Try to understand output of -fdump-ipa-inline

[Edgar Mobile]

Greetings,

I try to find out why a function (inline keyword, defined in header) is not inlined. Example for -fdump-ipa-inline output:

Considering void Vertex::update(const Data&)/5927 with 40 size
 to be inlined into void SomeClass::updatePoly(const Data&, Polyline&)/11181 in /somepath/SomeClass.cpp:663
 Estimated badness is -0.000083, frequency 4.69.

The function is never inlined. unfortunately, the code is proprietary, so I cannot post everything.

Can anyone explain me the message above to find out why?
Thanks