Re: Try to understand output of -fdump-ipa-inline

[Edgar Mobile <heideggm@hotmail.com>]

I tried to create a *.so example from it for which I literally copied the calling and called function. It is inlined correctly.

In the original project, g++ seems to be determined to create a plt entry for the to-be-inlined function although I gave it the visibility=hidden attribute (also -fvisibility=hidden in the g++ parameters).

Will a plt entry prevent a function from being inlined?
Is there a way to find out why g++ creates a plt entry although I'm trying to prevent this?

Regards

________________________________
From: Navid Rahimi <navidrahimi@microsoft.com>
Sent: Tuesday, July 19, 2022 6:27 PM
To: gcc-help@gcc.gnu.org <gcc-help@gcc.gnu.org>; Edgar Mobile <heideggm@hotmail.com>
Subject: Re: Try to understand output of -fdump-ipa-inline

Have you tried to make a similar example? What I do in this situation is try to replicate exact situation but in a smaller case.

Inlining decision happens in multiple levels. It is hard to find out what is the exact reason this way.

Just as experiment, try it with always_inline [1] too.

1. https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html



Best wishes,
Navid.

________________________________________
From: Gcc-help <gcc-help-bounces+navidrahimi=microsoft.com@gcc.gnu.org> on behalf of Edgar Mobile via Gcc-help <gcc-help@gcc.gnu.org>
Sent: Tuesday, July 19, 2022 06:56
To: gcc-help@gcc.gnu.org
Subject: [EXTERNAL] Try to understand output of -fdump-ipa-inline

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