I have been testing inline function calls in C++.
Thread model: win32
gcc version 4.3.3 (4.3.3-tdm-1 mingw32)
Stroustrup in The C++ Programming language wirtes:
The inline specifier is a hint to the compiler that it should attempt to generate code [...] inline rather than laying down the code for the function once and then calling through the usual function call mechanism.
However, I have found out that the generated code is simply not inline. There is a CALL instrction for the isquare function.
Why is this happening? How can I use inline functions then?
EDIT: The command line options used:
**** Build of configuration Debug for project InlineCpp ****
**** Internal Builder is used for build ****
g++ -O0 -g3 -Wall -c -fmessage-length=0 -osrc\InlineCpp.o ..\src\InlineCpp.cpp
g++ -oInlineCpp.exe src\InlineCpp.o
Like Michael Kohne mentioned, the inline keyword is always a hint, and GCC in the case of your function decided not to inline it.
Since you are using Gcc you can force inline with the __attribute((always_inline)).
Example:
/* Prototype. */
inline void foo (const char) __attribute__((always_inline));
Source:GCC inline docs
There is no generic C++ way to FORCE the compiler to create inline functions. Note the word 'hint' in the text you quoted - the compiler is not obliged to listen to you.
If you really, absolutely have to make something be in-line, you'll need a compiler specific keyword, OR you'll need to use macros instead of functions.
EDIT: njsf gives the proper gcc keyword in his response.
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