[LLVMdev] inlining hint

[Dale Johannesen]

On Aug 26, 2009, at 11:54 AMPDT, Devang Patel wrote:

> On Wed, Aug 26, 2009 at 10:59 AM, Dale Johannesen<dalej at apple.com>  
> wrote:
>> You may have noticed I added an "inlinehint" attribute to the IR
>> yesterday, to represent user declarations that hint inlining would be
>> a good idea ("inline" keyword).  Chris and I have been discussing how
>> to hook it up to the C++ FE.  Consider:
>>
>> class X {
>>    int A(int x) {....}
>>    inline int B(int x);
>> };
>> inline int X::B(int x) {...}
>>
>> Per the language standard, A and B are semantically identical, both
>> "inline".  It's been suggested that we should omit the inlinehint on
>> A, on the grounds that many C++ programmers do not know this, and
>> therefore misuse the construct.   I want to get some other views on
>> this.  Do you think it's a good idea?
>> (For those of you who consider yourselves C++ programmers - and not  
>> FE
>> language lawyers, who are supposed to know what the standard says -
>> did you know this?)
>
> I do not understand how the "inlinehint" will help.  How will it
> influence the inliner ?

The hint should make it more attractive to inline.  I don't know the  
details yet and they will require some experimenting.