Re: Performance Ada and C

[ak@muc.de]

Markus Kuhn <Markus.Kuhn@cl.cam.ac.uk> writes:
> 
> Basically the only difference is that I replaced the macros in the C
> version by inline functions. Are as far as performance and optimization
> are concerned, I just think of inlined functions as a sort of macros
> with type checking, so this should not cause the difference.

At least in the C frontend inline functions are not equivalent to macros
(in contrary to the documenation). The gcc backend seems to miss several
optimizations that it does with C-style macros (mainly CSE). Also the 
register allocator (on x86) seems to have some problems with inline functions.

I assume Gnat has the same problem. 

egcs-current has a new GCSE pass that might help a bit, but there are 
still other problems (e.g. if you work with objects gcc is very bad to
keep small objects in registers if you use inline functions - it always
flushes them at the border of the inline etc.)

-Andi

P.S.: Is something like the Stepanov Benchmark available for Ada95?