Re: [boost] [ptr_container] abstraction penalty

From: Thorsten Ottosen (thorsten.ottosen_at_[hidden])
Date: 2007-06-20 05:13:09

Michael Marcin skrev:
> Hi,
> 
> I have a problem with my compiler (ARM's RVCT 2.2.1).
> It is not generating optimal code for ptr_containers, specifically I've been 
> looking at ptr_vector.
> I love using ptr_containers to convery ownership but I rely on them being 
> zero overhead over std::vector with explicit delete loops for at least 
> simple operations like a for each loop.
> 
> I would hope these 2 files (attached) would generate identical assembly for 
> the foo function but they are not even close (attached as txt).
> 
> I know there are a lot of compilers that are a lot smarter than this one. 
> Unfortunately I'm stuck with this one so I need to teach this compiler to 
> generate better code (by modifying the ptr_container library) or stop using 
> ptr_containers (cry).

Hi Michael,

Some compilers have a problem doing near-perfect inlining,
which can be a real killer.

I'll try to investigate this.

-Thorsten