Re: need to focus on java performance?

[Bryce McKinlay <mckinlay at redhat dot com>]

Per Bothner wrote:
> We really need to look at this in the context of shared libraries and
> the dynamic linker: Shared libraries add their own overheads and
> indirection.  The question is can we make use of the shared library
> indirection without adding extra indirection?

The BC-ABI bypasses PIC indirection for the most part. For example, 
under the C++ ABI a call to a static method would be indirected though 
the PLT, with the PLT entry set at runtime by the linker to jump to the 
actual address of the function. With BC, the atable contains the actual 
function address - ie we swap one type of indirection for another. In 
this case, the BC indirection actually turns out to be faster (on 
benchmarks, at least), due to less branches.

Bryce