[avr-gcc-list] FW: [PATCH 4.5 0/N]: Integrate GCC with the complex math library MPC

[Weddington, Eric]

To all AVR GCC maintainers and distribution builders,

The post below just came across the gcc-patches mailing list. AFAIK, these 
patches will be going into gcc future 4.5. The MPC package that it refers to 
will probably become a required prerequisite package some time in the future, 
like GMP and MPFR.

Also, how can AVR GCC take advantage of this in the future?

Eric Weddington
 

> -----Original Message-----
> From: Kaveh R. GHAZI [mailto:address@hidden 
> Sent: Sunday, March 15, 2009 10:10 AM
> To: address@hidden
> Subject: [PATCH 4.5 0/N]: Integrate GCC with the complex math 
> library MPC
> 
> This series of patches integrates GCC with the complex math 
> library MPC.
> MPC is the complex analogue to MPFR.  It is written by some 
> of the same
> folks with the same accuracy and precision principles.  MPC 
> is licensed
> under the LGPL.  See: http://www.multiprecision.org/mpc/
> 
> Among the potential benefits of using MPC are:
> 
> 1.  Folding of complex builtins with constant arguments in the
>     middle-end, e.g. csin(a + bI) -> c + dI.  Of course complex
>     builtins may not start out with a constant argument, but various
>     optimizations may infer what the argument is and allow the folding
>     to occur.
> 
> 2.  Folding of fortran intrinsics.  (These optimizations don't go
>     through the middle-end and so right now have duplicate 
> functionality).
> 
> 3.  Addressing complex folding bugs like PR30789 that can be tricky
>     to fix (even with MPFR).
> 
> 
> MPC is currently under 0.x version development and is not entirely
> complete with respect to c99 complex builtins yet (but their 
> plan is to do
> all of the c99 math functions with c99 semantics for the 
> special cases.)
> Also as far as I'm aware, MPC is not yet included with 
> distros or binary
> sites like MPFR is.
> 
> Because of these issues, I have written the patch to make MPC's use
> *optional* for now.  So GCC developers without MPC should not notice
> anything.  And I have only implemented item #1 above for middle-end
> builtins all conditionalized on configure finding the library 
> and ensuring
> the necessary bits are available.  We can obviously revisit 
> this decision
> and hard require MPC when it's more mature.
> 
> Although not all C99 functions are complete in the latest 
> MPC, I'd like to
> get the bulk infrastructure installed now.  As new complex 
> functions are
> added to MPC I will update the middle-end and testcases 
> accordingly.  The
> patches that follow are split up by maintenance domain to 
> make reviewing
> easier.
> 
>               Thanks,
>               --Kaveh
> 
> --
> Kaveh R. Ghazi                        address@hidden
>