C++ ABI and ILP64

[Markus F.X.J. Oberhumer]

I'm currently playing around making and testing an experimental port of AMD64 
for the ILP64 programming model, and I'd like some feedback about missing C++ 
types in cp/mangle.c as reported in bug http://gcc.gnu.org/PR18744 .

Currently MIPS (with the -mint64 option) is the only official gcc ILP64 
target, but porting AMD64 (by adding a -mint64 option as well) is pretty 
straightforward, and with a little bit of glibc headers patching you can 
actually compile and run simple programs with your existing Linux LP64 system 
libraries without the need to build a full chroot ILP64 toolchain.

In case you're wondering, we're working on very high speed data compression 
libraries, and apart from being useful for portability testing (e.g. for 
those old Cray machines) ILP64 also seems to generate a little bit better 
code for our purposes, mainly because a number of implicit unsigned char -> 
int -> size_t promotions within complex expressions can be shortened to char 
-> size_t, so this is not purely academic.

~Markus

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Markus F.X.J. Oberhumer
http://www.oberhumer.com/