[LLVMdev] Adding custom operation intrinsic for ASIP architectures.

[Mikael Lepistö]

Hi,

I was talking with aKor in #llvm how we could implement custom operation 
support for our ASIP architecture. We came into solution that the best 
way would be to write new custom operation intrinsic and optimization 
pass for raising certain type of function calls to those intrinsics 
(similar to raising mallocs).

Basically our custom operation are like calls, with operand name and 
multiple inputs and outputs. e.g. C code:
__llvm__custom_op_add(a,b,c) would be raised to customop add(i32 %tmp1, 
i32 %tmp24 , i32 %tmp25). Those "__llvm__custom_op_" prefixed function 
will not have function body, but pure declarations in C code level.

Comments are welcome, especially if there anyone else, that needs this 
kind of functionality or if people has already implemented something 
similar.

Mikael Lepistö