On 2/5/24 20:57, hameeza ahmed via Gcc wrote:
Hello,
I want to add an intrinsic in gcc toolchain that will generate the assembly
instruction. As it is said I need
to add a pattern to the gcc/config/riscv/riscv.md file to describe the
instruction. Can you please help me. Are there any tutorial that you can
recommend for this?
The process of adding target specific intrinsics is fairly target
specific. There isn't any guide that I'm aware of; your best bet is
going to be to find an existing intrinsic that roughly matches yours and
copy how that intrinsic works.
The good news is intrinsics don't have to expose full semantics of the
underlying instrution -- you can get away with just referencing any
values read and values written, but not the semantics of the operation.
Meaning that when you look for an intrinsic to copy-n-paste, you're
mostly concerned about the number and types of arguments.
Having said that, there is a GCC internals manual which describes the
RTL language, the format of backend patterns, expanders, etc. While the
vast majority will not be relevant to your effort, it is likely worth
bookmarking it for future reference.
jeff
