[PATCH] D40023: [RISCV] Implement ABI lowering

[Simon Dardis via Phabricator via cfe-commits]

sdardis added a comment.

> Mips is the only other implementer of shouldSignExtUnsignedType but is unaffected, as unlike classifyArgumentType, classifyReturnType will not extend i32 values (@sdardis: is this a bug?).

I believe this is an oversight that is addressed in the backend. The MIPS64 backend treats 'trunc i64 %x to i32' as '(SLL (EXTRACT_SUBREG GPR64:$src, sub_32), 0)', which is required to match MIPS32 arithmetic works on MIPS64.

I will take a longer look at this issue.

Thanks.


https://reviews.llvm.org/D40023