[PATCH] D74977: [RISCV][GlobalISel] Add lowerFormalArguments for calling convention

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added inline comments.


================
Comment at: llvm/test/CodeGen/RISCV/GlobalISel/irtranslator/args.ll:257
+  ret void
+}
----------------
nitinjohnraj wrote:
> arsenm wrote:
> > Probably should have some byval, sret, and cases where the argument list runs out of registers. Same for return values / hidden sret
> > Probably should have some byval, sret, 
> Correct me if I'm wrong, but byval and sret both require support for aggregate types, which this patch doesn't support. 
> 
> > sret, and cases where the argument list runs out of registers.
> Do you have an example of a similar test? I wasn't aware that we could run out of registers at this phase, I thought that we could have an unlimited number of virtual registers.
This is wrong. sret and byval do not really have anything to do with aggregate types, and apply to pointers. You see them on a pointer argument, not aggregate. They would typically be used with an aggregate in memory type, but the in-memory type can be anything


You're mapping to an ABI constraint. If you had 4 32-bit registers for argument passing, you would run out of argument passing registers and have one stack passed argument for (i32, i32, i32, i32, i32).


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D74977/new/

https://reviews.llvm.org/D74977