[PATCH] D45395: [RISCV] Implement tail call optimization

[Alex Bradbury via Phabricator via llvm-commits]

asb added inline comments.


================
Comment at: lib/Target/RISCV/RISCVISelLowering.cpp:787
+  // The callee has to preserve all registers the caller needs to preserve.
+  const RISCVRegisterInfo *TRI = Subtarget.getRegisterInfo();
+  const uint32_t *CallerPreserved = TRI->getCallPreservedMask(MF, CallerCC);
----------------
mgrang wrote:
> TODO: I couldn't write a test case to simulate this.
> 
> @asb What calling convention could result in a difference between caller and callee saved regs?
Right now, the calling convention is always the same so this isn't testable. It's helpful to be future-proof though.


Repository:
  rL LLVM

https://reviews.llvm.org/D45395