[PATCH] D74303: [CFI] cfi directive insertion for callee-save-registers in CFIInstrInserter pass

[Wei Mi via Phabricator via llvm-commits]

wmi marked an inline comment as done.
wmi added inline comments.


================
Comment at: llvm/lib/CodeGen/CFIInstrInserter.cpp:94
+    CSRRegOffset(unsigned R, int O) : Reg(R), Offset(O) {}
+    unsigned Reg = INVALID_REG;
+    int Offset = INVALID_OFFSET;
----------------
thegameg wrote:
> wmi wrote:
> > thegameg wrote:
> > > `0`/`$noreg` should be considered an invalid register here, no?
> > Register number used in CFI instruction is got from MCRegisterInfo::getDwarfRegNum, which is different from the physical register number. For $rax, CFI.getRegister() returns 0.   
> Maybe `llvm::Optional<T>` is cleaner in this case? (I don't feel strongly about this, though)
Good suggestion. Optional<T> looks cleaner. 


Repository:
  rL LLVM

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D74303/new/

https://reviews.llvm.org/D74303