[SIMode] Fix typo in Status constructor

[RKSimon]

Summary

As noted in https://www.viva64.com/en/b/0629/ (Snippet No. 36) and the scan-build CI reports (https://llvm.org/reports/scan-build/report-SIModeRegister.cpp-Status-1-1.html#EndPath), rL348754 introduced a typo due to ambiguity in the Status constructor due to argument variable names shadowing the member variable names.

[arsenm]

lib/Target/AMDGPU/SIModeRegister.cpp

47 ↗

(On Diff #198267)

Should use something other than a leading underscore to disambiguate

[RKSimon]

lib/Target/AMDGPU/SIModeRegister.cpp

47 ↗

(On Diff #198267)

No problem, its up to you - an alternative would be to write:

this->Mode &= this->Mask.

[arsenm]

lib/Target/AMDGPU/SIModeRegister.cpp

47 ↗

(On Diff #198267)

Trailing underscore is also OK, I just don't want to be violating the reserved names rule

[RKSimon]

Use trailing underscores

[RKSimon]

@timcorringham @arsenm Any more comments?

[timcorringham]

Sorry not to have noticed this sooner - I was just about to make a fix myself. I chose to change the constructor to

Status(unsigned NewMask, unsigned NewMode) : Mask(NewMask), Mode(NewMode & NewMask) {};

but your change is fine.

[RKSimon]

NewMask/NewMode it is then - thanks @timcorringham

llvm/trunk/lib/Target/AMDGPU/SIModeRegister.cpp

 struct Status {
   // Mask is a bitmask where a '1' indicates the corresponding Mode bit has a
   // known value
   unsigned Mask;
   unsigned Mode;
 
   Status() : Mask(0), Mode(0){};
 
-  Status(unsigned Mask, unsigned Mode) : Mask(Mask), Mode(Mode) {
+  Status(unsigned NewMask, unsigned NewMode) : Mask(NewMask), Mode(NewMode) {
     Mode &= Mask;
   };
 
   // merge two status values such that only values that don't conflict are
   // preserved
   Status merge(const Status &S) const {
     return Status((Mask | S.Mask), ((Mode & ~S.Mask) | (S.Mode & S.Mask)));
   }