A few initializations to please Valgrind. NFC

[JesperAntonsson]

Summary

Three fairly trivial null initializations to avoid Valgrind complaints.

[bjope]

include/llvm/CodeGen/MachineOperand.h

194–197

Shouldn't we initialize TiedTo here as well?

195

I think it would look nicer if all these bools were initialized to false instead of 0.

[JesperAntonsson]

Updated according to Bjorns suggestions: added TiedTo initializations and made bool args initialize to false instead of 0.

[chandlerc]

If MSan doesn't complain about these, I'm inclined to leave them uninitialized. I'm not sure how valuable it is to workaround valgrind false-positives.

If MSan does complain, that's a different matter...

[JesperAntonsson]

Should have been abandoned a long time ago.

include/llvm/CodeGen/MachineOperand.h

struct {
         const BlockAddress *BA;   // For MO_BlockAddress.
       } Val;
       // Low bits of offset are in SmallContents.OffsetLo.
       int OffsetHi;               // An offset from the object, high 32 bits.
     } OffsetedInfo;
   } Contents;
 
   explicit MachineOperand(MachineOperandType K)
-    : OpKind(K), SubReg_TargetFlags(0), ParentMI(nullptr) {}
+    : OpKind(K), SubReg_TargetFlags(0), TiedTo(0),
+      IsDef(false), IsImp(false), IsKill(false), IsDead(false), IsUndef(false),
+      IsInternalRead(false), IsEarlyClobber(false), IsDebug(false),
+      ParentMI(nullptr) {}
 public:
   /// getType - Returns the MachineOperandType for this operand.
   ///
   MachineOperandType getType() const { return (MachineOperandType)OpKind; }
 
   unsigned getTargetFlags() const {
     return isReg() ? 0 : SubReg_TargetFlags;
   }

lib/CodeGen/AsmPrinter/DwarfDebug.h

class DwarfDebug : public DebugHandlerBase {
   SetVector<const DISubprogram *, SmallVector<const DISubprogram *, 16>,
             SmallPtrSet<const DISubprogram *, 16>>
       ProcessedSPNodes;
 
   /// If nonnull, stores the current machine function we're processing.
   const MachineFunction *CurFn = nullptr;
 
   /// If nonnull, stores the CU in which the previous subprogram was contained.
-  const DwarfCompileUnit *PrevCU;
+  const DwarfCompileUnit *PrevCU = nullptr;
 
   /// As an optimization, there is no need to emit an entry in the directory
   /// table for the same directory as DW_AT_comp_dir.
   StringRef CompilationDir;
 
   /// Holder for the file specific debug information.
   DwarfFile InfoHolder;
 

lib/Transforms/Scalar/SROA.cpp

static Value *getAdjustedPtr(IRBuilderTy &IRB, const DataLayout &DL, Value *Ptr,
   SmallPtrSet<Value *, 4> Visited;
   Visited.insert(Ptr);
   SmallVector<Value *, 4> Indices;
 
   // We may end up computing an offset pointer that has the wrong type. If we
   // never are able to compute one directly that has the correct type, we'll
   // fall back to it, so keep it and the base it was computed from around here.
   Value *OffsetPtr = nullptr;
-  Value *OffsetBasePtr;
+  Value *OffsetBasePtr = nullptr;
 
   // Remember any i8 pointer we come across to re-use if we need to do a raw
   // byte offset.
   Value *Int8Ptr = nullptr;
   APInt Int8PtrOffset(Offset.getBitWidth(), 0);
 
   Type *TargetTy = PointerTy->getPointerElementType();