Machine{Instr|Operand}: Clarify some isIdenticalTo() subtleties.

llvm-svn: 281956

2 files changed, 5 insertions, 4 deletions

diff --git a/llvm/include/llvm/CodeGen/MachineInstr.h b/llvm/include/llvm/CodeGen/MachineInstr.h
index 3da62a33781..c645c20cc17 100644
--- a/llvm/include/llvm/CodeGen/MachineInstr.h
+++ b/llvm/include/llvm/CodeGen/MachineInstr.h
@@ -721,8 +721,9 @@ public:
     IgnoreVRegDefs  // Ignore virtual register definitions
   };
 
-  /// Return true if this instruction is identical to (same
-  /// opcode and same operands as) the specified instruction.
+  /// Return true if this instruction is identical to \p Other.
+  /// Identical meaning same opcode and all operands reported as
+  /// isIdenticalOp()  (equal except for liveness flags).
   bool isIdenticalTo(const MachineInstr &Other,
                      MICheckType Check = CheckDefs) const;
 
diff --git a/llvm/include/llvm/CodeGen/MachineOperand.h b/llvm/include/llvm/CodeGen/MachineOperand.h
index 05e6f466184..cf4607957f9 100644
--- a/llvm/include/llvm/CodeGen/MachineOperand.h
+++ b/llvm/include/llvm/CodeGen/MachineOperand.h
@@ -566,8 +566,8 @@ public:
   // Other methods.
   //===--------------------------------------------------------------------===//
 
-  /// isIdenticalTo - Return true if this operand is identical to the specified
-  /// operand. Note: This method ignores isKill and isDead properties.
+  /// Returns true if this operand is identical to the specified operand except
+  /// for liveness related flags (isKill, isUndef and isDead).
   bool isIdenticalTo(const MachineOperand &Other) const;
 
   /// \brief MachineOperand hash_value overload.