fix documentation comments; NFC

llvm-svn: 263345

include/llvm/IR/Instruction.h

@@ -42,23 +42,23 @@ class Instruction : public User,
   DebugLoc DbgLoc;                         // 'dbg' Metadata cache.
 
   enum {
-    /// HasMetadataBit - This is a bit stored in the SubClassData field which
+    /// This is a bit stored in the SubClassData field which indicates whether
-    /// indicates whether this instruction has metadata attached to it or not.
+    /// this instruction has metadata attached to it or not.
     HasMetadataBit = 1 << 15
   };
 public:
   // Out of line virtual method, so the vtable, etc has a home.
   ~Instruction() override;
 
-  /// user_back - Specialize the methods defined in Value, as we know that an
+  /// Specialize the methods defined in Value, as we know that an instruction
-  /// instruction can only be used by other instructions.
+  /// can only be used by other instructions.
   Instruction       *user_back()       { return cast<Instruction>(*user_begin());}
   const Instruction *user_back() const { return cast<Instruction>(*user_begin());}
 
   inline const BasicBlock *getParent() const { return Parent; }
   inline       BasicBlock *getParent()       { return Parent; }
 
-  /// \brief Return the module owning the function this instruction belongs to
+  /// Return the module owning the function this instruction belongs to
   /// or nullptr it the function does not have a module.
   ///
   /// Note: this is undefined behavior if the instruction does not have a
@@ -66,20 +66,18 @@ public:
   const Module *getModule() const;
   Module *getModule();
 
-  /// \brief Return the function this instruction belongs to.
+  /// Return the function this instruction belongs to.
   ///
   /// Note: it is undefined behavior to call this on an instruction not
   /// currently inserted into a function.
   const Function *getFunction() const;
   Function *getFunction();
 
-  /// removeFromParent - This method unlinks 'this' from the containing basic
+  /// This method unlinks 'this' from the containing basic block, but does not
-  /// block, but does not delete it.
+  /// delete it.
-  ///
   void removeFromParent();
 
-  /// eraseFromParent - This method unlinks 'this' from the containing basic
+  /// This method unlinks 'this' from the containing basic block and deletes it.
-  /// block and deletes it.
   ///
   /// \returns an iterator pointing to the element after the erased one
   SymbolTableList<Instruction>::iterator eraseFromParent();
@@ -92,16 +90,15 @@ public:
   /// specified instruction.
   void insertAfter(Instruction *InsertPos);
 
-  /// moveBefore - Unlink this instruction from its current basic block and
+  /// Unlink this instruction from its current basic block and insert it into
-  /// insert it into the basic block that MovePos lives in, right before
+  /// the basic block that MovePos lives in, right before MovePos.
-  /// MovePos.
   void moveBefore(Instruction *MovePos);
 
   //===--------------------------------------------------------------------===//
   // Subclass classification.
   //===--------------------------------------------------------------------===//
 
-  /// getOpcode() returns a member of one of the enums like Instruction::Add.
+  /// Returns a member of one of the enums like Instruction::Add.
   unsigned getOpcode() const { return getValueID() - InstructionVal; }
 
   const char *getOpcodeName() const { return getOpcodeName(getOpcode()); }
@@ -121,28 +118,27 @@ public:
     return Opcode >= BinaryOpsBegin && Opcode < BinaryOpsEnd;
   }
 
-  /// @brief Determine if the Opcode is one of the shift instructions.
+  /// Determine if the Opcode is one of the shift instructions.
   static inline bool isShift(unsigned Opcode) {
     return Opcode >= Shl && Opcode <= AShr;
   }
 
-  /// isLogicalShift - Return true if this is a logical shift left or a logical
+  /// Return true if this is a logical shift left or a logical shift right.
-  /// shift right.
   inline bool isLogicalShift() const {
     return getOpcode() == Shl || getOpcode() == LShr;
   }
 
-  /// isArithmeticShift - Return true if this is an arithmetic shift right.
+  /// Return true if this is an arithmetic shift right.
   inline bool isArithmeticShift() const {
     return getOpcode() == AShr;
   }
 
-  /// @brief Determine if the OpCode is one of the CastInst instructions.
+  /// Determine if the OpCode is one of the CastInst instructions.
   static inline bool isCast(unsigned OpCode) {
     return OpCode >= CastOpsBegin && OpCode < CastOpsEnd;
   }
 
-  /// @brief Determine if the OpCode is one of the FuncletPadInst instructions.
+  /// Determine if the OpCode is one of the FuncletPadInst instructions.
   static inline bool isFuncletPad(unsigned OpCode) {
     return OpCode >= FuncletPadOpsBegin && OpCode < FuncletPadOpsEnd;
   }
@@ -151,55 +147,53 @@ public:
   // Metadata manipulation.
   //===--------------------------------------------------------------------===//
 
-  /// hasMetadata() - Return true if this instruction has any metadata attached
+  /// Return true if this instruction has any metadata attached to it.
-  /// to it.
   bool hasMetadata() const { return DbgLoc || hasMetadataHashEntry(); }
 
-  /// hasMetadataOtherThanDebugLoc - Return true if this instruction has
+  /// Return true if this instruction has metadata attached to it other than a
-  /// metadata attached to it other than a debug location.
+  /// debug location.
   bool hasMetadataOtherThanDebugLoc() const {
     return hasMetadataHashEntry();
   }
 
-  /// getMetadata - Get the metadata of given kind attached to this Instruction.
+  /// Get the metadata of given kind attached to this Instruction.
   /// If the metadata is not found then return null.
   MDNode *getMetadata(unsigned KindID) const {
     if (!hasMetadata()) return nullptr;
     return getMetadataImpl(KindID);
   }
 
-  /// getMetadata - Get the metadata of given kind attached to this Instruction.
+  /// Get the metadata of given kind attached to this Instruction.
   /// If the metadata is not found then return null.
   MDNode *getMetadata(StringRef Kind) const {
     if (!hasMetadata()) return nullptr;
     return getMetadataImpl(Kind);
   }
 
-  /// getAllMetadata - Get all metadata attached to this Instruction.  The first
+  /// Get all metadata attached to this Instruction. The first element of each
-  /// element of each pair returned is the KindID, the second element is the
+  /// pair returned is the KindID, the second element is the metadata value.
-  /// metadata value.  This list is returned sorted by the KindID.
+  /// This list is returned sorted by the KindID.
   void
   getAllMetadata(SmallVectorImpl<std::pair<unsigned, MDNode *>> &MDs) const {
     if (hasMetadata())
       getAllMetadataImpl(MDs);
   }
 
-  /// getAllMetadataOtherThanDebugLoc - This does the same thing as
+  /// This does the same thing as getAllMetadata, except that it filters out the
-  /// getAllMetadata, except that it filters out the debug location.
+  /// debug location.
   void getAllMetadataOtherThanDebugLoc(
       SmallVectorImpl<std::pair<unsigned, MDNode *>> &MDs) const {
     if (hasMetadataOtherThanDebugLoc())
       getAllMetadataOtherThanDebugLocImpl(MDs);
   }
 
-  /// getAAMetadata - Fills the AAMDNodes structure with AA metadata from
+  /// Fills the AAMDNodes structure with AA metadata from this instruction.
-  /// this instruction. When Merge is true, the existing AA metadata is
+  /// When Merge is true, the existing AA metadata is merged with that from this
-  /// merged with that from this instruction providing the most-general result.
+  /// instruction providing the most-general result.
   void getAAMetadata(AAMDNodes &N, bool Merge = false) const;
 
-  /// setMetadata - Set the metadata of the specified kind to the specified
+  /// Set the metadata of the specified kind to the specified node. This updates
-  /// node.  This updates/replaces metadata if already present, or removes it if
+  /// or replaces metadata if already present, or removes it if Node is null.
-  /// Node is null.
   void setMetadata(unsigned KindID, MDNode *Node);
   void setMetadata(StringRef Kind, MDNode *Node);
 
@@ -220,14 +214,13 @@ public:
   }
   /// @}
 
-  /// setAAMetadata - Sets the metadata on this instruction from the
+  /// Sets the metadata on this instruction from the AAMDNodes structure.
-  /// AAMDNodes structure.
   void setAAMetadata(const AAMDNodes &N);
 
-  /// setDebugLoc - Set the debug location information for this instruction.
+  /// Set the debug location information for this instruction.
   void setDebugLoc(DebugLoc Loc) { DbgLoc = std::move(Loc); }
 
-  /// getDebugLoc - Return the debug location for this node as a DebugLoc.
+  /// Return the debug location for this node as a DebugLoc.
   const DebugLoc &getDebugLoc() const { return DbgLoc; }
 
   /// Set or clear the unsafe-algebra flag on this instruction, which must be an
@@ -289,8 +282,7 @@ public:
   void copyFastMathFlags(const Instruction *I);
 
 private:
-  /// hasMetadataHashEntry - Return true if we have an entry in the on-the-side
+  /// Return true if we have an entry in the on-the-side metadata hash.
-  /// metadata hash.
   bool hasMetadataHashEntry() const {
     return (getSubclassDataFromValue() & HasMetadataBit) != 0;
   }
@@ -302,6 +294,7 @@ private:
   getAllMetadataImpl(SmallVectorImpl<std::pair<unsigned, MDNode *>> &) const;
   void getAllMetadataOtherThanDebugLocImpl(
       SmallVectorImpl<std::pair<unsigned, MDNode *>> &) const;
+  /// Clear all hashtable-based metadata from this instruction.
   void clearMetadataHashEntries();
 public:
   //===--------------------------------------------------------------------===//
@@ -309,7 +302,7 @@ public:
   //===--------------------------------------------------------------------===//
 
 
-  /// isAssociative - Return true if the instruction is associative:
+  /// Return true if the instruction is associative:
   ///
   ///   Associative operators satisfy:  x op (y op z) === (x op y) op z
   ///
@@ -318,7 +311,7 @@ public:
   bool isAssociative() const;
   static bool isAssociative(unsigned op);
 
-  /// isCommutative - Return true if the instruction is commutative:
+  /// Return true if the instruction is commutative:
   ///
   ///   Commutative operators satisfy: (x op y) === (y op x)
   ///
@@ -328,7 +321,7 @@ public:
   bool isCommutative() const { return isCommutative(getOpcode()); }
   static bool isCommutative(unsigned op);
 
-  /// isIdempotent - Return true if the instruction is idempotent:
+  /// Return true if the instruction is idempotent:
   ///
   ///   Idempotent operators satisfy:  x op x === x
   ///
@@ -337,7 +330,7 @@ public:
   bool isIdempotent() const { return isIdempotent(getOpcode()); }
   static bool isIdempotent(unsigned op);
 
-  /// isNilpotent - Return true if the instruction is nilpotent:
+  /// Return true if the instruction is nilpotent:
   ///
   ///   Nilpotent operators satisfy:  x op x === Id,
   ///
@@ -349,37 +342,31 @@ public:
   bool isNilpotent() const { return isNilpotent(getOpcode()); }
   static bool isNilpotent(unsigned op);
 
-  /// mayWriteToMemory - Return true if this instruction may modify memory.
+  /// Return true if this instruction may modify memory.
-  ///
   bool mayWriteToMemory() const;
 
-  /// mayReadFromMemory - Return true if this instruction may read memory.
+  /// Return true if this instruction may read memory.
-  ///
   bool mayReadFromMemory() const;
 
-  /// mayReadOrWriteMemory - Return true if this instruction may read or
+  /// Return true if this instruction may read or write memory.
-  /// write memory.
-  ///
   bool mayReadOrWriteMemory() const {
     return mayReadFromMemory() || mayWriteToMemory();
   }
 
-  /// isAtomic - Return true if this instruction has an
+  /// Return true if this instruction has an AtomicOrdering of unordered or
-  /// AtomicOrdering of unordered or higher.
+  /// higher.
-  ///
   bool isAtomic() const;
 
-  /// mayThrow - Return true if this instruction may throw an exception.
+  /// Return true if this instruction may throw an exception.
-  ///
   bool mayThrow() const;
 
-  /// mayReturn - Return true if this is a function that may return.
+  /// Return true if this is a function that may return.
-  /// this is true for all normal instructions. The only exception
+  /// This is true for all normal instructions. The only exception
   /// is functions that are marked with the 'noreturn' attribute.
   ///
   bool mayReturn() const;
 
-  /// mayHaveSideEffects - Return true if the instruction may have side effects.
+  /// Return true if the instruction may have side effects.
   ///
   /// Note that this does not consider malloc and alloca to have side
   /// effects because the newly allocated memory is completely invisible to
@@ -389,7 +376,7 @@ public:
     return mayWriteToMemory() || mayThrow() || !mayReturn();
   }
 
-  /// \brief Return true if the instruction is a variety of EH-block.
+  /// Return true if the instruction is a variety of EH-block.
   bool isEHPad() const {
     switch (getOpcode()) {
     case Instruction::CatchSwitch:
@@ -402,21 +389,21 @@ public:
     }
   }
 
-  /// clone() - Create a copy of 'this' instruction that is identical in all
+  /// Create a copy of 'this' instruction that is identical in all ways except
-  /// ways except the following:
+  /// the following:
   ///   * The instruction has no parent
   ///   * The instruction has no name
   ///
   Instruction *clone() const;
 
-  /// isIdenticalTo - Return true if the specified instruction is exactly
+  /// Return true if the specified instruction is exactly identical to the
-  /// identical to the current one.  This means that all operands match and any
+  /// current one. This means that all operands match and any extra information
-  /// extra information (e.g. load is volatile) agree.
+  /// (e.g. load is volatile) agree.
   bool isIdenticalTo(const Instruction *I) const;
 
-  /// isIdenticalToWhenDefined - This is like isIdenticalTo, except that it
+  /// This is like isIdenticalTo, except that it ignores the
-  /// ignores the SubclassOptionalData flags, which specify conditions
+  /// SubclassOptionalData flags, which specify conditions under which the
-  /// under which the instruction's result is undefined.
+  /// instruction's result is undefined.
   bool isIdenticalToWhenDefined(const Instruction *I) const;
 
   /// When checking for operation equivalence (using isSameOperationAs) it is
@@ -439,10 +426,9 @@ public:
   /// @brief Determine if one instruction is the same operation as another.
   bool isSameOperationAs(const Instruction *I, unsigned flags = 0) const;
 
-  /// isUsedOutsideOfBlock - Return true if there are any uses of this
+  /// Return true if there are any uses of this instruction in blocks other than
-  /// instruction in blocks other than the specified block.  Note that PHI nodes
+  /// the specified block. Note that PHI nodes are considered to evaluate their
-  /// are considered to evaluate their operands in the corresponding predecessor
+  /// operands in the corresponding predecessor block.
-  /// block.
   bool isUsedOutsideOfBlock(const BasicBlock *BB) const;