Initial Commit

thirdparty/capstone/suite/synctools/tablegen/include/llvm/IR/User.h

@@ -0,0 +1,339 @@
+//===- llvm/User.h - User class definition ----------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This class defines the interface that one who uses a Value must implement.
+// Each instance of the Value class keeps track of what User's have handles
+// to it.
+//
+//  * Instructions are the largest class of Users.
+//  * Constants may be users of other constants (think arrays and stuff)
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_IR_USER_H
+#define LLVM_IR_USER_H
+
+#include "llvm/ADT/iterator.h"
+#include "llvm/ADT/iterator_range.h"
+#include "llvm/IR/Use.h"
+#include "llvm/IR/Value.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/ErrorHandling.h"
+#include <cassert>
+#include <cstddef>
+#include <cstdint>
+#include <iterator>
+
+namespace llvm {
+
+template <typename T> class ArrayRef;
+template <typename T> class MutableArrayRef;
+
+/// Compile-time customization of User operands.
+///
+/// Customizes operand-related allocators and accessors.
+template <class>
+struct OperandTraits;
+
+class User : public Value {
+  template <unsigned>
+  friend struct HungoffOperandTraits;
+
+  LLVM_ATTRIBUTE_ALWAYS_INLINE static void *
+  allocateFixedOperandUser(size_t, unsigned, unsigned);
+
+protected:
+  /// Allocate a User with an operand pointer co-allocated.
+  ///
+  /// This is used for subclasses which need to allocate a variable number
+  /// of operands, ie, 'hung off uses'.
+  void *operator new(size_t Size);
+
+  /// Allocate a User with the operands co-allocated.
+  ///
+  /// This is used for subclasses which have a fixed number of operands.
+  void *operator new(size_t Size, unsigned Us);
+
+  /// Allocate a User with the operands co-allocated.  If DescBytes is non-zero
+  /// then allocate an additional DescBytes bytes before the operands. These
+  /// bytes can be accessed by calling getDescriptor.
+  ///
+  /// DescBytes needs to be divisible by sizeof(void *).  The allocated
+  /// descriptor, if any, is aligned to sizeof(void *) bytes.
+  ///
+  /// This is used for subclasses which have a fixed number of operands.
+  void *operator new(size_t Size, unsigned Us, unsigned DescBytes);
+
+  User(Type *ty, unsigned vty, Use *, unsigned NumOps)
+      : Value(ty, vty) {
+    assert(NumOps < (1u << NumUserOperandsBits) && "Too many operands");
+    NumUserOperands = NumOps;
+    // If we have hung off uses, then the operand list should initially be
+    // null.
+    assert((!HasHungOffUses || !getOperandList()) &&
+           "Error in initializing hung off uses for User");
+  }
+
+  /// Allocate the array of Uses, followed by a pointer
+  /// (with bottom bit set) to the User.
+  /// \param IsPhi identifies callers which are phi nodes and which need
+  /// N BasicBlock* allocated along with N
+  void allocHungoffUses(unsigned N, bool IsPhi = false);
+
+  /// Grow the number of hung off uses.  Note that allocHungoffUses
+  /// should be called if there are no uses.
+  void growHungoffUses(unsigned N, bool IsPhi = false);
+
+protected:
+  ~User() = default; // Use deleteValue() to delete a generic Instruction.
+
+public:
+  User(const User &) = delete;
+
+  /// Free memory allocated for User and Use objects.
+  void operator delete(void *Usr);
+  /// Placement delete - required by std, called if the ctor throws.
+  void operator delete(void *Usr, unsigned) {
+    // Note: If a subclass manipulates the information which is required to calculate the
+    // Usr memory pointer, e.g. NumUserOperands, the operator delete of that subclass has
+    // to restore the changed information to the original value, since the dtor of that class
+    // is not called if the ctor fails.
+    User::operator delete(Usr);
+
+#ifndef LLVM_ENABLE_EXCEPTIONS
+    llvm_unreachable("Constructor throws?");
+#endif
+  }
+  /// Placement delete - required by std, called if the ctor throws.
+  void operator delete(void *Usr, unsigned, unsigned) {
+    // Note: If a subclass manipulates the information which is required to calculate the
+    // Usr memory pointer, e.g. NumUserOperands, the operator delete of that subclass has
+    // to restore the changed information to the original value, since the dtor of that class
+    // is not called if the ctor fails.
+    User::operator delete(Usr);
+
+#ifndef LLVM_ENABLE_EXCEPTIONS
+    llvm_unreachable("Constructor throws?");
+#endif
+  }
+
+protected:
+  template <int Idx, typename U> static Use &OpFrom(const U *that) {
+    return Idx < 0
+      ? OperandTraits<U>::op_end(const_cast<U*>(that))[Idx]
+      : OperandTraits<U>::op_begin(const_cast<U*>(that))[Idx];
+  }
+
+  template <int Idx> Use &Op() {
+    return OpFrom<Idx>(this);
+  }
+  template <int Idx> const Use &Op() const {
+    return OpFrom<Idx>(this);
+  }
+
+private:
+  const Use *getHungOffOperands() const {
+    return *(reinterpret_cast<const Use *const *>(this) - 1);
+  }
+
+  Use *&getHungOffOperands() { return *(reinterpret_cast<Use **>(this) - 1); }
+
+  const Use *getIntrusiveOperands() const {
+    return reinterpret_cast<const Use *>(this) - NumUserOperands;
+  }
+
+  Use *getIntrusiveOperands() {
+    return reinterpret_cast<Use *>(this) - NumUserOperands;
+  }
+
+  void setOperandList(Use *NewList) {
+    assert(HasHungOffUses &&
+           "Setting operand list only required for hung off uses");
+    getHungOffOperands() = NewList;
+  }
+
+public:
+  const Use *getOperandList() const {
+    return HasHungOffUses ? getHungOffOperands() : getIntrusiveOperands();
+  }
+  Use *getOperandList() {
+    return const_cast<Use *>(static_cast<const User *>(this)->getOperandList());
+  }
+
+  Value *getOperand(unsigned i) const {
+    assert(i < NumUserOperands && "getOperand() out of range!");
+    return getOperandList()[i];
+  }
+
+  void setOperand(unsigned i, Value *Val) {
+    assert(i < NumUserOperands && "setOperand() out of range!");
+    assert((!isa<Constant>((const Value*)this) ||
+            isa<GlobalValue>((const Value*)this)) &&
+           "Cannot mutate a constant with setOperand!");
+    getOperandList()[i] = Val;
+  }
+
+  const Use &getOperandUse(unsigned i) const {
+    assert(i < NumUserOperands && "getOperandUse() out of range!");
+    return getOperandList()[i];
+  }
+  Use &getOperandUse(unsigned i) {
+    assert(i < NumUserOperands && "getOperandUse() out of range!");
+    return getOperandList()[i];
+  }
+
+  unsigned getNumOperands() const { return NumUserOperands; }
+
+  /// Returns the descriptor co-allocated with this User instance.
+  ArrayRef<const uint8_t> getDescriptor() const;
+
+  /// Returns the descriptor co-allocated with this User instance.
+  MutableArrayRef<uint8_t> getDescriptor();
+
+  /// Set the number of operands on a GlobalVariable.
+  ///
+  /// GlobalVariable always allocates space for a single operands, but
+  /// doesn't always use it.
+  ///
+  /// FIXME: As that the number of operands is used to find the start of
+  /// the allocated memory in operator delete, we need to always think we have
+  /// 1 operand before delete.
+  void setGlobalVariableNumOperands(unsigned NumOps) {
+    assert(NumOps <= 1 && "GlobalVariable can only have 0 or 1 operands");
+    NumUserOperands = NumOps;
+  }
+
+  /// Subclasses with hung off uses need to manage the operand count
+  /// themselves.  In these instances, the operand count isn't used to find the
+  /// OperandList, so there's no issue in having the operand count change.
+  void setNumHungOffUseOperands(unsigned NumOps) {
+    assert(HasHungOffUses && "Must have hung off uses to use this method");
+    assert(NumOps < (1u << NumUserOperandsBits) && "Too many operands");
+    NumUserOperands = NumOps;
+  }
+
+  /// A droppable user is a user for which uses can be dropped without affecting
+  /// correctness and should be dropped rather than preventing a transformation
+  /// from happening.
+  bool isDroppable() const;
+
+  // ---------------------------------------------------------------------------
+  // Operand Iterator interface...
+  //
+  using op_iterator = Use*;
+  using const_op_iterator = const Use*;
+  using op_range = iterator_range<op_iterator>;
+  using const_op_range = iterator_range<const_op_iterator>;
+
+  op_iterator       op_begin()       { return getOperandList(); }
+  const_op_iterator op_begin() const { return getOperandList(); }
+  op_iterator       op_end()         {
+    return getOperandList() + NumUserOperands;
+  }
+  const_op_iterator op_end()   const {
+    return getOperandList() + NumUserOperands;
+  }
+  op_range operands() {
+    return op_range(op_begin(), op_end());
+  }
+  const_op_range operands() const {
+    return const_op_range(op_begin(), op_end());
+  }
+
+  /// Iterator for directly iterating over the operand Values.
+  struct value_op_iterator
+      : iterator_adaptor_base<value_op_iterator, op_iterator,
+                              std::random_access_iterator_tag, Value *,
+                              ptrdiff_t, Value *, Value *> {
+    explicit value_op_iterator(Use *U = nullptr) : iterator_adaptor_base(U) {}
+
+    Value *operator*() const { return *I; }
+    Value *operator->() const { return operator*(); }
+  };
+
+  value_op_iterator value_op_begin() {
+    return value_op_iterator(op_begin());
+  }
+  value_op_iterator value_op_end() {
+    return value_op_iterator(op_end());
+  }
+  iterator_range<value_op_iterator> operand_values() {
+    return make_range(value_op_begin(), value_op_end());
+  }
+
+  struct const_value_op_iterator
+      : iterator_adaptor_base<const_value_op_iterator, const_op_iterator,
+                              std::random_access_iterator_tag, const Value *,
+                              ptrdiff_t, const Value *, const Value *> {
+    explicit const_value_op_iterator(const Use *U = nullptr) :
+      iterator_adaptor_base(U) {}
+
+    const Value *operator*() const { return *I; }
+    const Value *operator->() const { return operator*(); }
+  };
+
+  const_value_op_iterator value_op_begin() const {
+    return const_value_op_iterator(op_begin());
+  }
+  const_value_op_iterator value_op_end() const {
+    return const_value_op_iterator(op_end());
+  }
+  iterator_range<const_value_op_iterator> operand_values() const {
+    return make_range(value_op_begin(), value_op_end());
+  }
+
+  /// Drop all references to operands.
+  ///
+  /// This function is in charge of "letting go" of all objects that this User
+  /// refers to.  This allows one to 'delete' a whole class at a time, even
+  /// though there may be circular references...  First all references are
+  /// dropped, and all use counts go to zero.  Then everything is deleted for
+  /// real.  Note that no operations are valid on an object that has "dropped
+  /// all references", except operator delete.
+  void dropAllReferences() {
+    for (Use &U : operands())
+      U.set(nullptr);
+  }
+
+  /// Replace uses of one Value with another.
+  ///
+  /// Replaces all references to the "From" definition with references to the
+  /// "To" definition.
+  void replaceUsesOfWith(Value *From, Value *To);
+
+  // Methods for support type inquiry through isa, cast, and dyn_cast:
+  static bool classof(const Value *V) {
+    return isa<Instruction>(V) || isa<Constant>(V);
+  }
+};
+
+// Either Use objects, or a Use pointer can be prepended to User.
+static_assert(alignof(Use) >= alignof(User),
+              "Alignment is insufficient after objects prepended to User");
+static_assert(alignof(Use *) >= alignof(User),
+              "Alignment is insufficient after objects prepended to User");
+
+template<> struct simplify_type<User::op_iterator> {
+  using SimpleType = Value*;
+
+  static SimpleType getSimplifiedValue(User::op_iterator &Val) {
+    return Val->get();
+  }
+};
+template<> struct simplify_type<User::const_op_iterator> {
+  using SimpleType = /*const*/ Value*;
+
+  static SimpleType getSimplifiedValue(User::const_op_iterator &Val) {
+    return Val->get();
+  }
+};
+
+} // end namespace llvm
+
+#endif // LLVM_IR_USER_H