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thirdparty/capstone/suite/synctools/tablegen/include/llvm/CodeGen/SelectionDAGAddressAnalysis.h

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+//===- SelectionDAGAddressAnalysis.h - DAG Address Analysis -----*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CODEGEN_SELECTIONDAGADDRESSANALYSIS_H
+#define LLVM_CODEGEN_SELECTIONDAGADDRESSANALYSIS_H
+
+#include "llvm/CodeGen/SelectionDAGNodes.h"
+#include <cstdint>
+
+namespace llvm {
+
+class SelectionDAG;
+
+/// Helper struct to parse and store a memory address as base + index + offset.
+/// We ignore sign extensions when it is safe to do so.
+/// The following two expressions are not equivalent. To differentiate we need
+/// to store whether there was a sign extension involved in the index
+/// computation.
+///  (load (i64 add (i64 copyfromreg %c)
+///                 (i64 signextend (add (i8 load %index)
+///                                      (i8 1))))
+/// vs
+///
+/// (load (i64 add (i64 copyfromreg %c)
+///                (i64 signextend (i32 add (i32 signextend (i8 load %index))
+///                                         (i32 1)))))
+class BaseIndexOffset {
+private:
+  SDValue Base;
+  SDValue Index;
+  Optional<int64_t> Offset;
+  bool IsIndexSignExt = false;
+
+public:
+  BaseIndexOffset() = default;
+  BaseIndexOffset(SDValue Base, SDValue Index, bool IsIndexSignExt)
+      : Base(Base), Index(Index), IsIndexSignExt(IsIndexSignExt) {}
+  BaseIndexOffset(SDValue Base, SDValue Index, int64_t Offset,
+                  bool IsIndexSignExt)
+      : Base(Base), Index(Index), Offset(Offset),
+        IsIndexSignExt(IsIndexSignExt) {}
+
+  SDValue getBase() { return Base; }
+  SDValue getBase() const { return Base; }
+  SDValue getIndex() { return Index; }
+  SDValue getIndex() const { return Index; }
+  bool hasValidOffset() const { return Offset.hasValue(); }
+  int64_t getOffset() const { return *Offset; }
+
+  // Returns true if `Other` and `*this` are both some offset from the same base
+  // pointer. In that case, `Off` is set to the offset between `*this` and
+  // `Other` (negative if `Other` is before `*this`).
+  bool equalBaseIndex(const BaseIndexOffset &Other, const SelectionDAG &DAG,
+                      int64_t &Off) const;
+
+  bool equalBaseIndex(const BaseIndexOffset &Other,
+                      const SelectionDAG &DAG) const {
+    int64_t Off;
+    return equalBaseIndex(Other, DAG, Off);
+  }
+
+  // Returns true if `Other` (with size `OtherSize`) can be proven to be fully
+  // contained in `*this` (with size `Size`).
+  bool contains(const SelectionDAG &DAG, int64_t BitSize,
+                const BaseIndexOffset &Other, int64_t OtherBitSize,
+                int64_t &BitOffset) const;
+
+  bool contains(const SelectionDAG &DAG, int64_t BitSize,
+                const BaseIndexOffset &Other, int64_t OtherBitSize) const {
+    int64_t BitOffset;
+    return contains(DAG, BitSize, Other, OtherBitSize, BitOffset);
+  }
+
+  // Returns true `Op0` and `Op1` can be proven to alias/not alias, in
+  // which case `IsAlias` is set to true/false.
+  static bool computeAliasing(const SDNode *Op0,
+                              const Optional<int64_t> NumBytes0,
+                              const SDNode *Op1,
+                              const Optional<int64_t> NumBytes1,
+                              const SelectionDAG &DAG, bool &IsAlias);
+
+  /// Parses tree in N for base, index, offset addresses.
+  static BaseIndexOffset match(const SDNode *N, const SelectionDAG &DAG);
+
+  void print(raw_ostream& OS) const;
+  void dump() const;
+};
+
+} // end namespace llvm
+
+#endif // LLVM_CODEGEN_SELECTIONDAGADDRESSANALYSIS_H