include/llvm/CodeGen/SelectionDAGAddressAnalysis.h

   1 //===- SelectionDAGAddressAnalysis.h - DAG Address Analysis -----*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef LLVM_CODEGEN_SELECTIONDAGADDRESSANALYSIS_H
  10 #define LLVM_CODEGEN_SELECTIONDAGADDRESSANALYSIS_H
  11
  12 #include "llvm/CodeGen/SelectionDAGNodes.h"
  13 #include <cstdint>
  14
  15 namespace llvm {
  16
  17 class SelectionDAG;
  18
  19 /// Helper struct to parse and store a memory address as base + index + offset.
  20 /// We ignore sign extensions when it is safe to do so.
  21 /// The following two expressions are not equivalent. To differentiate we need
  22 /// to store whether there was a sign extension involved in the index
  23 /// computation.
  24 ///  (load (i64 add (i64 copyfromreg %c)
  25 ///                 (i64 signextend (add (i8 load %index)
  26 ///                                      (i8 1))))
  27 /// vs
  28 ///
  29 /// (load (i64 add (i64 copyfromreg %c)
  30 ///                (i64 signextend (i32 add (i32 signextend (i8 load %index))
  31 ///                                         (i32 1)))))
  32 class BaseIndexOffset {
  33 private:
  34   SDValue Base;
  35   SDValue Index;
  36   int64_t Offset = 0;
  37   bool IsIndexSignExt = false;
  38
  39 public:
  40   BaseIndexOffset() = default;
  41   BaseIndexOffset(SDValue Base, SDValue Index, int64_t Offset,
  42                   bool IsIndexSignExt)
  43       : Base(Base), Index(Index), Offset(Offset),
  44         IsIndexSignExt(IsIndexSignExt) {}
  45
  46   SDValue getBase() { return Base; }
  47   SDValue getBase() const { return Base; }
  48   SDValue getIndex() { return Index; }
  49   SDValue getIndex() const { return Index; }
  50
  51   bool equalBaseIndex(const BaseIndexOffset &Other,
  52                       const SelectionDAG &DAG) const {
  53     int64_t Off;
  54     return equalBaseIndex(Other, DAG, Off);
  55   }
  56
  57   bool equalBaseIndex(const BaseIndexOffset &Other, const SelectionDAG &DAG,
  58                       int64_t &Off) const;
  59
  60   /// Parses tree in Ptr for base, index, offset addresses.
  61   static BaseIndexOffset match(const LSBaseSDNode *N, const SelectionDAG &DAG);
  62
  63   void print(raw_ostream& OS) const;
  64   void dump() const;
  65 };
  66
  67 } // end namespace llvm
  68
  69 #endif // LLVM_CODEGEN_SELECTIONDAGADDRESSANALYSIS_H