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