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; 42 BaseIndexOffset(SDValue Base, SDValue Index, int64_t Offset, 43 bool IsIndexSignExt) 44 : Base(Base), Index(Index), Offset(Offset), 45 IsIndexSignExt(IsIndexSignExt) {} 46 47 SDValue getBase() { return Base; } 48 SDValue getIndex() { return Index; } 49 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(SDValue Ptr, const SelectionDAG &DAG); 60 }; 61 62 } // end namespace llvm 63 64 #endif // LLVM_CODEGEN_SELECTIONDAGADDRESSANALYSIS_H 65
