1 //===-- ARMAsmPrinter.h - ARM implementation of AsmPrinter ------*- 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_LIB_TARGET_ARM_ARMASMPRINTER_H
11 #define LLVM_LIB_TARGET_ARM_ARMASMPRINTER_H
12 
13 #include "ARMSubtarget.h"
14 #include "llvm/CodeGen/AsmPrinter.h"
15 #include "llvm/Target/TargetMachine.h"
16 
17 namespace llvm {
18 
19 class ARMFunctionInfo;
20 class MCOperand;
21 class MachineConstantPool;
22 class MachineOperand;
23 class MCSymbol;
24 
25 namespace ARM {
26   enum DW_ISA {
27     DW_ISA_ARM_thumb = 1,
28     DW_ISA_ARM_arm = 2
29   };
30 }
31 
32 class LLVM_LIBRARY_VISIBILITY ARMAsmPrinter : public AsmPrinter {
33 
34   /// Subtarget - Keep a pointer to the ARMSubtarget around so that we can
35   /// make the right decision when printing asm code for different targets.
36   const ARMSubtarget *Subtarget;
37 
38   /// AFI - Keep a pointer to ARMFunctionInfo for the current
39   /// MachineFunction.
40   ARMFunctionInfo *AFI;
41 
42   /// MCP - Keep a pointer to constantpool entries of the current
43   /// MachineFunction.
44   const MachineConstantPool *MCP;
45 
46   /// InConstantPool - Maintain state when emitting a sequence of constant
47   /// pool entries so we can properly mark them as data regions.
48   bool InConstantPool;
49 
50   /// ThumbIndirectPads - These maintain a per-function list of jump pad
51   /// labels used for ARMv4t thumb code to make register indirect calls.
52   SmallVector<std::pair<unsigned, MCSymbol*>, 4> ThumbIndirectPads;
53 
54   /// OptimizationGoals - Maintain a combined optimization goal for all
55   /// functions in a module: one of Tag_ABI_optimization_goals values,
56   /// -1 if uninitialized, 0 if conflicting goals
57   int OptimizationGoals;
58 
59   /// List of globals that have had their storage promoted to a constant
60   /// pool. This lives between calls to runOnMachineFunction and collects
61   /// data from every MachineFunction. It is used during doFinalization
62   /// when all non-function globals are emitted.
63   SmallPtrSet<const GlobalVariable*,2> PromotedGlobals;
64   /// Set of globals in PromotedGlobals that we've emitted labels for.
65   /// We need to emit labels even for promoted globals so that DWARF
66   /// debug info can link properly.
67   SmallPtrSet<const GlobalVariable*,2> EmittedPromotedGlobalLabels;
68 
69 public:
70   explicit ARMAsmPrinter(TargetMachine &TM,
71                          std::unique_ptr<MCStreamer> Streamer);
72 
73   StringRef getPassName() const override {
74     return "ARM Assembly Printer";
75   }
76 
77   void printOperand(const MachineInstr *MI, int OpNum, raw_ostream &O);
78 
79   bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNum,
80                        unsigned AsmVariant, const char *ExtraCode,
81                        raw_ostream &O) override;
82   bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNum,
83                              unsigned AsmVariant, const char *ExtraCode,
84                              raw_ostream &O) override;
85 
86   void emitInlineAsmEnd(const MCSubtargetInfo &StartInfo,
87                         const MCSubtargetInfo *EndInfo) const override;
88 
89   void EmitJumpTableAddrs(const MachineInstr *MI);
90   void EmitJumpTableInsts(const MachineInstr *MI);
91   void EmitJumpTableTBInst(const MachineInstr *MI, unsigned OffsetWidth);
92   void EmitInstruction(const MachineInstr *MI) override;
93   bool runOnMachineFunction(MachineFunction &F) override;
94 
95   void EmitConstantPool() override {
96     // we emit constant pools customly!
97   }
98   void EmitFunctionBodyEnd() override;
99   void EmitFunctionEntryLabel() override;
100   void EmitStartOfAsmFile(Module &M) override;
101   void EmitEndOfAsmFile(Module &M) override;
102   void EmitXXStructor(const DataLayout &DL, const Constant *CV) override;
103   void EmitGlobalVariable(const GlobalVariable *GV) override;
104 
105   // lowerOperand - Convert a MachineOperand into the equivalent MCOperand.
106   bool lowerOperand(const MachineOperand &MO, MCOperand &MCOp);
107 
108   //===------------------------------------------------------------------===//
109   // XRay implementation
110   //===------------------------------------------------------------------===//
111 public:
112   // XRay-specific lowering for ARM.
113   void LowerPATCHABLE_FUNCTION_ENTER(const MachineInstr &MI);
114   void LowerPATCHABLE_FUNCTION_EXIT(const MachineInstr &MI);
115   void LowerPATCHABLE_TAIL_CALL(const MachineInstr &MI);
116   // Helper function that emits the XRay sleds we've collected for a particular
117   // function.
118   void EmitXRayTable();
119 
120 private:
121   void EmitSled(const MachineInstr &MI, SledKind Kind);
122 
123   // Helpers for EmitStartOfAsmFile() and EmitEndOfAsmFile()
124   void emitAttributes();
125 
126   // Generic helper used to emit e.g. ARMv5 mul pseudos
127   void EmitPatchedInstruction(const MachineInstr *MI, unsigned TargetOpc);
128 
129   void EmitUnwindingInstruction(const MachineInstr *MI);
130 
131   // emitPseudoExpansionLowering - tblgen'erated.
132   bool emitPseudoExpansionLowering(MCStreamer &OutStreamer,
133                                    const MachineInstr *MI);
134 
135 public:
136   unsigned getISAEncoding() override {
137     // ARM/Darwin adds ISA to the DWARF info for each function.
138     const Triple &TT = TM.getTargetTriple();
139     if (!TT.isOSBinFormatMachO())
140       return 0;
141     bool isThumb = TT.getArch() == Triple::thumb ||
142                    TT.getArch() == Triple::thumbeb ||
143                    TT.getSubArch() == Triple::ARMSubArch_v7m ||
144                    TT.getSubArch() == Triple::ARMSubArch_v6m;
145     return isThumb ? ARM::DW_ISA_ARM_thumb : ARM::DW_ISA_ARM_arm;
146   }
147 
148 private:
149   MCOperand GetSymbolRef(const MachineOperand &MO, const MCSymbol *Symbol);
150   MCSymbol *GetARMJTIPICJumpTableLabel(unsigned uid) const;
151 
152   MCSymbol *GetARMGVSymbol(const GlobalValue *GV, unsigned char TargetFlags);
153 
154 public:
155   /// EmitMachineConstantPoolValue - Print a machine constantpool value to
156   /// the .s file.
157   void EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) override;
158 };
159 } // end namespace llvm
160 
161 #endif
162