1 // WebAssemblyMachineFunctionInfo.h-WebAssembly machine function info-*- 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 /// \file
11 /// \brief This file declares WebAssembly-specific per-machine-function
12 /// information.
13 ///
14 //===----------------------------------------------------------------------===//
15 
16 #ifndef LLVM_LIB_TARGET_WEBASSEMBLY_WEBASSEMBLYMACHINEFUNCTIONINFO_H
17 #define LLVM_LIB_TARGET_WEBASSEMBLY_WEBASSEMBLYMACHINEFUNCTIONINFO_H
18 
19 #include "llvm/CodeGen/MachineRegisterInfo.h"
20 
21 namespace llvm {
22 
23 /// This class is derived from MachineFunctionInfo and contains private
24 /// WebAssembly-specific information for each MachineFunction.
25 class WebAssemblyFunctionInfo final : public MachineFunctionInfo {
26   MachineFunction &MF;
27 
28   std::vector<MVT> Params;
29 
30   /// A mapping from CodeGen vreg index to WebAssembly register number.
31   std::vector<unsigned> WARegs;
32 
33   /// A mapping from CodeGen vreg index to a boolean value indicating whether
34   /// the given register is considered to be "stackified", meaning it has been
35   /// determined or made to meet the stack requirements:
36   ///   - single use (per path)
37   ///   - single def (per path)
38   ///   - defined and used in LIFO order with other stack registers
39   BitVector VRegStackified;
40 
41 public:
42   explicit WebAssemblyFunctionInfo(MachineFunction &MF) : MF(MF) {}
43   ~WebAssemblyFunctionInfo() override;
44 
45   void addParam(MVT VT) { Params.push_back(VT); }
46   const std::vector<MVT> &getParams() const { return Params; }
47 
48   static const unsigned UnusedReg = -1u;
49 
50   void stackifyVReg(unsigned VReg) {
51     if (TargetRegisterInfo::virtReg2Index(VReg) >= VRegStackified.size())
52       VRegStackified.resize(TargetRegisterInfo::virtReg2Index(VReg) + 1);
53     VRegStackified.set(TargetRegisterInfo::virtReg2Index(VReg));
54   }
55   bool isVRegStackified(unsigned VReg) const {
56     if (TargetRegisterInfo::virtReg2Index(VReg) >= VRegStackified.size())
57       return false;
58     return VRegStackified.test(TargetRegisterInfo::virtReg2Index(VReg));
59   }
60 
61   void initWARegs();
62   void setWAReg(unsigned VReg, unsigned WAReg) {
63     assert(WAReg != UnusedReg);
64     assert(TargetRegisterInfo::virtReg2Index(VReg) < WARegs.size());
65     WARegs[TargetRegisterInfo::virtReg2Index(VReg)] = WAReg;
66   }
67   unsigned getWAReg(unsigned VReg) const {
68     assert(TargetRegisterInfo::virtReg2Index(VReg) < WARegs.size());
69     return WARegs[TargetRegisterInfo::virtReg2Index(VReg)];
70   }
71   // If new virtual registers are created after initWARegs has been called,
72   // this function can be used to add WebAssembly register mappings for them.
73   void addWAReg(unsigned VReg, unsigned WAReg) {
74     assert(VReg = WARegs.size());
75     WARegs.push_back(WAReg);
76   }
77 };
78 
79 } // end namespace llvm
80 
81 #endif
82