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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 "MCTargetDesc/WebAssemblyMCTargetDesc.h"
20 #include "llvm/CodeGen/MachineRegisterInfo.h"
21 
22 namespace llvm {
23 
24 /// This class is derived from MachineFunctionInfo and contains private
25 /// WebAssembly-specific information for each MachineFunction.
26 class WebAssemblyFunctionInfo final : public MachineFunctionInfo {
27   MachineFunction &MF;
28 
29   std::vector<MVT> Params;
30 
31   /// A mapping from CodeGen vreg index to WebAssembly register number.
32   std::vector<unsigned> WARegs;
33 
34   /// A mapping from CodeGen vreg index to a boolean value indicating whether
35   /// the given register is considered to be "stackified", meaning it has been
36   /// determined or made to meet the stack requirements:
37   ///   - single use (per path)
38   ///   - single def (per path)
39   ///   - defined and used in LIFO order with other stack registers
40   BitVector VRegStackified;
41 
42   // One entry for each possible target reg. we expect it to be small.
43   std::vector<unsigned> PhysRegs;
44 
45 public:
WebAssemblyFunctionInfo(MachineFunction & MF)46   explicit WebAssemblyFunctionInfo(MachineFunction &MF) : MF(MF) {
47     PhysRegs.resize(WebAssembly::NUM_TARGET_REGS, -1U);
48   }
49   ~WebAssemblyFunctionInfo() override;
50 
addParam(MVT VT)51   void addParam(MVT VT) { Params.push_back(VT); }
getParams()52   const std::vector<MVT> &getParams() const { return Params; }
53 
54   static const unsigned UnusedReg = -1u;
55 
stackifyVReg(unsigned VReg)56   void stackifyVReg(unsigned VReg) {
57     if (TargetRegisterInfo::virtReg2Index(VReg) >= VRegStackified.size())
58       VRegStackified.resize(TargetRegisterInfo::virtReg2Index(VReg) + 1);
59     VRegStackified.set(TargetRegisterInfo::virtReg2Index(VReg));
60   }
isVRegStackified(unsigned VReg)61   bool isVRegStackified(unsigned VReg) const {
62     if (TargetRegisterInfo::virtReg2Index(VReg) >= VRegStackified.size())
63       return false;
64     return VRegStackified.test(TargetRegisterInfo::virtReg2Index(VReg));
65   }
66 
67   void initWARegs();
setWAReg(unsigned VReg,unsigned WAReg)68   void setWAReg(unsigned VReg, unsigned WAReg) {
69     assert(WAReg != UnusedReg);
70     assert(TargetRegisterInfo::virtReg2Index(VReg) < WARegs.size());
71     WARegs[TargetRegisterInfo::virtReg2Index(VReg)] = WAReg;
72   }
getWAReg(unsigned Reg)73   unsigned getWAReg(unsigned Reg) const {
74     if (TargetRegisterInfo::isVirtualRegister(Reg)) {
75       assert(TargetRegisterInfo::virtReg2Index(Reg) < WARegs.size());
76       return WARegs[TargetRegisterInfo::virtReg2Index(Reg)];
77     }
78     return PhysRegs[Reg];
79   }
80   // If new virtual registers are created after initWARegs has been called,
81   // this function can be used to add WebAssembly register mappings for them.
addWAReg(unsigned VReg,unsigned WAReg)82   void addWAReg(unsigned VReg, unsigned WAReg) {
83     assert(VReg = WARegs.size());
84     WARegs.push_back(WAReg);
85   }
86 
addPReg(unsigned PReg,unsigned WAReg)87   void addPReg(unsigned PReg, unsigned WAReg) {
88     assert(PReg < WebAssembly::NUM_TARGET_REGS);
89     assert(WAReg < -1U);
90     PhysRegs[PReg] = WAReg;
91   }
getPhysRegs()92   const std::vector<unsigned> &getPhysRegs() const { return PhysRegs; }
93 };
94 
95 } // end namespace llvm
96 
97 #endif
98