• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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   // A virtual register holding the pointer to the vararg buffer for vararg
43   // functions. It is created and set in TLI::LowerFormalArguments and read by
44   // TLI::LowerVASTART
45   unsigned VarargVreg = -1U;
46 
47  public:
WebAssemblyFunctionInfo(MachineFunction & MF)48   explicit WebAssemblyFunctionInfo(MachineFunction &MF) : MF(MF) {}
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 
getVarargBufferVreg()54   unsigned getVarargBufferVreg() const {
55     assert(VarargVreg != -1U && "Vararg vreg hasn't been set");
56     return VarargVreg;
57   }
setVarargBufferVreg(unsigned Reg)58   void setVarargBufferVreg(unsigned Reg) { VarargVreg = Reg; }
59 
60   static const unsigned UnusedReg = -1u;
61 
stackifyVReg(unsigned VReg)62   void stackifyVReg(unsigned VReg) {
63     if (TargetRegisterInfo::virtReg2Index(VReg) >= VRegStackified.size())
64       VRegStackified.resize(TargetRegisterInfo::virtReg2Index(VReg) + 1);
65     VRegStackified.set(TargetRegisterInfo::virtReg2Index(VReg));
66   }
isVRegStackified(unsigned VReg)67   bool isVRegStackified(unsigned VReg) const {
68     if (TargetRegisterInfo::virtReg2Index(VReg) >= VRegStackified.size())
69       return false;
70     return VRegStackified.test(TargetRegisterInfo::virtReg2Index(VReg));
71   }
72 
73   void initWARegs();
setWAReg(unsigned VReg,unsigned WAReg)74   void setWAReg(unsigned VReg, unsigned WAReg) {
75     assert(WAReg != UnusedReg);
76     assert(TargetRegisterInfo::virtReg2Index(VReg) < WARegs.size());
77     WARegs[TargetRegisterInfo::virtReg2Index(VReg)] = WAReg;
78   }
getWAReg(unsigned Reg)79   unsigned getWAReg(unsigned Reg) const {
80     assert(TargetRegisterInfo::virtReg2Index(Reg) < WARegs.size());
81     return WARegs[TargetRegisterInfo::virtReg2Index(Reg)];
82   }
83 
84   // For a given stackified WAReg, return the id number to print with push/pop.
getWARegStackId(unsigned Reg)85   static unsigned getWARegStackId(unsigned Reg) {
86     assert(Reg & INT32_MIN);
87     return Reg & INT32_MAX;
88   }
89 };
90 
91 } // end namespace llvm
92 
93 #endif
94