WebAssemblyMachineFunctionInfo.h revision 314564 
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
22namespace llvm {
23
24/// This class is derived from MachineFunctionInfo and contains private
25/// WebAssembly-specific information for each MachineFunction.
26class WebAssemblyFunctionInfo final : public MachineFunctionInfo {
27  MachineFunction &MF;
28
29  std::vector<MVT> Params;
30  std::vector<MVT> Results;
31  std::vector<MVT> Locals;
32
33  /// A mapping from CodeGen vreg index to WebAssembly register number.
34  std::vector<unsigned> WARegs;
35
36  /// A mapping from CodeGen vreg index to a boolean value indicating whether
37  /// the given register is considered to be "stackified", meaning it has been
38  /// determined or made to meet the stack requirements:
39  ///   - single use (per path)
40  ///   - single def (per path)
41  ///   - defined and used in LIFO order with other stack registers
42  BitVector VRegStackified;
43
44  // A virtual register holding the pointer to the vararg buffer for vararg
45  // functions. It is created and set in TLI::LowerFormalArguments and read by
46  // TLI::LowerVASTART
47  unsigned VarargVreg = -1U;
48
49  // A virtual register holding the base pointer for functions that have
50  // overaligned values on the user stack.
51  unsigned BasePtrVreg = -1U;
52
53 public:
54  explicit WebAssemblyFunctionInfo(MachineFunction &MF) : MF(MF) {}
55  ~WebAssemblyFunctionInfo() override;
56
57  void addParam(MVT VT) { Params.push_back(VT); }
58  const std::vector<MVT> &getParams() const { return Params; }
59
60  void addResult(MVT VT) { Results.push_back(VT); }
61  const std::vector<MVT> &getResults() const { return Results; }
62
63  void addLocal(MVT VT) { Locals.push_back(VT); }
64  const std::vector<MVT> &getLocals() const { return Locals; }
65
66  unsigned getVarargBufferVreg() const {
67    assert(VarargVreg != -1U && "Vararg vreg hasn't been set");
68    return VarargVreg;
69  }
70  void setVarargBufferVreg(unsigned Reg) { VarargVreg = Reg; }
71
72  unsigned getBasePointerVreg() const {
73    assert(BasePtrVreg != -1U && "Base ptr vreg hasn't been set");
74    return BasePtrVreg;
75  }
76  void setBasePointerVreg(unsigned Reg) { BasePtrVreg = Reg; }
77
78  static const unsigned UnusedReg = -1u;
79
80  void stackifyVReg(unsigned VReg) {
81    assert(MF.getRegInfo().getUniqueVRegDef(VReg));
82    if (TargetRegisterInfo::virtReg2Index(VReg) >= VRegStackified.size())
83      VRegStackified.resize(TargetRegisterInfo::virtReg2Index(VReg) + 1);
84    VRegStackified.set(TargetRegisterInfo::virtReg2Index(VReg));
85  }
86  bool isVRegStackified(unsigned VReg) const {
87    if (TargetRegisterInfo::virtReg2Index(VReg) >= VRegStackified.size())
88      return false;
89    return VRegStackified.test(TargetRegisterInfo::virtReg2Index(VReg));
90  }
91
92  void initWARegs();
93  void setWAReg(unsigned VReg, unsigned WAReg) {
94    assert(WAReg != UnusedReg);
95    assert(TargetRegisterInfo::virtReg2Index(VReg) < WARegs.size());
96    WARegs[TargetRegisterInfo::virtReg2Index(VReg)] = WAReg;
97  }
98  unsigned getWAReg(unsigned Reg) const {
99    assert(TargetRegisterInfo::virtReg2Index(Reg) < WARegs.size());
100    return WARegs[TargetRegisterInfo::virtReg2Index(Reg)];
101  }
102
103  // For a given stackified WAReg, return the id number to print with push/pop.
104  static unsigned getWARegStackId(unsigned Reg) {
105    assert(Reg & INT32_MIN);
106    return Reg & INT32_MAX;
107  }
108};
109
110void ComputeLegalValueVTs(const Function &F, const TargetMachine &TM,
111                          Type *Ty, SmallVectorImpl<MVT> &ValueVTs);
112
113void ComputeSignatureVTs(const Function &F, const TargetMachine &TM,
114                         SmallVectorImpl<MVT> &Params,
115                         SmallVectorImpl<MVT> &Results);
116
117} // end namespace llvm
118
119#endif
120