WebAssemblyMachineFunctionInfo.h revision 321369 
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 setNumLocals(size_t NumLocals) { Locals.resize(NumLocals, MVT::i32); }
64  void setLocal(size_t i, MVT VT) { Locals[i] = VT; }
65  void addLocal(MVT VT) { Locals.push_back(VT); }
66  const std::vector<MVT> &getLocals() const { return Locals; }
67
68  unsigned getVarargBufferVreg() const {
69    assert(VarargVreg != -1U && "Vararg vreg hasn't been set");
70    return VarargVreg;
71  }
72  void setVarargBufferVreg(unsigned Reg) { VarargVreg = Reg; }
73
74  unsigned getBasePointerVreg() const {
75    assert(BasePtrVreg != -1U && "Base ptr vreg hasn't been set");
76    return BasePtrVreg;
77  }
78  void setBasePointerVreg(unsigned Reg) { BasePtrVreg = Reg; }
79
80  static const unsigned UnusedReg = -1u;
81
82  void stackifyVReg(unsigned VReg) {
83    assert(MF.getRegInfo().getUniqueVRegDef(VReg));
84    if (TargetRegisterInfo::virtReg2Index(VReg) >= VRegStackified.size())
85      VRegStackified.resize(TargetRegisterInfo::virtReg2Index(VReg) + 1);
86    VRegStackified.set(TargetRegisterInfo::virtReg2Index(VReg));
87  }
88  bool isVRegStackified(unsigned VReg) const {
89    if (TargetRegisterInfo::virtReg2Index(VReg) >= VRegStackified.size())
90      return false;
91    return VRegStackified.test(TargetRegisterInfo::virtReg2Index(VReg));
92  }
93
94  void initWARegs();
95  void setWAReg(unsigned VReg, unsigned WAReg) {
96    assert(WAReg != UnusedReg);
97    assert(TargetRegisterInfo::virtReg2Index(VReg) < WARegs.size());
98    WARegs[TargetRegisterInfo::virtReg2Index(VReg)] = WAReg;
99  }
100  unsigned getWAReg(unsigned Reg) const {
101    assert(TargetRegisterInfo::virtReg2Index(Reg) < WARegs.size());
102    return WARegs[TargetRegisterInfo::virtReg2Index(Reg)];
103  }
104
105  // For a given stackified WAReg, return the id number to print with push/pop.
106  static unsigned getWARegStackId(unsigned Reg) {
107    assert(Reg & INT32_MIN);
108    return Reg & INT32_MAX;
109  }
110};
111
112void ComputeLegalValueVTs(const Function &F, const TargetMachine &TM,
113                          Type *Ty, SmallVectorImpl<MVT> &ValueVTs);
114
115void ComputeSignatureVTs(const Function &F, const TargetMachine &TM,
116                         SmallVectorImpl<MVT> &Params,
117                         SmallVectorImpl<MVT> &Results);
118
119} // end namespace llvm
120
121#endif
122