xref: /freebsd/contrib/llvm-project/llvm/lib/Target/RISCV/RISCVMachineFunctionInfo.h (revision b1879975794772ee51f0b4865753364c7d7626c3)
1 //=- RISCVMachineFunctionInfo.h - RISC-V machine function info ----*- C++ -*-=//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file declares RISCV-specific per-machine-function information.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_LIB_TARGET_RISCV_RISCVMACHINEFUNCTIONINFO_H
14 #define LLVM_LIB_TARGET_RISCV_RISCVMACHINEFUNCTIONINFO_H
15 
16 #include "RISCVSubtarget.h"
17 #include "llvm/CodeGen/MIRYamlMapping.h"
18 #include "llvm/CodeGen/MachineFrameInfo.h"
19 #include "llvm/CodeGen/MachineFunction.h"
20 
21 namespace llvm {
22 
23 class RISCVMachineFunctionInfo;
24 
25 namespace yaml {
26 struct RISCVMachineFunctionInfo final : public yaml::MachineFunctionInfo {
27   int VarArgsFrameIndex;
28   int VarArgsSaveSize;
29 
30   RISCVMachineFunctionInfo() = default;
31   RISCVMachineFunctionInfo(const llvm::RISCVMachineFunctionInfo &MFI);
32 
33   void mappingImpl(yaml::IO &YamlIO) override;
34   ~RISCVMachineFunctionInfo() = default;
35 };
36 
37 template <> struct MappingTraits<RISCVMachineFunctionInfo> {
38   static void mapping(IO &YamlIO, RISCVMachineFunctionInfo &MFI) {
39     YamlIO.mapOptional("varArgsFrameIndex", MFI.VarArgsFrameIndex);
40     YamlIO.mapOptional("varArgsSaveSize", MFI.VarArgsSaveSize);
41   }
42 };
43 } // end namespace yaml
44 
45 /// RISCVMachineFunctionInfo - This class is derived from MachineFunctionInfo
46 /// and contains private RISCV-specific information for each MachineFunction.
47 class RISCVMachineFunctionInfo : public MachineFunctionInfo {
48 private:
49   /// FrameIndex for start of varargs area
50   int VarArgsFrameIndex = 0;
51   /// Size of the save area used for varargs
52   int VarArgsSaveSize = 0;
53   /// FrameIndex used for transferring values between 64-bit FPRs and a pair
54   /// of 32-bit GPRs via the stack.
55   int MoveF64FrameIndex = -1;
56   /// FrameIndex of the spill slot for the scratch register in BranchRelaxation.
57   int BranchRelaxationScratchFrameIndex = -1;
58   /// Size of any opaque stack adjustment due to save/restore libcalls.
59   unsigned LibCallStackSize = 0;
60   /// Size of RVV stack.
61   uint64_t RVVStackSize = 0;
62   /// Alignment of RVV stack.
63   Align RVVStackAlign;
64   /// Padding required to keep RVV stack aligned within the main stack.
65   uint64_t RVVPadding = 0;
66   /// Size of stack frame to save callee saved registers
67   unsigned CalleeSavedStackSize = 0;
68   /// Is there any vector argument or return?
69   bool IsVectorCall = false;
70 
71   /// Registers that have been sign extended from i32.
72   SmallVector<Register, 8> SExt32Registers;
73 
74   /// Size of stack frame for Zcmp PUSH/POP
75   unsigned RVPushStackSize = 0;
76   unsigned RVPushRegs = 0;
77   int RVPushRlist = llvm::RISCVZC::RLISTENCODE::INVALID_RLIST;
78 
79 public:
80   RISCVMachineFunctionInfo(const Function &F, const TargetSubtargetInfo *STI) {}
81 
82   MachineFunctionInfo *
83   clone(BumpPtrAllocator &Allocator, MachineFunction &DestMF,
84         const DenseMap<MachineBasicBlock *, MachineBasicBlock *> &Src2DstMBB)
85       const override;
86 
87   int getVarArgsFrameIndex() const { return VarArgsFrameIndex; }
88   void setVarArgsFrameIndex(int Index) { VarArgsFrameIndex = Index; }
89 
90   unsigned getVarArgsSaveSize() const { return VarArgsSaveSize; }
91   void setVarArgsSaveSize(int Size) { VarArgsSaveSize = Size; }
92 
93   int getMoveF64FrameIndex(MachineFunction &MF) {
94     if (MoveF64FrameIndex == -1)
95       MoveF64FrameIndex =
96           MF.getFrameInfo().CreateStackObject(8, Align(8), false);
97     return MoveF64FrameIndex;
98   }
99 
100   int getBranchRelaxationScratchFrameIndex() const {
101     return BranchRelaxationScratchFrameIndex;
102   }
103   void setBranchRelaxationScratchFrameIndex(int Index) {
104     BranchRelaxationScratchFrameIndex = Index;
105   }
106 
107   unsigned getReservedSpillsSize() const {
108     return LibCallStackSize + RVPushStackSize;
109   }
110 
111   unsigned getLibCallStackSize() const { return LibCallStackSize; }
112   void setLibCallStackSize(unsigned Size) { LibCallStackSize = Size; }
113 
114   bool useSaveRestoreLibCalls(const MachineFunction &MF) const {
115     // We cannot use fixed locations for the callee saved spill slots if the
116     // function uses a varargs save area, or is an interrupt handler.
117     return !isPushable(MF) &&
118            MF.getSubtarget<RISCVSubtarget>().enableSaveRestore() &&
119            VarArgsSaveSize == 0 && !MF.getFrameInfo().hasTailCall() &&
120            !MF.getFunction().hasFnAttribute("interrupt");
121   }
122 
123   uint64_t getRVVStackSize() const { return RVVStackSize; }
124   void setRVVStackSize(uint64_t Size) { RVVStackSize = Size; }
125 
126   Align getRVVStackAlign() const { return RVVStackAlign; }
127   void setRVVStackAlign(Align StackAlign) { RVVStackAlign = StackAlign; }
128 
129   uint64_t getRVVPadding() const { return RVVPadding; }
130   void setRVVPadding(uint64_t Padding) { RVVPadding = Padding; }
131 
132   unsigned getCalleeSavedStackSize() const { return CalleeSavedStackSize; }
133   void setCalleeSavedStackSize(unsigned Size) { CalleeSavedStackSize = Size; }
134 
135   bool isPushable(const MachineFunction &MF) const {
136     // We cannot use fixed locations for the callee saved spill slots if the
137     // function uses a varargs save area.
138     // TODO: Use a separate placement for vararg registers to enable Zcmp.
139     return MF.getSubtarget<RISCVSubtarget>().hasStdExtZcmp() &&
140            !MF.getTarget().Options.DisableFramePointerElim(MF) &&
141            VarArgsSaveSize == 0;
142   }
143 
144   int getRVPushRlist() const { return RVPushRlist; }
145   void setRVPushRlist(int Rlist) { RVPushRlist = Rlist; }
146 
147   unsigned getRVPushRegs() const { return RVPushRegs; }
148   void setRVPushRegs(unsigned Regs) { RVPushRegs = Regs; }
149 
150   unsigned getRVPushStackSize() const { return RVPushStackSize; }
151   void setRVPushStackSize(unsigned Size) { RVPushStackSize = Size; }
152 
153   void initializeBaseYamlFields(const yaml::RISCVMachineFunctionInfo &YamlMFI);
154 
155   void addSExt32Register(Register Reg);
156   bool isSExt32Register(Register Reg) const;
157 
158   bool isVectorCall() const { return IsVectorCall; }
159   void setIsVectorCall() { IsVectorCall = true; }
160 };
161 
162 } // end namespace llvm
163 
164 #endif // LLVM_LIB_TARGET_RISCV_RISCVMACHINEFUNCTIONINFO_H
165