LLVM 20.0.0git
PPCFrameLowering.h
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1//===-- PPCFrameLowering.h - Define frame lowering for PowerPC --*- 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//
10//===----------------------------------------------------------------------===//
11
12#ifndef LLVM_LIB_TARGET_POWERPC_PPCFRAMELOWERING_H
13#define LLVM_LIB_TARGET_POWERPC_PPCFRAMELOWERING_H
14
15#include "llvm/ADT/STLExtras.h"
18
19namespace llvm {
20class PPCSubtarget;
21
23 const PPCSubtarget &Subtarget;
24 const uint64_t ReturnSaveOffset;
25 const uint64_t TOCSaveOffset;
26 const uint64_t FramePointerSaveOffset;
27 const unsigned LinkageSize;
28 const uint64_t BasePointerSaveOffset;
29 const uint64_t CRSaveOffset;
30
31 // Map each group of one or two GPRs to corresponding VSR for spilling.
32 // TODO: Use local table in methods to avoid this mutable member.
33 mutable DenseMap<unsigned, std::pair<Register, Register>> VSRContainingGPRs;
34
35 /**
36 * Find register[s] that can be used in function prologue and epilogue
37 *
38 * Find register[s] that can be use as scratch register[s] in function
39 * prologue and epilogue to save various registers (Link Register, Base
40 * Pointer, etc.). Prefer R0/R12, if available. Otherwise choose whatever
41 * register[s] are available.
42 *
43 * This method will return true if it is able to find enough unique scratch
44 * registers (1 or 2 depending on the requirement). If it is unable to find
45 * enough available registers in the block, it will return false and set
46 * any passed output parameter that corresponds to a required unique register
47 * to PPC::NoRegister.
48 *
49 * \param[in] MBB The machine basic block to find an available register for
50 * \param[in] UseAtEnd Specify whether the scratch register will be used at
51 * the end of the basic block (i.e., will the scratch
52 * register kill a register defined in the basic block)
53 * \param[in] TwoUniqueRegsRequired Specify whether this basic block will
54 * require two unique scratch registers.
55 * \param[out] SR1 The scratch register to use
56 * \param[out] SR2 The second scratch register. If this pointer is not null
57 * the function will attempt to set it to an available
58 * register regardless of whether there is a hard requirement
59 * for two unique scratch registers.
60 * \return true if the required number of registers was found.
61 * false if the required number of scratch register weren't available.
62 * If either output parameter refers to a required scratch register
63 * that isn't available, it will be set to an invalid value.
64 */
65 bool findScratchRegister(MachineBasicBlock *MBB,
66 bool UseAtEnd,
67 bool TwoUniqueRegsRequired = false,
68 Register *SR1 = nullptr,
69 Register *SR2 = nullptr) const;
70 bool twoUniqueScratchRegsRequired(MachineBasicBlock *MBB) const;
71
72 /**
73 * Create branch instruction for PPC::TCRETURN* (tail call return)
74 *
75 * \param[in] MBB that is terminated by PPC::TCRETURN*
76 */
77 void createTailCallBranchInstr(MachineBasicBlock &MBB) const;
78
79 /**
80 * Check if the conditions are correct to allow for the stack update
81 * to be moved past the CSR save/restore code.
82 */
83 bool stackUpdateCanBeMoved(MachineFunction &MF) const;
84
85public:
87
88 /**
89 * Determine the frame layout and update the machine function.
90 */
92 bool UseEstimate = false) const;
93
94 /**
95 * Determine the frame layout but do not update the machine function.
96 * The MachineFunction object can be const in this case as it is not
97 * modified.
98 */
100 bool UseEstimate = false,
101 unsigned *NewMaxCallFrameSize = nullptr) const;
102
103 /// emitProlog/emitEpilog - These methods insert prolog and epilog code into
104 /// the function.
105 void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
106 void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
108 MachineBasicBlock &PrologMBB) const override;
109
110 bool hasFP(const MachineFunction &MF) const override;
111 bool needsFP(const MachineFunction &MF) const;
112 void replaceFPWithRealFP(MachineFunction &MF) const;
113
115 RegScavenger *RS = nullptr) const override;
117 RegScavenger *RS = nullptr) const override;
119
123 const TargetRegisterInfo *TRI) const override;
124 /// This function will assign callee saved gprs to volatile vector registers
125 /// for prologue spills when applicable. It returns false if there are any
126 /// registers which were not spilled to volatile vector registers.
127 bool
129 const TargetRegisterInfo *TRI,
130 std::vector<CalleeSavedInfo> &CSI) const override;
131
134 MachineBasicBlock::iterator I) const override;
135
136 bool
140 const TargetRegisterInfo *TRI) const override;
141
142 /// targetHandlesStackFrameRounding - Returns true if the target is
143 /// responsible for rounding up the stack frame (probably at emitPrologue
144 /// time).
145 bool targetHandlesStackFrameRounding() const override { return true; }
146
147 /// getReturnSaveOffset - Return the previous frame offset to save the
148 /// return address.
149 uint64_t getReturnSaveOffset() const { return ReturnSaveOffset; }
150
151 /// getTOCSaveOffset - Return the previous frame offset to save the
152 /// TOC register -- 64-bit SVR4 ABI only.
154
155 /// getFramePointerSaveOffset - Return the previous frame offset to save the
156 /// frame pointer.
158
159 /// getBasePointerSaveOffset - Return the previous frame offset to save the
160 /// base pointer.
162
163 /// getLinkageSize - Return the size of the PowerPC ABI linkage area.
164 ///
165 unsigned getLinkageSize() const { return LinkageSize; }
166
167 const SpillSlot *
168 getCalleeSavedSpillSlots(unsigned &NumEntries) const override;
169
170 bool enableShrinkWrapping(const MachineFunction &MF) const override;
171
172 /// Methods used by shrink wrapping to determine if MBB can be used for the
173 /// function prologue/epilogue.
174 bool canUseAsPrologue(const MachineBasicBlock &MBB) const override;
175 bool canUseAsEpilogue(const MachineBasicBlock &MBB) const override;
176 void updateCalleeSaves(const MachineFunction &MF, BitVector &SavedRegs) const;
177
178 uint64_t getStackThreshold() const override;
179};
180} // End llvm namespace
181
182#endif
MachineBasicBlock & MBB
IRTranslator LLVM IR MI
#define I(x, y, z)
Definition: MD5.cpp:58
unsigned const TargetRegisterInfo * TRI
This file contains some templates that are useful if you are working with the STL at all.
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory),...
Definition: ArrayRef.h:41
MutableArrayRef - Represent a mutable reference to an array (0 or more elements consecutively in memo...
Definition: ArrayRef.h:307
uint64_t getReturnSaveOffset() const
getReturnSaveOffset - Return the previous frame offset to save the return address.
bool needsFP(const MachineFunction &MF) const
void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override
bool targetHandlesStackFrameRounding() const override
targetHandlesStackFrameRounding - Returns true if the target is responsible for rounding up the stack...
bool hasFP(const MachineFunction &MF) const override
hasFP - Return true if the specified function should have a dedicated frame pointer register.
bool canUseAsEpilogue(const MachineBasicBlock &MBB) const override
Check whether or not the given MBB can be used as a epilogue for the target.
uint64_t getStackThreshold() const override
getStackThreshold - Return the maximum stack size
void processFunctionBeforeFrameFinalized(MachineFunction &MF, RegScavenger *RS=nullptr) const override
processFunctionBeforeFrameFinalized - This method is called immediately before the specified function...
uint64_t getFramePointerSaveOffset() const
getFramePointerSaveOffset - Return the previous frame offset to save the frame pointer.
bool spillCalleeSavedRegisters(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI, ArrayRef< CalleeSavedInfo > CSI, const TargetRegisterInfo *TRI) const override
spillCalleeSavedRegisters - Issues instruction(s) to spill all callee saved registers and returns tru...
unsigned getLinkageSize() const
getLinkageSize - Return the size of the PowerPC ABI linkage area.
MachineBasicBlock::iterator eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB, MachineBasicBlock::iterator I) const override
This method is called during prolog/epilog code insertion to eliminate call frame setup and destroy p...
const SpillSlot * getCalleeSavedSpillSlots(unsigned &NumEntries) const override
getCalleeSavedSpillSlots - This method returns a pointer to an array of pairs, that contains an entry...
void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs, RegScavenger *RS=nullptr) const override
This method determines which of the registers reported by TargetRegisterInfo::getCalleeSavedRegs() sh...
bool canUseAsPrologue(const MachineBasicBlock &MBB) const override
Methods used by shrink wrapping to determine if MBB can be used for the function prologue/epilogue.
void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override
emitProlog/emitEpilog - These methods insert prolog and epilog code into the function.
bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI, MutableArrayRef< CalleeSavedInfo > CSI, const TargetRegisterInfo *TRI) const override
restoreCalleeSavedRegisters - Issues instruction(s) to restore all callee saved registers and returns...
void replaceFPWithRealFP(MachineFunction &MF) const
bool enableShrinkWrapping(const MachineFunction &MF) const override
Returns true if the target will correctly handle shrink wrapping.
uint64_t determineFrameLayout(const MachineFunction &MF, bool UseEstimate=false, unsigned *NewMaxCallFrameSize=nullptr) const
Determine the frame layout but do not update the machine function.
void addScavengingSpillSlot(MachineFunction &MF, RegScavenger *RS) const
bool assignCalleeSavedSpillSlots(MachineFunction &MF, const TargetRegisterInfo *TRI, std::vector< CalleeSavedInfo > &CSI) const override
This function will assign callee saved gprs to volatile vector registers for prologue spills when app...
uint64_t determineFrameLayoutAndUpdate(MachineFunction &MF, bool UseEstimate=false) const
Determine the frame layout and update the machine function.
void updateCalleeSaves(const MachineFunction &MF, BitVector &SavedRegs) const
void inlineStackProbe(MachineFunction &MF, MachineBasicBlock &PrologMBB) const override
Replace a StackProbe stub (if any) with the actual probe code inline.
uint64_t getTOCSaveOffset() const
getTOCSaveOffset - Return the previous frame offset to save the TOC register – 64-bit SVR4 ABI only.
uint64_t getBasePointerSaveOffset() const
getBasePointerSaveOffset - Return the previous frame offset to save the base pointer.
Wrapper class representing virtual and physical registers.
Definition: Register.h:19
Information about stack frame layout on the target.
TargetRegisterInfo base class - We assume that the target defines a static array of TargetRegisterDes...
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18