1 //===-- X86TargetFrameLowering.h - Define frame lowering for X86 -*- C++ -*-==//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This class implements X86-specific bits of TargetFrameLowering class.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_LIB_TARGET_X86_X86FRAMELOWERING_H
15 #define LLVM_LIB_TARGET_X86_X86FRAMELOWERING_H
17 #include "llvm/Target/TargetFrameLowering.h"
22 class X86RegisterInfo;
24 class X86FrameLowering : public TargetFrameLowering {
26 X86FrameLowering(const X86Subtarget &STI, unsigned StackAlignOverride);
28 // Cached subtarget predicates.
30 const X86Subtarget &STI;
31 const TargetInstrInfo &TII;
32 const X86RegisterInfo *RegInfo;
36 /// Is64Bit implies that x86_64 instructions are available.
41 /// True if the 64-bit frame or stack pointer should be used. True for most
42 /// 64-bit targets with the exception of x32. If this is false, 32-bit
43 /// instruction operands should be used to manipulate StackPtr and FramePtr.
44 bool Uses64BitFramePtr;
46 /// Emit a call to the target's stack probe function. This is required for all
47 /// large stack allocations on Windows. The caller is required to materialize
48 /// the number of bytes to probe in RAX/EAX.
49 void emitStackProbeCall(MachineFunction &MF, MachineBasicBlock &MBB,
50 MachineBasicBlock::iterator MBBI, DebugLoc DL) const;
52 void emitCalleeSavedFrameMoves(MachineBasicBlock &MBB,
53 MachineBasicBlock::iterator MBBI,
56 /// emitProlog/emitEpilog - These methods insert prolog and epilog code into
58 void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
59 void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
61 void adjustForSegmentedStacks(MachineFunction &MF,
62 MachineBasicBlock &PrologueMBB) const override;
64 void adjustForHiPEPrologue(MachineFunction &MF,
65 MachineBasicBlock &PrologueMBB) const override;
67 void processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
68 RegScavenger *RS = nullptr) const override;
71 assignCalleeSavedSpillSlots(MachineFunction &MF,
72 const TargetRegisterInfo *TRI,
73 std::vector<CalleeSavedInfo> &CSI) const override;
75 bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
76 MachineBasicBlock::iterator MI,
77 const std::vector<CalleeSavedInfo> &CSI,
78 const TargetRegisterInfo *TRI) const override;
80 bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
81 MachineBasicBlock::iterator MI,
82 const std::vector<CalleeSavedInfo> &CSI,
83 const TargetRegisterInfo *TRI) const override;
85 bool hasFP(const MachineFunction &MF) const override;
86 bool hasReservedCallFrame(const MachineFunction &MF) const override;
87 bool canSimplifyCallFramePseudos(const MachineFunction &MF) const override;
88 bool needsFrameIndexResolution(const MachineFunction &MF) const override;
90 int getFrameIndexOffset(const MachineFunction &MF, int FI) const override;
91 int getFrameIndexReference(const MachineFunction &MF, int FI,
92 unsigned &FrameReg) const override;
94 int getFrameIndexOffsetFromSP(const MachineFunction &MF, int FI) const;
95 int getFrameIndexReferenceFromSP(const MachineFunction &MF, int FI,
96 unsigned &FrameReg) const override;
98 void eliminateCallFramePseudoInstr(MachineFunction &MF,
99 MachineBasicBlock &MBB,
100 MachineBasicBlock::iterator MI) const override;
102 /// Check the instruction before/after the passed instruction. If
103 /// it is an ADD/SUB/LEA instruction it is deleted argument and the
104 /// stack adjustment is returned as a positive value for ADD/LEA and
105 /// a negative for SUB.
106 int mergeSPUpdates(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
107 unsigned StackPtr, bool doMergeWithPrevious) const;
109 /// Emit a series of instructions to increment / decrement the stack
110 /// pointer by a constant value.
111 void emitSPUpdate(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
112 unsigned StackPtr, int64_t NumBytes, bool Is64BitTarget,
113 bool Is64BitStackPtr, bool UseLEA,
114 const TargetInstrInfo &TII,
115 const TargetRegisterInfo &TRI) const;
117 /// Check that LEA can be used on SP in an epilogue sequence for \p MF.
118 bool canUseLEAForSPInEpilogue(const MachineFunction &MF) const;
120 /// Check whether or not the given \p MBB can be used as a epilogue
122 /// The epilogue will be inserted before the first terminator of that block.
123 /// This method is used by the shrink-wrapping pass to decide if
124 /// \p MBB will be correctly handled by the target.
125 bool canUseAsEpilogue(const MachineBasicBlock &MBB) const override;
128 /// convertArgMovsToPushes - This method tries to convert a call sequence
129 /// that uses sub and mov instructions to put the argument onto the stack
130 /// into a series of pushes.
131 /// Returns true if the transformation succeeded, false if not.
132 bool convertArgMovsToPushes(MachineFunction &MF,
133 MachineBasicBlock &MBB,
134 MachineBasicBlock::iterator I,
135 uint64_t Amount) const;
137 uint64_t calculateMaxStackAlign(const MachineFunction &MF) const;
140 } // End llvm namespace