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https://github.com/c64scene-ar/llvm-6502.git
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65482b1bb8
"For ARM stack frames that utilize variable sized objects and have either large local stack areas or require dynamic stack realignment, allocate a base register via which to access the local frame. This allows efficient access to frame indices not accessible via the FP (either due to being out of range or due to dynamic realignment) or the SP (due to variable sized object allocation). In particular, this greatly improves efficiency of access to spill slots in Thumb functions which contain VLAs." r112986 fixed a latent bug exposed by the above. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112989 91177308-0d34-0410-b5e6-96231b3b80d8
189 lines
7.1 KiB
C++
189 lines
7.1 KiB
C++
//===- ARMBaseRegisterInfo.h - ARM Register Information Impl ----*- C++ -*-===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file contains the base ARM implementation of TargetRegisterInfo class.
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//
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//===----------------------------------------------------------------------===//
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#ifndef ARMBASEREGISTERINFO_H
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#define ARMBASEREGISTERINFO_H
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#include "ARM.h"
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#include "llvm/Target/TargetRegisterInfo.h"
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#include "ARMGenRegisterInfo.h.inc"
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namespace llvm {
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class ARMSubtarget;
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class ARMBaseInstrInfo;
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class Type;
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/// Register allocation hints.
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namespace ARMRI {
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enum {
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RegPairOdd = 1,
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RegPairEven = 2
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};
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}
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/// isARMLowRegister - Returns true if the register is low register r0-r7.
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///
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static inline bool isARMLowRegister(unsigned Reg) {
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using namespace ARM;
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switch (Reg) {
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case R0: case R1: case R2: case R3:
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case R4: case R5: case R6: case R7:
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return true;
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default:
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return false;
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}
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}
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class ARMBaseRegisterInfo : public ARMGenRegisterInfo {
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protected:
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const ARMBaseInstrInfo &TII;
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const ARMSubtarget &STI;
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/// FramePtr - ARM physical register used as frame ptr.
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unsigned FramePtr;
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/// BasePtr - ARM physical register used as a base ptr in complex stack
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/// frames. I.e., when we need a 3rd base, not just SP and FP, due to
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/// variable size stack objects.
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unsigned BasePtr;
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// Can be only subclassed.
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explicit ARMBaseRegisterInfo(const ARMBaseInstrInfo &tii,
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const ARMSubtarget &STI);
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// Return the opcode that implements 'Op', or 0 if no opcode
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unsigned getOpcode(int Op) const;
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public:
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/// getRegisterNumbering - Given the enum value for some register, e.g.
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/// ARM::LR, return the number that it corresponds to (e.g. 14). It
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/// also returns true in isSPVFP if the register is a single precision
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/// VFP register.
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static unsigned getRegisterNumbering(unsigned RegEnum, bool *isSPVFP = 0);
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/// Code Generation virtual methods...
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const unsigned *getCalleeSavedRegs(const MachineFunction *MF = 0) const;
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BitVector getReservedRegs(const MachineFunction &MF) const;
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/// getMatchingSuperRegClass - Return a subclass of the specified register
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/// class A so that each register in it has a sub-register of the
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/// specified sub-register index which is in the specified register class B.
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virtual const TargetRegisterClass *
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getMatchingSuperRegClass(const TargetRegisterClass *A,
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const TargetRegisterClass *B, unsigned Idx) const;
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/// canCombineSubRegIndices - Given a register class and a list of
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/// subregister indices, return true if it's possible to combine the
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/// subregister indices into one that corresponds to a larger
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/// subregister. Return the new subregister index by reference. Note the
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/// new index may be zero if the given subregisters can be combined to
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/// form the whole register.
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virtual bool canCombineSubRegIndices(const TargetRegisterClass *RC,
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SmallVectorImpl<unsigned> &SubIndices,
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unsigned &NewSubIdx) const;
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const TargetRegisterClass *getPointerRegClass(unsigned Kind = 0) const;
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std::pair<TargetRegisterClass::iterator,TargetRegisterClass::iterator>
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getAllocationOrder(const TargetRegisterClass *RC,
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unsigned HintType, unsigned HintReg,
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const MachineFunction &MF) const;
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unsigned ResolveRegAllocHint(unsigned Type, unsigned Reg,
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const MachineFunction &MF) const;
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void UpdateRegAllocHint(unsigned Reg, unsigned NewReg,
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MachineFunction &MF) const;
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bool hasFP(const MachineFunction &MF) const;
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bool hasBasePointer(const MachineFunction &MF) const;
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bool canRealignStack(const MachineFunction &MF) const;
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bool needsStackRealignment(const MachineFunction &MF) const;
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int64_t getFrameIndexInstrOffset(const MachineInstr *MI, int Idx) const;
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bool needsFrameBaseReg(MachineInstr *MI, int64_t Offset) const;
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void materializeFrameBaseRegister(MachineBasicBlock::iterator I,
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unsigned BaseReg, int FrameIdx,
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int64_t Offset) const;
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void resolveFrameIndex(MachineBasicBlock::iterator I,
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unsigned BaseReg, int64_t Offset) const;
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bool isFrameOffsetLegal(const MachineInstr *MI, int64_t Offset) const;
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bool cannotEliminateFrame(const MachineFunction &MF) const;
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void processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
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RegScavenger *RS = NULL) const;
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// Debug information queries.
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unsigned getRARegister() const;
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unsigned getFrameRegister(const MachineFunction &MF) const;
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int getFrameIndexReference(const MachineFunction &MF, int FI,
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unsigned &FrameReg) const;
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int ResolveFrameIndexReference(const MachineFunction &MF, int FI,
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unsigned &FrameReg, int SPAdj) const;
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int getFrameIndexOffset(const MachineFunction &MF, int FI) const;
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// Exception handling queries.
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unsigned getEHExceptionRegister() const;
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unsigned getEHHandlerRegister() const;
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int getDwarfRegNum(unsigned RegNum, bool isEH) const;
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bool isLowRegister(unsigned Reg) const;
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/// emitLoadConstPool - Emits a load from constpool to materialize the
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/// specified immediate.
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virtual void emitLoadConstPool(MachineBasicBlock &MBB,
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MachineBasicBlock::iterator &MBBI,
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DebugLoc dl,
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unsigned DestReg, unsigned SubIdx,
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int Val,
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ARMCC::CondCodes Pred = ARMCC::AL,
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unsigned PredReg = 0) const;
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/// Code Generation virtual methods...
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virtual bool isReservedReg(const MachineFunction &MF, unsigned Reg) const;
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virtual bool requiresRegisterScavenging(const MachineFunction &MF) const;
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virtual bool requiresFrameIndexScavenging(const MachineFunction &MF) const;
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virtual bool requiresVirtualBaseRegisters(const MachineFunction &MF) const;
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virtual bool hasReservedCallFrame(const MachineFunction &MF) const;
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virtual bool canSimplifyCallFramePseudos(const MachineFunction &MF) const;
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virtual void eliminateCallFramePseudoInstr(MachineFunction &MF,
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MachineBasicBlock &MBB,
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MachineBasicBlock::iterator I) const;
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virtual void eliminateFrameIndex(MachineBasicBlock::iterator II,
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int SPAdj, RegScavenger *RS = NULL) const;
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virtual void emitPrologue(MachineFunction &MF) const;
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virtual void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const;
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private:
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unsigned estimateRSStackSizeLimit(MachineFunction &MF) const;
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unsigned getRegisterPairEven(unsigned Reg, const MachineFunction &MF) const;
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unsigned getRegisterPairOdd(unsigned Reg, const MachineFunction &MF) const;
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};
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} // end namespace llvm
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#endif
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