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Diffstat (limited to 'contrib/llvm-project/llvm/lib/Target/Mips/Mips16InstrInfo.cpp')
| -rw-r--r-- | contrib/llvm-project/llvm/lib/Target/Mips/Mips16InstrInfo.cpp | 495 |
1 files changed, 495 insertions, 0 deletions
diff --git a/contrib/llvm-project/llvm/lib/Target/Mips/Mips16InstrInfo.cpp b/contrib/llvm-project/llvm/lib/Target/Mips/Mips16InstrInfo.cpp new file mode 100644 index 000000000000..c234c309d760 --- /dev/null +++ b/contrib/llvm-project/llvm/lib/Target/Mips/Mips16InstrInfo.cpp @@ -0,0 +1,495 @@ +//===- Mips16InstrInfo.cpp - Mips16 Instruction Information ---------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This file contains the Mips16 implementation of the TargetInstrInfo class. +// +//===----------------------------------------------------------------------===// + +#include "Mips16InstrInfo.h" +#include "llvm/ADT/BitVector.h" +#include "llvm/CodeGen/MachineBasicBlock.h" +#include "llvm/CodeGen/MachineFrameInfo.h" +#include "llvm/CodeGen/MachineFunction.h" +#include "llvm/CodeGen/MachineInstr.h" +#include "llvm/CodeGen/MachineInstrBuilder.h" +#include "llvm/CodeGen/MachineMemOperand.h" +#include "llvm/CodeGen/MachineOperand.h" +#include "llvm/CodeGen/RegisterScavenging.h" +#include "llvm/CodeGen/TargetRegisterInfo.h" +#include "llvm/IR/DebugLoc.h" +#include "llvm/MC/MCAsmInfo.h" +#include "llvm/Support/Debug.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/MathExtras.h" +#include "llvm/Support/raw_ostream.h" +#include <cassert> +#include <cctype> +#include <cstdint> +#include <cstdlib> +#include <cstring> +#include <iterator> +#include <vector> + +using namespace llvm; + +#define DEBUG_TYPE "mips16-instrinfo" + +Mips16InstrInfo::Mips16InstrInfo(const MipsSubtarget &STI) + : MipsInstrInfo(STI, Mips::Bimm16) {} + +const MipsRegisterInfo &Mips16InstrInfo::getRegisterInfo() const { + return RI; +} + +/// isLoadFromStackSlot - If the specified machine instruction is a direct +/// load from a stack slot, return the virtual or physical register number of +/// the destination along with the FrameIndex of the loaded stack slot. If +/// not, return 0. This predicate must return 0 if the instruction has +/// any side effects other than loading from the stack slot. +unsigned Mips16InstrInfo::isLoadFromStackSlot(const MachineInstr &MI, + int &FrameIndex) const { + return 0; +} + +/// isStoreToStackSlot - If the specified machine instruction is a direct +/// store to a stack slot, return the virtual or physical register number of +/// the source reg along with the FrameIndex of the loaded stack slot. If +/// not, return 0. This predicate must return 0 if the instruction has +/// any side effects other than storing to the stack slot. +unsigned Mips16InstrInfo::isStoreToStackSlot(const MachineInstr &MI, + int &FrameIndex) const { + return 0; +} + +void Mips16InstrInfo::copyPhysReg(MachineBasicBlock &MBB, + MachineBasicBlock::iterator I, + const DebugLoc &DL, unsigned DestReg, + unsigned SrcReg, bool KillSrc) const { + unsigned Opc = 0; + + if (Mips::CPU16RegsRegClass.contains(DestReg) && + Mips::GPR32RegClass.contains(SrcReg)) + Opc = Mips::MoveR3216; + else if (Mips::GPR32RegClass.contains(DestReg) && + Mips::CPU16RegsRegClass.contains(SrcReg)) + Opc = Mips::Move32R16; + else if ((SrcReg == Mips::HI0) && + (Mips::CPU16RegsRegClass.contains(DestReg))) + Opc = Mips::Mfhi16, SrcReg = 0; + else if ((SrcReg == Mips::LO0) && + (Mips::CPU16RegsRegClass.contains(DestReg))) + Opc = Mips::Mflo16, SrcReg = 0; + + assert(Opc && "Cannot copy registers"); + + MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(Opc)); + + if (DestReg) + MIB.addReg(DestReg, RegState::Define); + + if (SrcReg) + MIB.addReg(SrcReg, getKillRegState(KillSrc)); +} + +bool Mips16InstrInfo::isCopyInstrImpl(const MachineInstr &MI, + const MachineOperand *&Src, + const MachineOperand *&Dest) const { + if (MI.isMoveReg()) { + Dest = &MI.getOperand(0); + Src = &MI.getOperand(1); + return true; + } + return false; +} + +void Mips16InstrInfo::storeRegToStack(MachineBasicBlock &MBB, + MachineBasicBlock::iterator I, + unsigned SrcReg, bool isKill, int FI, + const TargetRegisterClass *RC, + const TargetRegisterInfo *TRI, + int64_t Offset) const { + DebugLoc DL; + if (I != MBB.end()) DL = I->getDebugLoc(); + MachineMemOperand *MMO = GetMemOperand(MBB, FI, MachineMemOperand::MOStore); + unsigned Opc = 0; + if (Mips::CPU16RegsRegClass.hasSubClassEq(RC)) + Opc = Mips::SwRxSpImmX16; + assert(Opc && "Register class not handled!"); + BuildMI(MBB, I, DL, get(Opc)).addReg(SrcReg, getKillRegState(isKill)). + addFrameIndex(FI).addImm(Offset) + .addMemOperand(MMO); +} + +void Mips16InstrInfo::loadRegFromStack(MachineBasicBlock &MBB, + MachineBasicBlock::iterator I, + unsigned DestReg, int FI, + const TargetRegisterClass *RC, + const TargetRegisterInfo *TRI, + int64_t Offset) const { + DebugLoc DL; + if (I != MBB.end()) DL = I->getDebugLoc(); + MachineMemOperand *MMO = GetMemOperand(MBB, FI, MachineMemOperand::MOLoad); + unsigned Opc = 0; + + if (Mips::CPU16RegsRegClass.hasSubClassEq(RC)) + Opc = Mips::LwRxSpImmX16; + assert(Opc && "Register class not handled!"); + BuildMI(MBB, I, DL, get(Opc), DestReg).addFrameIndex(FI).addImm(Offset) + .addMemOperand(MMO); +} + +bool Mips16InstrInfo::expandPostRAPseudo(MachineInstr &MI) const { + MachineBasicBlock &MBB = *MI.getParent(); + switch (MI.getDesc().getOpcode()) { + default: + return false; + case Mips::RetRA16: + ExpandRetRA16(MBB, MI, Mips::JrcRa16); + break; + } + + MBB.erase(MI.getIterator()); + return true; +} + +/// GetOppositeBranchOpc - Return the inverse of the specified +/// opcode, e.g. turning BEQ to BNE. +unsigned Mips16InstrInfo::getOppositeBranchOpc(unsigned Opc) const { + switch (Opc) { + case Mips::BeqzRxImmX16: return Mips::BnezRxImmX16; + case Mips::BnezRxImmX16: return Mips::BeqzRxImmX16; + case Mips::BeqzRxImm16: return Mips::BnezRxImm16; + case Mips::BnezRxImm16: return Mips::BeqzRxImm16; + case Mips::BteqzT8CmpX16: return Mips::BtnezT8CmpX16; + case Mips::BteqzT8SltX16: return Mips::BtnezT8SltX16; + case Mips::BteqzT8SltiX16: return Mips::BtnezT8SltiX16; + case Mips::Btnez16: return Mips::Bteqz16; + case Mips::BtnezX16: return Mips::BteqzX16; + case Mips::BtnezT8CmpiX16: return Mips::BteqzT8CmpiX16; + case Mips::BtnezT8SltuX16: return Mips::BteqzT8SltuX16; + case Mips::BtnezT8SltiuX16: return Mips::BteqzT8SltiuX16; + case Mips::Bteqz16: return Mips::Btnez16; + case Mips::BteqzX16: return Mips::BtnezX16; + case Mips::BteqzT8CmpiX16: return Mips::BtnezT8CmpiX16; + case Mips::BteqzT8SltuX16: return Mips::BtnezT8SltuX16; + case Mips::BteqzT8SltiuX16: return Mips::BtnezT8SltiuX16; + case Mips::BtnezT8CmpX16: return Mips::BteqzT8CmpX16; + case Mips::BtnezT8SltX16: return Mips::BteqzT8SltX16; + case Mips::BtnezT8SltiX16: return Mips::BteqzT8SltiX16; + } + llvm_unreachable("Illegal opcode!"); +} + +static void addSaveRestoreRegs(MachineInstrBuilder &MIB, + const std::vector<CalleeSavedInfo> &CSI, + unsigned Flags = 0) { + for (unsigned i = 0, e = CSI.size(); i != e; ++i) { + // Add the callee-saved register as live-in. Do not add if the register is + // RA and return address is taken, because it has already been added in + // method MipsTargetLowering::lowerRETURNADDR. + // It's killed at the spill, unless the register is RA and return address + // is taken. + unsigned Reg = CSI[e-i-1].getReg(); + switch (Reg) { + case Mips::RA: + case Mips::S0: + case Mips::S1: + MIB.addReg(Reg, Flags); + break; + case Mips::S2: + break; + default: + llvm_unreachable("unexpected mips16 callee saved register"); + + } + } +} + +// Adjust SP by FrameSize bytes. Save RA, S0, S1 +void Mips16InstrInfo::makeFrame(unsigned SP, int64_t FrameSize, + MachineBasicBlock &MBB, + MachineBasicBlock::iterator I) const { + DebugLoc DL; + MachineFunction &MF = *MBB.getParent(); + MachineFrameInfo &MFI = MF.getFrameInfo(); + const BitVector Reserved = RI.getReservedRegs(MF); + bool SaveS2 = Reserved[Mips::S2]; + MachineInstrBuilder MIB; + unsigned Opc = ((FrameSize <= 128) && !SaveS2)? Mips::Save16:Mips::SaveX16; + MIB = BuildMI(MBB, I, DL, get(Opc)); + const std::vector<CalleeSavedInfo> &CSI = MFI.getCalleeSavedInfo(); + addSaveRestoreRegs(MIB, CSI); + if (SaveS2) + MIB.addReg(Mips::S2); + if (isUInt<11>(FrameSize)) + MIB.addImm(FrameSize); + else { + int Base = 2040; // should create template function like isUInt that + // returns largest possible n bit unsigned integer + int64_t Remainder = FrameSize - Base; + MIB.addImm(Base); + if (isInt<16>(-Remainder)) + BuildAddiuSpImm(MBB, I, -Remainder); + else + adjustStackPtrBig(SP, -Remainder, MBB, I, Mips::V0, Mips::V1); + } +} + +// Adjust SP by FrameSize bytes. Restore RA, S0, S1 +void Mips16InstrInfo::restoreFrame(unsigned SP, int64_t FrameSize, + MachineBasicBlock &MBB, + MachineBasicBlock::iterator I) const { + DebugLoc DL = I != MBB.end() ? I->getDebugLoc() : DebugLoc(); + MachineFunction *MF = MBB.getParent(); + MachineFrameInfo &MFI = MF->getFrameInfo(); + const BitVector Reserved = RI.getReservedRegs(*MF); + bool SaveS2 = Reserved[Mips::S2]; + MachineInstrBuilder MIB; + unsigned Opc = ((FrameSize <= 128) && !SaveS2)? + Mips::Restore16:Mips::RestoreX16; + + if (!isUInt<11>(FrameSize)) { + unsigned Base = 2040; + int64_t Remainder = FrameSize - Base; + FrameSize = Base; // should create template function like isUInt that + // returns largest possible n bit unsigned integer + + if (isInt<16>(Remainder)) + BuildAddiuSpImm(MBB, I, Remainder); + else + adjustStackPtrBig(SP, Remainder, MBB, I, Mips::A0, Mips::A1); + } + MIB = BuildMI(MBB, I, DL, get(Opc)); + const std::vector<CalleeSavedInfo> &CSI = MFI.getCalleeSavedInfo(); + addSaveRestoreRegs(MIB, CSI, RegState::Define); + if (SaveS2) + MIB.addReg(Mips::S2, RegState::Define); + MIB.addImm(FrameSize); +} + +// Adjust SP by Amount bytes where bytes can be up to 32bit number. +// This can only be called at times that we know that there is at least one free +// register. +// This is clearly safe at prologue and epilogue. +void Mips16InstrInfo::adjustStackPtrBig(unsigned SP, int64_t Amount, + MachineBasicBlock &MBB, + MachineBasicBlock::iterator I, + unsigned Reg1, unsigned Reg2) const { + DebugLoc DL; + // + // li reg1, constant + // move reg2, sp + // add reg1, reg1, reg2 + // move sp, reg1 + // + // + MachineInstrBuilder MIB1 = BuildMI(MBB, I, DL, get(Mips::LwConstant32), Reg1); + MIB1.addImm(Amount).addImm(-1); + MachineInstrBuilder MIB2 = BuildMI(MBB, I, DL, get(Mips::MoveR3216), Reg2); + MIB2.addReg(Mips::SP, RegState::Kill); + MachineInstrBuilder MIB3 = BuildMI(MBB, I, DL, get(Mips::AdduRxRyRz16), Reg1); + MIB3.addReg(Reg1); + MIB3.addReg(Reg2, RegState::Kill); + MachineInstrBuilder MIB4 = BuildMI(MBB, I, DL, get(Mips::Move32R16), + Mips::SP); + MIB4.addReg(Reg1, RegState::Kill); +} + +void Mips16InstrInfo::adjustStackPtrBigUnrestricted( + unsigned SP, int64_t Amount, MachineBasicBlock &MBB, + MachineBasicBlock::iterator I) const { + llvm_unreachable("adjust stack pointer amount exceeded"); +} + +/// Adjust SP by Amount bytes. +void Mips16InstrInfo::adjustStackPtr(unsigned SP, int64_t Amount, + MachineBasicBlock &MBB, + MachineBasicBlock::iterator I) const { + if (Amount == 0) + return; + + if (isInt<16>(Amount)) // need to change to addiu sp, ....and isInt<16> + BuildAddiuSpImm(MBB, I, Amount); + else + adjustStackPtrBigUnrestricted(SP, Amount, MBB, I); +} + +/// This function generates the sequence of instructions needed to get the +/// result of adding register REG and immediate IMM. +unsigned Mips16InstrInfo::loadImmediate(unsigned FrameReg, int64_t Imm, + MachineBasicBlock &MBB, + MachineBasicBlock::iterator II, + const DebugLoc &DL, + unsigned &NewImm) const { + // + // given original instruction is: + // Instr rx, T[offset] where offset is too big. + // + // lo = offset & 0xFFFF + // hi = ((offset >> 16) + (lo >> 15)) & 0xFFFF; + // + // let T = temporary register + // li T, hi + // shl T, 16 + // add T, Rx, T + // + RegScavenger rs; + int32_t lo = Imm & 0xFFFF; + NewImm = lo; + int Reg =0; + int SpReg = 0; + + rs.enterBasicBlock(MBB); + rs.forward(II); + // + // We need to know which registers can be used, in the case where there + // are not enough free registers. We exclude all registers that + // are used in the instruction that we are helping. + // // Consider all allocatable registers in the register class initially + BitVector Candidates = + RI.getAllocatableSet + (*II->getParent()->getParent(), &Mips::CPU16RegsRegClass); + // Exclude all the registers being used by the instruction. + for (unsigned i = 0, e = II->getNumOperands(); i != e; ++i) { + MachineOperand &MO = II->getOperand(i); + if (MO.isReg() && MO.getReg() != 0 && !MO.isDef() && + !TargetRegisterInfo::isVirtualRegister(MO.getReg())) + Candidates.reset(MO.getReg()); + } + + // If the same register was used and defined in an instruction, then + // it will not be in the list of candidates. + // + // we need to analyze the instruction that we are helping. + // we need to know if it defines register x but register x is not + // present as an operand of the instruction. this tells + // whether the register is live before the instruction. if it's not + // then we don't need to save it in case there are no free registers. + int DefReg = 0; + for (unsigned i = 0, e = II->getNumOperands(); i != e; ++i) { + MachineOperand &MO = II->getOperand(i); + if (MO.isReg() && MO.isDef()) { + DefReg = MO.getReg(); + break; + } + } + + BitVector Available = rs.getRegsAvailable(&Mips::CPU16RegsRegClass); + Available &= Candidates; + // + // we use T0 for the first register, if we need to save something away. + // we use T1 for the second register, if we need to save something away. + // + unsigned FirstRegSaved =0, SecondRegSaved=0; + unsigned FirstRegSavedTo = 0, SecondRegSavedTo = 0; + + Reg = Available.find_first(); + + if (Reg == -1) { + Reg = Candidates.find_first(); + Candidates.reset(Reg); + if (DefReg != Reg) { + FirstRegSaved = Reg; + FirstRegSavedTo = Mips::T0; + copyPhysReg(MBB, II, DL, FirstRegSavedTo, FirstRegSaved, true); + } + } + else + Available.reset(Reg); + BuildMI(MBB, II, DL, get(Mips::LwConstant32), Reg).addImm(Imm).addImm(-1); + NewImm = 0; + if (FrameReg == Mips::SP) { + SpReg = Available.find_first(); + if (SpReg == -1) { + SpReg = Candidates.find_first(); + // Candidates.reset(SpReg); // not really needed + if (DefReg!= SpReg) { + SecondRegSaved = SpReg; + SecondRegSavedTo = Mips::T1; + } + if (SecondRegSaved) + copyPhysReg(MBB, II, DL, SecondRegSavedTo, SecondRegSaved, true); + } + else + Available.reset(SpReg); + copyPhysReg(MBB, II, DL, SpReg, Mips::SP, false); + BuildMI(MBB, II, DL, get(Mips:: AdduRxRyRz16), Reg).addReg(SpReg, RegState::Kill) + .addReg(Reg); + } + else + BuildMI(MBB, II, DL, get(Mips:: AdduRxRyRz16), Reg).addReg(FrameReg) + .addReg(Reg, RegState::Kill); + if (FirstRegSaved || SecondRegSaved) { + II = std::next(II); + if (FirstRegSaved) + copyPhysReg(MBB, II, DL, FirstRegSaved, FirstRegSavedTo, true); + if (SecondRegSaved) + copyPhysReg(MBB, II, DL, SecondRegSaved, SecondRegSavedTo, true); + } + return Reg; +} + +unsigned Mips16InstrInfo::getAnalyzableBrOpc(unsigned Opc) const { + return (Opc == Mips::BeqzRxImmX16 || Opc == Mips::BimmX16 || + Opc == Mips::Bimm16 || + Opc == Mips::Bteqz16 || Opc == Mips::Btnez16 || + Opc == Mips::BeqzRxImm16 || Opc == Mips::BnezRxImm16 || + Opc == Mips::BnezRxImmX16 || Opc == Mips::BteqzX16 || + Opc == Mips::BteqzT8CmpX16 || Opc == Mips::BteqzT8CmpiX16 || + Opc == Mips::BteqzT8SltX16 || Opc == Mips::BteqzT8SltuX16 || + Opc == Mips::BteqzT8SltiX16 || Opc == Mips::BteqzT8SltiuX16 || + Opc == Mips::BtnezX16 || Opc == Mips::BtnezT8CmpX16 || + Opc == Mips::BtnezT8CmpiX16 || Opc == Mips::BtnezT8SltX16 || + Opc == Mips::BtnezT8SltuX16 || Opc == Mips::BtnezT8SltiX16 || + Opc == Mips::BtnezT8SltiuX16 ) ? Opc : 0; +} + +void Mips16InstrInfo::ExpandRetRA16(MachineBasicBlock &MBB, + MachineBasicBlock::iterator I, + unsigned Opc) const { + BuildMI(MBB, I, I->getDebugLoc(), get(Opc)); +} + +const MCInstrDesc &Mips16InstrInfo::AddiuSpImm(int64_t Imm) const { + if (validSpImm8(Imm)) + return get(Mips::AddiuSpImm16); + else + return get(Mips::AddiuSpImmX16); +} + +void Mips16InstrInfo::BuildAddiuSpImm + (MachineBasicBlock &MBB, MachineBasicBlock::iterator I, int64_t Imm) const { + DebugLoc DL; + BuildMI(MBB, I, DL, AddiuSpImm(Imm)).addImm(Imm); +} + +const MipsInstrInfo *llvm::createMips16InstrInfo(const MipsSubtarget &STI) { + return new Mips16InstrInfo(STI); +} + +bool Mips16InstrInfo::validImmediate(unsigned Opcode, unsigned Reg, + int64_t Amount) { + switch (Opcode) { + case Mips::LbRxRyOffMemX16: + case Mips::LbuRxRyOffMemX16: + case Mips::LhRxRyOffMemX16: + case Mips::LhuRxRyOffMemX16: + case Mips::SbRxRyOffMemX16: + case Mips::ShRxRyOffMemX16: + case Mips::LwRxRyOffMemX16: + case Mips::SwRxRyOffMemX16: + case Mips::SwRxSpImmX16: + case Mips::LwRxSpImmX16: + return isInt<16>(Amount); + case Mips::AddiuRxRyOffMemX16: + if ((Reg == Mips::PC) || (Reg == Mips::SP)) + return isInt<16>(Amount); + return isInt<15>(Amount); + } + llvm_unreachable("unexpected Opcode in validImmediate"); +} |