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Diffstat (limited to 'contrib/llvm/lib/Target/SystemZ/SystemZInstrInfo.cpp')
| -rw-r--r-- | contrib/llvm/lib/Target/SystemZ/SystemZInstrInfo.cpp | 444 |
1 files changed, 444 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/SystemZ/SystemZInstrInfo.cpp b/contrib/llvm/lib/Target/SystemZ/SystemZInstrInfo.cpp new file mode 100644 index 0000000..0718c83 --- /dev/null +++ b/contrib/llvm/lib/Target/SystemZ/SystemZInstrInfo.cpp @@ -0,0 +1,444 @@ +//===-- SystemZInstrInfo.cpp - SystemZ instruction information ------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file contains the SystemZ implementation of the TargetInstrInfo class. +// +//===----------------------------------------------------------------------===// + +#include "SystemZInstrInfo.h" +#include "SystemZInstrBuilder.h" + +#define GET_INSTRINFO_CTOR +#define GET_INSTRMAP_INFO +#include "SystemZGenInstrInfo.inc" + +using namespace llvm; + +SystemZInstrInfo::SystemZInstrInfo(SystemZTargetMachine &tm) + : SystemZGenInstrInfo(SystemZ::ADJCALLSTACKDOWN, SystemZ::ADJCALLSTACKUP), + RI(tm, *this) { +} + +// MI is a 128-bit load or store. Split it into two 64-bit loads or stores, +// each having the opcode given by NewOpcode. +void SystemZInstrInfo::splitMove(MachineBasicBlock::iterator MI, + unsigned NewOpcode) const { + MachineBasicBlock *MBB = MI->getParent(); + MachineFunction &MF = *MBB->getParent(); + + // Get two load or store instructions. Use the original instruction for one + // of them (arbitarily the second here) and create a clone for the other. + MachineInstr *EarlierMI = MF.CloneMachineInstr(MI); + MBB->insert(MI, EarlierMI); + + // Set up the two 64-bit registers. + MachineOperand &HighRegOp = EarlierMI->getOperand(0); + MachineOperand &LowRegOp = MI->getOperand(0); + HighRegOp.setReg(RI.getSubReg(HighRegOp.getReg(), SystemZ::subreg_high)); + LowRegOp.setReg(RI.getSubReg(LowRegOp.getReg(), SystemZ::subreg_low)); + + // The address in the first (high) instruction is already correct. + // Adjust the offset in the second (low) instruction. + MachineOperand &HighOffsetOp = EarlierMI->getOperand(2); + MachineOperand &LowOffsetOp = MI->getOperand(2); + LowOffsetOp.setImm(LowOffsetOp.getImm() + 8); + + // Set the opcodes. + unsigned HighOpcode = getOpcodeForOffset(NewOpcode, HighOffsetOp.getImm()); + unsigned LowOpcode = getOpcodeForOffset(NewOpcode, LowOffsetOp.getImm()); + assert(HighOpcode && LowOpcode && "Both offsets should be in range"); + + EarlierMI->setDesc(get(HighOpcode)); + MI->setDesc(get(LowOpcode)); +} + +// Split ADJDYNALLOC instruction MI. +void SystemZInstrInfo::splitAdjDynAlloc(MachineBasicBlock::iterator MI) const { + MachineBasicBlock *MBB = MI->getParent(); + MachineFunction &MF = *MBB->getParent(); + MachineFrameInfo *MFFrame = MF.getFrameInfo(); + MachineOperand &OffsetMO = MI->getOperand(2); + + uint64_t Offset = (MFFrame->getMaxCallFrameSize() + + SystemZMC::CallFrameSize + + OffsetMO.getImm()); + unsigned NewOpcode = getOpcodeForOffset(SystemZ::LA, Offset); + assert(NewOpcode && "No support for huge argument lists yet"); + MI->setDesc(get(NewOpcode)); + OffsetMO.setImm(Offset); +} + +// If MI is a simple load or store for a frame object, return the register +// it loads or stores and set FrameIndex to the index of the frame object. +// Return 0 otherwise. +// +// Flag is SimpleBDXLoad for loads and SimpleBDXStore for stores. +static int isSimpleMove(const MachineInstr *MI, int &FrameIndex, int Flag) { + const MCInstrDesc &MCID = MI->getDesc(); + if ((MCID.TSFlags & Flag) && + MI->getOperand(1).isFI() && + MI->getOperand(2).getImm() == 0 && + MI->getOperand(3).getReg() == 0) { + FrameIndex = MI->getOperand(1).getIndex(); + return MI->getOperand(0).getReg(); + } + return 0; +} + +unsigned SystemZInstrInfo::isLoadFromStackSlot(const MachineInstr *MI, + int &FrameIndex) const { + return isSimpleMove(MI, FrameIndex, SystemZII::SimpleBDXLoad); +} + +unsigned SystemZInstrInfo::isStoreToStackSlot(const MachineInstr *MI, + int &FrameIndex) const { + return isSimpleMove(MI, FrameIndex, SystemZII::SimpleBDXStore); +} + +bool SystemZInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB, + MachineBasicBlock *&TBB, + MachineBasicBlock *&FBB, + SmallVectorImpl<MachineOperand> &Cond, + bool AllowModify) const { + // Most of the code and comments here are boilerplate. + + // Start from the bottom of the block and work up, examining the + // terminator instructions. + MachineBasicBlock::iterator I = MBB.end(); + while (I != MBB.begin()) { + --I; + if (I->isDebugValue()) + continue; + + // Working from the bottom, when we see a non-terminator instruction, we're + // done. + if (!isUnpredicatedTerminator(I)) + break; + + // A terminator that isn't a branch can't easily be handled by this + // analysis. + unsigned ThisCond; + const MachineOperand *ThisTarget; + if (!isBranch(I, ThisCond, ThisTarget)) + return true; + + // Can't handle indirect branches. + if (!ThisTarget->isMBB()) + return true; + + if (ThisCond == SystemZ::CCMASK_ANY) { + // Handle unconditional branches. + if (!AllowModify) { + TBB = ThisTarget->getMBB(); + continue; + } + + // If the block has any instructions after a JMP, delete them. + while (llvm::next(I) != MBB.end()) + llvm::next(I)->eraseFromParent(); + + Cond.clear(); + FBB = 0; + + // Delete the JMP if it's equivalent to a fall-through. + if (MBB.isLayoutSuccessor(ThisTarget->getMBB())) { + TBB = 0; + I->eraseFromParent(); + I = MBB.end(); + continue; + } + + // TBB is used to indicate the unconditinal destination. + TBB = ThisTarget->getMBB(); + continue; + } + + // Working from the bottom, handle the first conditional branch. + if (Cond.empty()) { + // FIXME: add X86-style branch swap + FBB = TBB; + TBB = ThisTarget->getMBB(); + Cond.push_back(MachineOperand::CreateImm(ThisCond)); + continue; + } + + // Handle subsequent conditional branches. + assert(Cond.size() == 1); + assert(TBB); + + // Only handle the case where all conditional branches branch to the same + // destination. + if (TBB != ThisTarget->getMBB()) + return true; + + // If the conditions are the same, we can leave them alone. + unsigned OldCond = Cond[0].getImm(); + if (OldCond == ThisCond) + continue; + + // FIXME: Try combining conditions like X86 does. Should be easy on Z! + } + + return false; +} + +unsigned SystemZInstrInfo::RemoveBranch(MachineBasicBlock &MBB) const { + // Most of the code and comments here are boilerplate. + MachineBasicBlock::iterator I = MBB.end(); + unsigned Count = 0; + + while (I != MBB.begin()) { + --I; + if (I->isDebugValue()) + continue; + unsigned Cond; + const MachineOperand *Target; + if (!isBranch(I, Cond, Target)) + break; + if (!Target->isMBB()) + break; + // Remove the branch. + I->eraseFromParent(); + I = MBB.end(); + ++Count; + } + + return Count; +} + +unsigned +SystemZInstrInfo::InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB, + MachineBasicBlock *FBB, + const SmallVectorImpl<MachineOperand> &Cond, + DebugLoc DL) const { + // In this function we output 32-bit branches, which should always + // have enough range. They can be shortened and relaxed by later code + // in the pipeline, if desired. + + // Shouldn't be a fall through. + assert(TBB && "InsertBranch must not be told to insert a fallthrough"); + assert((Cond.size() == 1 || Cond.size() == 0) && + "SystemZ branch conditions have one component!"); + + if (Cond.empty()) { + // Unconditional branch? + assert(!FBB && "Unconditional branch with multiple successors!"); + BuildMI(&MBB, DL, get(SystemZ::JG)).addMBB(TBB); + return 1; + } + + // Conditional branch. + unsigned Count = 0; + unsigned CC = Cond[0].getImm(); + BuildMI(&MBB, DL, get(SystemZ::BRCL)).addImm(CC).addMBB(TBB); + ++Count; + + if (FBB) { + // Two-way Conditional branch. Insert the second branch. + BuildMI(&MBB, DL, get(SystemZ::JG)).addMBB(FBB); + ++Count; + } + return Count; +} + +void +SystemZInstrInfo::copyPhysReg(MachineBasicBlock &MBB, + MachineBasicBlock::iterator MBBI, DebugLoc DL, + unsigned DestReg, unsigned SrcReg, + bool KillSrc) const { + // Split 128-bit GPR moves into two 64-bit moves. This handles ADDR128 too. + if (SystemZ::GR128BitRegClass.contains(DestReg, SrcReg)) { + copyPhysReg(MBB, MBBI, DL, RI.getSubReg(DestReg, SystemZ::subreg_high), + RI.getSubReg(SrcReg, SystemZ::subreg_high), KillSrc); + copyPhysReg(MBB, MBBI, DL, RI.getSubReg(DestReg, SystemZ::subreg_low), + RI.getSubReg(SrcReg, SystemZ::subreg_low), KillSrc); + return; + } + + // Everything else needs only one instruction. + unsigned Opcode; + if (SystemZ::GR32BitRegClass.contains(DestReg, SrcReg)) + Opcode = SystemZ::LR; + else if (SystemZ::GR64BitRegClass.contains(DestReg, SrcReg)) + Opcode = SystemZ::LGR; + else if (SystemZ::FP32BitRegClass.contains(DestReg, SrcReg)) + Opcode = SystemZ::LER; + else if (SystemZ::FP64BitRegClass.contains(DestReg, SrcReg)) + Opcode = SystemZ::LDR; + else if (SystemZ::FP128BitRegClass.contains(DestReg, SrcReg)) + Opcode = SystemZ::LXR; + else + llvm_unreachable("Impossible reg-to-reg copy"); + + BuildMI(MBB, MBBI, DL, get(Opcode), DestReg) + .addReg(SrcReg, getKillRegState(KillSrc)); +} + +void +SystemZInstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB, + MachineBasicBlock::iterator MBBI, + unsigned SrcReg, bool isKill, + int FrameIdx, + const TargetRegisterClass *RC, + const TargetRegisterInfo *TRI) const { + DebugLoc DL = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc(); + + // Callers may expect a single instruction, so keep 128-bit moves + // together for now and lower them after register allocation. + unsigned LoadOpcode, StoreOpcode; + getLoadStoreOpcodes(RC, LoadOpcode, StoreOpcode); + addFrameReference(BuildMI(MBB, MBBI, DL, get(StoreOpcode)) + .addReg(SrcReg, getKillRegState(isKill)), FrameIdx); +} + +void +SystemZInstrInfo::loadRegFromStackSlot(MachineBasicBlock &MBB, + MachineBasicBlock::iterator MBBI, + unsigned DestReg, int FrameIdx, + const TargetRegisterClass *RC, + const TargetRegisterInfo *TRI) const { + DebugLoc DL = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc(); + + // Callers may expect a single instruction, so keep 128-bit moves + // together for now and lower them after register allocation. + unsigned LoadOpcode, StoreOpcode; + getLoadStoreOpcodes(RC, LoadOpcode, StoreOpcode); + addFrameReference(BuildMI(MBB, MBBI, DL, get(LoadOpcode), DestReg), + FrameIdx); +} + +bool +SystemZInstrInfo::expandPostRAPseudo(MachineBasicBlock::iterator MI) const { + switch (MI->getOpcode()) { + case SystemZ::L128: + splitMove(MI, SystemZ::LG); + return true; + + case SystemZ::ST128: + splitMove(MI, SystemZ::STG); + return true; + + case SystemZ::LX: + splitMove(MI, SystemZ::LD); + return true; + + case SystemZ::STX: + splitMove(MI, SystemZ::STD); + return true; + + case SystemZ::ADJDYNALLOC: + splitAdjDynAlloc(MI); + return true; + + default: + return false; + } +} + +bool SystemZInstrInfo:: +ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const { + assert(Cond.size() == 1 && "Invalid branch condition!"); + Cond[0].setImm(Cond[0].getImm() ^ SystemZ::CCMASK_ANY); + return false; +} + +bool SystemZInstrInfo::isBranch(const MachineInstr *MI, unsigned &Cond, + const MachineOperand *&Target) const { + switch (MI->getOpcode()) { + case SystemZ::BR: + case SystemZ::J: + case SystemZ::JG: + Cond = SystemZ::CCMASK_ANY; + Target = &MI->getOperand(0); + return true; + + case SystemZ::BRC: + case SystemZ::BRCL: + Cond = MI->getOperand(0).getImm(); + Target = &MI->getOperand(1); + return true; + + default: + assert(!MI->getDesc().isBranch() && "Unknown branch opcode"); + return false; + } +} + +void SystemZInstrInfo::getLoadStoreOpcodes(const TargetRegisterClass *RC, + unsigned &LoadOpcode, + unsigned &StoreOpcode) const { + if (RC == &SystemZ::GR32BitRegClass || RC == &SystemZ::ADDR32BitRegClass) { + LoadOpcode = SystemZ::L; + StoreOpcode = SystemZ::ST32; + } else if (RC == &SystemZ::GR64BitRegClass || + RC == &SystemZ::ADDR64BitRegClass) { + LoadOpcode = SystemZ::LG; + StoreOpcode = SystemZ::STG; + } else if (RC == &SystemZ::GR128BitRegClass || + RC == &SystemZ::ADDR128BitRegClass) { + LoadOpcode = SystemZ::L128; + StoreOpcode = SystemZ::ST128; + } else if (RC == &SystemZ::FP32BitRegClass) { + LoadOpcode = SystemZ::LE; + StoreOpcode = SystemZ::STE; + } else if (RC == &SystemZ::FP64BitRegClass) { + LoadOpcode = SystemZ::LD; + StoreOpcode = SystemZ::STD; + } else if (RC == &SystemZ::FP128BitRegClass) { + LoadOpcode = SystemZ::LX; + StoreOpcode = SystemZ::STX; + } else + llvm_unreachable("Unsupported regclass to load or store"); +} + +unsigned SystemZInstrInfo::getOpcodeForOffset(unsigned Opcode, + int64_t Offset) const { + const MCInstrDesc &MCID = get(Opcode); + int64_t Offset2 = (MCID.TSFlags & SystemZII::Is128Bit ? Offset + 8 : Offset); + if (isUInt<12>(Offset) && isUInt<12>(Offset2)) { + // Get the instruction to use for unsigned 12-bit displacements. + int Disp12Opcode = SystemZ::getDisp12Opcode(Opcode); + if (Disp12Opcode >= 0) + return Disp12Opcode; + + // All address-related instructions can use unsigned 12-bit + // displacements. + return Opcode; + } + if (isInt<20>(Offset) && isInt<20>(Offset2)) { + // Get the instruction to use for signed 20-bit displacements. + int Disp20Opcode = SystemZ::getDisp20Opcode(Opcode); + if (Disp20Opcode >= 0) + return Disp20Opcode; + + // Check whether Opcode allows signed 20-bit displacements. + if (MCID.TSFlags & SystemZII::Has20BitOffset) + return Opcode; + } + return 0; +} + +void SystemZInstrInfo::loadImmediate(MachineBasicBlock &MBB, + MachineBasicBlock::iterator MBBI, + unsigned Reg, uint64_t Value) const { + DebugLoc DL = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc(); + unsigned Opcode; + if (isInt<16>(Value)) + Opcode = SystemZ::LGHI; + else if (SystemZ::isImmLL(Value)) + Opcode = SystemZ::LLILL; + else if (SystemZ::isImmLH(Value)) { + Opcode = SystemZ::LLILH; + Value >>= 16; + } else { + assert(isInt<32>(Value) && "Huge values not handled yet"); + Opcode = SystemZ::LGFI; + } + BuildMI(MBB, MBBI, DL, get(Opcode), Reg).addImm(Value); +} |
