#include "ARM.h"
#include "ARMBaseInstrInfo.h"
#include "ARMBaseRegisterInfo.h"
+#include "ARMISelLowering.h"
#include "ARMMachineFunctionInfo.h"
#include "ARMSubtarget.h"
#include "MCTargetDesc/ARMAddressingModes.h"
+#include "Thumb1RegisterInfo.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallPtrSet.h"
const TargetInstrInfo *TII;
const TargetRegisterInfo *TRI;
const ARMSubtarget *STI;
+ const TargetLowering *TL;
ARMFunctionInfo *AFI;
RegScavenger *RS;
bool isThumb1, isThumb2;
void findUsesOfImpDef(SmallVectorImpl<MachineOperand *> &UsesOfImpDefs,
const MemOpQueue &MemOps, unsigned DefReg,
unsigned RangeBegin, unsigned RangeEnd);
-
+ void UpdateBaseRegUses(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MBBI,
+ DebugLoc dl, unsigned Base, unsigned WordOffset,
+ ARMCC::CondCodes Pred, unsigned PredReg);
bool MergeOps(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
int Offset, unsigned Base, bool BaseKill, int Opcode,
ARMCC::CondCodes Pred, unsigned PredReg, unsigned Scratch,
ARMCC::CondCodes Pred, unsigned PredReg,
unsigned Scratch, MemOpQueue &MemOps,
SmallVectorImpl<MachineBasicBlock::iterator> &Merges);
-
void AdvanceRS(MachineBasicBlock &MBB, MemOpQueue &MemOps);
bool FixInvalidRegPairOp(MachineBasicBlock &MBB,
MachineBasicBlock::iterator &MBBI);
case ARM_AM::db: return ARM::STMDB;
case ARM_AM::ib: return ARM::STMIB;
}
+ case ARM::tLDRi:
+ // tLDMIA is writeback-only - unless the base register is in the input
+ // reglist.
+ ++NumLDMGened;
+ switch (Mode) {
+ default: llvm_unreachable("Unhandled submode!");
+ case ARM_AM::ia: return ARM::tLDMIA;
+ }
+ case ARM::tSTRi:
+ // There is no non-writeback tSTMIA either.
+ ++NumSTMGened;
+ switch (Mode) {
+ default: llvm_unreachable("Unhandled submode!");
+ case ARM_AM::ia: return ARM::tSTMIA_UPD;
+ }
case ARM::t2LDRi8:
case ARM::t2LDRi12:
++NumLDMGened;
case ARM::LDMIA_UPD:
case ARM::STMIA:
case ARM::STMIA_UPD:
+ case ARM::tLDMIA:
+ case ARM::tLDMIA_UPD:
+ case ARM::tSTMIA_UPD:
case ARM::t2LDMIA_RET:
case ARM::t2LDMIA:
case ARM::t2LDMIA_UPD:
} // end namespace ARM_AM
} // end namespace llvm
+static bool isT1i32Load(unsigned Opc) {
+ return Opc == ARM::tLDRi;
+}
+
static bool isT2i32Load(unsigned Opc) {
return Opc == ARM::t2LDRi12 || Opc == ARM::t2LDRi8;
}
static bool isi32Load(unsigned Opc) {
- return Opc == ARM::LDRi12 || isT2i32Load(Opc);
+ return Opc == ARM::LDRi12 || isT1i32Load(Opc) || isT2i32Load(Opc) ;
+}
+
+static bool isT1i32Store(unsigned Opc) {
+ return Opc == ARM::tSTRi;
}
static bool isT2i32Store(unsigned Opc) {
}
static bool isi32Store(unsigned Opc) {
- return Opc == ARM::STRi12 || isT2i32Store(Opc);
+ return Opc == ARM::STRi12 || isT1i32Store(Opc) || isT2i32Store(Opc);
+}
+
+static unsigned getImmScale(unsigned Opc) {
+ switch (Opc) {
+ default: llvm_unreachable("Unhandled opcode!");
+ case ARM::tLDRi:
+ case ARM::tSTRi:
+ return 1;
+ case ARM::tLDRHi:
+ case ARM::tSTRHi:
+ return 2;
+ case ARM::tLDRBi:
+ case ARM::tSTRBi:
+ return 4;
+ }
+}
+
+/// Update future uses of the base register with the offset introduced
+/// due to writeback. This function only works on Thumb1.
+void
+ARMLoadStoreOpt::UpdateBaseRegUses(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MBBI,
+ DebugLoc dl, unsigned Base,
+ unsigned WordOffset,
+ ARMCC::CondCodes Pred, unsigned PredReg) {
+ assert(isThumb1 && "Can only update base register uses for Thumb1!");
+
+ // Start updating any instructions with immediate offsets. Insert a sub before
+ // the first non-updateable instruction (if any).
+ for (; MBBI != MBB.end(); ++MBBI) {
+ if (MBBI->readsRegister(Base)) {
+ unsigned Opc = MBBI->getOpcode();
+ int Offset;
+ bool InsertSub = false;
+
+ if (Opc == ARM::tLDRi || Opc == ARM::tSTRi ||
+ Opc == ARM::tLDRHi || Opc == ARM::tSTRHi ||
+ Opc == ARM::tLDRBi || Opc == ARM::tSTRBi) {
+ // Loads and stores with immediate offsets can be updated, but only if
+ // the new offset isn't negative.
+ // The MachineOperand containing the offset immediate is the last one
+ // before predicates.
+ MachineOperand &MO =
+ MBBI->getOperand(MBBI->getDesc().getNumOperands() - 3);
+ // The offsets are scaled by 1, 2 or 4 depending on the Opcode
+ Offset = MO.getImm() - WordOffset * getImmScale(Opc);
+ if (Offset >= 0)
+ MO.setImm(Offset);
+ else
+ InsertSub = true;
+
+ } else if (Opc == ARM::tSUBi8 || Opc == ARM::tADDi8) {
+ // SUB/ADD using this register. Merge it with the update.
+ // If the merged offset is too large, insert a new sub instead.
+ MachineOperand &MO =
+ MBBI->getOperand(MBBI->getDesc().getNumOperands() - 3);
+ Offset = (Opc == ARM::tSUBi8) ?
+ MO.getImm() + WordOffset * 4 :
+ MO.getImm() - WordOffset * 4 ;
+ if (TL->isLegalAddImmediate(Offset)) {
+ MO.setImm(Offset);
+ // The base register has now been reset, so exit early.
+ return;
+ } else {
+ InsertSub = true;
+ }
+
+ } else {
+ // Can't update the instruction.
+ InsertSub = true;
+ }
+
+ if (InsertSub) {
+ // An instruction above couldn't be updated, so insert a sub.
+ AddDefaultT1CC(BuildMI(MBB, MBBI, dl, TII->get(ARM::tSUBi8), Base))
+ .addReg(Base, getKillRegState(true)).addImm(WordOffset * 4)
+ .addImm(Pred).addReg(PredReg);
+ return;
+ }
+ }
+
+ if (MBBI->killsRegister(Base))
+ // Register got killed. Stop updating.
+ return;
+ }
+
+ // The end of the block was reached. This means register liveness escapes the
+ // block, and it's necessary to insert a sub before the last instruction.
+ if (MBB.succ_size() > 0)
+ // But only insert the SUB if there is actually a successor block.
+ // FIXME: Check more carefully if register is live at this point, e.g. by
+ // also examining the successor block's register liveness information.
+ AddDefaultT1CC(BuildMI(MBB, --MBBI, dl, TII->get(ARM::tSUBi8), Base))
+ .addReg(Base, getKillRegState(true)).addImm(WordOffset * 4)
+ .addImm(Pred).addReg(PredReg);
}
/// MergeOps - Create and insert a LDM or STM with Base as base register and
return false;
ARM_AM::AMSubMode Mode = ARM_AM::ia;
- // VFP and Thumb2 do not support IB or DA modes.
+ // VFP and Thumb2 do not support IB or DA modes. Thumb1 only supports IA.
bool isNotVFP = isi32Load(Opcode) || isi32Store(Opcode);
- bool haveIBAndDA = isNotVFP && !isThumb2;
+ bool haveIBAndDA = isNotVFP && !isThumb2 && !isThumb1;
+
if (Offset == 4 && haveIBAndDA) {
Mode = ARM_AM::ib;
} else if (Offset == -4 * (int)NumRegs + 4 && haveIBAndDA) {
Mode = ARM_AM::da;
- } else if (Offset == -4 * (int)NumRegs && isNotVFP) {
+ } else if (Offset == -4 * (int)NumRegs && isNotVFP && !isThumb1) {
// VLDM/VSTM do not support DB mode without also updating the base reg.
Mode = ARM_AM::db;
} else if (Offset != 0) {
if (NewBase == 0)
return false;
}
- int BaseOpc = !isThumb2 ? ARM::ADDri : ARM::t2ADDri;
+
+ int BaseOpc =
+ isThumb2 ? ARM::t2ADDri :
+ isThumb1 ? ARM::tADDi8 : ARM::ADDri;
+
if (Offset < 0) {
- BaseOpc = !isThumb2 ? ARM::SUBri : ARM::t2SUBri;
+ BaseOpc =
+ isThumb2 ? ARM::t2SUBri :
+ isThumb1 ? ARM::tSUBi8 : ARM::SUBri;
Offset = - Offset;
}
- int ImmedOffset = isThumb2
- ? ARM_AM::getT2SOImmVal(Offset) : ARM_AM::getSOImmVal(Offset);
- if (ImmedOffset == -1)
- // FIXME: Try t2ADDri12 or t2SUBri12?
- return false; // Probably not worth it then.
-
- BuildMI(MBB, MBBI, dl, TII->get(BaseOpc), NewBase)
- .addReg(Base, getKillRegState(BaseKill)).addImm(Offset)
- .addImm(Pred).addReg(PredReg).addReg(0);
+
+ if (!TL->isLegalAddImmediate(Offset))
+ // FIXME: Try add with register operand?
+ return false; // Probably not worth it then.
+
+ if (isThumb1) {
+ if (Base != NewBase) {
+ // Need to insert a MOV to the new base first.
+ // FIXME: If the immediate fits in 3 bits, use ADD instead.
+ BuildMI(MBB, MBBI, dl, TII->get(ARM::tMOVr), NewBase)
+ .addReg(Base, getKillRegState(BaseKill))
+ .addImm(Pred).addReg(PredReg);
+ }
+ AddDefaultT1CC(BuildMI(MBB, MBBI, dl, TII->get(BaseOpc), NewBase))
+ .addReg(NewBase, getKillRegState(true)).addImm(Offset)
+ .addImm(Pred).addReg(PredReg);
+ } else {
+ BuildMI(MBB, MBBI, dl, TII->get(BaseOpc), NewBase)
+ .addReg(Base, getKillRegState(BaseKill)).addImm(Offset)
+ .addImm(Pred).addReg(PredReg).addReg(0);
+ }
+
Base = NewBase;
BaseKill = true; // New base is always killed straight away.
}
bool isDef = (isi32Load(Opcode) || Opcode == ARM::VLDRS ||
Opcode == ARM::VLDRD);
+
+ // Get LS multiple opcode. Note that for Thumb1 this might be an opcode with
+ // base register writeback.
Opcode = getLoadStoreMultipleOpcode(Opcode, Mode);
if (!Opcode) return false;
- MachineInstrBuilder MIB = BuildMI(MBB, MBBI, dl, TII->get(Opcode))
- .addReg(Base, getKillRegState(BaseKill))
- .addImm(Pred).addReg(PredReg);
+
+ bool Writeback = isThumb1; // Thumb1 LDM/STM have base reg writeback.
+
+ // Exception: If the base register is in the input reglist, Thumb1 LDM is
+ // non-writeback. Check for this.
+ if (Opcode == ARM::tLDRi && isThumb1)
+ for (unsigned I = 0; I < NumRegs; ++I)
+ if (Base == Regs[I].first) {
+ Writeback = false;
+ break;
+ }
+
+ MachineInstrBuilder MIB;
+
+ if (Writeback) {
+ if (Opcode == ARM::tLDMIA)
+ // Update tLDMIA with writeback if necessary.
+ Opcode = ARM::tLDMIA_UPD;
+
+ // The base isn't dead after a merged instruction with writeback. Update
+ // future uses of the base with the added offset (if possible), or reset
+ // the base register as necessary.
+ if (!BaseKill)
+ UpdateBaseRegUses(MBB, MBBI, dl, Base, NumRegs, Pred, PredReg);
+
+ MIB = BuildMI(MBB, MBBI, dl, TII->get(Opcode));
+
+ // Thumb1: we might need to set base writeback when building the MI.
+ MIB.addReg(Base, getDefRegState(true))
+ .addReg(Base, getKillRegState(BaseKill));
+ } else {
+ // No writeback, simply build the MachineInstr.
+ MIB = BuildMI(MBB, MBBI, dl, TII->get(Opcode));
+ MIB.addReg(Base, getKillRegState(BaseKill));
+ }
+
+ MIB.addImm(Pred).addReg(PredReg);
+
for (unsigned i = 0; i != NumRegs; ++i)
MIB = MIB.addReg(Regs[i].first, getDefRegState(isDef)
| getKillRegState(Regs[i].second));
bool CheckCPSRDef = false;
switch (MI->getOpcode()) {
default: return false;
+ case ARM::tSUBi8:
case ARM::t2SUBri:
case ARM::SUBri:
CheckCPSRDef = true;
if (Bytes == 0 || (Limit && Bytes >= Limit))
return false;
- unsigned Scale = (MI->getOpcode() == ARM::tSUBspi) ? 4 : 1; // FIXME
+ unsigned Scale = (MI->getOpcode() == ARM::tSUBspi ||
+ MI->getOpcode() == ARM::tSUBi8) ? 4 : 1; // FIXME
if (!(MI->getOperand(0).getReg() == Base &&
MI->getOperand(1).getReg() == Base &&
- (MI->getOperand(2).getImm()*Scale) == Bytes &&
+ (MI->getOperand(2).getImm() * Scale) == Bytes &&
getInstrPredicate(MI, MyPredReg) == Pred &&
MyPredReg == PredReg))
return false;
bool CheckCPSRDef = false;
switch (MI->getOpcode()) {
default: return false;
+ case ARM::tADDi8:
case ARM::t2ADDri:
case ARM::ADDri:
CheckCPSRDef = true;
// Make sure the offset fits in 8 bits.
return false;
- unsigned Scale = (MI->getOpcode() == ARM::tADDspi) ? 4 : 1; // FIXME
+ unsigned Scale = (MI->getOpcode() == ARM::tADDspi ||
+ MI->getOpcode() == ARM::tADDi8) ? 4 : 1; // FIXME
if (!(MI->getOperand(0).getReg() == Base &&
MI->getOperand(1).getReg() == Base &&
- (MI->getOperand(2).getImm()*Scale) == Bytes &&
+ (MI->getOperand(2).getImm() * Scale) == Bytes &&
getInstrPredicate(MI, MyPredReg) == Pred &&
MyPredReg == PredReg))
return false;
default: return 0;
case ARM::LDRi12:
case ARM::STRi12:
+ case ARM::tLDRi:
+ case ARM::tSTRi:
case ARM::t2LDRi8:
case ARM::t2LDRi12:
case ARM::t2STRi8:
case ARM::STMDA:
case ARM::STMDB:
case ARM::STMIB:
+ case ARM::tLDMIA:
+ case ARM::tLDMIA_UPD:
+ case ARM::tSTMIA_UPD:
case ARM::t2LDMIA:
case ARM::t2LDMDB:
case ARM::t2STMIA:
MachineBasicBlock::iterator MBBI,
bool &Advance,
MachineBasicBlock::iterator &I) {
+ // Thumb1 is already using updating loads/stores.
+ if (isThumb1) return false;
+
MachineInstr *MI = MBBI;
unsigned Base = MI->getOperand(0).getReg();
bool BaseKill = MI->getOperand(0).isKill();
const TargetInstrInfo *TII,
bool &Advance,
MachineBasicBlock::iterator &I) {
+ // Thumb1 doesn't have updating LDR/STR.
+ // FIXME: Use LDM/STM with single register instead.
+ if (isThumb1) return false;
+
MachineInstr *MI = MBBI;
unsigned Base = MI->getOperand(1).getReg();
bool BaseKill = MI->getOperand(1).isKill();
return MI->getOperand(1).isReg();
case ARM::LDRi12:
case ARM::STRi12:
+ case ARM::tLDRi:
+ case ARM::tSTRi:
case ARM::t2LDRi8:
case ARM::t2LDRi12:
case ARM::t2STRi8:
Opcode == ARM::LDRi12 || Opcode == ARM::STRi12)
return OffField;
+ // Thumb1 immediate offsets are scaled by 4
+ if (Opcode == ARM::tLDRi || Opcode == ARM::tSTRi)
+ return OffField * 4;
+
int Offset = isAM3 ? ARM_AM::getAM3Offset(OffField)
: ARM_AM::getAM5Offset(OffField) * 4;
if (isAM3) {
// Try to find a free register to use as a new base in case it's needed.
// First advance to the instruction just before the start of the chain.
AdvanceRS(MBB, MemOps);
+
// Find a scratch register.
- unsigned Scratch = RS->FindUnusedReg(&ARM::GPRRegClass);
+ unsigned Scratch =
+ RS->FindUnusedReg(isThumb1 ? &ARM::tGPRRegClass : &ARM::GPRRegClass);
+
// Process the load / store instructions.
RS->forward(std::prev(MBBI));
/// =>
/// ldmfd sp!, {..., pc}
bool ARMLoadStoreOpt::MergeReturnIntoLDM(MachineBasicBlock &MBB) {
+ // Thumb1 LDM doesn't allow high registers.
+ if (isThumb1) return false;
if (MBB.empty()) return false;
MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr();
bool ARMLoadStoreOpt::runOnMachineFunction(MachineFunction &Fn) {
const TargetMachine &TM = Fn.getTarget();
+ TL = TM.getTargetLowering();
AFI = Fn.getInfo<ARMFunctionInfo>();
TII = TM.getInstrInfo();
TRI = TM.getRegisterInfo();
isThumb2 = AFI->isThumb2Function();
isThumb1 = AFI->isThumbFunction() && !isThumb2;
- // Don't do anything in this pass with Thumb1 for now.
- if (isThumb1) return false;
-
bool Modified = false;
for (MachineFunction::iterator MFI = Fn.begin(), E = Fn.end(); MFI != E;
++MFI) {
MRI = &Fn.getRegInfo();
MF = &Fn;
- ARMFunctionInfo *AFI = Fn.getInfo<ARMFunctionInfo>();
- bool isThumb1 = AFI->isThumbFunction() && !AFI->isThumb2Function();
- // Don't do anything in this pass with Thumb1 for now.
- if (isThumb1) return false;
-
bool Modified = false;
for (MachineFunction::iterator MFI = Fn.begin(), E = Fn.end(); MFI != E;
++MFI)
projects / oota-llvm.git / commitdiff