//===----------------------------------------------------------------------===//
#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/ADT/SmallVector.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineMemOperand.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/PseudoSourceValue.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
using namespace llvm;
// commuteInstruction - The default implementation of this method just exchanges
-// operand 1 and 2.
+// the two operands returned by findCommutedOpIndices.
MachineInstr *TargetInstrInfoImpl::commuteInstruction(MachineInstr *MI,
bool NewMI) const {
- assert(MI->getOperand(1).isRegister() && MI->getOperand(2).isRegister() &&
+ const TargetInstrDesc &TID = MI->getDesc();
+ bool HasDef = TID.getNumDefs();
+ if (HasDef && !MI->getOperand(0).isReg())
+ // No idea how to commute this instruction. Target should implement its own.
+ return 0;
+ unsigned Idx1, Idx2;
+ if (!findCommutedOpIndices(MI, Idx1, Idx2)) {
+ std::string msg;
+ raw_string_ostream Msg(msg);
+ Msg << "Don't know how to commute: " << *MI;
+ report_fatal_error(Msg.str());
+ }
+
+ assert(MI->getOperand(Idx1).isReg() && MI->getOperand(Idx2).isReg() &&
"This only knows how to commute register operands so far");
- unsigned Reg1 = MI->getOperand(1).getReg();
- unsigned Reg2 = MI->getOperand(2).getReg();
- bool Reg1IsKill = MI->getOperand(1).isKill();
- bool Reg2IsKill = MI->getOperand(2).isKill();
+ unsigned Reg1 = MI->getOperand(Idx1).getReg();
+ unsigned Reg2 = MI->getOperand(Idx2).getReg();
+ bool Reg1IsKill = MI->getOperand(Idx1).isKill();
+ bool Reg2IsKill = MI->getOperand(Idx2).isKill();
bool ChangeReg0 = false;
- if (MI->getOperand(0).getReg() == Reg1) {
+ if (HasDef && MI->getOperand(0).getReg() == Reg1) {
// Must be two address instruction!
assert(MI->getDesc().getOperandConstraint(0, TOI::TIED_TO) &&
"Expecting a two-address instruction!");
if (NewMI) {
// Create a new instruction.
- unsigned Reg0 = ChangeReg0 ? Reg2 : MI->getOperand(0).getReg();
- bool Reg0IsDead = MI->getOperand(0).isDead();
+ unsigned Reg0 = HasDef
+ ? (ChangeReg0 ? Reg2 : MI->getOperand(0).getReg()) : 0;
+ bool Reg0IsDead = HasDef ? MI->getOperand(0).isDead() : false;
MachineFunction &MF = *MI->getParent()->getParent();
- return BuildMI(MF, MI->getDesc())
- .addReg(Reg0, true, false, false, Reg0IsDead)
- .addReg(Reg2, false, false, Reg2IsKill)
- .addReg(Reg1, false, false, Reg1IsKill);
+ if (HasDef)
+ return BuildMI(MF, MI->getDebugLoc(), MI->getDesc())
+ .addReg(Reg0, RegState::Define | getDeadRegState(Reg0IsDead))
+ .addReg(Reg2, getKillRegState(Reg2IsKill))
+ .addReg(Reg1, getKillRegState(Reg2IsKill));
+ else
+ return BuildMI(MF, MI->getDebugLoc(), MI->getDesc())
+ .addReg(Reg2, getKillRegState(Reg2IsKill))
+ .addReg(Reg1, getKillRegState(Reg2IsKill));
}
if (ChangeReg0)
MI->getOperand(0).setReg(Reg2);
- MI->getOperand(2).setReg(Reg1);
- MI->getOperand(1).setReg(Reg2);
- MI->getOperand(2).setIsKill(Reg1IsKill);
- MI->getOperand(1).setIsKill(Reg2IsKill);
+ MI->getOperand(Idx2).setReg(Reg1);
+ MI->getOperand(Idx1).setReg(Reg2);
+ MI->getOperand(Idx2).setIsKill(Reg1IsKill);
+ MI->getOperand(Idx1).setIsKill(Reg2IsKill);
return MI;
}
-/// CommuteChangesDestination - Return true if commuting the specified
-/// instruction will also changes the destination operand. Also return the
-/// current operand index of the would be new destination register by
-/// reference. This can happen when the commutable instruction is also a
-/// two-address instruction.
-bool TargetInstrInfoImpl::CommuteChangesDestination(MachineInstr *MI,
- unsigned &OpIdx) const{
- assert(MI->getOperand(1).isRegister() && MI->getOperand(2).isRegister() &&
- "This only knows how to commute register operands so far");
- if (MI->getOperand(0).getReg() == MI->getOperand(1).getReg()) {
- // Must be two address instruction!
- assert(MI->getDesc().getOperandConstraint(0, TOI::TIED_TO) &&
- "Expecting a two-address instruction!");
- OpIdx = 2;
- return true;
- }
- return false;
+/// findCommutedOpIndices - If specified MI is commutable, return the two
+/// operand indices that would swap value. Return true if the instruction
+/// is not in a form which this routine understands.
+bool TargetInstrInfoImpl::findCommutedOpIndices(MachineInstr *MI,
+ unsigned &SrcOpIdx1,
+ unsigned &SrcOpIdx2) const {
+ const TargetInstrDesc &TID = MI->getDesc();
+ if (!TID.isCommutable())
+ return false;
+ // This assumes v0 = op v1, v2 and commuting would swap v1 and v2. If this
+ // is not true, then the target must implement this.
+ SrcOpIdx1 = TID.getNumDefs();
+ SrcOpIdx2 = SrcOpIdx1 + 1;
+ if (!MI->getOperand(SrcOpIdx1).isReg() ||
+ !MI->getOperand(SrcOpIdx2).isReg())
+ // No idea.
+ return false;
+ return true;
}
for (unsigned j = 0, i = 0, e = MI->getNumOperands(); i != e; ++i) {
if (TID.OpInfo[i].isPredicate()) {
MachineOperand &MO = MI->getOperand(i);
- if (MO.isRegister()) {
+ if (MO.isReg()) {
MO.setReg(Pred[j].getReg());
MadeChange = true;
- } else if (MO.isImmediate()) {
+ } else if (MO.isImm()) {
MO.setImm(Pred[j].getImm());
MadeChange = true;
- } else if (MO.isMachineBasicBlock()) {
+ } else if (MO.isMBB()) {
MO.setMBB(Pred[j].getMBB());
MadeChange = true;
}
void TargetInstrInfoImpl::reMaterialize(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
unsigned DestReg,
- const MachineInstr *Orig) const {
+ unsigned SubIdx,
+ const MachineInstr *Orig,
+ const TargetRegisterInfo &TRI) const {
MachineInstr *MI = MBB.getParent()->CloneMachineInstr(Orig);
- MI->getOperand(0).setReg(DestReg);
+ MI->substituteRegister(MI->getOperand(0).getReg(), DestReg, SubIdx, TRI);
MBB.insert(I, MI);
}
+bool TargetInstrInfoImpl::produceSameValue(const MachineInstr *MI0,
+ const MachineInstr *MI1) const {
+ return MI0->isIdenticalTo(MI1, MachineInstr::IgnoreVRegDefs);
+}
+
+MachineInstr *TargetInstrInfoImpl::duplicate(MachineInstr *Orig,
+ MachineFunction &MF) const {
+ assert(!Orig->getDesc().isNotDuplicable() &&
+ "Instruction cannot be duplicated");
+ return MF.CloneMachineInstr(Orig);
+}
+
unsigned
TargetInstrInfoImpl::GetFunctionSizeInBytes(const MachineFunction &MF) const {
unsigned FnSize = 0;
}
return FnSize;
}
+
+/// foldMemoryOperand - Attempt to fold a load or store of the specified stack
+/// slot into the specified machine instruction for the specified operand(s).
+/// If this is possible, a new instruction is returned with the specified
+/// operand folded, otherwise NULL is returned. The client is responsible for
+/// removing the old instruction and adding the new one in the instruction
+/// stream.
+MachineInstr*
+TargetInstrInfo::foldMemoryOperand(MachineFunction &MF,
+ MachineInstr* MI,
+ const SmallVectorImpl<unsigned> &Ops,
+ int FrameIndex) const {
+ unsigned Flags = 0;
+ for (unsigned i = 0, e = Ops.size(); i != e; ++i)
+ if (MI->getOperand(Ops[i]).isDef())
+ Flags |= MachineMemOperand::MOStore;
+ else
+ Flags |= MachineMemOperand::MOLoad;
+
+ // Ask the target to do the actual folding.
+ MachineInstr *NewMI = foldMemoryOperandImpl(MF, MI, Ops, FrameIndex);
+ if (!NewMI) return 0;
+
+ assert((!(Flags & MachineMemOperand::MOStore) ||
+ NewMI->getDesc().mayStore()) &&
+ "Folded a def to a non-store!");
+ assert((!(Flags & MachineMemOperand::MOLoad) ||
+ NewMI->getDesc().mayLoad()) &&
+ "Folded a use to a non-load!");
+ const MachineFrameInfo &MFI = *MF.getFrameInfo();
+ assert(MFI.getObjectOffset(FrameIndex) != -1);
+ MachineMemOperand *MMO =
+ MF.getMachineMemOperand(PseudoSourceValue::getFixedStack(FrameIndex),
+ Flags, /*Offset=*/0,
+ MFI.getObjectSize(FrameIndex),
+ MFI.getObjectAlignment(FrameIndex));
+ NewMI->addMemOperand(MF, MMO);
+
+ return NewMI;
+}
+
+/// foldMemoryOperand - Same as the previous version except it allows folding
+/// of any load and store from / to any address, not just from a specific
+/// stack slot.
+MachineInstr*
+TargetInstrInfo::foldMemoryOperand(MachineFunction &MF,
+ MachineInstr* MI,
+ const SmallVectorImpl<unsigned> &Ops,
+ MachineInstr* LoadMI) const {
+ assert(LoadMI->getDesc().canFoldAsLoad() && "LoadMI isn't foldable!");
+#ifndef NDEBUG
+ for (unsigned i = 0, e = Ops.size(); i != e; ++i)
+ assert(MI->getOperand(Ops[i]).isUse() && "Folding load into def!");
+#endif
+
+ // Ask the target to do the actual folding.
+ MachineInstr *NewMI = foldMemoryOperandImpl(MF, MI, Ops, LoadMI);
+ if (!NewMI) return 0;
+
+ // Copy the memoperands from the load to the folded instruction.
+ NewMI->setMemRefs(LoadMI->memoperands_begin(),
+ LoadMI->memoperands_end());
+
+ return NewMI;
+}
+
+bool
+TargetInstrInfo::isReallyTriviallyReMaterializableGeneric(const MachineInstr *
+ MI,
+ AliasAnalysis *
+ AA) const {
+ const MachineFunction &MF = *MI->getParent()->getParent();
+ const MachineRegisterInfo &MRI = MF.getRegInfo();
+ const TargetMachine &TM = MF.getTarget();
+ const TargetInstrInfo &TII = *TM.getInstrInfo();
+ const TargetRegisterInfo &TRI = *TM.getRegisterInfo();
+
+ // A load from a fixed stack slot can be rematerialized. This may be
+ // redundant with subsequent checks, but it's target-independent,
+ // simple, and a common case.
+ int FrameIdx = 0;
+ if (TII.isLoadFromStackSlot(MI, FrameIdx) &&
+ MF.getFrameInfo()->isImmutableObjectIndex(FrameIdx))
+ return true;
+
+ const TargetInstrDesc &TID = MI->getDesc();
+
+ // Avoid instructions obviously unsafe for remat.
+ if (TID.hasUnmodeledSideEffects() || TID.isNotDuplicable() ||
+ TID.mayStore())
+ return false;
+
+ // Avoid instructions which load from potentially varying memory.
+ if (TID.mayLoad() && !MI->isInvariantLoad(AA))
+ return false;
+
+ // If any of the registers accessed are non-constant, conservatively assume
+ // the instruction is not rematerializable.
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ const MachineOperand &MO = MI->getOperand(i);
+ if (!MO.isReg()) continue;
+ unsigned Reg = MO.getReg();
+ if (Reg == 0)
+ continue;
+
+ // Check for a well-behaved physical register.
+ if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
+ if (MO.isUse()) {
+ // If the physreg has no defs anywhere, it's just an ambient register
+ // and we can freely move its uses. Alternatively, if it's allocatable,
+ // it could get allocated to something with a def during allocation.
+ if (!MRI.def_empty(Reg))
+ return false;
+ BitVector AllocatableRegs = TRI.getAllocatableSet(MF, 0);
+ if (AllocatableRegs.test(Reg))
+ return false;
+ // Check for a def among the register's aliases too.
+ for (const unsigned *Alias = TRI.getAliasSet(Reg); *Alias; ++Alias) {
+ unsigned AliasReg = *Alias;
+ if (!MRI.def_empty(AliasReg))
+ return false;
+ if (AllocatableRegs.test(AliasReg))
+ return false;
+ }
+ } else {
+ // A physreg def. We can't remat it.
+ return false;
+ }
+ continue;
+ }
+
+ // Only allow one virtual-register def, and that in the first operand.
+ if (MO.isDef() != (i == 0))
+ return false;
+
+ // For the def, it should be the only def of that register.
+ if (MO.isDef() && (llvm::next(MRI.def_begin(Reg)) != MRI.def_end() ||
+ MRI.isLiveIn(Reg)))
+ return false;
+
+ // Don't allow any virtual-register uses. Rematting an instruction with
+ // virtual register uses would length the live ranges of the uses, which
+ // is not necessarily a good idea, certainly not "trivial".
+ if (MO.isUse())
+ return false;
+ }
+
+ // Everything checked out.
+ return true;
+}
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