#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineInstrBuilder.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).isReg() && MI->getOperand(2).isReg() &&
+ 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;
+ llvm_report_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->getDebugLoc(), MI->getDesc())
- .addReg(Reg0, RegState::Define | getDeadRegState(Reg0IsDead))
- .addReg(Reg2, getKillRegState(Reg2IsKill))
- .addReg(Reg1, getKillRegState(Reg2IsKill));
+ 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).isReg() && MI->getOperand(2).isReg() &&
- "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;
}
void TargetInstrInfoImpl::reMaterialize(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
unsigned DestReg,
+ unsigned SubIdx,
const MachineInstr *Orig) const {
MachineInstr *MI = MBB.getParent()->CloneMachineInstr(Orig);
- MI->getOperand(0).setReg(DestReg);
+ MachineOperand &MO = MI->getOperand(0);
+ MO.setReg(DestReg);
+ MO.setSubReg(SubIdx);
MBB.insert(I, MI);
}
+bool TargetInstrInfoImpl::isDeadInstruction(const MachineInstr *MI) const {
+ const TargetInstrDesc &TID = MI->getDesc();
+ if (TID.mayLoad() || TID.mayStore() || TID.isCall() || TID.isTerminator() ||
+ TID.isCall() || TID.isBarrier() || TID.isReturn() ||
+ TID.hasUnmodeledSideEffects())
+ return false;
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ const MachineOperand &MO = MI->getOperand(i);
+ if (!MO.isReg() || !MO.getReg())
+ continue;
+ if (MO.isDef() && !MO.isDead())
+ return false;
+ if (MO.isUse() && MO.isKill())
+ // FIXME: We can't remove kill markers or else the scavenger will assert.
+ // An alternative is to add a ADD pseudo instruction to replace kill
+ // markers.
+ return false;
+ }
+ return true;
+}
+
unsigned
TargetInstrInfoImpl::GetFunctionSizeInBytes(const MachineFunction &MF) const {
unsigned FnSize = 0;