Add option to commuteInstruction() which forces it to create a new (commuted) instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52308 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/TargetInstrInfoImpl.cpp b/lib/CodeGen/TargetInstrInfoImpl.cpp
index 1bb08ab..ff9c129 100644
--- a/lib/CodeGen/TargetInstrInfoImpl.cpp
+++ b/lib/CodeGen/TargetInstrInfoImpl.cpp
@@ -14,24 +14,39 @@
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/CodeGen/MachineInstr.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
using namespace llvm;
// commuteInstruction - The default implementation of this method just exchanges
// operand 1 and 2.
-MachineInstr *TargetInstrInfoImpl::commuteInstruction(MachineInstr *MI) const {
+MachineInstr *TargetInstrInfoImpl::commuteInstruction(MachineInstr *MI,
+ bool NewMI) const {
assert(MI->getOperand(1).isRegister() && MI->getOperand(2).isRegister() &&
"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();
+ bool ChangeReg0 = false;
if (MI->getOperand(0).getReg() == Reg1) {
// Must be two address instruction!
assert(MI->getDesc().getOperandConstraint(0, TOI::TIED_TO) &&
"Expecting a two-address instruction!");
Reg2IsKill = false;
- MI->getOperand(0).setReg(Reg2);
+ ChangeReg0 = true;
}
+
+ if (NewMI) {
+ // Create a new instruction.
+ unsigned Reg0 = ChangeReg0 ? Reg2 : MI->getOperand(0).getReg();
+ bool Reg0IsDead = MI->getOperand(0).isDead();
+ return BuildMI(MI->getDesc()).addReg(Reg0, true, false, false, Reg0IsDead)
+ .addReg(Reg2, false, false, Reg2IsKill)
+ .addReg(Reg1, false, false, Reg1IsKill);
+ }
+
+ if (ChangeReg0)
+ MI->getOperand(0).setReg(Reg2);
MI->getOperand(2).setReg(Reg1);
MI->getOperand(1).setReg(Reg2);
MI->getOperand(2).setIsKill(Reg1IsKill);