+bool PeepholeOptimizer::isMoveImmediate(MachineInstr *MI,
+ SmallSet<unsigned, 4> &ImmDefRegs,
+ DenseMap<unsigned, MachineInstr*> &ImmDefMIs) {
+ const MCInstrDesc &MCID = MI->getDesc();
+ if (!MCID.isMoveImmediate())
+ return false;
+ if (MCID.getNumDefs() != 1)
+ return false;
+ unsigned Reg = MI->getOperand(0).getReg();
+ if (TargetRegisterInfo::isVirtualRegister(Reg)) {
+ ImmDefMIs.insert(std::make_pair(Reg, MI));
+ ImmDefRegs.insert(Reg);
+ return true;
+ }
+
+ return false;
+}
+
+/// FoldImmediate - Try folding register operands that are defined by move
+/// immediate instructions, i.e. a trivial constant folding optimization, if
+/// and only if the def and use are in the same BB.
+bool PeepholeOptimizer::FoldImmediate(MachineInstr *MI, MachineBasicBlock *MBB,
+ SmallSet<unsigned, 4> &ImmDefRegs,
+ DenseMap<unsigned, MachineInstr*> &ImmDefMIs) {
+ for (unsigned i = 0, e = MI->getDesc().getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = MI->getOperand(i);
+ if (!MO.isReg() || MO.isDef())
+ continue;
+ unsigned Reg = MO.getReg();
+ if (!TargetRegisterInfo::isVirtualRegister(Reg))
+ continue;
+ if (ImmDefRegs.count(Reg) == 0)
+ continue;
+ DenseMap<unsigned, MachineInstr*>::iterator II = ImmDefMIs.find(Reg);
+ assert(II != ImmDefMIs.end());
+ if (TII->FoldImmediate(MI, II->second, Reg, MRI)) {
+ ++NumImmFold;
+ return true;
+ }
+ }
+ return false;
+}
+