bool optimizeCmpInstr(MachineInstr *MI, MachineBasicBlock *MBB);
bool optimizeExtInstr(MachineInstr *MI, MachineBasicBlock *MBB,
SmallPtrSetImpl<MachineInstr*> &LocalMIs);
- bool optimizeSelect(MachineInstr *MI);
+ bool optimizeSelect(MachineInstr *MI,
+ SmallPtrSetImpl<MachineInstr *> &LocalMIs);
bool optimizeCondBranch(MachineInstr *MI);
bool optimizeCopyOrBitcast(MachineInstr *MI);
bool optimizeCoalescableCopy(MachineInstr *MI);
}
/// Optimize a select instruction.
-bool PeepholeOptimizer::optimizeSelect(MachineInstr *MI) {
+bool PeepholeOptimizer::optimizeSelect(MachineInstr *MI,
+ SmallPtrSetImpl<MachineInstr *> &LocalMIs) {
unsigned TrueOp = 0;
unsigned FalseOp = 0;
bool Optimizable = false;
return false;
if (!Optimizable)
return false;
- if (!TII->optimizeSelect(MI))
+ if (!TII->optimizeSelect(MI, LocalMIs))
return false;
MI->eraseFromParent();
++NumSelects;
MachineBasicBlock *MBB = &*I;
bool SeenMoveImm = false;
+
+ // During this forward scan, at some point it needs to answer the question
+ // "given a pointer to an MI in the current BB, is it located before or
+ // after the current instruction".
+ // To perform this, the following set keeps track of the MIs already seen
+ // during the scan, if a MI is not in the set, it is assumed to be located
+ // after. Newly created MIs have to be inserted in the set as well.
SmallPtrSet<MachineInstr*, 16> LocalMIs;
SmallSet<unsigned, 4> ImmDefRegs;
DenseMap<unsigned, MachineInstr*> ImmDefMIs;
if ((isUncoalescableCopy(*MI) &&
optimizeUncoalescableCopy(MI, LocalMIs)) ||
(MI->isCompare() && optimizeCmpInstr(MI, MBB)) ||
- (MI->isSelect() && optimizeSelect(MI))) {
+ (MI->isSelect() && optimizeSelect(MI, LocalMIs))) {
// MI is deleted.
LocalMIs.erase(MI);
Changed = true;