static cl::opt<bool>
SplitEdges("machine-sink-split",
cl::desc("Split critical edges during machine sinking"),
- cl::init(false), cl::Hidden);
-static cl::opt<unsigned>
-SplitLimit("split-limit",
- cl::init(~0u), cl::Hidden);
+ cl::init(true), cl::Hidden);
STATISTIC(NumSunk, "Number of machine instructions sunk");
STATISTIC(NumSplit, "Number of critical edges split");
public:
static char ID; // Pass identification
- MachineSinking() : MachineFunctionPass(ID) {}
+ MachineSinking() : MachineFunctionPass(ID) {
+ initializeMachineSinkingPass(*PassRegistry::getPassRegistry());
+ }
virtual bool runOnMachineFunction(MachineFunction &MF);
} // end anonymous namespace
char MachineSinking::ID = 0;
-INITIALIZE_PASS(MachineSinking, "machine-sink",
- "Machine code sinking", false, false);
+INITIALIZE_PASS_BEGIN(MachineSinking, "machine-sink",
+ "Machine code sinking", false, false)
+INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)
+INITIALIZE_PASS_DEPENDENCY(MachineLoopInfo)
+INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
+INITIALIZE_PASS_END(MachineSinking, "machine-sink",
+ "Machine code sinking", false, false)
FunctionPass *llvm::createMachineSinkingPass() { return new MachineSinking(); }
if (MI->isDebugValue())
continue;
- if (PerformTrivialForwardCoalescing(MI, &MBB))
+ bool Joined = PerformTrivialForwardCoalescing(MI, &MBB);
+ if (Joined) {
+ MadeChange = true;
continue;
+ }
if (SinkInstruction(MI, SawStore))
++NumSunk, MadeChange = true;
if (!CEBCandidates.insert(std::make_pair(From, To)))
return true;
- if (!(MI->isCopyLike() || MI->getDesc().isAsCheapAsAMove()))
+ if (!MI->isCopy() && !MI->getDesc().isAsCheapAsAMove())
return true;
// MI is cheap, we probably don't want to break the critical edge for it.
return 0;
// Avoid breaking back edge. From == To means backedge for single BB loop.
- if (!SplitEdges || NumSplit == SplitLimit || FromBB == ToBB)
+ if (!SplitEdges || FromBB == ToBB)
return 0;
// Check for backedges of more "complex" loops.
return FromBB->SplitCriticalEdge(ToBB, this);
}
+static bool AvoidsSinking(MachineInstr *MI, MachineRegisterInfo *MRI) {
+ return MI->isInsertSubreg() || MI->isSubregToReg() || MI->isRegSequence();
+}
+
/// SinkInstruction - Determine whether it is safe to sink the specified machine
/// instruction out of its current block into a successor.
bool MachineSinking::SinkInstruction(MachineInstr *MI, bool &SawStore) {
+ // Don't sink insert_subreg, subreg_to_reg, reg_sequence. These are meant to
+ // be close to the source to make it easier to coalesce.
+ if (AvoidsSinking(MI, MRI))
+ return false;
+
// Check if it's safe to move the instruction.
if (!MI->isSafeToMove(TII, AA, SawStore))
return false;
// BreakPHIEdge is true if all the uses are in the successor MBB being
// sunken into and they are all PHI nodes. In this case, machine-sink must
// break the critical edge first.
- if (NumSplit == SplitLimit)
- return false;
MachineBasicBlock *NewSucc = SplitCriticalEdge(MI, ParentBlock,
SuccToSinkTo, BreakPHIEdge);
if (!NewSucc) {