SelectionDAG switch lowering: Replace unreachable default with most popular case.

[oota-llvm.git] / lib / CodeGen / SelectionDAG / ResourcePriorityQueue.cpp

diff --git a/lib/CodeGen/SelectionDAG/ResourcePriorityQueue.cpp b/lib/CodeGen/SelectionDAG/ResourcePriorityQueue.cpp
index 1dd2128b8b69dd8b412ab502a8bdc9c047f4fb7d..db38b76cf93a982b34a5992fa3cd32d1421f09d6 100644 (file)
--- a/lib/CodeGen/SelectionDAG/ResourcePriorityQueue.cpp
+++ b/lib/CodeGen/SelectionDAG/ResourcePriorityQueue.cpp
@@ -19,7 +19,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#define DEBUG_TYPE "scheduler"
 #include "llvm/CodeGen/ResourcePriorityQueue.h"
 #include "llvm/CodeGen/MachineInstr.h"
 #include "llvm/CodeGen/SelectionDAGNodes.h"
@@ -28,9 +27,12 @@
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Target/TargetLowering.h"
 #include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetSubtargetInfo.h"
 
 using namespace llvm;
 
+#define DEBUG_TYPE "scheduler"
+
 static cl::opt<bool> DisableDFASched("disable-dfa-sched", cl::Hidden,
   cl::ZeroOrMore, cl::init(false),
   cl::desc("Disable use of DFA during scheduling"));
@@ -39,32 +41,29 @@ static cl::opt<signed> RegPressureThreshold(
   "dfa-sched-reg-pressure-threshold", cl::Hidden, cl::ZeroOrMore, cl::init(5),
   cl::desc("Track reg pressure and switch priority to in-depth"));
 
+ResourcePriorityQueue::ResourcePriorityQueue(SelectionDAGISel *IS)
+    : Picker(this), InstrItins(IS->MF->getSubtarget().getInstrItineraryData()) {
+  const TargetSubtargetInfo &STI = IS->MF->getSubtarget();
+  TRI = STI.getRegisterInfo();
+  TLI = IS->TLI;
+  TII = STI.getInstrInfo();
+  ResourcesModel = TII->CreateTargetScheduleState(STI);
+  // This hard requirement could be relaxed, but for now
+  // do not let it procede.
+  assert(ResourcesModel && "Unimplemented CreateTargetScheduleState.");
+
+  unsigned NumRC = TRI->getNumRegClasses();
+  RegLimit.resize(NumRC);
+  RegPressure.resize(NumRC);
+  std::fill(RegLimit.begin(), RegLimit.end(), 0);
+  std::fill(RegPressure.begin(), RegPressure.end(), 0);
+  for (TargetRegisterInfo::regclass_iterator I = TRI->regclass_begin(),
+                                             E = TRI->regclass_end();
+       I != E; ++I)
+    RegLimit[(*I)->getID()] = TRI->getRegPressureLimit(*I, *IS->MF);
 
-ResourcePriorityQueue::ResourcePriorityQueue(SelectionDAGISel *IS) :
-  Picker(this),
- InstrItins(IS->getTargetLowering()->getTargetMachine().getInstrItineraryData())
-{
-   TII = IS->getTargetLowering()->getTargetMachine().getInstrInfo();
-   TRI = IS->getTargetLowering()->getTargetMachine().getRegisterInfo();
-   TLI = IS->getTargetLowering();
-
-   const TargetMachine &tm = (*IS->MF).getTarget();
-   ResourcesModel = tm.getInstrInfo()->CreateTargetScheduleState(&tm,NULL);
-   // This hard requirement could be relaxed, but for now
-   // do not let it procede.
-   assert (ResourcesModel && "Unimplemented CreateTargetScheduleState.");
-
-   unsigned NumRC = TRI->getNumRegClasses();
-   RegLimit.resize(NumRC);
-   RegPressure.resize(NumRC);
-   std::fill(RegLimit.begin(), RegLimit.end(), 0);
-   std::fill(RegPressure.begin(), RegPressure.end(), 0);
-   for (TargetRegisterInfo::regclass_iterator I = TRI->regclass_begin(),
-        E = TRI->regclass_end(); I != E; ++I)
-     RegLimit[(*I)->getID()] = TRI->getRegPressureLimit(*I, *IS->MF);
-
-   ParallelLiveRanges = 0;
-   HorizontalVerticalBalance = 0;
+  ParallelLiveRanges = 0;
+  HorizontalVerticalBalance = 0;
 }
 
 unsigned
@@ -214,7 +213,7 @@ bool resource_sort::operator()(const SUnit *LHS, const SUnit *RHS) const {
 /// getSingleUnscheduledPred - If there is exactly one unscheduled predecessor
 /// of SU, return it, otherwise return null.
 SUnit *ResourcePriorityQueue::getSingleUnscheduledPred(SUnit *SU) {
-  SUnit *OnlyAvailablePred = 0;
+  SUnit *OnlyAvailablePred = nullptr;
   for (SUnit::const_pred_iterator I = SU->Preds.begin(), E = SU->Preds.end();
        I != E; ++I) {
     SUnit &Pred = *I->getSUnit();
@@ -222,7 +221,7 @@ SUnit *ResourcePriorityQueue::getSingleUnscheduledPred(SUnit *SU) {
       // We found an available, but not scheduled, predecessor.  If it's the
       // only one we have found, keep track of it... otherwise give up.
       if (OnlyAvailablePred && OnlyAvailablePred != &Pred)
-        return 0;
+        return nullptr;
       OnlyAvailablePred = &Pred;
     }
   }
@@ -318,7 +317,7 @@ void ResourcePriorityQueue::reserveResources(SUnit *SU) {
 
   // If packet is now full, reset the state so in the next cycle
   // we start fresh.
-  if (Packet.size() >= InstrItins->SchedModel->IssueWidth) {
+  if (Packet.size() >= InstrItins->SchedModel.IssueWidth) {
     ResourcesModel->clearResources();
     Packet.clear();
   }
@@ -441,7 +440,7 @@ signed ResourcePriorityQueue::SUSchedulingCost(SUnit *SU) {
     ResCount -= (regPressureDelta(SU) * ScaleTwo);
   }
 
-  // These are platform specific things.
+  // These are platform-specific things.
   // Will need to go into the back end
   // and accessed from here via a hook.
   for (SDNode *N = SU->getNode(); N; N = N->getGluedNode()) {
@@ -581,7 +580,7 @@ void ResourcePriorityQueue::adjustPriorityOfUnscheduledPreds(SUnit *SU) {
   if (SU->isAvailable) return;  // All preds scheduled.
 
   SUnit *OnlyAvailablePred = getSingleUnscheduledPred(SU);
-  if (OnlyAvailablePred == 0 || !OnlyAvailablePred->isAvailable)
+  if (!OnlyAvailablePred || !OnlyAvailablePred->isAvailable)
     return;
 
   // Okay, we found a single predecessor that is available, but not scheduled.
@@ -598,12 +597,12 @@ void ResourcePriorityQueue::adjustPriorityOfUnscheduledPreds(SUnit *SU) {
 /// to be placed in scheduling sequence.
 SUnit *ResourcePriorityQueue::pop() {
   if (empty())
-    return 0;
+    return nullptr;
 
   std::vector<SUnit *>::iterator Best = Queue.begin();
   if (!DisableDFASched) {
     signed BestCost = SUSchedulingCost(*Best);
-    for (std::vector<SUnit *>::iterator I = llvm::next(Queue.begin()),
+    for (std::vector<SUnit *>::iterator I = std::next(Queue.begin()),
            E = Queue.end(); I != E; ++I) {
 
       if (SUSchedulingCost(*I) > BestCost) {
@@ -614,14 +613,14 @@ SUnit *ResourcePriorityQueue::pop() {
   }
   // Use default TD scheduling mechanism.
   else {
-    for (std::vector<SUnit *>::iterator I = llvm::next(Queue.begin()),
+    for (std::vector<SUnit *>::iterator I = std::next(Queue.begin()),
        E = Queue.end(); I != E; ++I)
       if (Picker(*Best, *I))
         Best = I;
   }
 
   SUnit *V = *Best;
-  if (Best != prior(Queue.end()))
+  if (Best != std::prev(Queue.end()))
     std::swap(*Best, Queue.back());
 
   Queue.pop_back();
@@ -633,7 +632,7 @@ SUnit *ResourcePriorityQueue::pop() {
 void ResourcePriorityQueue::remove(SUnit *SU) {
   assert(!Queue.empty() && "Queue is empty!");
   std::vector<SUnit *>::iterator I = std::find(Queue.begin(), Queue.end(), SU);
-  if (I != prior(Queue.end()))
+  if (I != std::prev(Queue.end()))
     std::swap(*I, Queue.back());
 
   Queue.pop_back();