Don't try to form FGETSIGN after legalization; it is possible in some cases, but...
[oota-llvm.git] / lib / CodeGen / RegAllocPBQP.cpp
index f36d7d3dd869487d4643902a997f503443373176..a053cccc9e03b7ad2e699c02ba02fc2590ca728c 100644 (file)
 
 #define DEBUG_TYPE "regalloc"
 
+#include "LiveRangeEdit.h"
 #include "RenderMachineFunction.h"
-#include "Splitter.h"
+#include "Spiller.h"
 #include "VirtRegMap.h"
-#include "VirtRegRewriter.h"
+#include "RegisterCoalescer.h"
+#include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/CodeGen/CalcSpillWeights.h"
 #include "llvm/CodeGen/LiveIntervalAnalysis.h"
 #include "llvm/CodeGen/LiveStackAnalysis.h"
 #include "llvm/CodeGen/RegAllocPBQP.h"
+#include "llvm/CodeGen/MachineDominators.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/MachineLoopInfo.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
@@ -46,7 +49,6 @@
 #include "llvm/CodeGen/PBQP/Graph.h"
 #include "llvm/CodeGen/PBQP/Heuristics/Briggs.h"
 #include "llvm/CodeGen/RegAllocRegistry.h"
-#include "llvm/CodeGen/RegisterCoalescer.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Target/TargetInstrInfo.h"
@@ -67,11 +69,6 @@ pbqpCoalescing("pbqp-coalescing",
                 cl::desc("Attempt coalescing during PBQP register allocation."),
                 cl::init(false), cl::Hidden);
 
-static cl::opt<bool>
-pbqpPreSplitting("pbqp-pre-splitting",
-                 cl::desc("Pre-split before PBQP register allocation."),
-                 cl::init(false), cl::Hidden);
-
 namespace {
 
 ///
@@ -84,15 +81,14 @@ public:
   static char ID;
 
   /// Construct a PBQP register allocator.
-  RegAllocPBQP(std::auto_ptr<PBQPBuilder> b)
-      : MachineFunctionPass(ID), builder(b) {
+  RegAllocPBQP(std::auto_ptr<PBQPBuilder> b, char *cPassID=0)
+      : MachineFunctionPass(ID), builder(b), customPassID(cPassID) {
     initializeSlotIndexesPass(*PassRegistry::getPassRegistry());
     initializeLiveIntervalsPass(*PassRegistry::getPassRegistry());
-    initializeRegisterCoalescerAnalysisGroup(*PassRegistry::getPassRegistry());
+    initializeRegisterCoalescerPass(*PassRegistry::getPassRegistry());
     initializeCalculateSpillWeightsPass(*PassRegistry::getPassRegistry());
     initializeLiveStacksPass(*PassRegistry::getPassRegistry());
     initializeMachineLoopInfoPass(*PassRegistry::getPassRegistry());
-    initializeLoopSplitterPass(*PassRegistry::getPassRegistry());
     initializeVirtRegMapPass(*PassRegistry::getPassRegistry());
     initializeRenderMachineFunctionPass(*PassRegistry::getPassRegistry());
   }
@@ -122,6 +118,8 @@ private:
 
   std::auto_ptr<PBQPBuilder> builder;
 
+  char *customPassID;
+
   MachineFunction *mf;
   const TargetMachine *tm;
   const TargetRegisterInfo *tri;
@@ -130,6 +128,7 @@ private:
   MachineRegisterInfo *mri;
   RenderMachineFunction *rmf;
 
+  std::auto_ptr<Spiller> spiller;
   LiveIntervals *lis;
   LiveStacks *lss;
   VirtRegMap *vrm;
@@ -139,10 +138,6 @@ private:
   /// \brief Finds the initial set of vreg intervals to allocate.
   void findVRegIntervalsToAlloc();
 
-  /// \brief Adds a stack interval if the given live interval has been
-  /// spilled. Used to support stack slot coloring.
-  void addStackInterval(const LiveInterval *spilled,MachineRegisterInfo* mri);
-
   /// \brief Given a solved PBQP problem maps this solution back to a register
   /// assignment.
   bool mapPBQPToRegAlloc(const PBQPRAProblem &problem,
@@ -222,10 +217,9 @@ std::auto_ptr<PBQPRAProblem> PBQPBuilder::build(MachineFunction *mf,
     // Compute an initial allowed set for the current vreg.
     typedef std::vector<unsigned> VRAllowed;
     VRAllowed vrAllowed;
-    for (TargetRegisterClass::iterator aoItr = trc->allocation_order_begin(*mf),
-                                       aoEnd = trc->allocation_order_end(*mf);
-         aoItr != aoEnd; ++aoItr) {
-      unsigned preg = *aoItr;
+    ArrayRef<unsigned> rawOrder = trc->getRawAllocationOrder(*mf);
+    for (unsigned i = 0; i != rawOrder.size(); ++i) {
+      unsigned preg = rawOrder[i];
       if (!reservedRegs.test(preg)) {
         vrAllowed.push_back(preg);
       }
@@ -238,11 +232,13 @@ std::auto_ptr<PBQPRAProblem> PBQPBuilder::build(MachineFunction *mf,
       unsigned preg = *pregItr;
       const LiveInterval *pregLI = &lis->getInterval(preg);
 
-      if (pregLI->empty())
+      if (pregLI->empty()) {
         continue;
+      }
 
-      if (!vregLI->overlaps(*pregLI))
+      if (!vregLI->overlaps(*pregLI)) {
         continue;
+      }
 
       // Remove the register from the allowed set.
       VRAllowed::iterator eraseItr =
@@ -318,10 +314,10 @@ void PBQPBuilder::addInterferenceCosts(
   assert(costMat.getRows() == vr1Allowed.size() + 1 && "Matrix height mismatch.");
   assert(costMat.getCols() == vr2Allowed.size() + 1 && "Matrix width mismatch.");
 
-  for (unsigned i = 0; i < vr1Allowed.size(); ++i) {
+  for (unsigned i = 0; i != vr1Allowed.size(); ++i) {
     unsigned preg1 = vr1Allowed[i];
 
-    for (unsigned j = 0; j < vr2Allowed.size(); ++j) {
+    for (unsigned j = 0; j != vr2Allowed.size(); ++j) {
       unsigned preg2 = vr2Allowed[j];
 
       if (tri->regsOverlap(preg1, preg2)) {
@@ -355,11 +351,13 @@ std::auto_ptr<PBQPRAProblem> PBQPBuilderWithCoalescing::build(
          miItr != miEnd; ++miItr) {
       const MachineInstr *mi = &*miItr;
 
-      if (!cp.setRegisters(mi))
+      if (!cp.setRegisters(mi)) {
         continue; // Not coalescable.
+      }
 
-      if (cp.getSrcReg() == cp.getDstReg())
+      if (cp.getSrcReg() == cp.getDstReg()) {
         continue; // Already coalesced.
+      }
 
       unsigned dst = cp.getDstReg(),
                src = cp.getSrcReg();
@@ -372,13 +370,15 @@ std::auto_ptr<PBQPRAProblem> PBQPBuilderWithCoalescing::build(
                                                    loopInfo->getLoopDepth(mbb));
 
       if (cp.isPhys()) {
-        if (!lis->isAllocatable(dst))
+        if (!lis->isAllocatable(dst)) {
           continue;
+        }
 
         const PBQPRAProblem::AllowedSet &allowed = p->getAllowedSet(src);
         unsigned pregOpt = 0;  
-        while (pregOpt < allowed.size() && allowed[pregOpt] != dst)
+        while (pregOpt < allowed.size() && allowed[pregOpt] != dst) {
           ++pregOpt;
+        }
         if (pregOpt < allowed.size()) {
           ++pregOpt; // +1 to account for spill option.
           PBQP::Graph::NodeItr node = p->getNodeForVReg(src);
@@ -425,9 +425,9 @@ void PBQPBuilderWithCoalescing::addVirtRegCoalesce(
   assert(costMat.getRows() == vr1Allowed.size() + 1 && "Size mismatch.");
   assert(costMat.getCols() == vr2Allowed.size() + 1 && "Size mismatch.");
 
-  for (unsigned i = 0; i < vr1Allowed.size(); ++i) {
+  for (unsigned i = 0; i != vr1Allowed.size(); ++i) {
     unsigned preg1 = vr1Allowed[i];
-    for (unsigned j = 0; j < vr2Allowed.size(); ++j) {
+    for (unsigned j = 0; j != vr2Allowed.size(); ++j) {
       unsigned preg2 = vr2Allowed[j];
 
       if (preg1 == preg2) {
@@ -439,18 +439,23 @@ void PBQPBuilderWithCoalescing::addVirtRegCoalesce(
 
 
 void RegAllocPBQP::getAnalysisUsage(AnalysisUsage &au) const {
+  au.setPreservesCFG();
+  au.addRequired<AliasAnalysis>();
+  au.addPreserved<AliasAnalysis>();
   au.addRequired<SlotIndexes>();
   au.addPreserved<SlotIndexes>();
   au.addRequired<LiveIntervals>();
   //au.addRequiredID(SplitCriticalEdgesID);
-  au.addRequired<RegisterCoalescer>();
+  au.addRequiredID(RegisterCoalescerPassID);
+  if (customPassID)
+    au.addRequiredID(*customPassID);
   au.addRequired<CalculateSpillWeights>();
   au.addRequired<LiveStacks>();
   au.addPreserved<LiveStacks>();
+  au.addRequired<MachineDominatorTree>();
+  au.addPreserved<MachineDominatorTree>();
   au.addRequired<MachineLoopInfo>();
   au.addPreserved<MachineLoopInfo>();
-  if (pbqpPreSplitting)
-    au.addRequired<LoopSplitter>();
   au.addRequired<VirtRegMap>();
   au.addRequired<RenderMachineFunction>();
   MachineFunctionPass::getAnalysisUsage(au);
@@ -473,34 +478,12 @@ void RegAllocPBQP::findVRegIntervalsToAlloc() {
     // finalizeAlloc.
     if (!li->empty()) {
       vregsToAlloc.insert(li->reg);
-    }
-    else {
+    } else {
       emptyIntervalVRegs.insert(li->reg);
     }
   }
 }
 
-void RegAllocPBQP::addStackInterval(const LiveInterval *spilled,
-                                    MachineRegisterInfo* mri) {
-  int stackSlot = vrm->getStackSlot(spilled->reg);
-
-  if (stackSlot == VirtRegMap::NO_STACK_SLOT)
-    return;
-
-  const TargetRegisterClass *RC = mri->getRegClass(spilled->reg);
-  LiveInterval &stackInterval = lss->getOrCreateInterval(stackSlot, RC);
-
-  VNInfo *vni;
-  if (stackInterval.getNumValNums() != 0)
-    vni = stackInterval.getValNumInfo(0);
-  else
-    vni = stackInterval.getNextValue(
-      SlotIndex(), 0, lss->getVNInfoAllocator());
-
-  LiveInterval &rhsInterval = lis->getInterval(spilled->reg);
-  stackInterval.MergeRangesInAsValue(rhsInterval, vni);
-}
-
 bool RegAllocPBQP::mapPBQPToRegAlloc(const PBQPRAProblem &problem,
                                      const PBQP::Solution &solution) {
   // Set to true if we have any spills
@@ -525,23 +508,16 @@ bool RegAllocPBQP::mapPBQPToRegAlloc(const PBQPRAProblem &problem,
       vrm->assignVirt2Phys(vreg, preg);      
     } else if (problem.isSpillOption(vreg, alloc)) {
       vregsToAlloc.erase(vreg);
-      const LiveInterval* spillInterval = &lis->getInterval(vreg);
-      double oldWeight = spillInterval->weight;
-      SmallVector<LiveInterval*, 8> spillIs;
-      rmf->rememberUseDefs(spillInterval);
-      std::vector<LiveInterval*> newSpills =
-        lis->addIntervalsForSpills(*spillInterval, spillIs, loopInfo, *vrm);
-      addStackInterval(spillInterval, mri);
-      rmf->rememberSpills(spillInterval, newSpills);
-
-      (void) oldWeight;
+      SmallVector<LiveInterval*, 8> newSpills;
+      LiveRangeEdit LRE(lis->getInterval(vreg), newSpills);
+      spiller->spill(LRE);
+
       DEBUG(dbgs() << "VREG " << vreg << " -> SPILLED (Cost: "
-                   << oldWeight << ", New vregs: ");
+                   << LRE.getParent().weight << ", New vregs: ");
 
       // Copy any newly inserted live intervals into the list of regs to
       // allocate.
-      for (std::vector<LiveInterval*>::const_iterator
-           itr = newSpills.begin(), end = newSpills.end();
+      for (LiveRangeEdit::iterator itr = LRE.begin(), end = LRE.end();
            itr != end; ++itr) {
         assert(!(*itr)->empty() && "Empty spill range.");
         DEBUG(dbgs() << (*itr)->reg << " ");
@@ -551,7 +527,7 @@ bool RegAllocPBQP::mapPBQPToRegAlloc(const PBQPRAProblem &problem,
       DEBUG(dbgs() << ")\n");
 
       // We need another round if spill intervals were added.
-      anotherRoundNeeded |= !newSpills.empty();
+      anotherRoundNeeded |= !LRE.empty();
     } else {
       assert(false && "Unknown allocation option.");
     }
@@ -575,7 +551,7 @@ void RegAllocPBQP::finalizeAlloc() const {
 
     if (physReg == 0) {
       const TargetRegisterClass *liRC = mri->getRegClass(li->reg);
-      physReg = *liRC->allocation_order_begin(*mf);
+      physReg = liRC->getRawAllocationOrder(*mf).front();
     }
 
     vrm->assignVirt2Phys(li->reg, physReg);
@@ -594,11 +570,9 @@ void RegAllocPBQP::finalizeAlloc() const {
     // Get the physical register for this interval
     if (TargetRegisterInfo::isPhysicalRegister(li->reg)) {
       reg = li->reg;
-    }
-    else if (vrm->isAssignedReg(li->reg)) {
+    } else if (vrm->isAssignedReg(li->reg)) {
       reg = vrm->getPhys(li->reg);
-    }
-    else {
+    } else {
       // Ranges which are assigned a stack slot only are ignored.
       continue;
     }
@@ -615,7 +589,7 @@ void RegAllocPBQP::finalizeAlloc() const {
       // Find the set of basic blocks which this range is live into...
       if (lis->findLiveInMBBs(lrItr->start, lrItr->end,  liveInMBBs)) {
         // And add the physreg for this interval to their live-in sets.
-        for (unsigned i = 0; i < liveInMBBs.size(); ++i) {
+        for (unsigned i = 0; i != liveInMBBs.size(); ++i) {
           if (liveInMBBs[i] != entryMBB) {
             if (!liveInMBBs[i]->isLiveIn(reg)) {
               liveInMBBs[i]->addLiveIn(reg);
@@ -643,6 +617,7 @@ bool RegAllocPBQP::runOnMachineFunction(MachineFunction &MF) {
   rmf = &getAnalysis<RenderMachineFunction>();
 
   vrm = &getAnalysis<VirtRegMap>();
+  spiller.reset(createInlineSpiller(*this, MF, *vrm));
 
 
   DEBUG(dbgs() << "PBQP Register Allocating for " << mf->getFunction()->getName() << "\n");
@@ -691,16 +666,15 @@ bool RegAllocPBQP::runOnMachineFunction(MachineFunction &MF) {
   DEBUG(dbgs() << "Post alloc VirtRegMap:\n" << *vrm << "\n");
 
   // Run rewriter
-  std::auto_ptr<VirtRegRewriter> rewriter(createVirtRegRewriter());
-
-  rewriter->runOnMachineFunction(*mf, *vrm, lis);
+  vrm->rewrite(lis->getSlotIndexes());
 
   return true;
 }
 
 FunctionPass* llvm::createPBQPRegisterAllocator(
-                                           std::auto_ptr<PBQPBuilder> builder) {
-  return new RegAllocPBQP(builder);
+                                           std::auto_ptr<PBQPBuilder> builder,
+                                           char *customPassID) {
+  return new RegAllocPBQP(builder, customPassID);
 }
 
 FunctionPass* llvm::createDefaultPBQPRegisterAllocator() {