Switch PBQP to the modern InlineSpiller framework.

It is worth noting that the old spiller would split live ranges around
basic blocks. The new spiller doesn't do that.

PBQP should do its own live range splitting with
SplitEditor::splitSingleBlock() if desired.  See
RAGreedy::tryBlockSplit().

llvm-svn: 144476

Author: stoklund

llvm/lib/CodeGen/RegAllocPBQP.cpp

@@ -31,7 +31,9 @@
 
 #define DEBUG_TYPE "regalloc"
 
+#include "LiveRangeEdit.h"
 #include "RenderMachineFunction.h"
+#include "Spiller.h"
 #include "Splitter.h"
 #include "VirtRegMap.h"
 #include "VirtRegRewriter.h"
@@ -132,6 +134,7 @@ class RegAllocPBQP : public MachineFunctionPass {
   MachineRegisterInfo *mri;
   RenderMachineFunction *rmf;
 
+  std::auto_ptr<Spiller> spiller;
   LiveIntervals *lis;
   LiveStacks *lss;
   VirtRegMap *vrm;
@@ -141,10 +144,6 @@ class RegAllocPBQP : public MachineFunctionPass {
   /// \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,
@@ -488,29 +487,6 @@ void RegAllocPBQP::findVRegIntervalsToAlloc() {
   }
 }
 
-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
@@ -535,22 +511,16 @@ 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;
-      rmf->rememberUseDefs(spillInterval);
-      std::vector<LiveInterval*> newSpills =
-        lis->addIntervalsForSpills(*spillInterval, 0, 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 << " ");
@@ -560,7 +530,7 @@ 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.");
     }
@@ -650,6 +620,7 @@ 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");