Revert r129518, "Change ELF systems to use CFI for producing the EH tables. This...

[oota-llvm.git] / lib / CodeGen / LiveIntervalUnion.cpp

diff --git a/lib/CodeGen/LiveIntervalUnion.cpp b/lib/CodeGen/LiveIntervalUnion.cpp
index 079468a4f0398971d642fc7e0f3795337873359e..b67f96667bfd90af7fb2a96406bb21f3f4ea6bed 100644 (file)
--- a/lib/CodeGen/LiveIntervalUnion.cpp
+++ b/lib/CodeGen/LiveIntervalUnion.cpp
@@ -16,6 +16,7 @@
 #define DEBUG_TYPE "regalloc"
 #include "LiveIntervalUnion.h"
 #include "llvm/ADT/SparseBitVector.h"
+#include "llvm/CodeGen/MachineLoopRanges.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Target/TargetRegisterInfo.h"
@@ -27,24 +28,34 @@ using namespace llvm;
 void LiveIntervalUnion::unify(LiveInterval &VirtReg) {
   if (VirtReg.empty())
     return;
+  ++Tag;
 
   // Insert each of the virtual register's live segments into the map.
   LiveInterval::iterator RegPos = VirtReg.begin();
   LiveInterval::iterator RegEnd = VirtReg.end();
   SegmentIter SegPos = Segments.find(RegPos->start);
 
-  for (;;) {
+  while (SegPos.valid()) {
     SegPos.insert(RegPos->start, RegPos->end, &VirtReg);
     if (++RegPos == RegEnd)
       return;
     SegPos.advanceTo(RegPos->start);
   }
+
+  // We have reached the end of Segments, so it is no longer necessary to search
+  // for the insertion position.
+  // It is faster to insert the end first.
+  --RegEnd;
+  SegPos.insert(RegEnd->start, RegEnd->end, &VirtReg);
+  for (; RegPos != RegEnd; ++RegPos, ++SegPos)
+    SegPos.insert(RegPos->start, RegPos->end, &VirtReg);
 }
 
 // Remove a live virtual register's segments from this union.
 void LiveIntervalUnion::extract(LiveInterval &VirtReg) {
   if (VirtReg.empty())
     return;
+  ++Tag;
 
   // Remove each of the virtual register's live segments from the map.
   LiveInterval::iterator RegPos = VirtReg.begin();
@@ -68,23 +79,22 @@ void LiveIntervalUnion::extract(LiveInterval &VirtReg) {
 
 void
 LiveIntervalUnion::print(raw_ostream &OS, const TargetRegisterInfo *TRI) const {
-  OS << "LIU ";
-  TRI->printReg(RepReg, OS);
+  OS << "LIU " << PrintReg(RepReg, TRI);
   if (empty()) {
     OS << " empty\n";
     return;
   }
   for (LiveSegments::const_iterator SI = Segments.begin(); SI.valid(); ++SI) {
-    OS << " [" << SI.start() << ' ' << SI.stop() << "):";
-    TRI->printReg(SI.value()->reg, OS);
+    OS << " [" << SI.start() << ' ' << SI.stop() << "):"
+       << PrintReg(SI.value()->reg, TRI);
   }
   OS << '\n';
 }
 
 void LiveIntervalUnion::InterferenceResult::print(raw_ostream &OS,
                                           const TargetRegisterInfo *TRI) const {
-  OS << '[' << start() << ';' << stop() << "):";
-  TRI->printReg(interference()->reg, OS);
+  OS << '[' << start() << ';' << stop() << "):"
+     << PrintReg(interference()->reg, TRI);
 }
 
 void LiveIntervalUnion::Query::print(raw_ostream &OS,
@@ -166,6 +176,7 @@ LiveIntervalUnion::Query::firstInterference() {
     return FirstInterference;
   CheckedFirstInterference = true;
   InterferenceResult &IR = FirstInterference;
+  IR.LiveUnionI.setMap(LiveUnion->getMap());
 
   // Quickly skip interference check for empty sets.
   if (VirtReg->empty() || LiveUnion->empty()) {
@@ -174,10 +185,10 @@ LiveIntervalUnion::Query::firstInterference() {
     // VirtReg starts first, perform double binary search.
     IR.VirtRegI = VirtReg->find(LiveUnion->startIndex());
     if (IR.VirtRegI != VirtReg->end())
-      IR.LiveUnionI = LiveUnion->find(IR.VirtRegI->start);
+      IR.LiveUnionI.find(IR.VirtRegI->start);
   } else {
     // LiveUnion starts first, perform double binary search.
-    IR.LiveUnionI = LiveUnion->find(VirtReg->beginIndex());
+    IR.LiveUnionI.find(VirtReg->beginIndex());
     if (IR.LiveUnionI.valid())
       IR.VirtRegI = VirtReg->find(IR.LiveUnionI.start());
     else
@@ -233,11 +244,11 @@ bool LiveIntervalUnion::Query::isSeenInterference(LiveInterval *VirtReg) const {
 //
 // For comments on how to speed it up, see Query::findIntersection().
 unsigned LiveIntervalUnion::Query::
-collectInterferingVRegs(unsigned MaxInterferingRegs) {
+collectInterferingVRegs(unsigned MaxInterferingRegs, float MaxWeight) {
   InterferenceResult IR = firstInterference();
   LiveInterval::iterator VirtRegEnd = VirtReg->end();
   LiveInterval *RecentInterferingVReg = NULL;
-  while (IR.LiveUnionI.valid()) {
+  if (IR.VirtRegI != VirtRegEnd) while (IR.LiveUnionI.valid()) {
     // Advance the union's iterator to reach an unseen interfering vreg.
     do {
       if (IR.LiveUnionI.value() == RecentInterferingVReg)
@@ -275,6 +286,11 @@ collectInterferingVRegs(unsigned MaxInterferingRegs) {
       // Cache the most recent interfering vreg to bypass isSeenInterference.
       RecentInterferingVReg = IR.LiveUnionI.value();
       ++IR.LiveUnionI;
+
+      // Stop collecting when the max weight is exceeded.
+      if (RecentInterferingVReg->weight >= MaxWeight)
+        return InterferingVRegs.size();
+
       continue;
     }
     // VirtRegI may have advanced far beyond LiveUnionI,
@@ -284,3 +300,30 @@ collectInterferingVRegs(unsigned MaxInterferingRegs) {
   SeenAllInterferences = true;
   return InterferingVRegs.size();
 }
+
+bool LiveIntervalUnion::Query::checkLoopInterference(MachineLoopRange *Loop) {
+  // VirtReg is likely live throughout the loop, so start by checking LIU-Loop
+  // overlaps.
+  IntervalMapOverlaps<LiveIntervalUnion::Map, MachineLoopRange::Map>
+    Overlaps(LiveUnion->getMap(), Loop->getMap());
+  if (!Overlaps.valid())
+    return false;
+
+  // The loop is overlapping an LIU assignment. Check VirtReg as well.
+  LiveInterval::iterator VRI = VirtReg->find(Overlaps.start());
+
+  for (;;) {
+    if (VRI == VirtReg->end())
+      return false;
+    if (VRI->start < Overlaps.stop())
+      return true;
+
+    Overlaps.advanceTo(VRI->start);
+    if (!Overlaps.valid())
+      return false;
+    if (Overlaps.start() < VRI->end)
+      return true;
+
+    VRI = VirtReg->advanceTo(VRI, Overlaps.start());
+  }
+}