From d9e926da26872ba52796fc9b0c006533614ec207 Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <stoklund@2pi.dk>
Date: Tue, 13 Sep 2011 18:05:29 +0000
Subject: [PATCH] Add SplitEditor::markOverlappedComplement().

This function is used to flag values where the complement interval may
overlap other intervals.  Call it from overlapIntv, and use the flag to
fully recompute those live ranges in transferValues().

llvm-svn: 139612
---
 lib/CodeGen/SplitKit.cpp | 15 +++++++++++++--
 lib/CodeGen/SplitKit.h   | 15 +++++++++++++++
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/lib/CodeGen/SplitKit.cpp b/lib/CodeGen/SplitKit.cpp
index 4bf3a7aab0c..89e85bd3838 100644
--- a/lib/CodeGen/SplitKit.cpp
+++ b/lib/CodeGen/SplitKit.cpp
@@ -317,6 +317,7 @@ void SplitEditor::reset(LiveRangeEdit &LRE, ComplementSpillMode SM) {
   Edit = &LRE;
   SpillMode = SM;
   OpenIdx = 0;
+  OverlappedComplement.clear();
   RegAssign.clear();
   Values.clear();
 
@@ -391,6 +392,16 @@ void SplitEditor::markComplexMapped(unsigned RegIdx, const VNInfo *ParentVNI) {
   VNI = 0;
 }
 
+void SplitEditor::markOverlappedComplement(const VNInfo *ParentVNI) {
+  if (OverlappedComplement.insert(ParentVNI))
+    markComplexMapped(0, ParentVNI);
+}
+
+bool SplitEditor::needsRecompute(unsigned RegIdx, const VNInfo *ParentVNI) {
+  return (RegIdx == 0 && OverlappedComplement.count(ParentVNI)) ||
+    Edit->didRematerialize(ParentVNI);
+}
+
 VNInfo *SplitEditor::defFromParent(unsigned RegIdx,
                                    VNInfo *ParentVNI,
                                    SlotIndex UseIdx,
@@ -575,7 +586,7 @@ void SplitEditor::overlapIntv(SlotIndex Start, SlotIndex End) {
 
   // The complement interval will be extended as needed by LRCalc.extend().
   if (ParentVNI)
-    markComplexMapped(0, ParentVNI);
+    markOverlappedComplement(ParentVNI);
   DEBUG(dbgs() << "    overlapIntv [" << Start << ';' << End << "):");
   RegAssign.insert(Start, End, OpenIdx);
   DEBUG(dump());
@@ -623,7 +634,7 @@ bool SplitEditor::transferValues() {
 
       // Skip rematerialized values, we need to use LRCalc.extend() and
       // extendPHIKillRanges() to completely recompute the live ranges.
-      if (Edit->didRematerialize(ParentVNI)) {
+      if (needsRecompute(RegIdx, ParentVNI)) {
         DEBUG(dbgs() << "(remat)");
         Skipped = true;
         Start = End;
diff --git a/lib/CodeGen/SplitKit.h b/lib/CodeGen/SplitKit.h
index 1a4937ccda2..5abdd4c62e6 100644
--- a/lib/CodeGen/SplitKit.h
+++ b/lib/CodeGen/SplitKit.h
@@ -250,6 +250,10 @@ private:
   /// The current spill mode, selected by reset().
   ComplementSpillMode SpillMode;
 
+  /// Parent interval values where the complement interval may be overlapping
+  /// other intervals.
+  SmallPtrSet<const VNInfo*, 8> OverlappedComplement;
+
   typedef IntervalMap<SlotIndex, unsigned> RegAssignMap;
 
   /// Allocator for the interval map. This will eventually be shared with
@@ -296,6 +300,17 @@ private:
   /// of the number of defs.
   void markComplexMapped(unsigned RegIdx, const VNInfo *ParentVNI);
 
+  /// markOverlappedComplement - Mark ParentVNI as being overlapped in the
+  /// complement interval.  The complement interval may overlap other intervals
+  /// after overlapIntv has been called, or when in spill mode.
+  void markOverlappedComplement(const VNInfo *ParentVNI);
+
+  /// needsRecompute - Returns true if the live range of ParentVNI needs to be
+  /// recomputed in RegIdx using LiveRangeCalc::extend.  This is the case if
+  /// the value has been rematerialized, or when back-copies have been hoisted
+  /// in spill mode.
+  bool needsRecompute(unsigned RegIdx, const VNInfo *ParentVNI);
+
   /// defFromParent - Define Reg from ParentVNI at UseIdx using either
   /// rematerialization or a COPY from parent. Return the new value.
   VNInfo *defFromParent(unsigned RegIdx,