Add LiveInterval::find and use it for most LiveRange searching operations

instead of calling lower_bound or upper_bound directly.

This cleans up the search logic a bit because {lower,upper}_bound compare
LR->start by default, and it is usually simpler to search LR->end.

Funnelling all searches through one function also makes it possible to replace
the search algorithm with something faster than binary search.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114448 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/LiveInterval.h

@@ -271,6 +271,19 @@ namespace llvm {
       return I;
     }
 
+    /// find - Return an iterator pointing to the first range that ends after
+    /// Pos, or end(). This is the same as advanceTo(begin(), Pos), but faster
+    /// when searching large intervals.
+    ///
+    /// If Pos is contained in a LiveRange, that range is returned.
+    /// If Pos is in a hole, the following LiveRange is returned.
+    /// If Pos is beyond endIndex, end() is returned.
+    iterator find(SlotIndex Pos);
+
+    const_iterator find(SlotIndex Pos) const {
+      return const_cast<LiveInterval*>(this)->find(Pos);
+    }
+
     void clear() {
       valnos.clear();
       ranges.clear();
@@ -386,12 +399,18 @@ namespace llvm {
       return index >= endIndex();
     }
 
-    bool liveAt(SlotIndex index) const;
+    bool liveAt(SlotIndex index) const {
+      const_iterator r = find(index);
+      return r != end() && r->start <= index;
+    }
 
     /// killedAt - Return true if a live range ends at index. Note that the kill
     /// point is not contained in the half-open live range. It is usually the
     /// getDefIndex() slot following its last use.
-    bool killedAt(SlotIndex index) const;
+    bool killedAt(SlotIndex index) const {
+      const_iterator r = find(index.getUseIndex());
+      return r != end() && r->end == index;
+    }
 
     /// killedInRange - Return true if the interval has kills in [Start,End).
     /// Note that the kill point is considered the end of a live range, so it is
@@ -421,11 +440,15 @@ namespace llvm {
 
     /// FindLiveRangeContaining - Return an iterator to the live range that
     /// contains the specified index, or end() if there is none.
-    const_iterator FindLiveRangeContaining(SlotIndex Idx) const;
+    iterator FindLiveRangeContaining(SlotIndex Idx) {
+      iterator I = find(Idx);
+      return I != end() && I->start <= Idx ? I : end();
+    }
 
-    /// FindLiveRangeContaining - Return an iterator to the live range that
+    const_iterator FindLiveRangeContaining(SlotIndex Idx) const {
-    /// contains the specified index, or end() if there is none.
+      const_iterator I = find(Idx);
-    iterator FindLiveRangeContaining(SlotIndex Idx);
+      return I != end() && I->start <= Idx ? I : end();
+    }
 
     /// findDefinedVNInfo - Find the by the specified
     /// index (register interval) or defined
@@ -467,7 +490,10 @@ namespace llvm {
 
     /// isInOneLiveRange - Return true if the range specified is entirely in the
     /// a single LiveRange of the live interval.
-    bool isInOneLiveRange(SlotIndex Start, SlotIndex End);
+    bool isInOneLiveRange(SlotIndex Start, SlotIndex End) const {
+      const_iterator r = find(Start);
+      return r != end() && r->containsRange(Start, End);
+    }
 
     /// removeRange - Remove the specified range from this interval.  Note that
     /// the range must be a single LiveRange in its entirety.

lib/CodeGen/LiveInterval.cpp

@@ -30,37 +30,14 @@
 #include <algorithm>
 using namespace llvm;
 
-// An example for liveAt():
+// compEnd - Compare LiveRange end to Pos.
-//
+// This argument ordering works for upper_bound.
-// this = [1,4), liveAt(0) will return false. The instruction defining this
+static inline bool compEnd(SlotIndex Pos, const LiveRange &LR) {
-// spans slots [0,3]. The interval belongs to an spilled definition of the
+  return Pos < LR.end;
-// variable it represents. This is because slot 1 is used (def slot) and spans
-// up to slot 3 (store slot).
-//
-bool LiveInterval::liveAt(SlotIndex I) const {
-  Ranges::const_iterator r = std::upper_bound(ranges.begin(), ranges.end(), I);
-
-  if (r == ranges.begin())
-    return false;
-
-  --r;
-  return r->contains(I);
 }
 
-/// killedAt - Return true if a live range ends at index. Note that the kill
+LiveInterval::iterator LiveInterval::find(SlotIndex Pos) {
-/// point is not contained in the half-open live range. It is usually the
+  return std::upper_bound(begin(), end(), Pos, compEnd);
-/// getDefIndex() slot following its last use.
-bool LiveInterval::killedAt(SlotIndex I) const {
-  Ranges::const_iterator r = std::lower_bound(ranges.begin(), ranges.end(), I);
-
-  // Now r points to the first interval with start >= I, or ranges.end().
-  if (r == ranges.begin())
-    return false;
-
-  --r;
-  // Now r points to the last interval with end <= I.
-  // r->end is the kill point.
-  return r->end == I;
 }
 
 /// killedInRange - Return true if the interval has kills in [Start,End).
@@ -309,25 +286,14 @@ LiveInterval::addRangeFrom(LiveRange LR, iterator From) {
   return ranges.insert(it, LR);
 }
 
-/// isInOneLiveRange - Return true if the range specified is entirely in
-/// a single LiveRange of the live interval.
-bool LiveInterval::isInOneLiveRange(SlotIndex Start, SlotIndex End) {
-  Ranges::iterator I = std::upper_bound(ranges.begin(), ranges.end(), Start);
-  if (I == ranges.begin())
-    return false;
-  --I;
-  return I->containsRange(Start, End);
-}
-
 
 /// removeRange - Remove the specified range from this interval.  Note that
 /// the range must be in a single LiveRange in its entirety.
 void LiveInterval::removeRange(SlotIndex Start, SlotIndex End,
                                bool RemoveDeadValNo) {
   // Find the LiveRange containing this span.
-  Ranges::iterator I = std::upper_bound(ranges.begin(), ranges.end(), Start);
+  Ranges::iterator I = find(Start);
-  assert(I != ranges.begin() && "Range is not in interval!");
+  assert(I != ranges.end() && "Range is not in interval!");
-  --I;
   assert(I->containsRange(Start, End) && "Range is not entirely in interval!");
 
   // If the span we are removing is at the start of the LiveRange, adjust it.
@@ -384,32 +350,6 @@ void LiveInterval::removeValNo(VNInfo *ValNo) {
   markValNoForDeletion(ValNo);
 }
 
-/// getLiveRangeContaining - Return the live range that contains the
-/// specified index, or null if there is none.
-LiveInterval::const_iterator
-LiveInterval::FindLiveRangeContaining(SlotIndex Idx) const {
-  const_iterator It = std::upper_bound(begin(), end(), Idx);
-  if (It != ranges.begin()) {
-    --It;
-    if (It->contains(Idx))
-      return It;
-  }
-
-  return end();
-}
-
-LiveInterval::iterator
-LiveInterval::FindLiveRangeContaining(SlotIndex Idx) {
-  iterator It = std::upper_bound(begin(), end(), Idx);
-  if (It != begin()) {
-    --It;
-    if (It->contains(Idx))
-      return It;
-  }
-
-  return end();
-}
-
 /// findDefinedVNInfo - Find the VNInfo defined by the specified
 /// index (register interval).
 VNInfo *LiveInterval::findDefinedVNInfoForRegInt(SlotIndex Idx) const {