vendor/llvm/llvm-r126079

1 files changed, 161 insertions, 0 deletions

diff --git a/lib/Support/IntervalMap.cpp b/lib/Support/IntervalMap.cpp
new file mode 100644
index 0000000000000..4dfcc404ca428
--- /dev/null
+++ b/lib/Support/IntervalMap.cpp
@@ -0,0 +1,161 @@
+//===- lib/Support/IntervalMap.cpp - A sorted interval map ----------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the few non-templated functions in IntervalMap.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/IntervalMap.h"
+
+namespace llvm {
+namespace IntervalMapImpl {
+
+void Path::replaceRoot(void *Root, unsigned Size, IdxPair Offsets) {
+  assert(!path.empty() && "Can't replace missing root");
+  path.front() = Entry(Root, Size, Offsets.first);
+  path.insert(path.begin() + 1, Entry(subtree(0), Offsets.second));
+}
+
+NodeRef Path::getLeftSibling(unsigned Level) const {
+  // The root has no siblings.
+  if (Level == 0)
+    return NodeRef();
+
+  // Go up the tree until we can go left.
+  unsigned l = Level - 1;
+  while (l && path[l].offset == 0)
+    --l;
+
+  // We can't go left.
+  if (path[l].offset == 0)
+    return NodeRef();
+
+  // NR is the subtree containing our left sibling.
+  NodeRef NR = path[l].subtree(path[l].offset - 1);
+
+  // Keep right all the way down.
+  for (++l; l != Level; ++l)
+    NR = NR.subtree(NR.size() - 1);
+  return NR;
+}
+
+void Path::moveLeft(unsigned Level) {
+  assert(Level != 0 && "Cannot move the root node");
+
+  // Go up the tree until we can go left.
+  unsigned l = 0;
+  if (valid()) {
+    l = Level - 1;
+    while (path[l].offset == 0) {
+      assert(l != 0 && "Cannot move beyond begin()");
+      --l;
+    }
+  } else if (height() < Level)
+    // end() may have created a height=0 path.
+    path.resize(Level + 1, Entry(0, 0, 0));
+
+  // NR is the subtree containing our left sibling.
+  --path[l].offset;
+  NodeRef NR = subtree(l);
+
+  // Get the rightmost node in the subtree.
+  for (++l; l != Level; ++l) {
+    path[l] = Entry(NR, NR.size() - 1);
+    NR = NR.subtree(NR.size() - 1);
+  }
+  path[l] = Entry(NR, NR.size() - 1);
+}
+
+NodeRef Path::getRightSibling(unsigned Level) const {
+  // The root has no siblings.
+  if (Level == 0)
+    return NodeRef();
+
+  // Go up the tree until we can go right.
+  unsigned l = Level - 1;
+  while (l && atLastEntry(l))
+    --l;
+
+  // We can't go right.
+  if (atLastEntry(l))
+    return NodeRef();
+
+  // NR is the subtree containing our right sibling.
+  NodeRef NR = path[l].subtree(path[l].offset + 1);
+
+  // Keep left all the way down.
+  for (++l; l != Level; ++l)
+    NR = NR.subtree(0);
+  return NR;
+}
+
+void Path::moveRight(unsigned Level) {
+  assert(Level != 0 && "Cannot move the root node");
+
+  // Go up the tree until we can go right.
+  unsigned l = Level - 1;
+  while (l && atLastEntry(l))
+    --l;
+
+  // NR is the subtree containing our right sibling. If we hit end(), we have
+  // offset(0) == node(0).size().
+  if (++path[l].offset == path[l].size)
+    return;
+  NodeRef NR = subtree(l);
+
+  for (++l; l != Level; ++l) {
+    path[l] = Entry(NR, 0);
+    NR = NR.subtree(0);
+  }
+  path[l] = Entry(NR, 0);
+}
+
+
+IdxPair distribute(unsigned Nodes, unsigned Elements, unsigned Capacity,
+                   const unsigned *CurSize, unsigned NewSize[],
+                   unsigned Position, bool Grow) {
+  assert(Elements + Grow <= Nodes * Capacity && "Not enough room for elements");
+  assert(Position <= Elements && "Invalid position");
+  if (!Nodes)
+    return IdxPair();
+
+  // Trivial algorithm: left-leaning even distribution.
+  const unsigned PerNode = (Elements + Grow) / Nodes;
+  const unsigned Extra = (Elements + Grow) % Nodes;
+  IdxPair PosPair = IdxPair(Nodes, 0);
+  unsigned Sum = 0;
+  for (unsigned n = 0; n != Nodes; ++n) {
+    Sum += NewSize[n] = PerNode + (n < Extra);
+    if (PosPair.first == Nodes && Sum > Position)
+      PosPair = IdxPair(n, Position - (Sum - NewSize[n]));
+  }
+  assert(Sum == Elements + Grow && "Bad distribution sum");
+
+  // Subtract the Grow element that was added.
+  if (Grow) {
+    assert(PosPair.first < Nodes && "Bad algebra");
+    assert(NewSize[PosPair.first] && "Too few elements to need Grow");
+    --NewSize[PosPair.first];
+  }
+
+#ifndef NDEBUG
+  Sum = 0;
+  for (unsigned n = 0; n != Nodes; ++n) {
+    assert(NewSize[n] <= Capacity && "Overallocated node");
+    Sum += NewSize[n];
+  }
+  assert(Sum == Elements && "Bad distribution sum");
+#endif
+
+  return PosPair;
+}
+
+} // namespace IntervalMapImpl
+} // namespace llvm
+