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-rw-r--r--lib/Support/IntervalMap.cpp161
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diff --git a/lib/Support/IntervalMap.cpp b/lib/Support/IntervalMap.cpp
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+//===- 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
+
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