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diff --git a/clang-r353983e/include/llvm/Transforms/Utils/BypassSlowDivision.h b/clang-r353983e/include/llvm/Transforms/Utils/BypassSlowDivision.h
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+++ b/clang-r353983e/include/llvm/Transforms/Utils/BypassSlowDivision.h
@@ -0,0 +1,69 @@
+//===- llvm/Transforms/Utils/BypassSlowDivision.h ---------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains an optimization for div and rem on architectures that
+// execute short instructions significantly faster than longer instructions.
+// For example, on Intel Atom 32-bit divides are slow enough that during
+// runtime it is profitable to check the value of the operands, and if they are
+// positive and less than 256 use an unsigned 8-bit divide.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TRANSFORMS_UTILS_BYPASSSLOWDIVISION_H
+#define LLVM_TRANSFORMS_UTILS_BYPASSSLOWDIVISION_H
+
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/DenseMapInfo.h"
+#include <cstdint>
+
+namespace llvm {
+
+class BasicBlock;
+class Value;
+
+struct DivRemMapKey {
+  bool SignedOp;
+  Value *Dividend;
+  Value *Divisor;
+
+  DivRemMapKey(bool InSignedOp, Value *InDividend, Value *InDivisor)
+      : SignedOp(InSignedOp), Dividend(InDividend), Divisor(InDivisor) {}
+};
+
+template <> struct DenseMapInfo<DivRemMapKey> {
+  static bool isEqual(const DivRemMapKey &Val1, const DivRemMapKey &Val2) {
+    return Val1.SignedOp == Val2.SignedOp && Val1.Dividend == Val2.Dividend &&
+           Val1.Divisor == Val2.Divisor;
+  }
+
+  static DivRemMapKey getEmptyKey() {
+    return DivRemMapKey(false, nullptr, nullptr);
+  }
+
+  static DivRemMapKey getTombstoneKey() {
+    return DivRemMapKey(true, nullptr, nullptr);
+  }
+
+  static unsigned getHashValue(const DivRemMapKey &Val) {
+    return (unsigned)(reinterpret_cast<uintptr_t>(Val.Dividend) ^
+                      reinterpret_cast<uintptr_t>(Val.Divisor)) ^
+           (unsigned)Val.SignedOp;
+  }
+};
+
+/// This optimization identifies DIV instructions in a BB that can be
+/// profitably bypassed and carried out with a shorter, faster divide.
+///
+/// This optimization may add basic blocks immediately after BB; for obvious
+/// reasons, you shouldn't pass those blocks to bypassSlowDivision.
+bool bypassSlowDivision(
+    BasicBlock *BB, const DenseMap<unsigned int, unsigned int> &BypassWidth);
+
+} // end namespace llvm
+
+#endif // LLVM_TRANSFORMS_UTILS_BYPASSSLOWDIVISION_H