[llvm-commits] [llvm] r150890 - in /llvm/trunk: include/llvm/ADT/Hashing.h lib/Support/CMakeLists.txt lib/Support/Hashing.cpp unittests/ADT/HashingTest.cpp unittests/CMakeLists.txt
Talin
viridia at gmail.com
Sat Feb 18 13:00:50 PST 2012
Author: talin
Date: Sat Feb 18 15:00:49 2012
New Revision: 150890
URL: http://llvm.org/viewvc/llvm-project?rev=150890&view=rev
Log:
Hashing.h - utilities for hashing various data types.
Added:
llvm/trunk/include/llvm/ADT/Hashing.h
llvm/trunk/lib/Support/Hashing.cpp
llvm/trunk/unittests/ADT/HashingTest.cpp
Modified:
llvm/trunk/lib/Support/CMakeLists.txt
llvm/trunk/unittests/CMakeLists.txt
Added: llvm/trunk/include/llvm/ADT/Hashing.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/Hashing.h?rev=150890&view=auto
==============================================================================
--- llvm/trunk/include/llvm/ADT/Hashing.h (added)
+++ llvm/trunk/include/llvm/ADT/Hashing.h Sat Feb 18 15:00:49 2012
@@ -0,0 +1,180 @@
+//===-- llvm/ADT/Hashing.h - Utilities for hashing --------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines utilities for computing hash values for various data types.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ADT_HASHING_H
+#define LLVM_ADT_HASHING_H
+
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/AlignOf.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/DataTypes.h"
+
+namespace llvm {
+
+/// Class to compute a hash value from multiple data fields of arbitrary
+/// types. Note that if you are hashing a single data type, such as a
+/// string, it may be cheaper to use a hash algorithm that is tailored
+/// for that specific data type.
+/// Typical Usage:
+/// GeneralHash Hash;
+/// Hash.add(someValue);
+/// Hash.add(someOtherValue);
+/// return Hash.finish();
+/// Adapted from MurmurHash2 by Austin Appleby
+class GeneralHash {
+private:
+ enum {
+ M = 0x5bd1e995
+ };
+ unsigned Hash;
+ unsigned Count;
+public:
+ GeneralHash(unsigned Seed = 0) : Hash(Seed), Count(0) {}
+
+ /// Add a pointer value.
+ /// Note: this adds pointers to the hash using sizes and endianness that
+ /// depend on the host. It doesn't matter however, because hashing on
+ /// pointer values is inherently unstable.
+ template<typename T>
+ GeneralHash& add(const T *PtrVal) {
+ addBits(&PtrVal, &PtrVal + 1);
+ return *this;
+ }
+
+ /// Add an ArrayRef of arbitrary data.
+ template<typename T>
+ GeneralHash& add(ArrayRef<T> ArrayVal) {
+ addBits(ArrayVal.begin(), ArrayVal.end());
+ return *this;
+ }
+
+ /// Add a string
+ GeneralHash& add(StringRef StrVal) {
+ addBits(StrVal.begin(), StrVal.end());
+ return *this;
+ }
+
+ /// Add an signed 32-bit integer.
+ GeneralHash& add(int32_t Data) {
+ addInt(uint32_t(Data));
+ return *this;
+ }
+
+ /// Add an unsigned 32-bit integer.
+ GeneralHash& add(uint32_t Data) {
+ addInt(Data);
+ return *this;
+ }
+
+ /// Add an signed 64-bit integer.
+ GeneralHash& add(int64_t Data) {
+ addInt(uint64_t(Data));
+ return *this;
+ }
+
+ /// Add an unsigned 64-bit integer.
+ GeneralHash& add(uint64_t Data) {
+ addInt(Data);
+ return *this;
+ }
+
+ /// Add a float
+ GeneralHash& add(float Data) {
+ union {
+ float D; uint32_t I;
+ };
+ D = Data;
+ addInt(I);
+ return *this;
+ }
+
+ /// Add a double
+ GeneralHash& add(double Data) {
+ union {
+ double D; uint64_t I;
+ };
+ D = Data;
+ addInt(I);
+ return *this;
+ }
+
+ // Do a few final mixes of the hash to ensure the last few
+ // bytes are well-incorporated.
+ unsigned finish() {
+ mix(Count);
+ Hash ^= Hash >> 13;
+ Hash *= M;
+ Hash ^= Hash >> 15;
+ return Hash;
+ }
+
+private:
+ void mix(uint32_t Data) {
+ ++Count;
+ Data *= M;
+ Data ^= Data >> 24;
+ Data *= M;
+ Hash *= M;
+ Hash ^= Data;
+ }
+
+ // Add a single uint32 value
+ void addInt(uint32_t Val) {
+ mix(Val);
+ }
+
+ // Add a uint64 value
+ void addInt(uint64_t Val) {
+ mix(uint32_t(Val >> 32));
+ mix(uint32_t(Val));
+ }
+
+ template<typename T, bool isAligned>
+ struct addBitsImpl {
+ static void add(GeneralHash &Hash, const T *I, const T *E) {
+ Hash.addUnaligned(
+ reinterpret_cast<const uint8_t *>(I),
+ reinterpret_cast<const uint8_t *>(E));
+ }
+ };
+
+ template<typename T>
+ struct addBitsImpl<T, true> {
+ static void add(GeneralHash &Hash, const T *I, const T *E) {
+ Hash.addAligned(
+ reinterpret_cast<const uint32_t *>(I),
+ reinterpret_cast<const uint32_t *>(E));
+ }
+ };
+
+ // Add a range of bits from I to E.
+ template<typename T>
+ void addBits(const T *I, const T *E) {
+ addBitsImpl<T, AlignOf<T>::Alignment_GreaterEqual_4Bytes>::add(*this, I, E);
+ }
+
+ // Add a range of uint32s
+ void addAligned(const uint32_t *I, const uint32_t *E) {
+ while (I < E) {
+ mix(*I++);
+ }
+ }
+
+ // Add a possibly unaligned sequence of bytes.
+ void addUnaligned(const uint8_t *I, const uint8_t *E);
+};
+
+} // end namespace llvm
+
+#endif
Modified: llvm/trunk/lib/Support/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/CMakeLists.txt?rev=150890&r1=150889&r2=150890&view=diff
==============================================================================
--- llvm/trunk/lib/Support/CMakeLists.txt (original)
+++ llvm/trunk/lib/Support/CMakeLists.txt Sat Feb 18 15:00:49 2012
@@ -26,6 +26,7 @@
FoldingSet.cpp
FormattedStream.cpp
GraphWriter.cpp
+ Hashing.cpp
IntEqClasses.cpp
IntervalMap.cpp
IntrusiveRefCntPtr.cpp
Added: llvm/trunk/lib/Support/Hashing.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/Hashing.cpp?rev=150890&view=auto
==============================================================================
--- llvm/trunk/lib/Support/Hashing.cpp (added)
+++ llvm/trunk/lib/Support/Hashing.cpp Sat Feb 18 15:00:49 2012
@@ -0,0 +1,46 @@
+//===-- llvm/ADT/Hashing.cpp - Utilities for hashing ------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/Hashing.h"
+
+namespace llvm {
+
+// Add a possibly unaligned sequence of bytes.
+void GeneralHash::addUnaligned(const uint8_t *I, const uint8_t *E) {
+ ptrdiff_t Length = E - I;
+ if (uintptr_t(I) & 3 == 0) {
+ while (Length > 3) {
+ mix(*reinterpret_cast<const uint32_t *>(I));
+ I += 4;
+ Length -= 4;
+ }
+ } else {
+ while (Length > 3) {
+ mix(
+ uint32_t(I[0]) +
+ (uint32_t(I[1]) << 8) +
+ (uint32_t(I[2]) << 16) +
+ (uint32_t(I[3]) << 24));
+ I += 4;
+ Length -= 4;
+ }
+ }
+
+ if (Length & 3) {
+ uint32_t Data = 0;
+ switch (Length & 3) {
+ case 3: Data |= uint32_t(I[2]) << 16; // fall through
+ case 2: Data |= uint32_t(I[1]) << 8; // fall through
+ case 1: Data |= uint32_t(I[0]); break;
+ }
+ mix(Data);
+ }
+}
+
+}
Added: llvm/trunk/unittests/ADT/HashingTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/ADT/HashingTest.cpp?rev=150890&view=auto
==============================================================================
--- llvm/trunk/unittests/ADT/HashingTest.cpp (added)
+++ llvm/trunk/unittests/ADT/HashingTest.cpp Sat Feb 18 15:00:49 2012
@@ -0,0 +1,57 @@
+//===- llvm/unittest/ADT/HashingTest.cpp ----------------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Hashing.h unit tests.
+//
+//===----------------------------------------------------------------------===//
+
+#include "gtest/gtest.h"
+#include "llvm/ADT/Hashing.h"
+
+using namespace llvm;
+
+namespace {
+
+TEST(HashingTest, EmptyHashTest) {
+ GeneralHash Hash;
+ ASSERT_EQ(0u, Hash.finish());
+}
+
+TEST(HashingTest, IntegerHashTest) {
+ ASSERT_TRUE(GeneralHash().add(1).finish() == GeneralHash().add(1).finish());
+ ASSERT_TRUE(GeneralHash().add(1).finish() != GeneralHash().add(2).finish());
+}
+
+TEST(HashingTest, StringHashTest) {
+ ASSERT_TRUE(
+ GeneralHash().add("abc").finish() == GeneralHash().add("abc").finish());
+ ASSERT_TRUE(
+ GeneralHash().add("abc").finish() != GeneralHash().add("abcd").finish());
+}
+
+TEST(HashingTest, FloatHashTest) {
+ ASSERT_TRUE(
+ GeneralHash().add(1.0f).finish() == GeneralHash().add(1.0f).finish());
+ ASSERT_TRUE(
+ GeneralHash().add(1.0f).finish() != GeneralHash().add(2.0f).finish());
+}
+
+TEST(HashingTest, DoubleHashTest) {
+ ASSERT_TRUE(GeneralHash().add(1.).finish() == GeneralHash().add(1.).finish());
+ ASSERT_TRUE(GeneralHash().add(1.).finish() != GeneralHash().add(2.).finish());
+}
+
+TEST(HashingTest, IntegerArrayHashTest) {
+ int a[] = { 1, 2 };
+ int b[] = { 1, 3 };
+ ASSERT_TRUE(GeneralHash().add(a).finish() == GeneralHash().add(a).finish());
+ ASSERT_TRUE(GeneralHash().add(a).finish() != GeneralHash().add(b).finish());
+}
+
+}
Modified: llvm/trunk/unittests/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/CMakeLists.txt?rev=150890&r1=150889&r2=150890&view=diff
==============================================================================
--- llvm/trunk/unittests/CMakeLists.txt (original)
+++ llvm/trunk/unittests/CMakeLists.txt Sat Feb 18 15:00:49 2012
@@ -60,6 +60,7 @@
ADT/DenseMapTest.cpp
ADT/DenseSetTest.cpp
ADT/FoldingSet.cpp
+ ADT/HashingTest.cpp
ADT/ilistTest.cpp
ADT/ImmutableSetTest.cpp
ADT/IntEqClassesTest.cpp
More information about the llvm-commits
mailing list