Add xxhash to llvm.

It will be used for fast fingerprinting in lld at least.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282493 91177308-0d34-0410-b5e6-96231b3b80d8

Author: espindola

include/llvm/Support/xxhash.h

@@ -0,0 +1,47 @@
+/*
+   xxHash - Extremely Fast Hash algorithm
+   Header File
+   Copyright (C) 2012-2016, Yann Collet.
+
+   BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
+
+   Redistribution and use in source and binary forms, with or without
+   modification, are permitted provided that the following conditions are
+   met:
+
+       * Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+       * Redistributions in binary form must reproduce the above
+   copyright notice, this list of conditions and the following disclaimer
+   in the documentation and/or other materials provided with the
+   distribution.
+
+   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+   You can contact the author at :
+   - xxHash source repository : https://github.com/Cyan4973/xxHash
+*/
+
+/* based on revision d2df04efcbef7d7f6886d345861e5dfda4edacc1 Removed
+ * everything but a simple interface for computing XXh64. */
+
+#ifndef LLVM_SUPPORT_XXHASH_H
+#define LLVM_SUPPORT_XXHASH_H
+
+#include "llvm/ADT/StringRef.h"
+
+namespace llvm {
+uint64_t xxHash64(llvm::StringRef Data);
+}
+
+#endif

lib/Support/CMakeLists.txt

@@ -106,6 +106,7 @@ add_llvm_library(LLVMSupport
   regexec.c
   regfree.c
   regstrlcpy.c
+  xxhash.cpp
 
 # System
   Atomic.cpp

lib/Support/xxhash.cpp

@@ -0,0 +1,134 @@
+/*
+*  xxHash - Fast Hash algorithm
+*  Copyright (C) 2012-2016, Yann Collet
+*
+*  BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
+*
+*  Redistribution and use in source and binary forms, with or without
+*  modification, are permitted provided that the following conditions are
+*  met:
+*
+*  * Redistributions of source code must retain the above copyright
+*  notice, this list of conditions and the following disclaimer.
+*  * Redistributions in binary form must reproduce the above
+*  copyright notice, this list of conditions and the following disclaimer
+*  in the documentation and/or other materials provided with the
+*  distribution.
+*
+*  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+*  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+*  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+*  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+*  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+*  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+*  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+*  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+*  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+*  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+*  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*
+*  You can contact the author at :
+*  - xxHash homepage: http://www.xxhash.com
+*  - xxHash source repository : https://github.com/Cyan4973/xxHash
+*/
+
+/* based on revision d2df04efcbef7d7f6886d345861e5dfda4edacc1 Removed
+ * everything but a simple interface for computing XXh64. */
+
+#include "llvm/Support/xxhash.h"
+#include "llvm/Support/Endian.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+using namespace llvm;
+using namespace support;
+
+static uint64_t rotl64(uint64_t X, size_t R) {
+  return (X << R) | (X >> (64 - R));
+}
+
+static const uint64_t PRIME64_1 = 11400714785074694791ULL;
+static const uint64_t PRIME64_2 = 14029467366897019727ULL;
+static const uint64_t PRIME64_3 = 1609587929392839161ULL;
+static const uint64_t PRIME64_4 = 9650029242287828579ULL;
+static const uint64_t PRIME64_5 = 2870177450012600261ULL;
+
+static uint64_t round(uint64_t Acc, uint64_t Input) {
+  Acc += Input * PRIME64_2;
+  Acc = rotl64(Acc, 31);
+  Acc *= PRIME64_1;
+  return Acc;
+}
+
+static uint64_t mergeRound(uint64_t Acc, uint64_t Val) {
+  Val = round(0, Val);
+  Acc ^= Val;
+  Acc = Acc * PRIME64_1 + PRIME64_4;
+  return Acc;
+}
+
+uint64_t llvm::xxHash64(StringRef Data) {
+  size_t Len = Data.size();
+  uint64_t Seed = 0;
+  const char *P = Data.data();
+  const char *const BEnd = P + Len;
+  uint64_t H64;
+
+  if (Len >= 32) {
+    const char *const Limit = BEnd - 32;
+    uint64_t V1 = Seed + PRIME64_1 + PRIME64_2;
+    uint64_t V2 = Seed + PRIME64_2;
+    uint64_t V3 = Seed + 0;
+    uint64_t V4 = Seed - PRIME64_1;
+
+    do {
+      V1 = round(V1, endian::read64le(P));
+      P += 8;
+      V2 = round(V2, endian::read64le(P));
+      P += 8;
+      V3 = round(V3, endian::read64le(P));
+      P += 8;
+      V4 = round(V4, endian::read64le(P));
+      P += 8;
+    } while (P <= Limit);
+
+    H64 = rotl64(V1, 1) + rotl64(V2, 7) + rotl64(V3, 12) + rotl64(V4, 18);
+    H64 = mergeRound(H64, V1);
+    H64 = mergeRound(H64, V2);
+    H64 = mergeRound(H64, V3);
+    H64 = mergeRound(H64, V4);
+
+  } else {
+    H64 = Seed + PRIME64_5;
+  }
+
+  H64 += (uint64_t)Len;
+
+  while (P + 8 <= BEnd) {
+    uint64_t const K1 = round(0, endian::read64le(P));
+    H64 ^= K1;
+    H64 = rotl64(H64, 27) * PRIME64_1 + PRIME64_4;
+    P += 8;
+  }
+
+  if (P + 4 <= BEnd) {
+    H64 ^= (uint64_t)(endian::read32le(P)) * PRIME64_1;
+    H64 = rotl64(H64, 23) * PRIME64_2 + PRIME64_3;
+    P += 4;
+  }
+
+  while (P < BEnd) {
+    H64 ^= (*P) * PRIME64_5;
+    H64 = rotl64(H64, 11) * PRIME64_1;
+    P++;
+  }
+
+  H64 ^= H64 >> 33;
+  H64 *= PRIME64_2;
+  H64 ^= H64 >> 29;
+  H64 *= PRIME64_3;
+  H64 ^= H64 >> 32;
+
+  return H64;
+}

unittests/Support/CMakeLists.txt

@@ -52,6 +52,7 @@ add_llvm_unittest(SupportTests
   raw_ostream_test.cpp
   raw_pwrite_stream_test.cpp
   raw_sha1_ostream_test.cpp
+  xxhashTest.cpp
   )
 
 # ManagedStatic.cpp uses <pthread>.

unittests/Support/xxhashTest.cpp

@@ -0,0 +1,20 @@
+//===- llvm/unittest/Support/xxhashTest.cpp -------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/xxhash.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+
+TEST(xxhashTest, Basic) {
+  EXPECT_EQ(0x33bf00a859c4ba3fU, xxHash64("foo"));
+  EXPECT_EQ(0x48a37c90ad27a659U, xxHash64("bar"));
+  EXPECT_EQ(0x69196c1b3af0bff9U,
+            xxHash64("0123456789abcdefghijklmnopqrstuvwxyz"));
+}