coleenp@3865: /*
minqi@5103:  * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
coleenp@3865:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
coleenp@3865:  *
coleenp@3865:  * This code is free software; you can redistribute it and/or modify it
coleenp@3865:  * under the terms of the GNU General Public License version 2 only, as
coleenp@3865:  * published by the Free Software Foundation.
coleenp@3865:  *
coleenp@3865:  * This code is distributed in the hope that it will be useful, but WITHOUT
coleenp@3865:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
coleenp@3865:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
coleenp@3865:  * version 2 for more details (a copy is included in the LICENSE file that
coleenp@3865:  * accompanied this code).
coleenp@3865:  *
coleenp@3865:  * You should have received a copy of the GNU General Public License version
coleenp@3865:  * 2 along with this work; if not, write to the Free Software Foundation,
coleenp@3865:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
coleenp@3865:  *
coleenp@3865:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
coleenp@3865:  * or visit www.oracle.com if you need additional information or have any
coleenp@3865:  * questions.
coleenp@3865:  *
coleenp@3865:  */
coleenp@3865: 
coleenp@3865: #include "precompiled.hpp"
coleenp@3865: #include "classfile/altHashing.hpp"
coleenp@3865: #include "classfile/symbolTable.hpp"
coleenp@3865: #include "classfile/systemDictionary.hpp"
coleenp@3865: #include "oops/markOop.hpp"
coleenp@3865: #include "runtime/thread.hpp"
coleenp@3865: 
coleenp@3865: // Get the hash code of the classes mirror if it exists, otherwise just
coleenp@3865: // return a random number, which is one of the possible hash code used for
coleenp@3865: // objects.  We don't want to call the synchronizer hash code to install
coleenp@3865: // this value because it may safepoint.
coleenp@4037: intptr_t object_hash(Klass* k) {
coleenp@3865:   intptr_t hc = k->java_mirror()->mark()->hash();
coleenp@3865:   return hc != markOopDesc::no_hash ? hc : os::random();
coleenp@3865: }
coleenp@3865: 
coleenp@3865: // Seed value used for each alternative hash calculated.
coleenp@3865: jint AltHashing::compute_seed() {
coleenp@3865:   jlong nanos = os::javaTimeNanos();
coleenp@3865:   jlong now = os::javaTimeMillis();
coleenp@3865:   jint SEED_MATERIAL[8] = {
coleenp@3865:             (jint) object_hash(SystemDictionary::String_klass()),
coleenp@3865:             (jint) object_hash(SystemDictionary::System_klass()),
coleenp@3865:             (jint) os::random(),  // current thread isn't a java thread
coleenp@3865:             (jint) (((julong)nanos) >> 32),
coleenp@3865:             (jint) nanos,
coleenp@3865:             (jint) (((julong)now) >> 32),
coleenp@3865:             (jint) now,
coleenp@3865:             (jint) (os::javaTimeNanos() >> 2)
coleenp@3865:   };
coleenp@3865: 
coleenp@3865:   return murmur3_32(SEED_MATERIAL, 8);
coleenp@3865: }
coleenp@3865: 
coleenp@3865: 
coleenp@3865: // Murmur3 hashing for Symbol
coleenp@3865: jint AltHashing::murmur3_32(jint seed, const jbyte* data, int len) {
coleenp@3865:   jint h1 = seed;
coleenp@3865:   int count = len;
coleenp@3865:   int offset = 0;
coleenp@3865: 
coleenp@3865:   // body
coleenp@3865:   while (count >= 4) {
coleenp@3865:     jint k1 = (data[offset] & 0x0FF)
coleenp@3865:         | (data[offset + 1] & 0x0FF) << 8
coleenp@3865:         | (data[offset + 2] & 0x0FF) << 16
coleenp@3865:         | data[offset + 3] << 24;
coleenp@3865: 
coleenp@3865:     count -= 4;
coleenp@3865:     offset += 4;
coleenp@3865: 
coleenp@3865:     k1 *= 0xcc9e2d51;
coleenp@3865:     k1 = Integer_rotateLeft(k1, 15);
coleenp@3865:     k1 *= 0x1b873593;
coleenp@3865: 
coleenp@3865:     h1 ^= k1;
coleenp@3865:     h1 = Integer_rotateLeft(h1, 13);
coleenp@3865:     h1 = h1 * 5 + 0xe6546b64;
coleenp@3865:   }
coleenp@3865: 
coleenp@3865:   // tail
coleenp@3865: 
coleenp@3865:   if (count > 0) {
coleenp@3865:     jint k1 = 0;
coleenp@3865: 
coleenp@3865:     switch (count) {
coleenp@3865:       case 3:
coleenp@3865:         k1 ^= (data[offset + 2] & 0xff) << 16;
coleenp@3865:       // fall through
coleenp@3865:       case 2:
coleenp@3865:         k1 ^= (data[offset + 1] & 0xff) << 8;
coleenp@3865:       // fall through
coleenp@3865:       case 1:
coleenp@3865:         k1 ^= (data[offset] & 0xff);
coleenp@3865:       // fall through
coleenp@3865:       default:
coleenp@3865:         k1 *= 0xcc9e2d51;
coleenp@3865:         k1 = Integer_rotateLeft(k1, 15);
coleenp@3865:         k1 *= 0x1b873593;
coleenp@3865:         h1 ^= k1;
coleenp@3865:     }
coleenp@3865:   }
coleenp@3865: 
coleenp@3865:   // finalization
coleenp@3865:   h1 ^= len;
coleenp@3865: 
coleenp@3865:   // finalization mix force all bits of a hash block to avalanche
coleenp@3865:   h1 ^= ((unsigned int)h1) >> 16;
coleenp@3865:   h1 *= 0x85ebca6b;
coleenp@3865:   h1 ^= ((unsigned int)h1) >> 13;
coleenp@3865:   h1 *= 0xc2b2ae35;
coleenp@3865:   h1 ^= ((unsigned int)h1) >> 16;
coleenp@3865: 
coleenp@3865:   return h1;
coleenp@3865: }
coleenp@3865: 
coleenp@3865: // Murmur3 hashing for Strings
coleenp@3865: jint AltHashing::murmur3_32(jint seed, const jchar* data, int len) {
coleenp@3865:   jint h1 = seed;
coleenp@3865: 
coleenp@3865:   int off = 0;
coleenp@3865:   int count = len;
coleenp@3865: 
coleenp@3865:   // body
coleenp@3865:   while (count >= 2) {
coleenp@3865:     jchar d1 = data[off++] & 0xFFFF;
coleenp@3865:     jchar d2 = data[off++];
coleenp@3865:     jint k1 = (d1 | d2 << 16);
coleenp@3865: 
coleenp@3865:     count -= 2;
coleenp@3865: 
coleenp@3865:     k1 *= 0xcc9e2d51;
coleenp@3865:     k1 = Integer_rotateLeft(k1, 15);
coleenp@3865:     k1 *= 0x1b873593;
coleenp@3865: 
coleenp@3865:     h1 ^= k1;
coleenp@3865:     h1 = Integer_rotateLeft(h1, 13);
coleenp@3865:     h1 = h1 * 5 + 0xe6546b64;
coleenp@3865:   }
coleenp@3865: 
coleenp@3865:   // tail
coleenp@3865: 
coleenp@3865:   if (count > 0) {
coleenp@3865:     int k1 = data[off];
coleenp@3865: 
coleenp@3865:     k1 *= 0xcc9e2d51;
coleenp@3865:     k1 = Integer_rotateLeft(k1, 15);
coleenp@3865:     k1 *= 0x1b873593;
coleenp@3865:     h1 ^= k1;
coleenp@3865:   }
coleenp@3865: 
coleenp@3865:   // finalization
coleenp@3865:   h1 ^= len * 2; // (Character.SIZE / Byte.SIZE);
coleenp@3865: 
coleenp@3865:   // finalization mix force all bits of a hash block to avalanche
coleenp@3865:   h1 ^= ((unsigned int)h1) >> 16;
coleenp@3865:   h1 *= 0x85ebca6b;
coleenp@3865:   h1 ^= ((unsigned int)h1) >> 13;
coleenp@3865:   h1 *= 0xc2b2ae35;
coleenp@3865:   h1 ^= ((unsigned int)h1) >> 16;
coleenp@3865: 
coleenp@3865:   return h1;
coleenp@3865: }
coleenp@3865: 
coleenp@3865: // Hash used for the seed.
coleenp@3865: jint AltHashing::murmur3_32(jint seed, const int* data, int len) {
coleenp@3865:   jint h1 = seed;
coleenp@3865: 
coleenp@3865:   int off = 0;
coleenp@3865:   int end = len;
coleenp@3865: 
coleenp@3865:   // body
coleenp@3865:   while (off < end) {
coleenp@3865:     jint k1 = data[off++];
coleenp@3865: 
coleenp@3865:     k1 *= 0xcc9e2d51;
coleenp@3865:     k1 = Integer_rotateLeft(k1, 15);
coleenp@3865:     k1 *= 0x1b873593;
coleenp@3865: 
coleenp@3865:     h1 ^= k1;
coleenp@3865:     h1 = Integer_rotateLeft(h1, 13);
coleenp@3865:     h1 = h1 * 5 + 0xe6546b64;
coleenp@3865:   }
coleenp@3865: 
coleenp@3865:   // tail (always empty, as body is always 32-bit chunks)
coleenp@3865: 
coleenp@3865:   // finalization
coleenp@3865: 
coleenp@3865:   h1 ^= len * 4; // (Integer.SIZE / Byte.SIZE);
coleenp@3865: 
coleenp@3865:   // finalization mix force all bits of a hash block to avalanche
coleenp@3865:   h1 ^= ((juint)h1) >> 16;
coleenp@3865:   h1 *= 0x85ebca6b;
coleenp@3865:   h1 ^= ((juint)h1) >> 13;
coleenp@3865:   h1 *= 0xc2b2ae35;
coleenp@3865:   h1 ^= ((juint)h1) >> 16;
coleenp@3865: 
coleenp@3865:   return h1;
coleenp@3865: }
coleenp@3865: 
coleenp@3865: jint AltHashing::murmur3_32(const int* data, int len) {
coleenp@3865:   return murmur3_32(0, data, len);
coleenp@3865: }
coleenp@3865: 
coleenp@3865: #ifndef PRODUCT
coleenp@3865: // Overloaded versions for internal test.
coleenp@3865: jint AltHashing::murmur3_32(const jbyte* data, int len) {
coleenp@3865:   return murmur3_32(0, data, len);
coleenp@3865: }
coleenp@3865: 
coleenp@3865: jint AltHashing::murmur3_32(const jchar* data, int len) {
coleenp@3865:   return murmur3_32(0, data, len);
coleenp@3865: }
coleenp@3865: 
coleenp@3865: // Internal test for alternate hashing.  Translated from JDK version
coleenp@3865: // test/sun/misc/Hashing.java
coleenp@3865: static const jbyte ONE_BYTE[] = { (jbyte) 0x80};
coleenp@3865: static const jbyte TWO_BYTE[] = { (jbyte) 0x80, (jbyte) 0x81};
coleenp@3865: static const jchar ONE_CHAR[] = { (jchar) 0x8180};
coleenp@3865: static const jbyte THREE_BYTE[] = { (jbyte) 0x80, (jbyte) 0x81, (jbyte) 0x82};
coleenp@3865: static const jbyte FOUR_BYTE[] = { (jbyte) 0x80, (jbyte) 0x81, (jbyte) 0x82, (jbyte) 0x83};
coleenp@3865: static const jchar TWO_CHAR[] = { (jchar) 0x8180, (jchar) 0x8382};
coleenp@3865: static const jint ONE_INT[] = { 0x83828180};
coleenp@3865: static const jbyte SIX_BYTE[] = { (jbyte) 0x80, (jbyte) 0x81, (jbyte) 0x82, (jbyte) 0x83, (jbyte) 0x84, (jbyte) 0x85};
coleenp@3865: static const jchar THREE_CHAR[] = { (jchar) 0x8180, (jchar) 0x8382, (jchar) 0x8584};
coleenp@3865: static const jbyte EIGHT_BYTE[] = {
coleenp@3865:   (jbyte) 0x80, (jbyte) 0x81, (jbyte) 0x82,
coleenp@3865:   (jbyte) 0x83, (jbyte) 0x84, (jbyte) 0x85,
coleenp@3865:   (jbyte) 0x86, (jbyte) 0x87};
coleenp@3865: static const jchar FOUR_CHAR[] = {
coleenp@3865:   (jchar) 0x8180, (jchar) 0x8382,
coleenp@3865:   (jchar) 0x8584, (jchar) 0x8786};
coleenp@3865: 
coleenp@3865: static const jint TWO_INT[] = { 0x83828180, 0x87868584};
coleenp@3865: 
coleenp@3865: static const juint MURMUR3_32_X86_CHECK_VALUE = 0xB0F57EE3;
coleenp@3865: 
coleenp@3865: void AltHashing::testMurmur3_32_ByteArray() {
coleenp@3865:   // printf("testMurmur3_32_ByteArray\n");
coleenp@3865: 
minqi@5103:   jbyte vector[256];
minqi@5103:   jbyte hashes[4 * 256];
coleenp@3865: 
coleenp@3865:   for (int i = 0; i < 256; i++) {
coleenp@3865:     vector[i] = (jbyte) i;
coleenp@3865:   }
coleenp@3865: 
coleenp@3865:   // Hash subranges {}, {0}, {0,1}, {0,1,2}, ..., {0,...,255}
coleenp@3865:   for (int i = 0; i < 256; i++) {
coleenp@3865:     jint hash = murmur3_32(256 - i, vector, i);
coleenp@3865:     hashes[i * 4] = (jbyte) hash;
coleenp@3865:     hashes[i * 4 + 1] = (jbyte) (((juint)hash) >> 8);
coleenp@3865:     hashes[i * 4 + 2] = (jbyte) (((juint)hash) >> 16);
coleenp@3865:     hashes[i * 4 + 3] = (jbyte) (((juint)hash) >> 24);
coleenp@3865:   }
coleenp@3865: 
coleenp@3865:   // hash to get const result.
coleenp@3865:   juint final_hash = murmur3_32(hashes, 4*256);
coleenp@3865: 
coleenp@3865:   assert (MURMUR3_32_X86_CHECK_VALUE == final_hash,
coleenp@3865:     err_msg(
coleenp@3865:         "Calculated hash result not as expected. Expected %08X got %08X\n",
coleenp@3865:         MURMUR3_32_X86_CHECK_VALUE,
coleenp@3865:         final_hash));
coleenp@3865: }
coleenp@3865: 
coleenp@3865: void AltHashing::testEquivalentHashes() {
coleenp@3865:   jint jbytes, jchars, ints;
coleenp@3865: 
coleenp@3865:   // printf("testEquivalentHashes\n");
coleenp@3865: 
coleenp@3865:   jbytes = murmur3_32(TWO_BYTE, 2);
coleenp@3865:   jchars = murmur3_32(ONE_CHAR, 1);
coleenp@3865:   assert (jbytes == jchars,
coleenp@3865:     err_msg("Hashes did not match. b:%08x != c:%08x\n", jbytes, jchars));
coleenp@3865: 
coleenp@3865:   jbytes = murmur3_32(FOUR_BYTE, 4);
coleenp@3865:   jchars = murmur3_32(TWO_CHAR, 2);
coleenp@3865:   ints = murmur3_32(ONE_INT, 1);
coleenp@3865:   assert ((jbytes == jchars) && (jbytes == ints),
coleenp@3865:     err_msg("Hashes did not match. b:%08x != c:%08x != i:%08x\n", jbytes, jchars, ints));
coleenp@3865: 
coleenp@3865:   jbytes = murmur3_32(SIX_BYTE, 6);
coleenp@3865:   jchars = murmur3_32(THREE_CHAR, 3);
coleenp@3865:   assert (jbytes == jchars,
coleenp@3865:     err_msg("Hashes did not match. b:%08x != c:%08x\n", jbytes, jchars));
coleenp@3865: 
coleenp@3865:   jbytes = murmur3_32(EIGHT_BYTE, 8);
coleenp@3865:   jchars = murmur3_32(FOUR_CHAR, 4);
coleenp@3865:   ints = murmur3_32(TWO_INT, 2);
coleenp@3865:   assert ((jbytes == jchars) && (jbytes == ints),
coleenp@3865:     err_msg("Hashes did not match. b:%08x != c:%08x != i:%08x\n", jbytes, jchars, ints));
coleenp@3865: }
coleenp@3865: 
coleenp@3865: // Returns true if the alternate hashcode is correct
coleenp@3865: void AltHashing::test_alt_hash() {
coleenp@3865:   testMurmur3_32_ByteArray();
coleenp@3865:   testEquivalentHashes();
coleenp@3865: }
coleenp@3865: #endif // PRODUCT