Mercurial > hg > truffle
view src/share/vm/classfile/altHashing.cpp @ 9300:d73ad771a602
return immutable collections from (some) CompilationResult getters
author | Doug Simon <doug.simon@oracle.com> |
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date | Thu, 25 Apr 2013 17:45:44 +0200 |
parents | da91efe96a93 |
children | 6f817ce50129 |
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/* * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #include "classfile/altHashing.hpp" #include "classfile/symbolTable.hpp" #include "classfile/systemDictionary.hpp" #include "oops/markOop.hpp" #include "runtime/thread.hpp" // Get the hash code of the classes mirror if it exists, otherwise just // return a random number, which is one of the possible hash code used for // objects. We don't want to call the synchronizer hash code to install // this value because it may safepoint. intptr_t object_hash(Klass* k) { intptr_t hc = k->java_mirror()->mark()->hash(); return hc != markOopDesc::no_hash ? hc : os::random(); } // Seed value used for each alternative hash calculated. jint AltHashing::compute_seed() { jlong nanos = os::javaTimeNanos(); jlong now = os::javaTimeMillis(); jint SEED_MATERIAL[8] = { (jint) object_hash(SystemDictionary::String_klass()), (jint) object_hash(SystemDictionary::System_klass()), (jint) os::random(), // current thread isn't a java thread (jint) (((julong)nanos) >> 32), (jint) nanos, (jint) (((julong)now) >> 32), (jint) now, (jint) (os::javaTimeNanos() >> 2) }; return murmur3_32(SEED_MATERIAL, 8); } // Murmur3 hashing for Symbol jint AltHashing::murmur3_32(jint seed, const jbyte* data, int len) { jint h1 = seed; int count = len; int offset = 0; // body while (count >= 4) { jint k1 = (data[offset] & 0x0FF) | (data[offset + 1] & 0x0FF) << 8 | (data[offset + 2] & 0x0FF) << 16 | data[offset + 3] << 24; count -= 4; offset += 4; k1 *= 0xcc9e2d51; k1 = Integer_rotateLeft(k1, 15); k1 *= 0x1b873593; h1 ^= k1; h1 = Integer_rotateLeft(h1, 13); h1 = h1 * 5 + 0xe6546b64; } // tail if (count > 0) { jint k1 = 0; switch (count) { case 3: k1 ^= (data[offset + 2] & 0xff) << 16; // fall through case 2: k1 ^= (data[offset + 1] & 0xff) << 8; // fall through case 1: k1 ^= (data[offset] & 0xff); // fall through default: k1 *= 0xcc9e2d51; k1 = Integer_rotateLeft(k1, 15); k1 *= 0x1b873593; h1 ^= k1; } } // finalization h1 ^= len; // finalization mix force all bits of a hash block to avalanche h1 ^= ((unsigned int)h1) >> 16; h1 *= 0x85ebca6b; h1 ^= ((unsigned int)h1) >> 13; h1 *= 0xc2b2ae35; h1 ^= ((unsigned int)h1) >> 16; return h1; } // Murmur3 hashing for Strings jint AltHashing::murmur3_32(jint seed, const jchar* data, int len) { jint h1 = seed; int off = 0; int count = len; // body while (count >= 2) { jchar d1 = data[off++] & 0xFFFF; jchar d2 = data[off++]; jint k1 = (d1 | d2 << 16); count -= 2; k1 *= 0xcc9e2d51; k1 = Integer_rotateLeft(k1, 15); k1 *= 0x1b873593; h1 ^= k1; h1 = Integer_rotateLeft(h1, 13); h1 = h1 * 5 + 0xe6546b64; } // tail if (count > 0) { int k1 = data[off]; k1 *= 0xcc9e2d51; k1 = Integer_rotateLeft(k1, 15); k1 *= 0x1b873593; h1 ^= k1; } // finalization h1 ^= len * 2; // (Character.SIZE / Byte.SIZE); // finalization mix force all bits of a hash block to avalanche h1 ^= ((unsigned int)h1) >> 16; h1 *= 0x85ebca6b; h1 ^= ((unsigned int)h1) >> 13; h1 *= 0xc2b2ae35; h1 ^= ((unsigned int)h1) >> 16; return h1; } // Hash used for the seed. jint AltHashing::murmur3_32(jint seed, const int* data, int len) { jint h1 = seed; int off = 0; int end = len; // body while (off < end) { jint k1 = data[off++]; k1 *= 0xcc9e2d51; k1 = Integer_rotateLeft(k1, 15); k1 *= 0x1b873593; h1 ^= k1; h1 = Integer_rotateLeft(h1, 13); h1 = h1 * 5 + 0xe6546b64; } // tail (always empty, as body is always 32-bit chunks) // finalization h1 ^= len * 4; // (Integer.SIZE / Byte.SIZE); // finalization mix force all bits of a hash block to avalanche h1 ^= ((juint)h1) >> 16; h1 *= 0x85ebca6b; h1 ^= ((juint)h1) >> 13; h1 *= 0xc2b2ae35; h1 ^= ((juint)h1) >> 16; return h1; } jint AltHashing::murmur3_32(const int* data, int len) { return murmur3_32(0, data, len); } #ifndef PRODUCT // Overloaded versions for internal test. jint AltHashing::murmur3_32(const jbyte* data, int len) { return murmur3_32(0, data, len); } jint AltHashing::murmur3_32(const jchar* data, int len) { return murmur3_32(0, data, len); } // Internal test for alternate hashing. Translated from JDK version // test/sun/misc/Hashing.java static const jbyte ONE_BYTE[] = { (jbyte) 0x80}; static const jbyte TWO_BYTE[] = { (jbyte) 0x80, (jbyte) 0x81}; static const jchar ONE_CHAR[] = { (jchar) 0x8180}; static const jbyte THREE_BYTE[] = { (jbyte) 0x80, (jbyte) 0x81, (jbyte) 0x82}; static const jbyte FOUR_BYTE[] = { (jbyte) 0x80, (jbyte) 0x81, (jbyte) 0x82, (jbyte) 0x83}; static const jchar TWO_CHAR[] = { (jchar) 0x8180, (jchar) 0x8382}; static const jint ONE_INT[] = { 0x83828180}; static const jbyte SIX_BYTE[] = { (jbyte) 0x80, (jbyte) 0x81, (jbyte) 0x82, (jbyte) 0x83, (jbyte) 0x84, (jbyte) 0x85}; static const jchar THREE_CHAR[] = { (jchar) 0x8180, (jchar) 0x8382, (jchar) 0x8584}; static const jbyte EIGHT_BYTE[] = { (jbyte) 0x80, (jbyte) 0x81, (jbyte) 0x82, (jbyte) 0x83, (jbyte) 0x84, (jbyte) 0x85, (jbyte) 0x86, (jbyte) 0x87}; static const jchar FOUR_CHAR[] = { (jchar) 0x8180, (jchar) 0x8382, (jchar) 0x8584, (jchar) 0x8786}; static const jint TWO_INT[] = { 0x83828180, 0x87868584}; static const juint MURMUR3_32_X86_CHECK_VALUE = 0xB0F57EE3; void AltHashing::testMurmur3_32_ByteArray() { // printf("testMurmur3_32_ByteArray\n"); jbyte* vector = new jbyte[256]; jbyte* hashes = new jbyte[4 * 256]; for (int i = 0; i < 256; i++) { vector[i] = (jbyte) i; } // Hash subranges {}, {0}, {0,1}, {0,1,2}, ..., {0,...,255} for (int i = 0; i < 256; i++) { jint hash = murmur3_32(256 - i, vector, i); hashes[i * 4] = (jbyte) hash; hashes[i * 4 + 1] = (jbyte) (((juint)hash) >> 8); hashes[i * 4 + 2] = (jbyte) (((juint)hash) >> 16); hashes[i * 4 + 3] = (jbyte) (((juint)hash) >> 24); } // hash to get const result. juint final_hash = murmur3_32(hashes, 4*256); assert (MURMUR3_32_X86_CHECK_VALUE == final_hash, err_msg( "Calculated hash result not as expected. Expected %08X got %08X\n", MURMUR3_32_X86_CHECK_VALUE, final_hash)); } void AltHashing::testEquivalentHashes() { jint jbytes, jchars, ints; // printf("testEquivalentHashes\n"); jbytes = murmur3_32(TWO_BYTE, 2); jchars = murmur3_32(ONE_CHAR, 1); assert (jbytes == jchars, err_msg("Hashes did not match. b:%08x != c:%08x\n", jbytes, jchars)); jbytes = murmur3_32(FOUR_BYTE, 4); jchars = murmur3_32(TWO_CHAR, 2); ints = murmur3_32(ONE_INT, 1); assert ((jbytes == jchars) && (jbytes == ints), err_msg("Hashes did not match. b:%08x != c:%08x != i:%08x\n", jbytes, jchars, ints)); jbytes = murmur3_32(SIX_BYTE, 6); jchars = murmur3_32(THREE_CHAR, 3); assert (jbytes == jchars, err_msg("Hashes did not match. b:%08x != c:%08x\n", jbytes, jchars)); jbytes = murmur3_32(EIGHT_BYTE, 8); jchars = murmur3_32(FOUR_CHAR, 4); ints = murmur3_32(TWO_INT, 2); assert ((jbytes == jchars) && (jbytes == ints), err_msg("Hashes did not match. b:%08x != c:%08x != i:%08x\n", jbytes, jchars, ints)); } // Returns true if the alternate hashcode is correct void AltHashing::test_alt_hash() { testMurmur3_32_ByteArray(); testEquivalentHashes(); } #endif // PRODUCT