src/share/vm/oops/symbol.cpp

Thu, 21 Mar 2013 09:27:54 +0100

author
roland
date
Thu, 21 Mar 2013 09:27:54 +0100
changeset 4860
46f6f063b272
parent 4675
63e54c37ac64
child 4851
8c03fc47511d
permissions
-rw-r--r--

7153771: array bound check elimination for c1
Summary: when possible optimize out array bound checks, inserting predicates when needed.
Reviewed-by: never, kvn, twisti
Contributed-by: thomaswue <thomas.wuerthinger@oracle.com>

duke@435 1 /*
simonis@4675 2 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
duke@435 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435 4 *
duke@435 5 * This code is free software; you can redistribute it and/or modify it
duke@435 6 * under the terms of the GNU General Public License version 2 only, as
duke@435 7 * published by the Free Software Foundation.
duke@435 8 *
duke@435 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@435 13 * accompanied this code).
duke@435 14 *
duke@435 15 * You should have received a copy of the GNU General Public License version
duke@435 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@435 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435 18 *
trims@1907 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907 20 * or visit www.oracle.com if you need additional information or have any
trims@1907 21 * questions.
duke@435 22 *
duke@435 23 */
duke@435 24
coleenp@2497 25
stefank@2314 26 #include "precompiled.hpp"
coleenp@4037 27 #include "classfile/altHashing.hpp"
coleenp@4037 28 #include "classfile/classLoaderData.hpp"
coleenp@2497 29 #include "oops/symbol.hpp"
simonis@4675 30 #include "runtime/atomic.inline.hpp"
coleenp@2497 31 #include "runtime/os.hpp"
coleenp@2497 32 #include "memory/allocation.inline.hpp"
coleenp@4037 33 #include "memory/resourceArea.hpp"
duke@435 34
coleenp@3682 35 Symbol::Symbol(const u1* name, int length, int refcount) : _refcount(refcount), _length(length) {
coleenp@2497 36 _identity_hash = os::random();
coleenp@2497 37 for (int i = 0; i < _length; i++) {
coleenp@2497 38 byte_at_put(i, name[i]);
coleenp@2497 39 }
coleenp@2497 40 }
coleenp@2497 41
coleenp@3682 42 void* Symbol::operator new(size_t sz, int len, TRAPS) {
coleenp@4037 43 int alloc_size = size(len)*HeapWordSize;
zgu@3900 44 address res = (address) AllocateHeap(alloc_size, mtSymbol);
coleenp@3682 45 return res;
coleenp@3682 46 }
coleenp@3682 47
coleenp@3682 48 void* Symbol::operator new(size_t sz, int len, Arena* arena, TRAPS) {
coleenp@4037 49 int alloc_size = size(len)*HeapWordSize;
coleenp@3682 50 address res = (address)arena->Amalloc(alloc_size);
coleenp@3682 51 return res;
coleenp@2497 52 }
twisti@1573 53
coleenp@4037 54 void* Symbol::operator new(size_t sz, int len, ClassLoaderData* loader_data, TRAPS) {
coleenp@4037 55 address res;
coleenp@4037 56 int alloc_size = size(len)*HeapWordSize;
coleenp@4037 57 res = (address) Metaspace::allocate(loader_data, size(len), true,
coleenp@4037 58 Metaspace::NonClassType, CHECK_NULL);
coleenp@4037 59 return res;
coleenp@4037 60 }
coleenp@4037 61
coleenp@4037 62 void Symbol::operator delete(void *p) {
coleenp@4037 63 assert(((Symbol*)p)->refcount() == 0, "should not call this");
coleenp@4037 64 FreeHeap(p);
coleenp@4037 65 }
coleenp@4037 66
twisti@1573 67 // ------------------------------------------------------------------
coleenp@2497 68 // Symbol::equals
twisti@1573 69 //
twisti@1573 70 // Compares the symbol with a string of the given length.
coleenp@2497 71 bool Symbol::equals(const char* str, int len) const {
duke@435 72 int l = utf8_length();
duke@435 73 if (l != len) return false;
duke@435 74 while (l-- > 0) {
duke@435 75 if (str[l] != (char) byte_at(l))
duke@435 76 return false;
duke@435 77 }
duke@435 78 assert(l == -1, "we should be at the beginning");
duke@435 79 return true;
duke@435 80 }
duke@435 81
twisti@1573 82
twisti@1573 83 // ------------------------------------------------------------------
coleenp@2497 84 // Symbol::starts_with
twisti@1573 85 //
twisti@1573 86 // Tests if the symbol starts with the specified prefix of the given
twisti@1573 87 // length.
coleenp@2497 88 bool Symbol::starts_with(const char* prefix, int len) const {
twisti@1573 89 if (len > utf8_length()) return false;
twisti@1573 90 while (len-- > 0) {
twisti@1573 91 if (prefix[len] != (char) byte_at(len))
twisti@1573 92 return false;
twisti@1573 93 }
twisti@1573 94 assert(len == -1, "we should be at the beginning");
twisti@1573 95 return true;
twisti@1573 96 }
twisti@1573 97
twisti@1573 98
twisti@1573 99 // ------------------------------------------------------------------
coleenp@2497 100 // Symbol::index_of
twisti@1573 101 //
twisti@1573 102 // Finds if the given string is a substring of this symbol's utf8 bytes.
twisti@1573 103 // Return -1 on failure. Otherwise return the first index where str occurs.
coleenp@2497 104 int Symbol::index_of_at(int i, const char* str, int len) const {
twisti@1573 105 assert(i >= 0 && i <= utf8_length(), "oob");
twisti@1573 106 if (len <= 0) return 0;
twisti@1573 107 char first_char = str[0];
coleenp@2497 108 address bytes = (address) ((Symbol*)this)->base();
twisti@1573 109 address limit = bytes + utf8_length() - len; // inclusive limit
twisti@1573 110 address scan = bytes + i;
twisti@1573 111 if (scan > limit)
twisti@1573 112 return -1;
twisti@3969 113 for (; scan <= limit; scan++) {
twisti@1573 114 scan = (address) memchr(scan, first_char, (limit + 1 - scan));
twisti@1573 115 if (scan == NULL)
twisti@1573 116 return -1; // not found
twisti@1573 117 assert(scan >= bytes+i && scan <= limit, "scan oob");
twisti@1573 118 if (memcmp(scan, str, len) == 0)
twisti@1573 119 return (int)(scan - bytes);
twisti@1573 120 }
twisti@3969 121 return -1;
twisti@1573 122 }
twisti@1573 123
twisti@1573 124
coleenp@2497 125 char* Symbol::as_C_string(char* buf, int size) const {
duke@435 126 if (size > 0) {
duke@435 127 int len = MIN2(size - 1, utf8_length());
duke@435 128 for (int i = 0; i < len; i++) {
duke@435 129 buf[i] = byte_at(i);
duke@435 130 }
duke@435 131 buf[len] = '\0';
duke@435 132 }
duke@435 133 return buf;
duke@435 134 }
duke@435 135
coleenp@2497 136 char* Symbol::as_C_string() const {
duke@435 137 int len = utf8_length();
duke@435 138 char* str = NEW_RESOURCE_ARRAY(char, len + 1);
duke@435 139 return as_C_string(str, len + 1);
duke@435 140 }
duke@435 141
coleenp@2497 142 char* Symbol::as_C_string_flexible_buffer(Thread* t,
duke@435 143 char* buf, int size) const {
duke@435 144 char* str;
duke@435 145 int len = utf8_length();
duke@435 146 int buf_len = len + 1;
duke@435 147 if (size < buf_len) {
duke@435 148 str = NEW_RESOURCE_ARRAY(char, buf_len);
duke@435 149 } else {
duke@435 150 str = buf;
duke@435 151 }
duke@435 152 return as_C_string(str, buf_len);
duke@435 153 }
duke@435 154
coleenp@2497 155 void Symbol::print_symbol_on(outputStream* st) const {
vlivanov@4531 156 ResourceMark rm;
duke@435 157 st = st ? st : tty;
minqi@4267 158 st->print("%s", as_quoted_ascii());
minqi@4267 159 }
minqi@4267 160
minqi@4267 161 char* Symbol::as_quoted_ascii() const {
minqi@4267 162 const char *ptr = (const char *)&_body[0];
minqi@4267 163 int quoted_length = UTF8::quoted_ascii_length(ptr, utf8_length());
minqi@4267 164 char* result = NEW_RESOURCE_ARRAY(char, quoted_length + 1);
minqi@4267 165 UTF8::as_quoted_ascii(ptr, result, quoted_length + 1);
minqi@4267 166 return result;
duke@435 167 }
duke@435 168
coleenp@2497 169 jchar* Symbol::as_unicode(int& length) const {
coleenp@2497 170 Symbol* this_ptr = (Symbol*)this;
duke@435 171 length = UTF8::unicode_length((char*)this_ptr->bytes(), utf8_length());
duke@435 172 jchar* result = NEW_RESOURCE_ARRAY(jchar, length);
duke@435 173 if (length > 0) {
duke@435 174 UTF8::convert_to_unicode((char*)this_ptr->bytes(), result, length);
duke@435 175 }
duke@435 176 return result;
duke@435 177 }
duke@435 178
coleenp@2497 179 const char* Symbol::as_klass_external_name(char* buf, int size) const {
duke@435 180 if (size > 0) {
duke@435 181 char* str = as_C_string(buf, size);
duke@435 182 int length = (int)strlen(str);
duke@435 183 // Turn all '/'s into '.'s (also for array klasses)
duke@435 184 for (int index = 0; index < length; index++) {
duke@435 185 if (str[index] == '/') {
duke@435 186 str[index] = '.';
duke@435 187 }
duke@435 188 }
duke@435 189 return str;
duke@435 190 } else {
duke@435 191 return buf;
duke@435 192 }
duke@435 193 }
duke@435 194
coleenp@2497 195 const char* Symbol::as_klass_external_name() const {
duke@435 196 char* str = as_C_string();
duke@435 197 int length = (int)strlen(str);
duke@435 198 // Turn all '/'s into '.'s (also for array klasses)
duke@435 199 for (int index = 0; index < length; index++) {
duke@435 200 if (str[index] == '/') {
duke@435 201 str[index] = '.';
duke@435 202 }
duke@435 203 }
duke@435 204 return str;
duke@435 205 }
coleenp@2497 206
coleenp@4037 207 // Alternate hashing for unbalanced symbol tables.
coleenp@4037 208 unsigned int Symbol::new_hash(jint seed) {
coleenp@4037 209 ResourceMark rm;
coleenp@4037 210 // Use alternate hashing algorithm on this symbol.
coleenp@4037 211 return AltHashing::murmur3_32(seed, (const jbyte*)as_C_string(), utf8_length());
coleenp@4037 212 }
coleenp@2497 213
simonis@4675 214 void Symbol::increment_refcount() {
simonis@4675 215 // Only increment the refcount if positive. If negative either
simonis@4675 216 // overflow has occurred or it is a permanent symbol in a read only
simonis@4675 217 // shared archive.
simonis@4675 218 if (_refcount >= 0) {
simonis@4675 219 Atomic::inc(&_refcount);
simonis@4675 220 NOT_PRODUCT(Atomic::inc(&_total_count);)
simonis@4675 221 }
simonis@4675 222 }
simonis@4675 223
simonis@4675 224 void Symbol::decrement_refcount() {
simonis@4675 225 if (_refcount >= 0) {
simonis@4675 226 Atomic::dec(&_refcount);
simonis@4675 227 #ifdef ASSERT
simonis@4675 228 if (_refcount < 0) {
simonis@4675 229 print();
simonis@4675 230 assert(false, "reference count underflow for symbol");
simonis@4675 231 }
simonis@4675 232 #endif
simonis@4675 233 }
simonis@4675 234 }
simonis@4675 235
coleenp@2497 236 void Symbol::print_on(outputStream* st) const {
coleenp@2497 237 if (this == NULL) {
coleenp@2497 238 st->print_cr("NULL");
coleenp@2497 239 } else {
coleenp@2497 240 st->print("Symbol: '");
coleenp@2497 241 print_symbol_on(st);
coleenp@2497 242 st->print("'");
coleenp@2497 243 st->print(" count %d", refcount());
coleenp@2497 244 }
coleenp@2497 245 }
coleenp@2497 246
coleenp@2497 247 // The print_value functions are present in all builds, to support the
coleenp@2497 248 // disassembler and error reporting.
coleenp@2497 249 void Symbol::print_value_on(outputStream* st) const {
coleenp@2497 250 if (this == NULL) {
coleenp@2497 251 st->print("NULL");
coleenp@2497 252 } else {
coleenp@2497 253 st->print("'");
coleenp@2497 254 for (int i = 0; i < utf8_length(); i++) {
coleenp@2497 255 st->print("%c", byte_at(i));
coleenp@2497 256 }
coleenp@2497 257 st->print("'");
coleenp@2497 258 }
coleenp@2497 259 }
coleenp@2497 260
coleenp@3682 261 // SymbolTable prints this in its statistics
coleenp@2497 262 NOT_PRODUCT(int Symbol::_total_count = 0;)

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