runtime/Operations.h

   1 /*
   2  *  Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
   3  *  Copyright (C) 2002, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
   4  *
   5  *  This library is free software; you can redistribute it and/or
   6  *  modify it under the terms of the GNU Library General Public
   7  *  License as published by the Free Software Foundation; either
   8  *  version 2 of the License, or (at your option) any later version.
   9  *
  10  *  This library is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  *  Library General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU Library General Public License
  16  *  along with this library; see the file COPYING.LIB.  If not, write to
  17  *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  18  *  Boston, MA 02110-1301, USA.
  19  *
  20  */
  21
  22 #ifndef Operations_h
  23 #define Operations_h
  24
  25 #include "Interpreter.h"
  26 #include "JSImmediate.h"
  27 #include "JSNumberCell.h"
  28 #include "JSString.h"
  29
  30 namespace JSC {
  31
  32     NEVER_INLINE JSValue throwOutOfMemoryError(ExecState*);
  33     NEVER_INLINE JSValue jsAddSlowCase(CallFrame*, JSValue, JSValue);
  34     JSValue jsTypeStringForValue(CallFrame*, JSValue);
  35     bool jsIsObjectType(JSValue);
  36     bool jsIsFunctionType(JSValue);
  37
  38     ALWAYS_INLINE JSValue jsString(ExecState* exec, JSString* s1, JSString* s2)
  39     {
  40         if (!s1->length())
  41             return s2;
  42         if (!s2->length())
  43             return s1;
  44
  45         unsigned ropeLength = s1->ropeLength() + s2->ropeLength();
  46         JSGlobalData* globalData = &exec->globalData();
  47
  48         if (ropeLength <= JSString::s_maxInternalRopeLength)
  49             return new (globalData) JSString(globalData, ropeLength, s1, s2);
  50
  51         unsigned index = 0;
  52         RefPtr<JSString::Rope> rope = JSString::Rope::createOrNull(ropeLength);
  53         if (UNLIKELY(!rope))
  54             return throwOutOfMemoryError(exec);
  55         rope->append(index, s1);
  56         rope->append(index, s2);
  57         ASSERT(index == ropeLength);
  58         return new (globalData) JSString(globalData, rope.release());
  59     }
  60
  61     ALWAYS_INLINE JSValue jsString(ExecState* exec, const UString& u1, JSString* s2)
  62     {
  63         unsigned ropeLength = 1 + s2->ropeLength();
  64         JSGlobalData* globalData = &exec->globalData();
  65
  66         if (ropeLength <= JSString::s_maxInternalRopeLength)
  67             return new (globalData) JSString(globalData, ropeLength, u1, s2);
  68
  69         unsigned index = 0;
  70         RefPtr<JSString::Rope> rope = JSString::Rope::createOrNull(ropeLength);
  71         if (UNLIKELY(!rope))
  72             return throwOutOfMemoryError(exec);
  73         rope->append(index, u1);
  74         rope->append(index, s2);
  75         ASSERT(index == ropeLength);
  76         return new (globalData) JSString(globalData, rope.release());
  77     }
  78
  79     ALWAYS_INLINE JSValue jsString(ExecState* exec, JSString* s1, const UString& u2)
  80     {
  81         unsigned ropeLength = s1->ropeLength() + 1;
  82         JSGlobalData* globalData = &exec->globalData();
  83
  84         if (ropeLength <= JSString::s_maxInternalRopeLength)
  85             return new (globalData) JSString(globalData, ropeLength, s1, u2);
  86
  87         unsigned index = 0;
  88         RefPtr<JSString::Rope> rope = JSString::Rope::createOrNull(ropeLength);
  89         if (UNLIKELY(!rope))
  90             return throwOutOfMemoryError(exec);
  91         rope->append(index, s1);
  92         rope->append(index, u2);
  93         ASSERT(index == ropeLength);
  94         return new (globalData) JSString(globalData, rope.release());
  95     }
  96
  97     ALWAYS_INLINE JSValue jsString(ExecState* exec, Register* strings, unsigned count)
  98     {
  99         ASSERT(count >= 3);
 100
 101         unsigned ropeLength = 0;
 102         for (unsigned i = 0; i < count; ++i) {
 103             JSValue v = strings[i].jsValue();
 104             if (LIKELY(v.isString()))
 105                 ropeLength += asString(v)->ropeLength();
 106             else
 107                 ++ropeLength;
 108         }
 109
 110         JSGlobalData* globalData = &exec->globalData();
 111         if (ropeLength == 3)
 112             return new (globalData) JSString(exec, strings[0].jsValue(), strings[1].jsValue(), strings[2].jsValue());
 113
 114         RefPtr<JSString::Rope> rope = JSString::Rope::createOrNull(ropeLength);
 115         if (UNLIKELY(!rope))
 116             return throwOutOfMemoryError(exec);
 117
 118         unsigned index = 0;
 119         for (unsigned i = 0; i < count; ++i) {
 120             JSValue v = strings[i].jsValue();
 121             if (LIKELY(v.isString()))
 122                 rope->append(index, asString(v));
 123             else
 124                 rope->append(index, v.toString(exec));
 125         }
 126
 127         ASSERT(index == ropeLength);
 128         return new (globalData) JSString(globalData, rope.release());
 129     }
 130
 131     ALWAYS_INLINE JSValue jsString(ExecState* exec, JSValue thisValue, const ArgList& args)
 132     {
 133         unsigned ropeLength = 0;
 134         if (LIKELY(thisValue.isString()))
 135             ropeLength += asString(thisValue)->ropeLength();
 136         else
 137             ++ropeLength;
 138         for (unsigned i = 0; i < args.size(); ++i) {
 139             JSValue v = args.at(i);
 140             if (LIKELY(v.isString()))
 141                 ropeLength += asString(v)->ropeLength();
 142             else
 143                 ++ropeLength;
 144         }
 145
 146         RefPtr<JSString::Rope> rope = JSString::Rope::createOrNull(ropeLength);
 147         if (UNLIKELY(!rope))
 148             return throwOutOfMemoryError(exec);
 149
 150         unsigned index = 0;
 151         if (LIKELY(thisValue.isString()))
 152             rope->append(index, asString(thisValue));
 153         else
 154             rope->append(index, thisValue.toString(exec));
 155         for (unsigned i = 0; i < args.size(); ++i) {
 156             JSValue v = args.at(i);
 157             if (LIKELY(v.isString()))
 158                 rope->append(index, asString(v));
 159             else
 160                 rope->append(index, v.toString(exec));
 161         }
 162         ASSERT(index == ropeLength);
 163
 164         JSGlobalData* globalData = &exec->globalData();
 165         return new (globalData) JSString(globalData, rope.release());
 166     }
 167
 168     // ECMA 11.9.3
 169     inline bool JSValue::equal(ExecState* exec, JSValue v1, JSValue v2)
 170     {
 171         if (v1.isInt32() && v2.isInt32())
 172             return v1 == v2;
 173
 174         return equalSlowCase(exec, v1, v2);
 175     }
 176
 177     ALWAYS_INLINE bool JSValue::equalSlowCaseInline(ExecState* exec, JSValue v1, JSValue v2)
 178     {
 179         do {
 180             if (v1.isNumber() && v2.isNumber())
 181                 return v1.uncheckedGetNumber() == v2.uncheckedGetNumber();
 182
 183             bool s1 = v1.isString();
 184             bool s2 = v2.isString();
 185             if (s1 && s2)
 186                 return asString(v1)->value(exec) == asString(v2)->value(exec);
 187
 188             if (v1.isUndefinedOrNull()) {
 189                 if (v2.isUndefinedOrNull())
 190                     return true;
 191                 if (!v2.isCell())
 192                     return false;
 193                 return v2.asCell()->structure()->typeInfo().masqueradesAsUndefined();
 194             }
 195
 196             if (v2.isUndefinedOrNull()) {
 197                 if (!v1.isCell())
 198                     return false;
 199                 return v1.asCell()->structure()->typeInfo().masqueradesAsUndefined();
 200             }
 201
 202             if (v1.isObject()) {
 203                 if (v2.isObject())
 204                     return v1 == v2;
 205                 JSValue p1 = v1.toPrimitive(exec);
 206                 if (exec->hadException())
 207                     return false;
 208                 v1 = p1;
 209                 if (v1.isInt32() && v2.isInt32())
 210                     return v1 == v2;
 211                 continue;
 212             }
 213
 214             if (v2.isObject()) {
 215                 JSValue p2 = v2.toPrimitive(exec);
 216                 if (exec->hadException())
 217                     return false;
 218                 v2 = p2;
 219                 if (v1.isInt32() && v2.isInt32())
 220                     return v1 == v2;
 221                 continue;
 222             }
 223
 224             if (s1 || s2) {
 225                 double d1 = v1.toNumber(exec);
 226                 double d2 = v2.toNumber(exec);
 227                 return d1 == d2;
 228             }
 229
 230             if (v1.isBoolean()) {
 231                 if (v2.isNumber())
 232                     return static_cast<double>(v1.getBoolean()) == v2.uncheckedGetNumber();
 233             } else if (v2.isBoolean()) {
 234                 if (v1.isNumber())
 235                     return v1.uncheckedGetNumber() == static_cast<double>(v2.getBoolean());
 236             }
 237
 238             return v1 == v2;
 239         } while (true);
 240     }
 241
 242     // ECMA 11.9.3
 243     ALWAYS_INLINE bool JSValue::strictEqualSlowCaseInline(ExecState* exec, JSValue v1, JSValue v2)
 244     {
 245         ASSERT(v1.isCell() && v2.isCell());
 246
 247         if (v1.asCell()->isString() && v2.asCell()->isString())
 248             return asString(v1)->value(exec) == asString(v2)->value(exec);
 249
 250         return v1 == v2;
 251     }
 252
 253     inline bool JSValue::strictEqual(ExecState* exec, JSValue v1, JSValue v2)
 254     {
 255         if (v1.isInt32() && v2.isInt32())
 256             return v1 == v2;
 257
 258         if (v1.isNumber() && v2.isNumber())
 259             return v1.uncheckedGetNumber() == v2.uncheckedGetNumber();
 260
 261         if (!v1.isCell() || !v2.isCell())
 262             return v1 == v2;
 263
 264         return strictEqualSlowCaseInline(exec, v1, v2);
 265     }
 266
 267     ALWAYS_INLINE bool jsLess(CallFrame* callFrame, JSValue v1, JSValue v2)
 268     {
 269         if (v1.isInt32() && v2.isInt32())
 270             return v1.asInt32() < v2.asInt32();
 271
 272         double n1;
 273         double n2;
 274         if (v1.getNumber(n1) && v2.getNumber(n2))
 275             return n1 < n2;
 276
 277         JSGlobalData* globalData = &callFrame->globalData();
 278         if (isJSString(globalData, v1) && isJSString(globalData, v2))
 279             return asString(v1)->value(callFrame) < asString(v2)->value(callFrame);
 280
 281         JSValue p1;
 282         JSValue p2;
 283         bool wasNotString1 = v1.getPrimitiveNumber(callFrame, n1, p1);
 284         bool wasNotString2 = v2.getPrimitiveNumber(callFrame, n2, p2);
 285
 286         if (wasNotString1 | wasNotString2)
 287             return n1 < n2;
 288
 289         return asString(p1)->value(callFrame) < asString(p2)->value(callFrame);
 290     }
 291
 292     inline bool jsLessEq(CallFrame* callFrame, JSValue v1, JSValue v2)
 293     {
 294         if (v1.isInt32() && v2.isInt32())
 295             return v1.asInt32() <= v2.asInt32();
 296
 297         double n1;
 298         double n2;
 299         if (v1.getNumber(n1) && v2.getNumber(n2))
 300             return n1 <= n2;
 301
 302         JSGlobalData* globalData = &callFrame->globalData();
 303         if (isJSString(globalData, v1) && isJSString(globalData, v2))
 304             return !(asString(v2)->value(callFrame) < asString(v1)->value(callFrame));
 305
 306         JSValue p1;
 307         JSValue p2;
 308         bool wasNotString1 = v1.getPrimitiveNumber(callFrame, n1, p1);
 309         bool wasNotString2 = v2.getPrimitiveNumber(callFrame, n2, p2);
 310
 311         if (wasNotString1 | wasNotString2)
 312             return n1 <= n2;
 313
 314         return !(asString(p2)->value(callFrame) < asString(p1)->value(callFrame));
 315     }
 316
 317     // Fast-path choices here are based on frequency data from SunSpider:
 318     //    <times> Add case: <t1> <t2>
 319     //    ---------------------------
 320     //    5626160 Add case: 3 3 (of these, 3637690 are for immediate values)
 321     //    247412  Add case: 5 5
 322     //    20900   Add case: 5 6
 323     //    13962   Add case: 5 3
 324     //    4000    Add case: 3 5
 325
 326     ALWAYS_INLINE JSValue jsAdd(CallFrame* callFrame, JSValue v1, JSValue v2)
 327     {
 328         double left = 0.0, right;
 329         if (v1.getNumber(left) && v2.getNumber(right))
 330             return jsNumber(callFrame, left + right);
 331
 332         if (v1.isString()) {
 333             return v2.isString()
 334                 ? jsString(callFrame, asString(v1), asString(v2))
 335                 : jsString(callFrame, asString(v1), v2.toPrimitiveString(callFrame));
 336         }
 337
 338         // All other cases are pretty uncommon
 339         return jsAddSlowCase(callFrame, v1, v2);
 340     }
 341
 342     inline size_t normalizePrototypeChain(CallFrame* callFrame, JSValue base, JSValue slotBase, const Identifier& propertyName, size_t& slotOffset)
 343     {
 344         JSCell* cell = asCell(base);
 345         size_t count = 0;
 346
 347         while (slotBase != cell) {
 348             JSValue v = cell->structure()->prototypeForLookup(callFrame);
 349
 350             // If we didn't find slotBase in base's prototype chain, then base
 351             // must be a proxy for another object.
 352
 353             if (v.isNull())
 354                 return 0;
 355
 356             cell = asCell(v);
 357
 358             // Since we're accessing a prototype in a loop, it's a good bet that it
 359             // should not be treated as a dictionary.
 360             if (cell->structure()->isDictionary()) {
 361                 asObject(cell)->flattenDictionaryObject();
 362                 if (slotBase == cell)
 363                     slotOffset = cell->structure()->get(propertyName);
 364             }
 365
 366             ++count;
 367         }
 368
 369         ASSERT(count);
 370         return count;
 371     }
 372
 373     inline size_t normalizePrototypeChain(CallFrame* callFrame, JSCell* base)
 374     {
 375         size_t count = 0;
 376         while (1) {
 377             JSValue v = base->structure()->prototypeForLookup(callFrame);
 378             if (v.isNull())
 379                 return count;
 380
 381             base = asCell(v);
 382
 383             // Since we're accessing a prototype in a loop, it's a good bet that it
 384             // should not be treated as a dictionary.
 385             if (base->structure()->isDictionary())
 386                 asObject(base)->flattenDictionaryObject();
 387
 388             ++count;
 389         }
 390     }
 391
 392     ALWAYS_INLINE JSValue resolveBase(CallFrame* callFrame, Identifier& property, ScopeChainNode* scopeChain)
 393     {
 394         ScopeChainIterator iter = scopeChain->begin();
 395         ScopeChainIterator next = iter;
 396         ++next;
 397         ScopeChainIterator end = scopeChain->end();
 398         ASSERT(iter != end);
 399
 400         PropertySlot slot;
 401         JSObject* base;
 402         while (true) {
 403             base = *iter;
 404             if (next == end || base->getPropertySlot(callFrame, property, slot))
 405                 return base;
 406
 407             iter = next;
 408             ++next;
 409         }
 410
 411         ASSERT_NOT_REACHED();
 412         return JSValue();
 413     }
 414 } // namespace JSC
 415
 416 #endif // Operations_h