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     // ECMA 11.9.3
  39     inline bool JSValue::equal(ExecState* exec, JSValue v1, JSValue v2)
  40     {
  41         if (v1.isInt32() && v2.isInt32())
  42             return v1 == v2;
  43
  44         return equalSlowCase(exec, v1, v2);
  45     }
  46
  47     ALWAYS_INLINE bool JSValue::equalSlowCaseInline(ExecState* exec, JSValue v1, JSValue v2)
  48     {
  49         do {
  50             if (v1.isNumber() && v2.isNumber())
  51                 return v1.uncheckedGetNumber() == v2.uncheckedGetNumber();
  52
  53             bool s1 = v1.isString();
  54             bool s2 = v2.isString();
  55             if (s1 && s2)
  56                 return asString(v1)->value() == asString(v2)->value();
  57
  58             if (v1.isUndefinedOrNull()) {
  59                 if (v2.isUndefinedOrNull())
  60                     return true;
  61                 if (!v2.isCell())
  62                     return false;
  63                 return v2.asCell()->structure()->typeInfo().masqueradesAsUndefined();
  64             }
  65
  66             if (v2.isUndefinedOrNull()) {
  67                 if (!v1.isCell())
  68                     return false;
  69                 return v1.asCell()->structure()->typeInfo().masqueradesAsUndefined();
  70             }
  71
  72             if (v1.isObject()) {
  73                 if (v2.isObject())
  74                     return v1 == v2;
  75                 JSValue p1 = v1.toPrimitive(exec);
  76                 if (exec->hadException())
  77                     return false;
  78                 v1 = p1;
  79                 if (v1.isInt32() && v2.isInt32())
  80                     return v1 == v2;
  81                 continue;
  82             }
  83
  84             if (v2.isObject()) {
  85                 JSValue p2 = v2.toPrimitive(exec);
  86                 if (exec->hadException())
  87                     return false;
  88                 v2 = p2;
  89                 if (v1.isInt32() && v2.isInt32())
  90                     return v1 == v2;
  91                 continue;
  92             }
  93
  94             if (s1 || s2) {
  95                 double d1 = v1.toNumber(exec);
  96                 double d2 = v2.toNumber(exec);
  97                 return d1 == d2;
  98             }
  99
 100             if (v1.isBoolean()) {
 101                 if (v2.isNumber())
 102                     return static_cast<double>(v1.getBoolean()) == v2.uncheckedGetNumber();
 103             } else if (v2.isBoolean()) {
 104                 if (v1.isNumber())
 105                     return v1.uncheckedGetNumber() == static_cast<double>(v2.getBoolean());
 106             }
 107
 108             return v1 == v2;
 109         } while (true);
 110     }
 111
 112     // ECMA 11.9.3
 113     ALWAYS_INLINE bool JSValue::strictEqualSlowCaseInline(JSValue v1, JSValue v2)
 114     {
 115         ASSERT(v1.isCell() && v2.isCell());
 116
 117         if (v1.asCell()->isString() && v2.asCell()->isString())
 118             return asString(v1)->value() == asString(v2)->value();
 119
 120         return v1 == v2;
 121     }
 122
 123     inline bool JSValue::strictEqual(JSValue v1, JSValue v2)
 124     {
 125         if (v1.isInt32() && v2.isInt32())
 126             return v1 == v2;
 127
 128         if (v1.isNumber() && v2.isNumber())
 129             return v1.uncheckedGetNumber() == v2.uncheckedGetNumber();
 130
 131         if (!v1.isCell() || !v2.isCell())
 132             return v1 == v2;
 133
 134         return strictEqualSlowCaseInline(v1, v2);
 135     }
 136
 137     inline bool jsLess(CallFrame* callFrame, JSValue v1, JSValue v2)
 138     {
 139         if (v1.isInt32() && v2.isInt32())
 140             return v1.asInt32() < v2.asInt32();
 141
 142         double n1;
 143         double n2;
 144         if (v1.getNumber(n1) && v2.getNumber(n2))
 145             return n1 < n2;
 146
 147         JSGlobalData* globalData = &callFrame->globalData();
 148         if (isJSString(globalData, v1) && isJSString(globalData, v2))
 149             return asString(v1)->value() < asString(v2)->value();
 150
 151         JSValue p1;
 152         JSValue p2;
 153         bool wasNotString1 = v1.getPrimitiveNumber(callFrame, n1, p1);
 154         bool wasNotString2 = v2.getPrimitiveNumber(callFrame, n2, p2);
 155
 156         if (wasNotString1 | wasNotString2)
 157             return n1 < n2;
 158
 159         return asString(p1)->value() < asString(p2)->value();
 160     }
 161
 162     inline bool jsLessEq(CallFrame* callFrame, JSValue v1, JSValue v2)
 163     {
 164         if (v1.isInt32() && v2.isInt32())
 165             return v1.asInt32() <= v2.asInt32();
 166
 167         double n1;
 168         double n2;
 169         if (v1.getNumber(n1) && v2.getNumber(n2))
 170             return n1 <= n2;
 171
 172         JSGlobalData* globalData = &callFrame->globalData();
 173         if (isJSString(globalData, v1) && isJSString(globalData, v2))
 174             return !(asString(v2)->value() < asString(v1)->value());
 175
 176         JSValue p1;
 177         JSValue p2;
 178         bool wasNotString1 = v1.getPrimitiveNumber(callFrame, n1, p1);
 179         bool wasNotString2 = v2.getPrimitiveNumber(callFrame, n2, p2);
 180
 181         if (wasNotString1 | wasNotString2)
 182             return n1 <= n2;
 183
 184         return !(asString(p2)->value() < asString(p1)->value());
 185     }
 186
 187     // Fast-path choices here are based on frequency data from SunSpider:
 188     //    <times> Add case: <t1> <t2>
 189     //    ---------------------------
 190     //    5626160 Add case: 3 3 (of these, 3637690 are for immediate values)
 191     //    247412  Add case: 5 5
 192     //    20900   Add case: 5 6
 193     //    13962   Add case: 5 3
 194     //    4000    Add case: 3 5
 195
 196     ALWAYS_INLINE JSValue jsAdd(CallFrame* callFrame, JSValue v1, JSValue v2)
 197     {
 198         double left;
 199         double right = 0.0;
 200
 201         bool rightIsNumber = v2.getNumber(right);
 202         if (rightIsNumber && v1.getNumber(left))
 203             return jsNumber(callFrame, left + right);
 204
 205         bool leftIsString = v1.isString();
 206         if (leftIsString && v2.isString()) {
 207             RefPtr<UString::Rep> value = concatenate(asString(v1)->value().rep(), asString(v2)->value().rep());
 208             if (!value)
 209                 return throwOutOfMemoryError(callFrame);
 210             return jsString(callFrame, value.release());
 211         }
 212
 213         if (rightIsNumber & leftIsString) {
 214             RefPtr<UString::Rep> value = v2.isInt32() ?
 215                 concatenate(asString(v1)->value().rep(), v2.asInt32()) :
 216                 concatenate(asString(v1)->value().rep(), right);
 217
 218             if (!value)
 219                 return throwOutOfMemoryError(callFrame);
 220             return jsString(callFrame, value.release());
 221         }
 222
 223         // All other cases are pretty uncommon
 224         return jsAddSlowCase(callFrame, v1, v2);
 225     }
 226
 227     inline size_t normalizePrototypeChain(CallFrame* callFrame, JSValue base, JSValue slotBase, const Identifier& propertyName, size_t& slotOffset)
 228     {
 229         JSCell* cell = asCell(base);
 230         size_t count = 0;
 231
 232         while (slotBase != cell) {
 233             JSValue v = cell->structure()->prototypeForLookup(callFrame);
 234
 235             // If we didn't find slotBase in base's prototype chain, then base
 236             // must be a proxy for another object.
 237
 238             if (v.isNull())
 239                 return 0;
 240
 241             cell = asCell(v);
 242
 243             // Since we're accessing a prototype in a loop, it's a good bet that it
 244             // should not be treated as a dictionary.
 245             if (cell->structure()->isDictionary()) {
 246                 asObject(cell)->flattenDictionaryObject();
 247                 if (slotBase == cell)
 248                     slotOffset = cell->structure()->get(propertyName);
 249             }
 250
 251             ++count;
 252         }
 253
 254         ASSERT(count);
 255         return count;
 256     }
 257
 258     ALWAYS_INLINE JSValue resolveBase(CallFrame* callFrame, Identifier& property, ScopeChainNode* scopeChain)
 259     {
 260         ScopeChainIterator iter = scopeChain->begin();
 261         ScopeChainIterator next = iter;
 262         ++next;
 263         ScopeChainIterator end = scopeChain->end();
 264         ASSERT(iter != end);
 265
 266         PropertySlot slot;
 267         JSObject* base;
 268         while (true) {
 269             base = *iter;
 270             if (next == end || base->getPropertySlot(callFrame, property, slot))
 271                 return base;
 272
 273             iter = next;
 274             ++next;
 275         }
 276
 277         ASSERT_NOT_REACHED();
 278         return JSValue();
 279     }
 280
 281     ALWAYS_INLINE JSValue concatenateStrings(CallFrame* callFrame, Register* strings, unsigned count)
 282     {
 283         ASSERT(count >= 3);
 284
 285         // Estimate the amount of space required to hold the entire string.  If all
 286         // arguments are strings, we can easily calculate the exact amount of space
 287         // required.  For any other arguments, for now let's assume they may require
 288         // 11 UChars of storage.  This is enouch to hold any int, and likely is also
 289         // reasonable for the other immediates.  We may want to come back and tune
 290         // this value at some point.
 291         unsigned bufferSize = 0;
 292         for (unsigned i = 0; i < count; ++i) {
 293             JSValue v = strings[i].jsValue();
 294             if (LIKELY(v.isString()))
 295                 bufferSize += asString(v)->value().size();
 296             else
 297                 bufferSize += 11;
 298         }
 299
 300         // Allocate an output string to store the result.
 301         // If the first argument is a String, and if it has the capacity (or can grow
 302         // its capacity) to hold the entire result then use this as a base to concatenate
 303         // onto.  Otherwise, allocate a new empty output buffer.
 304         JSValue firstValue = strings[0].jsValue();
 305         RefPtr<UString::Rep> resultRep;
 306         if (firstValue.isString() && (resultRep = asString(firstValue)->value().rep())->reserveCapacity(bufferSize)) {
 307             // We're going to concatenate onto the first string - remove it from the list of items to be appended.
 308             ++strings;
 309             --count;
 310         } else
 311             resultRep = UString::Rep::createEmptyBuffer(bufferSize);
 312         UString result(resultRep);
 313
 314         // Loop over the openards, writing them into the output buffer.
 315         for (unsigned i = 0; i < count; ++i) {
 316             JSValue v = strings[i].jsValue();
 317             if (LIKELY(v.isString()))
 318                 result.append(asString(v)->value());
 319             else if (v.isInt32())
 320                 result.appendNumeric(v.asInt32());
 321             else {
 322                 double d;
 323                 if (v.getNumber(d))
 324                     result.appendNumeric(d);
 325                 else
 326                     result.append(v.toString(callFrame));
 327             }
 328         }
 329
 330         return jsString(callFrame, result);
 331     }
 332
 333 } // namespace JSC
 334
 335 #endif // Operations_h