Builtin function EQULAS partially rewritten in C++. Control branches that cal...

test/mjsunit/equals.js

+// Copyright 2008 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Flags: --allow-natives-syntax
+
+function IS_STRING(arg) { return (typeof(arg) === 'string'); }
+function IS_NUMBER(arg) { return (typeof(arg) === 'number'); }
+function IS_BOOLEAN(arg) { return (typeof(arg) === 'boolean'); }
+function IS_OBJECT(arg) { return %_IsObject(arg); }
+function IS_FUNCTION(arg) { return %_IsFunction(arg); }
+const NO_HINT = 0;
+
+// ECMA-262, section 11.9.1, page 55.
+function EQUALS(x, y) {
+  if (IS_STRING(x) && IS_STRING(y)) return %StringEquals(x, y);
+
+  // NOTE: We use iteration instead of recursion, because it is
+  // difficult to call EQUALS with the correct setting of 'this' in
+  // an efficient way.
+  while (true) {
+    if (IS_NUMBER(x)) {
+      if (y == null) return 1;  // not equal
+      return %NumberEquals(x, %ToNumber(y));
+    } else if (IS_STRING(x)) {
+      if (IS_STRING(y)) return %StringEquals(x, y);
+      if (IS_NUMBER(y)) return %NumberEquals(%ToNumber(x), y);
+      if (IS_BOOLEAN(y)) return %NumberEquals(%ToNumber(x), %ToNumber(y));
+      if (y == null) return 1;  // not equal
+      y = %ToPrimitive(y, NO_HINT);
+    } else if (IS_BOOLEAN(x)) {
+      if (IS_BOOLEAN(y)) {
+        return %_ObjectEquals(x, y) ? 0 : 1;
+      }
+      if (y == null) return 1;  // not equal
+      return %NumberEquals(%ToNumber(x), %ToNumber(y));
+    } else if (x == null) {
+      // NOTE: This checks for both null and undefined.
+      return (y == null) ? 0 : 1;
+    } else {
+      // x is not a number, boolean, null or undefined.
+      if (y == null) return 1;  // not equal
+      if (IS_OBJECT(y)) {
+        return %_ObjectEquals(x, y) ? 0 : 1;
+      }
+      if (IS_FUNCTION(y)) {
+        return %_ObjectEquals(x, y) ? 0 : 1;
+      }
+
+      x = %ToPrimitive(x, NO_HINT);
+    }
+  }
+}
+
+var values = [
+  0,
+  1,
+  -1,
+  NaN,
+  function() {return 0;},
+  function() {return 1;},
+  {},
+  'a',
+  'b',
+  'c',
+  {toString: function(){return 'a'}},
+  {valueOf: function(){return 1;}},
+  {valueOf: function(){return 'b'}},
+  [1, 2, 3],
+  ['1', '2', '3'],
+  {a: 'b'},
+  1.126,
+  void 0,
+  null,
+  undefined,
+  100000000000000000,
+  '1.126'
+];
+
+for (var i = 0; i < values.length; i++) {
+  for (var j = 0; j < values.length; j++) {
+    var x = values[i];
+    var y = values[j];
+
+    var r1 = EQUALS(x, y);  // Reference implementation.
+    var r2 = (x == y) ? 0 : 1;
+
+    assertEquals(r1, r2, 'Compared ' + x + ' vs ' + y);
+  }
+}
+