Fix bug 503: undefined <= undefined should return false on ARM.

Review URL: http://codereview.chromium.org/399001

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3309 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/codegen-arm.cc

@@ -4545,6 +4545,22 @@ static void EmitIdenticalObjectComparison(MacroAssembler* masm,
     if (cc != eq) {
       __ cmp(r4, Operand(FIRST_JS_OBJECT_TYPE));
       __ b(ge, slow);
+      // Normally here we fall through to return_equal, but undefined is
+      // special: (undefined == undefined) == true, but (undefined <= undefined)
+      // == false!  See ECMAScript 11.8.5.
+      if (cc == le || cc == ge) {
+        __ cmp(r4, Operand(ODDBALL_TYPE));
+        __ b(ne, &return_equal);
+        __ LoadRoot(r2, Heap::kUndefinedValueRootIndex);
+        __ cmp(r0, Operand(r2));
+        __ b(ne, &return_equal);
+        if (cc == le) {
+          __ mov(r0, Operand(GREATER));  // undefined <= undefined should fail.
+        } else  {
+          __ mov(r0, Operand(LESS));     // undefined >= undefined should fail.
+        }
+        __ mov(pc, Operand(lr));       // Return.
+      }
     }
   }
   __ bind(&return_equal);

test/mjsunit/regress/regress-503.js

+// Copyright 2009 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.
+
+assertTrue(undefined == undefined, 1);
+assertFalse(undefined <= undefined, 2);
+assertFalse(undefined >= undefined, 3);
+assertFalse(undefined < undefined, 4);
+assertFalse(undefined > undefined, 5);
+
+assertTrue(null == null, 6);
+assertTrue(null <= null, 7);
+assertTrue(null >= null, 8);
+assertFalse(null < null, 9);
+assertFalse(null > null, 10);
+
+assertTrue(void 0 == void 0, 11);
+assertFalse(void 0 <= void 0, 12);
+assertFalse(void 0 >= void 0, 13);
+assertFalse(void 0 < void 0, 14);
+assertFalse(void 0 > void 0, 15);
+
+var x = void 0;
+
+assertTrue(x == x, 16);
+assertFalse(x <= x, 17);
+assertFalse(x >= x, 18);
+assertFalse(x < x, 19);
+assertFalse(x > x, 20);
+
+var not_undefined = [null, 0, 1, 1/0, -1/0, "", true, false];
+for (var i = 0; i < not_undefined.length; i++) {
+  x = not_undefined[i];
+
+  assertTrue(x == x, "" + 21 + x);
+  assertTrue(x <= x, "" + 22 + x);
+  assertTrue(x >= x, "" + 23 + x);
+  assertFalse(x < x, "" + 24 + x);
+  assertFalse(x > x, "" + 25 + x);
+}