Iterate through all arguments for side effects in Math.min/max.

R=svenpanne@chromium.org
BUG=v8:2444

Review URL: https://chromiumcodereview.appspot.com/11444030

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13150 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/math.js

@@ -131,19 +131,16 @@ function MathMax(arg1, arg2) {  // length == 2
     // All comparisons failed, one of the arguments must be NaN.
     return 0/0;  // Compiler constant-folds this to NaN.
   }
-  if (length == 0) {
-    return -1/0;  // Compiler constant-folds this to -Infinity.
-  }
-  var r = arg1;
-  if (!IS_NUMBER(r)) r = NonNumberToNumber(r);
-  if (NUMBER_IS_NAN(r)) return r;
-  for (var i = 1; i < length; i++) {
+  var r = -1/0;  // Compiler constant-folds this to -Infinity.
+  for (var i = 0; i < length; i++) {
     var n = %_Arguments(i);
     if (!IS_NUMBER(n)) n = NonNumberToNumber(n);
-    if (NUMBER_IS_NAN(n)) return n;
     // Make sure +0 is considered greater than -0.  -0 is never a Smi, +0 can be
     // a Smi or heap number.
-    if (n > r || (r == 0 && n == 0 && !%_IsSmi(r) && 1 / r < 0)) r = n;
+    if (NUMBER_IS_NAN(n) || n > r ||
+        (r == 0 && n == 0 && !%_IsSmi(r) && 1 / r < 0)) {
+      r = n;
+    }
   }
   return r;
 }
@@ -164,19 +161,16 @@ function MathMin(arg1, arg2) {  // length == 2
     // All comparisons failed, one of the arguments must be NaN.
     return 0/0;  // Compiler constant-folds this to NaN.
   }
-  if (length == 0) {
-    return 1/0;  // Compiler constant-folds this to Infinity.
-  }
-  var r = arg1;
-  if (!IS_NUMBER(r)) r = NonNumberToNumber(r);
-  if (NUMBER_IS_NAN(r)) return r;
-  for (var i = 1; i < length; i++) {
+  var r = 1/0;  // Compiler constant-folds this to Infinity.
+  for (var i = 0; i < length; i++) {
     var n = %_Arguments(i);
     if (!IS_NUMBER(n)) n = NonNumberToNumber(n);
-    if (NUMBER_IS_NAN(n)) return n;
     // Make sure -0 is considered less than +0.  -0 is never a Smi, +0 can be a
     // Smi or a heap number.
-    if (n < r || (r == 0 && n == 0 && !%_IsSmi(n) && 1 / n < 0)) r = n;
+    if (NUMBER_IS_NAN(n) || n < r ||
+        (r == 0 && n == 0 && !%_IsSmi(n) && 1 / n < 0)) {
+      r = n;
+    }
   }
   return r;
 }

test/mjsunit/regress/regress-2444.js

+// Copyright 2012 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.
+
+
+var flags;
+
+function resetFlags(size) {
+  flags = Array(size);
+  while (size--) flags[size] = 0;
+}
+
+function assertFlags(array) {
+  assertArrayEquals(array, flags);
+}
+
+function object_factory(flag_index, value, expected_flags) {
+  var obj = {};
+  obj.valueOf = function() {
+    assertFlags(expected_flags);
+    flags[flag_index]++;
+    return value;
+  }
+  return obj;
+}
+
+
+assertEquals(-Infinity, Math.max());
+
+resetFlags(1);
+assertEquals(NaN,
+             Math.max(object_factory(0, NaN, [0])));
+assertFlags([1]);
+
+resetFlags(2);
+assertEquals(NaN,
+             Math.max(object_factory(0, NaN, [0, 0]),
+                      object_factory(1,   0, [1, 0])));
+assertFlags([1, 1]);
+
+resetFlags(3);
+assertEquals(NaN,
+             Math.max(object_factory(0, NaN, [0, 0, 0]),
+                      object_factory(1,   0, [1, 0, 0]),
+                      object_factory(2,   1, [1, 1, 0])));
+assertFlags([1, 1, 1]);
+
+resetFlags(3);
+assertEquals(NaN,
+             Math.max(object_factory(0,   2, [0, 0, 0]),
+                      object_factory(1,   0, [1, 0, 0]),
+                      object_factory(2, NaN, [1, 1, 0])));
+assertFlags([1, 1, 1]);
+
+resetFlags(3);
+assertEquals(2,
+             Math.max(object_factory(0,   2, [0, 0, 0]),
+                      object_factory(1,   0, [1, 0, 0]),
+                      object_factory(2,   1, [1, 1, 0])));
+assertFlags([1, 1, 1]);
+
+
+assertEquals(+Infinity, Math.min());
+
+resetFlags(1);
+assertEquals(NaN,
+             Math.min(object_factory(0, NaN, [0])));
+assertFlags([1]);
+
+resetFlags(2);
+assertEquals(NaN,
+             Math.min(object_factory(0, NaN, [0, 0]),
+                      object_factory(1,   0, [1, 0])));
+assertFlags([1, 1]);
+
+resetFlags(3);
+assertEquals(NaN,
+             Math.min(object_factory(0, NaN, [0, 0, 0]),
+                      object_factory(1,   0, [1, 0, 0]),
+                      object_factory(2,   1, [1, 1, 0])));
+assertFlags([1, 1, 1]);
+
+resetFlags(3);
+assertEquals(NaN,
+             Math.min(object_factory(0,   2, [0, 0, 0]),
+                      object_factory(1,   0, [1, 0, 0]),
+                      object_factory(2, NaN, [1, 1, 0])));
+assertFlags([1, 1, 1]);
+
+resetFlags(3);
+assertEquals(0,
+             Math.min(object_factory(0,   2, [0, 0, 0]),
+                      object_factory(1,   0, [1, 0, 0]),
+                      object_factory(2,   1, [1, 1, 0])));
+assertFlags([1, 1, 1]);
+
+