Harmony: implement Math.sign.

test/mjsunit/harmony/math-sign.js

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-#ifndef V8_HYDROGEN_BCH_H_
-#define V8_HYDROGEN_BCH_H_
+// Flags: --harmony-maths
 
-#include "hydrogen.h"
-
-namespace v8 {
-namespace internal {
-
-
-class HBoundsCheckHoistingPhase : public HPhase {
- public:
-  explicit HBoundsCheckHoistingPhase(HGraph* graph)
-      : HPhase("H_Bounds checks hoisting", graph) { }
-
-  void Run() {
-    HoistRedundantBoundsChecks();
-  }
-
- private:
-  void HoistRedundantBoundsChecks();
-
-  DISALLOW_COPY_AND_ASSIGN(HBoundsCheckHoistingPhase);
-};
-
-
-} }  // namespace v8::internal
-
-#endif  // V8_HYDROGEN_BCE_H_
+assertEquals("Infinity", String(1/Math.sign(0)));

[Dmitry Lomov (no reviews), 2013/10/21 06:57:58]

Needs tests for +0 and -0:
var x = 1e-200
var y = -1e-200
var z = x*y // -0, confirm by 1/z == -Infinity
Math.sign(z);

[Sven Panne, 2013/10/21 07:18:39]

Why do we need this? I thought the line below already tests exactly this.

[Yang, 2013/10/21 07:53:23]

The line below does test the -0 case. Using actual -0 seems better than going
out of the double range to get it.

+assertEquals("-Infinity", String(1/Math.sign(-0)));
+assertEquals(1, Math.sign(100));
+assertEquals(-1, Math.sign(-199));
+assertEquals(1, Math.sign(100.1));
+assertTrue(isNaN(Math.sign("abc")));
+assertTrue(isNaN(Math.sign({})));
+assertEquals(0, Math.sign([]));
+assertEquals(1, Math.sign([1]));
+assertEquals(-1, Math.sign([-100.1]));
+assertTrue(isNaN(Math.sign([1, 1])));
+assertEquals(1, Math.sign({ toString: function() { return "100"; } }));
+assertEquals(1, Math.sign({ toString: function() { return 100; } }));
+assertEquals(-1, Math.sign({ valueOf: function() { return -1.1; } }));
+assertEquals(-1, Math.sign({ valueOf: function() { return "-1.1"; } }));
+assertEquals(-1, Math.sign(-Infinity));
+assertEquals(1, Math.sign(Infinity));
+assertEquals(-1, Math.sign("-Infinity"));
+assertEquals(1, Math.sign("Infinity"));