Index: test/mjsunit/harmony/math-log1p.js |
diff --git a/test/mjsunit/harmony/math-log1p.js b/test/mjsunit/harmony/math-log1p.js |
new file mode 100644 |
index 0000000000000000000000000000000000000000..eefea6ee38020c0d6010a4080e54191238042eaa |
--- /dev/null |
+++ b/test/mjsunit/harmony/math-log1p.js |
@@ -0,0 +1,41 @@ |
+// Copyright 2014 the V8 project authors. All rights reserved. |
+// Use of this source code is governed by a BSD-style license that can be |
+// found in the LICENSE file. |
+ |
+// Flags: --harmony-maths |
+ |
+assertTrue(isNaN(Math.log1p(NaN))); |
+assertTrue(isNaN(Math.log1p(function() {}))); |
+assertTrue(isNaN(Math.log1p({ toString: function() { return NaN; } }))); |
+assertTrue(isNaN(Math.log1p({ valueOf: function() { return "abc"; } }))); |
+assertEquals("Infinity", String(1/Math.log1p(0))); |
+assertEquals("-Infinity", String(1/Math.log1p(-0))); |
+assertEquals("Infinity", String(Math.log1p(Infinity))); |
+assertEquals("-Infinity", String(Math.log1p(-1))); |
+assertTrue(isNaN(Math.log1p(-2))); |
+assertTrue(isNaN(Math.log1p(-Infinity))); |
+ |
+for (var x = 1E300; x > 1E-1; x *= 0.8) { |
+ var expected = Math.log(x + 1); |
+ assertEqualsDelta(expected, Math.log1p(x), expected * 1E-14); |
+} |
+ |
+// Values close to 0: |
+// Use Taylor expansion at 1 for log(x) as test expectation: |
+// log1p(x) == log(x + 1) == 0 + x / 1 - x^2 / 2 + x^3 / 3 - ... |
+function log1p(x) { |
+ var terms = []; |
+ var prod = x; |
+ for (var i = 1; i <= 20; i++) { |
+ terms.push(prod / i); |
+ prod *= -x; |
+ } |
+ var sum = 0; |
+ while (terms.length > 0) sum += terms.pop(); |
+ return sum; |
+} |
+ |
+for (var x = 1E-1; x > 1E-300; x *= 0.8) { |
+ var expected = log1p(x); |
+ assertEqualsDelta(expected, Math.log1p(x), expected * 1E-14); |
+} |