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8136874: Bug in port of fdlibm pow to Java

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Reviewed-by: bpb
This commit is contained in:
Joe Darcy 2015-09-30 15:25:29 -07:00
parent eda52119fb
commit 112eb7283e
2 changed files with 304 additions and 3 deletions
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6
jdk/src/java.base/share/classes/java/lang/FdLibm.java
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@ -352,15 +352,15 @@ class FdLibm {
double p_h, p_l, t1, t2;
// |y| is huge
if (y_abs > 0x1.0p31) { // if |y| > 2**31
if (y_abs > 0x1.00000_ffff_ffffp31) { // if |y| > ~2**31
final double INV_LN2 = 0x1.7154_7652_b82fep0; // 1.44269504088896338700e+00 = 1/ln2
final double INV_LN2_H = 0x1.715476p0; // 1.44269502162933349609e+00 = 24 bits of 1/ln2
final double INV_LN2_L = 0x1.4ae0_bf85_ddf44p-26; // 1.92596299112661746887e-08 = 1/ln2 tail
// Over/underflow if x is not close to one
if (x_abs < 0x1.fffffp-1) // |x| < 0.9999995231628418
if (x_abs < 0x1.fffff_0000_0000p-1) // |x| < ~0.9999995231628418
return (y < 0.0) ? s * INFINITY : s * 0.0;
if (x_abs > 1.0) // |x| > 1.0
if (x_abs > 0x1.00000_ffff_ffffp0) // |x| > ~1.0
return (y > 0.0) ? s * INFINITY : s * 0.0;
/*
* now |1-x| is tiny <= 2**-20, sufficient to compute

301
jdk/test/java/lang/StrictMath/PowTests.java Normal file
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@ -0,0 +1,301 @@
/*
* Copyright (c) 2003, 2015, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/*
* @test
* @bug 8136874
* @summary Tests for StrictMath.pow
* @author Joseph D. Darcy
*/
/**
* The tests in ../Math/PowTests.java test properties that should
* hold for any pow implementation, including the FDLIBM-based one
* required for StrictMath.pow. Therefore, the test cases in
* ../Math/PowTests.java are run against both the Math and
* StrictMath versions of pow. The role of this test is to verify
* that the FDLIBM pow algorithm is being used by running golden
* file tests on values that may vary from one conforming pow
* implementation to another.
*/
public class PowTests {
private PowTests(){}
private static final double INFINITY = Double.POSITIVE_INFINITY;
public static void main(String... args) {
int failures = 0;
failures += testPow();
if (failures > 0) {
System.err.println("Testing pow incurred "
+ failures + " failures.");
throw new RuntimeException();
}
}
private static int testPow() {
int failures = 0;
double [][] testCases = {
// Probe near decision points of the fdlibm algorithm
{0x1.00000_0000_0001p1, // |x| > 1.0
INFINITY, // infinity
INFINITY // 0
},
{0x1.fffffp-1, // |x| = 0.9999995231628418
0x1.0p31, // 2^31
0.0 // 0
},
{0x1.ffffe_ffffffffp-1, // |x| < 0.9999995231628418
0x1.0p31, // 2^31
0.0 // 0
},
{-0x1.ffffe_ffffffffp-1, // |x| < 0.9999995231628418
0x1.0p31, // 2^31
0.0 // 0
},
{0x1.fffffp-1, // |x| = 0.9999995231628418
0x1.0000000000001p31, // nextUp(2^31)
0.0 // 0
},
{0x1.fffffp-1, // |x| = 0.9999995231628418
0x1.0p31 + 1.0, // 2^31 + 1, odd integer
0.0 // 0
},
{0x1.fffffp-1, // |x| = 0.9999995231628418
0x1.0p31 + 2.0, // 2^31 + 2, even integer
0.0 // 0
},
{0x1.ffffe_ffffffffp-1, // |x| < 0.9999995231628418
0x1.0000000000001p31, // nextUp(2^31)
0.0 // 0
},
{-0x1.ffffe_ffffffffp-1, // |x| < 0.9999995231628418
0x1.0000000000001p31, // nextUp(2^31)
Double.NaN // 0
},
{-0x1.ffffe_ffffffffp-1, // |x| < 0.9999995231628418
0x1.0p31 + 1.0, // 2^31 + 1, odd integer
-0.0 // 0
},
{-0x1.ffffe_ffffffffp-1, // |x| < 0.9999995231628418
0x1.0p31 + 2.0, // 2^31 + 2, even integer
0.0 // 0
},
{0x1.0000000000001p0, // nextUp(1)
0x1.0000000000001p31, // nextUp(2^31)
0x1.00000800002p0
},
{0x1.0000000000001p0, // nextUp(1)
-0x1.0000000000001p31, // -nextUp(2^31)
0x1.fffff000004p-1
},
{-0x1.0000000000001p0, // -nextUp(1)
-0x1.0000000000001p31, // -nextUp(2^31)
Double.NaN
},
{-0x1.0000000000001p0, // -nextUp(1)
0x1.0p31 + 1.0, // 2^31 + 1, odd integer
-0x1.0000080000201p0
},
{-0x1.0000000000001p0, // -nextUp(1)
0x1.0p31 + 2.0, // 2^31 + 2, even integer
0x1.0000080000202p0
},
{0x1.00000_ffff_ffffp0,
0x1.00001_0000_0000p31,
INFINITY
},
// Huge y, |y| > 0x1.00000_ffff_ffffp31 ~2**31 is a decision point
// First y = 0x1.00001_0000_0000p31
{0x1.fffff_ffff_ffffp-1,
0x1.00001_0000_0000p31,
0x1.fffff7ffff9p-1
},
{0x1.fffff_ffff_fffep-1,
0x1.00001_0000_0000p31,
0x1.ffffefffff4p-1
},
{0x1.fffff_0000_0000p-1,
0x1.00001_0000_0000p31,
0.0
},
// Cycle through decision points on x values
{0x1.fffff_0000_0000p-1,
0x1.00001_0000_0000p31,
0.0
},
{-0x1.fffff_0000_0000p-1,
0x1.00001_0000_0000p31,
0.0
},
{0x1.ffffe_ffff_ffffp-1,
0x1.00001_0000_0000p31,
0.0
},
{-0x1.ffffe_ffff_ffffp-1,
0x1.00001_0000_0000p31,
0.0
},
{0x1.00000_ffff_ffffp0,
0x1.00001_0000_0000p31,
INFINITY
},
{0x1.00001_0000_0000p0,
0x1.00001_0000_0000p31,
INFINITY
},
{-0x1.00000_ffff_ffffp0,
0x1.00001_0000_0000p31,
INFINITY
},
{-0x1.00001_0000_0000p0,
0x1.00001_0000_0000p31,
INFINITY
},
// Now y = -0x1.00001_0000_0000p31
{0x1.fffff_0000_0000p-1,
-0x1.00001_0000_0000p31,
INFINITY
},
{-0x1.fffff_0000_0000p-1,
0x1.00001_0000_0000p31,
0.0
},
{0x1.ffffe_ffff_ffffp-1,
-0x1.00001_0000_0000p31,
INFINITY
},
{-0x1.ffffe_ffff_ffffp-1,
-0x1.00001_0000_0000p31,
INFINITY
},
{0x1.00000_ffff_ffffp0,
-0x1.00001_0000_0000p31,
0.0
},
{0x1.00001_0000_0000p0,
-0x1.00001_0000_0000p31,
0.0
},
{-0x1.00000_ffff_ffffp0,
-0x1.00001_0000_0000p31,
0.0
},
{-0x1.00001_0000_0000p0,
-0x1.00001_0000_0000p31,
0.0
},
//-----------------------
{0x1.ffffe_ffff_ffffp-1,
-0x1.00001_0000_0000p31,
INFINITY
},
{0x1.00001_0000_0000p0,
-0x1.00001_0000_0000p31,
0.0
},
{0x1.0000000000002p0, // 1.0000000000000004
0x1.f4add4p30, // 2.1E9
0x1.00000fa56f1a6p0 // 1.0000009325877754
},
// Verify no early overflow
{0x1.0000000000002p0, // 1.0000000000000004
0x1.0642acp31, // 2.2E9
0x1.000010642b465p0, // 1.0000009769967388
},
// Verify proper overflow
{0x1.0000000000002p0, // 1.0000000000000004
0x1.62e42fefa39fp60, // 1.59828858065033216E18
0x1.ffffffffffd9fp1023, // 1.7976931348621944E308
},
};
for (double[] testCase: testCases)
failures += testPowCase(testCase[0], testCase[1], testCase[2]);
return failures;
}
private static int testPowCase(double input1, double input2, double expected) {
int failures = 0;
failures += Tests.test("StrictMath.pow(double)", input1, input2,
StrictMath.pow(input1, input2), expected);
return failures;
}
}