Hello, Andrew!
>On 06/29/2010 10:22 AM, Ivan Maidanski wrote:
>> Hi!
>>
>> I've fixed a number of bugs in StrictMath class (the RI here is fdlibm of
>> some version).
>>
>> ChangeLog entries:
>>
>> * java/lang/StrictMath.java:
>> (acos(double)): Bug fix for x <= -1/2 case.
>> (atan(double)): Fix documentation typo.
>> (pow(double,double)): Fix a comment; put y == 1/2 case handling after
>> x == -0 case (since pow(-0, 1/2) == 0 but sqrt(-0) == -0); return -0
>> (or -INF) for pow(-0, 2*k) where k is non-zero integer; simplify
>> expression for "negative" variable.
>> (IEEEremainder(double,double)): Bug fix for x == -0 and x == -|y|
>> cases; bug fix for |y| >= 2**-1021 and |x| > |y|/2.
>> (remPiOver2(double[],double[],int,int)): Reset "recompute" at the
>> beginning of every do/while iteration.
>> (tan(double,double,boolean)): Negate the result if x <= -0.6744.
>
>Hi Ivan,
>
>Firstly please attach patches as type text; that way people can read
>them in their mailers.
I don't understand. I attach patches with .diff extension. Shall I use .txt?
>
>Can you please send test cases that pass with this patch?
Ok. I'll write them a bit later...
>
>diff -ru CVS/classpath/java/lang/StrictMath.java
>updated/classpath/java/lang/StrictMath.java
>--- CVS/classpath/java/lang/StrictMath.java 2010-06-29 10:11:06.000000000
>+0400
>+++ updated/classpath/java/lang/StrictMath.java 2010-06-29
>12:51:50.000000000 +0400
>@@ -1,5 +1,6 @@
> /* java.lang.StrictMath -- common mathematical functions, strict Java
>- Copyright (C) 1998, 2001, 2002, 2003, 2006 Free Software Foundation, Inc.
>+ Copyright (C) 1998, 2001, 2002, 2003, 2006, 2010
>+ Free Software Foundation, Inc.
>
> This file is part of GNU Classpath.
>
>@@ -456,9 +457,10 @@
> double r = x - (PI_L / 2 - x * (p / q));
> return negative ? PI / 2 + r : PI / 2 - r;
> }
>+ double z = (1 - x) * 0.5;
> if (negative) // x<=-0.5.
> {
>- double z = (1 + x) * 0.5;
>+ // z = (1+orig_x)*0.5
>
>Please don't leave commented lines in code. If they're wrong, please
>take them out.
This is not a commented code - it's a reference C code from fdlibm. It might be
better to use some words instead of a formular like "x is not modified in
fdlibm unlike in this implementation so we use 1-x (where x==-orig_x) instead
of 1+x".
>
>@@ -1554,10 +1553,18 @@
> else if (yisint == 1)
> ax = -ax;
> }
>+ else
>+ {
>+ // Check for x == -0 with odd y.
>+ if (1 / x < 0
>
>Why use "1 / x < 0" ?
What's else to use? The alternative is Double.doubleToRawLongBits(x) < 0 but
(1/x)<0 is cheaper (recall that |x| is zero).
>
>Andrew.
