mirror/gcc
2
0
Fork 0
mirror of git://gcc.gnu.org/git/gcc.git synced 2025-01-19 03:14:04 +08:00
Code Issues Packages Projects Releases Wiki Activity

BigDecimal (divide): Correctly handle ROUND_HALF_EVEN when amount is greater than 0.5.

Browse Source 
2003-08-01  Jerry Quinn  <jlquinn@optonline.net>
            Mark Wielaard  <mark@klomp.org>

       * java/math/BigDecimal (divide): Correctly handle
       ROUND_HALF_EVEN when amount is greater than 0.5.
       Simplify and optimize code.

Co-Authored-By: Mark Wielaard <mark@klomp.org>

From-SVN: r70049
This commit is contained in:
Jerry Quinn 2003-08-01 15:07:49 +00:00 committed by Mark Wielaard
parent cbd63935d8
commit 2f18d7a1a8
2 changed files with 45 additions and 35 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
libjava/ChangeLog
View File

@ -1,3 +1,10 @@
2003-08-01 Jerry Quinn <jlquinn@optonline.net>
Mark Wielaard <mark@klomp.org>
* java/math/BigDecimal (divide): Correctly handle
ROUND_HALF_EVEN when amount is greater than 0.5.
Simplify and optimize code.
2003-07-31 Tom Tromey <tromey@redhat.com>
More for PR libgcj/11737:

73
libjava/java/math/BigDecimal.java
View File

@ -1,5 +1,5 @@
/* java.math.BigDecimal -- Arbitrary precision decimals.
Copyright (C) 1999, 2000, 2001 Free Software Foundation, Inc.
Copyright (C) 1999, 2000, 2001, 2003 Free Software Foundation, Inc.
This file is part of GNU Classpath.
@ -273,7 +273,7 @@ public class BigDecimal extends Number implements Comparable
// Ensure that pow gets a non-negative value.
int valScale = val.scale;
BigInteger valIntVal = val.intVal;
int power = newScale + 1 - (scale - val.scale);
int power = newScale - (scale - val.scale);
if (power < 0)
{
// Effectively increase the scale of val to avoid an
@ -285,50 +285,53 @@ public class BigDecimal extends Number implements Comparable
BigInteger dividend = intVal.multiply (BigInteger.valueOf (10).pow (power));
BigInteger parts[] = dividend.divideAndRemainder (valIntVal);
// System.out.println("int: " + parts[0]);
// System.out.println("rem: " + parts[1]);
int roundDigit = parts[0].mod (BigInteger.valueOf (10)).intValue ();
BigInteger unrounded = parts[0].divide (BigInteger.valueOf (10));
if (roundDigit == 0 && parts[1].signum () == 0) // no rounding necessary
BigInteger unrounded = parts[0];
if (parts[1].signum () == 0) // no remainder, no rounding necessary
return new BigDecimal (unrounded, newScale);
int sign = unrounded.signum ();
if (roundingMode == ROUND_UNNECESSARY)
throw new ArithmeticException ("newScale is not large enough");
switch (roundingMode)
int sign = intVal.signum () * valIntVal.signum ();
if (roundingMode == ROUND_CEILING)
roundingMode = (sign > 0) ? ROUND_UP : ROUND_DOWN;
else if (roundingMode == ROUND_FLOOR)
roundingMode = (sign < 0) ? ROUND_UP : ROUND_DOWN;
else
{
case ROUND_UNNECESSARY:
throw new ArithmeticException ("newScale is not large enough");
case ROUND_CEILING:
roundingMode = (sign == 1) ? ROUND_UP : ROUND_DOWN;
break;
case ROUND_FLOOR:
roundingMode = (sign == 1) ? ROUND_DOWN : ROUND_UP;
break;
case ROUND_HALF_UP:
roundingMode = (roundDigit >= 5) ? ROUND_UP : ROUND_DOWN;
break;
case ROUND_HALF_DOWN:
roundingMode = (roundDigit > 5) ? ROUND_UP : ROUND_DOWN;
break;
case ROUND_HALF_EVEN:
if (roundDigit < 5)
roundingMode = ROUND_DOWN;
else
// half is -1 if remainder*2 < positive intValue (*power), 0 if equal,
// 1 if >. This implies that the remainder to round is less than,
// equal to, or greater than half way to the next digit.
BigInteger posRemainder
= parts[1].signum () < 0 ? parts[1].negate() : parts[1];
valIntVal = valIntVal.signum () < 0 ? valIntVal.negate () : valIntVal;
int half = posRemainder.shiftLeft(1).compareTo(valIntVal);
switch(roundingMode)
{
int rightmost =
unrounded.mod (BigInteger.valueOf (10)).intValue ();
if (rightmost % 2 == 1) // odd, then ROUND_HALF_UP
case ROUND_HALF_UP:
roundingMode = (half < 0) ? ROUND_DOWN : ROUND_UP;
break;
case ROUND_HALF_DOWN:
roundingMode = (half > 0) ? ROUND_UP : ROUND_DOWN;
break;
case ROUND_HALF_EVEN:
if (half < 0)
roundingMode = ROUND_DOWN;
else if (half > 0)
roundingMode = ROUND_UP;
else // even, then ROUND_HALF_DOWN
roundingMode = (roundDigit > 5) ? ROUND_UP : ROUND_DOWN;
else if (unrounded.testBit(0)) // odd, then ROUND_HALF_UP
roundingMode = ROUND_UP;
else // even, ROUND_HALF_DOWN
roundingMode = ROUND_DOWN;
break;
}
break;
}
if (roundingMode == ROUND_UP)
return new BigDecimal (unrounded.add (BigInteger.valueOf (1)), newScale);
unrounded = unrounded.add (BigInteger.valueOf (sign > 0 ? 1 : -1));
// roundingMode == ROUND_DOWN
return new BigDecimal (unrounded, newScale);