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6378503: In java.math.BigDecimal, division by one returns zero

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6446965: Using BigDecimal.divideToIntegralValue with extreme scales can lead to an incorrect result

Fix overflow of ints and ensure appropriate values passed to checkScaleNonZero()

Reviewed-by: darcy, martin
This commit is contained in:
Brian Burkhalter 2013-08-23 14:15:54 -07:00 committed by Brian Burkhalter
parent 6d2de008d7
commit 6c5c2d745a
3 changed files with 23 additions and 16 deletions
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32
jdk/src/share/classes/java/math/BigDecimal.java
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@ -2659,28 +2659,32 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
if (ys == 0) if (ys == 0)
return 1; return 1;
int sdiff = this.scale - val.scale; long sdiff = (long)this.scale - val.scale;
if (sdiff != 0) { if (sdiff != 0) {
// Avoid matching scales if the (adjusted) exponents differ // Avoid matching scales if the (adjusted) exponents differ
int xae = this.precision() - this.scale; // [-1] long xae = (long)this.precision() - this.scale; // [-1]
int yae = val.precision() - val.scale; // [-1] long yae = (long)val.precision() - val.scale; // [-1]
if (xae < yae) if (xae < yae)
return -1; return -1;
if (xae > yae) if (xae > yae)
return 1; return 1;
BigInteger rb = null; BigInteger rb = null;
if (sdiff < 0) { if (sdiff < 0) {
if ( (xs == INFLATED || // The cases sdiff <= Integer.MIN_VALUE intentionally fall through.
(xs = longMultiplyPowerTen(xs, -sdiff)) == INFLATED) && if ( sdiff > Integer.MIN_VALUE &&
(xs == INFLATED ||
(xs = longMultiplyPowerTen(xs, (int)-sdiff)) == INFLATED) &&
ys == INFLATED) { ys == INFLATED) {
rb = bigMultiplyPowerTen(-sdiff); rb = bigMultiplyPowerTen((int)-sdiff);
return rb.compareMagnitude(val.intVal); return rb.compareMagnitude(val.intVal);
} }
} else { // sdiff > 0 } else { // sdiff > 0
if ( (ys == INFLATED || // The cases sdiff > Integer.MAX_VALUE intentionally fall through.
(ys = longMultiplyPowerTen(ys, sdiff)) == INFLATED) && if ( sdiff <= Integer.MAX_VALUE &&
(ys == INFLATED ||
(ys = longMultiplyPowerTen(ys, (int)sdiff)) == INFLATED) &&
xs == INFLATED) { xs == INFLATED) {
rb = val.bigMultiplyPowerTen(sdiff); rb = val.bigMultiplyPowerTen((int)sdiff);
return this.intVal.compareMagnitude(rb); return this.intVal.compareMagnitude(rb);
} }
} }
@ -4545,7 +4549,7 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
if(cmp > 0) { // satisfy constraint (b) if(cmp > 0) { // satisfy constraint (b)
yscale -= 1; // [that is, divisor *= 10] yscale -= 1; // [that is, divisor *= 10]
int scl = checkScaleNonZero(preferredScale + yscale - xscale + mcp); int scl = checkScaleNonZero(preferredScale + yscale - xscale + mcp);
if (checkScaleNonZero((long) mcp + yscale) > xscale) { if (checkScaleNonZero((long) mcp + yscale - xscale) > 0) {
// assert newScale >= xscale // assert newScale >= xscale
int raise = checkScaleNonZero((long) mcp + yscale - xscale); int raise = checkScaleNonZero((long) mcp + yscale - xscale);
long scaledXs; long scaledXs;
@ -4626,7 +4630,7 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
// return BigDecimal object whose scale will be set to 'scl'. // return BigDecimal object whose scale will be set to 'scl'.
int scl = checkScaleNonZero(preferredScale + yscale - xscale + mcp); int scl = checkScaleNonZero(preferredScale + yscale - xscale + mcp);
BigDecimal quotient; BigDecimal quotient;
if (checkScaleNonZero((long) mcp + yscale) > xscale) { if (checkScaleNonZero((long) mcp + yscale - xscale) > 0) {
int raise = checkScaleNonZero((long) mcp + yscale - xscale); int raise = checkScaleNonZero((long) mcp + yscale - xscale);
long scaledXs; long scaledXs;
if ((scaledXs = longMultiplyPowerTen(xs, raise)) == INFLATED) { if ((scaledXs = longMultiplyPowerTen(xs, raise)) == INFLATED) {
@ -4673,7 +4677,7 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
// return BigDecimal object whose scale will be set to 'scl'. // return BigDecimal object whose scale will be set to 'scl'.
BigDecimal quotient; BigDecimal quotient;
int scl = checkScaleNonZero(preferredScale + yscale - xscale + mcp); int scl = checkScaleNonZero(preferredScale + yscale - xscale + mcp);
if (checkScaleNonZero((long) mcp + yscale) > xscale) { if (checkScaleNonZero((long) mcp + yscale - xscale) > 0) {
int raise = checkScaleNonZero((long) mcp + yscale - xscale); int raise = checkScaleNonZero((long) mcp + yscale - xscale);
BigInteger rb = bigMultiplyPowerTen(xs,raise); BigInteger rb = bigMultiplyPowerTen(xs,raise);
quotient = divideAndRound(rb, ys, scl, roundingMode, checkScaleNonZero(preferredScale)); quotient = divideAndRound(rb, ys, scl, roundingMode, checkScaleNonZero(preferredScale));
@ -4714,7 +4718,7 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
// return BigDecimal object whose scale will be set to 'scl'. // return BigDecimal object whose scale will be set to 'scl'.
BigDecimal quotient; BigDecimal quotient;
int scl = checkScaleNonZero(preferredScale + yscale - xscale + mcp); int scl = checkScaleNonZero(preferredScale + yscale - xscale + mcp);
if (checkScaleNonZero((long) mcp + yscale) > xscale) { if (checkScaleNonZero((long) mcp + yscale - xscale) > 0) {
int raise = checkScaleNonZero((long) mcp + yscale - xscale); int raise = checkScaleNonZero((long) mcp + yscale - xscale);
BigInteger rb = bigMultiplyPowerTen(xs,raise); BigInteger rb = bigMultiplyPowerTen(xs,raise);
quotient = divideAndRound(rb, ys, scl, roundingMode, checkScaleNonZero(preferredScale)); quotient = divideAndRound(rb, ys, scl, roundingMode, checkScaleNonZero(preferredScale));
@ -4745,7 +4749,7 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
// return BigDecimal object whose scale will be set to 'scl'. // return BigDecimal object whose scale will be set to 'scl'.
BigDecimal quotient; BigDecimal quotient;
int scl = checkScaleNonZero(preferredScale + yscale - xscale + mcp); int scl = checkScaleNonZero(preferredScale + yscale - xscale + mcp);
if (checkScaleNonZero((long) mcp + yscale) > xscale) { if (checkScaleNonZero((long) mcp + yscale - xscale) > 0) {
int raise = checkScaleNonZero((long) mcp + yscale - xscale); int raise = checkScaleNonZero((long) mcp + yscale - xscale);
BigInteger rb = bigMultiplyPowerTen(xs,raise); BigInteger rb = bigMultiplyPowerTen(xs,raise);
quotient = divideAndRound(rb, ys, scl, roundingMode, checkScaleNonZero(preferredScale)); quotient = divideAndRound(rb, ys, scl, roundingMode, checkScaleNonZero(preferredScale));

2
jdk/src/share/classes/java/math/BigInteger.java
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@ -2109,7 +2109,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
// This is a quick way to approximate the size of the result, // This is a quick way to approximate the size of the result,
// similar to doing log2[n] * exponent. This will give an upper bound // similar to doing log2[n] * exponent. This will give an upper bound
// of how big the result can be, and which algorithm to use. // of how big the result can be, and which algorithm to use.
int scaleFactor = remainingBits * exponent; long scaleFactor = (long)remainingBits * exponent;
// Use slightly different algorithms for small and large operands. // Use slightly different algorithms for small and large operands.
// See if the result will safely fit into a long. (Largest 2^63-1) // See if the result will safely fit into a long. (Largest 2^63-1)

5
jdk/test/java/math/BigDecimal/IntegralDivisionTests.java
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@ -22,7 +22,7 @@
*/ */
/* /*
* @test * @test
* @bug 4904082 4917089 6337226 * @bug 4904082 4917089 6337226 6378503
* @summary Tests that integral division and related methods return the proper result and scale. * @summary Tests that integral division and related methods return the proper result and scale.
* @author Joseph D. Darcy * @author Joseph D. Darcy
*/ */
@ -47,6 +47,9 @@ public class IntegralDivisionTests {
{new BigDecimal("400e1"), new BigDecimal("5"), new BigDecimal("80e1")}, {new BigDecimal("400e1"), new BigDecimal("5"), new BigDecimal("80e1")},
{new BigDecimal("400e1"), new BigDecimal("4.999999999"), new BigDecimal("8e2")}, {new BigDecimal("400e1"), new BigDecimal("4.999999999"), new BigDecimal("8e2")},
{new BigDecimal("40e2"), new BigDecimal("5"), new BigDecimal("8e2")}, {new BigDecimal("40e2"), new BigDecimal("5"), new BigDecimal("8e2")},
{BigDecimal.valueOf(1, Integer.MIN_VALUE),
BigDecimal.valueOf(1, -(Integer.MAX_VALUE & 0x7fffff00)),
BigDecimal.valueOf(1, -256)},
}; };
for(BigDecimal [] testCase: moreTestCases) { for(BigDecimal [] testCase: moreTestCases) {