diff --git a/jdk/src/share/classes/java/math/BigDecimal.java b/jdk/src/share/classes/java/math/BigDecimal.java index d95b1cb27b3..b7f6380948e 100644 --- a/jdk/src/share/classes/java/math/BigDecimal.java +++ b/jdk/src/share/classes/java/math/BigDecimal.java @@ -3537,13 +3537,25 @@ public class BigDecimal extends Number implements Comparable { else return expandBigIntegerTenPowers(n); } - // BigInteger.pow is slow, so make 10**n by constructing a - // BigInteger from a character string (still not very fast) - char tenpow[] = new char[n + 1]; - tenpow[0] = '1'; - for (int i = 1; i <= n; i++) - tenpow[i] = '0'; - return new BigInteger(tenpow,1, tenpow.length); + + if (n < 1024*524288) { + // BigInteger.pow is slow, so make 10**n by constructing a + // BigInteger from a character string (still not very fast) + // which occupies no more than 1GB (!) of memory. + char tenpow[] = new char[n + 1]; + tenpow[0] = '1'; + for (int i = 1; i <= n; i++) { + tenpow[i] = '0'; + } + return new BigInteger(tenpow, 1, tenpow.length); + } + + if ((n & 0x1) == 0x1) { + return BigInteger.TEN.multiply(bigTenToThe(n - 1)); + } else { + BigInteger tmp = bigTenToThe(n/2); + return tmp.multiply(tmp); + } } /**