Java 8 RFR 6378503: In java.math.BigDecimal, division by one returns zero

Brian Burkhalter brian.burkhalter at
Thu Jul 25 21:28:03 UTC 2013

Hi Joe,

On Jul 24, 2013, at 9:01 PM, Joe Darcy wrote:

> I took a look through the code and I don't see how sdiff == Integer.MIN_VALUE is handled.

This case, if compareMagnitude() does not return at lines 2668 or 2670, intentionally falls through to line 2690. Otherwise, if hypothetically sdiff were equal to Integer.MIN_VALUE, then evaluating line 2677 would overflow. It is not actually apparent to me however whether line 2671 would ever be reached were sdiff == Integer.MIN_VALUE.

> In any case, as long as the runtimes and memory usage are tractable, the set of test cases should be augmented to include sdiff == Integer.MIN_VALUE and (long)Integer.MIN_VALUE + 1, etc.

From what I can tell by inspection, sdiff mirrors the MathContext precision (mcp) and all paths will attempt to calculate 10^e where "e" is approximately or exactly mcp. This computation would run for days. I don't yet see a way to test these cases.



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