8081823: C2 performs unsigned comparison against -1 (original) (raw)

Vladimir Ivanov vladimir.x.ivanov at oracle.com
Mon Jun 8 17:45:20 UTC 2015

Looks good.

Best regards, Vladimir Ivanov

On 6/8/15 6:38 PM, Roland Westrelin wrote:

http://cr.openjdk.java.net/~roland/8081823/webrev.00/

C2 folds: if (i <= a || i > b) { as: if (i - a - 1 >u b - a - 1) { a == b is allowed and the test becomes then if (i-1 >u -1) { which is never true. Same is true with if (i > b || i <= a) {_ _The fix folds it as:_ _if (i - a - 1 >=u b - a) { which is always true for a == b Roland.

More information about the hotspot-compiler-dev mailing list