My first webrev review request: 6850337 interprets given option value badly

Ulf Zibis Ulf.Zibis at
Mon Jul 20 10:37:48 UTC 2009

Hi Andrew,

thanks for looking at my request. ....

Am 20.07.2009 02:25, Andrew John Hughes schrieb:
> 2009/7/19 Ulf Zibis <Ulf.Zibis at>:
>> Martin, Sherman, Neal,
>> do you like to sponsor and review my CR ?
>> Don't worry, it's very simple and small, best for getting familiar with the
>> workflow.
>> See:
>> Thanks,
>> Ulf
> As this bug is about a tool used during the build, your mail probably
> wants to be directed to the build list.

Good idea, thanks for forwarding.

> Are you sure this is not done by design and that mb is not in fact
> meant to be an exclusive rather than inclusive bound?

Option usage of says:
"    -md depth    max chain depth (default 3)"
"    -mb bits     max index bits (lg of table size, default 10)"
In case of setting -md to x the max chain depth properly results in x, 
but ...
in case of setting -mb to x the max lg of table size inproperly results 
in x-1 bits, as you can see in -verbose output of the hasher.

To ensure, that the default value is processed as it would be 10, 
variable maxBits is pre-set to 11, to "workaround" the bug.
When fixing this bug, any usage of this option should be corrected to 
x-1 to ensure identical results.

I don't think the different boundary behaviour of -md and -mb is done by 
design. Maybe processing of -md has been wrong too in first time and was 
corrected, but correction for -mb was overseen, as never used.

Maybe you could have a short call to the author Mark Reynolds to ensure 
this. Possibly he also has knowledge of other usage than in

> Have you checked that the OpenJDK can still be built with this change in place?

I have scanned over

The only usage of I've found in:

In this case, the option -mb  is not used. I assume, this is the reason, 
why nobody has experienced this bug before.

I have *not* scanned over
- .../langtools etc.
as I don't have a hg clone of them.

Maybe I should have done this, but I think, it's anyway good that 
experienced SUN engineer would do that scan too, and I guess, you have 
better tools to do that.


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