Re: ordered indexing for integers
Hallvard B Furuseth wrote:
Howard Chu writes:
> I think you misunderstood.
No, I wrote too briefly.
> No matter what you're actually testing for, there is no way you're going to
> get a TRUE result from comparing ( signed 32 bit integer > 0x7fffffff ).
Right, and chop <= (max ber_len_t)/2.3333 so the test is a no-op on
32-bit hosts. But on 64-bit hosts, chop can be an 8-byte integer
which would require the first byte in the output key to hold 10 bits:
inverse sign bit, 8 more bits (one for each chop byte), final sign bit.
If you simply rewrote the test it would eliminate all ambiguity.
>If it is actually possible for ( chop * 3 > 0x7fffffff ) then
this
> test won't detect that fact. You need to test for
> ( chop > 0x7fffffff / 3 )
The other point being, it saves a multiply; the division is a compile time
constant.
--
-- Howard Chu
Chief Architect, Symas Corp. http://www.symas.com
Director, Highland Sun http://highlandsun.com/hyc/
Chief Architect, OpenLDAP http://www.openldap.org/project/