Ticket #1069 (closed defect: fixed)

Opened 14 months ago

Last modified 14 months ago

SXHASH shouldn't collide on small fixnums

Reported by: fare Owned by: gb
Priority: normal Milestone:
Component: Performance Version: trunk
Keywords: ITA Cc:

Description

Collisions on small consecutive numbers mean hash-tables will be slower than expected, and systematic such collisions probably count as a performance bug.

(EQUAL (SXHASH 12) (SXHASH 13))
;;=> T

gz says it looks like 2n and 2n+1 can have same SXHASH, and gb points at CCL::STRIP-TAG-TO-FIXNUM.

Change History

comment:1 Changed 14 months ago by gb

  • Owner set to gb
  • Status changed from new to assigned

comment:2 Changed 14 months ago by gz

  • Keywords ITA added

comment:3 Changed 14 months ago by gb

  • Status changed from assigned to closed
  • Resolution set to fixed

(In [15775]) STRIP-TAG-TO-FIXNUM: if arg is a fixnum, return it. Fixes ticket:1069 in the trunk.

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