[LUCY-99] Merge sort elements of arbitrary width

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Component/s: Util
• Assignee: Marvin Humphrey
• Reporter: Marvin Humphrey
• Created: 09/Feb/10 01:33
• Updated: 13/Feb/10 00:41
• Resolved: 13/Feb/10 00:41

Description

The present implementation of mergesort in SortUtils only handles four-byte and
eight-byte elements, because it was intended only for sorting pointers, but it
would be convenient to make it possible to sort elements of arbitrary width.

We can add a width argument without sacrificing speed by taking advantage of
the fact that optimizing compilers such as GCC produce identical assembler for
invocations of memcpy() where the amount to copy is a small constant known
at compile time as for direct assigment.