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Re: Slow memcmp for aligned strings on Pentium 3
- From: Jerry Quinn <jlquinn at optonline dot net>
- To: gcc at gcc dot gnu dot org
- Date: Fri, 04 Apr 2003 09:49:01 -0500
- Subject: Re: Slow memcmp for aligned strings on Pentium 3
I just tried the same benchmark on a Pentium 4 out of curiosity. Slightly
different results:
Memory compare int:
10000
130000
Speed up: 0.076923
Memory compare 15 bytes:
10000
370000
Speed up: 0.027027
Memory compare 16 bytes:
20000
330000
Speed up: 0.060606
Memory compare 64 bytes:
10000
1040000
Speed up: 0.009615
Memory compare 256 bytes:
20000
2300000
Speed up: 0.008696
Perhaps this is to be expected since the routine uses shifts.
Jerry Quinn