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Re: [RFC] libstdc++ atomicity, x86 agnostic version
- From: Benjamin Kosnik <bkoz at redhat dot com>
- To: Paolo Carlini <pcarlini at suse dot de>
- Cc: libstdc++ at gcc dot gnu dot org, jakub at redhat dot com, mark at codesourcery dot com
- Date: Wed, 25 Feb 2004 13:43:15 -0600
- Subject: Re: [RFC] libstdc++ atomicity, x86 agnostic version
- Organization: Red Hat / Chicago
- References: <20040225120358.46071e6c.bkoz@redhat.com><403CE8AF.7030407@suse.de>
>This seems really sad and more specific tests should be performed: the
>current performance testsuite definitely is not tuned to benchmark that.
I don't dispute this. However, if you look at the use of the atomic
functions, I only see the allocator and string uses as being performance
critical.
And, we do have benchmarks to measure performance of these items....
Current:
string_append.cc char 1r 1u 0s 0mem 11pf
string_append.cc string 1r 1u 0s 0mem 1pf
string_append.cc char 9r 9u 0s 0mem 0pf
string_append.cc string 11r 11u 0s 0mem 0pf
string_append.cc char 89r 86u 3s 0mem 0pf
string_append.cc string 115r 110u 4s 0mem 0pf
string_cons_input_iterator.cc 2r 2u 0s 0mem 2pf
string_cons_input_iterator.cc 16r 15u 1s 0mem 0pf
string_cons_input_iterator.cc 157r 136u 21s 0mem 0pf
Current + patch:
string_append.cc char 0r 0u 0s 0mem 11pf
string_append.cc string 2r 2u 0s 0mem 1pf
string_append.cc char 8r 7u 1s 0mem 0pf
string_append.cc string 11r 11u 0s 0mem 0pf
string_append.cc char 88r 83u 5s 0mem 0pf
string_append.cc string 114r 110u 4s 0mem 0pf
string_cons_input_iterator.cc 2r 2u 0s 0mem 2pf
string_cons_input_iterator.cc 15r 13u 2s 0mem 0pf
string_cons_input_iterator.cc 156r 137u 19s 0mem 0pf
Sooo... although it may conflict with your (and mine!) initial
impression, I don't seeing this as impacting performance.
However, maybe you have something in particular in mind, that is not
being tested at the moment? If so, can you share it with me, so we can
see what the performance impacts will be?
best,
benjamin