Why do you want libc to be 5 times slower than other libraries?
1–10 of 13 posts
Re: Why do you want libc to be 5 times slower than other libraries?
#2Wasn't this the post that eventually caused the eglibc fork that eventually became the primary glibc fork and merged back in?
Re: Why do you want libc to be 5 times slower than other libraries?
#3This post is really old (2008) and probably already resolved.
Here is the jist of the optimization that this person provides:
memory and string functions in libc have poor performance because you are not using XMM registers and you have no efficient way of dealing with unaligned data. The most efficient way of copying data when source and destination have different alignments is to read aligned into XMM registers; shift and combine consecutive reads so that they fit the alignment of the destination; then write aligned
Re: Why do you want libc to be 5 times slower than other libraries?
#4Worth reading the followup: https://sourceware.org/ml/libc-help/2008-08/msg00009.html
Re: Why do you want libc to be 5 times slower than other libraries?
#5So some guy complains that a code path in libc is slow, but refuses to actually do anything to fix it. What's noteworthy here? Besides, this particular complaint is 7 years old. Poster: is this still an issue?
Re: Why do you want libc to be 5 times slower than other libraries?
#6For those that don't know, Agner's manuals ( http://agner.org/optimize/ ) are considered to be the #1 resource for learning and reference when programming optimized assembly
Re: Why do you want libc to be 5 times slower than other libraries?
#7So some guy complains that a code path in libc is slow, but refuses to actually do anything to fix it. What's noteworthy here? Besides, this particular complaint is 7 years old. Poster: is this still an issue?
Why are you automatically obliged to fix it JUST because you mentioned it? If they just didn't know in the first place then everyone would have benefited, and if they did then something was clearly seriously broken in that development community.
Re: Why do you want libc to be 5 times slower than other libraries?
#8So some guy complains that a code path in libc is slow, but refuses to actually do anything to fix it. What's noteworthy here? Besides, this particular complaint is 7 years old. Poster: is this still an issue?
Why are you automatically obliged to fix it JUST because you mentioned it? If they just didn't know in the first place then everyone would have benefited, and if they did then something was clearly seriously broken in that development community.
And from what I've heard, not that I would know, you've just described the rise of LLVM.
Re: Why do you want libc to be 5 times slower than other libraries?
#9> a.) GLIBC is a GPL licensed project where the copyright for the
code in question has been assigned to the Free Software Foundation. All
code that is contributed must be copyright assigned to the Free Software
Foundation. This means that, regardless of the license of the reference
code, we can not use 'open source' code from other projects unless it
has been explicitly copyright assigned to the FSF.
Such free software!
Re: Why do you want libc to be 5 times slower than other libraries?
#10So some guy complains that a code path in libc is slow, but refuses to actually do anything to fix it. What's noteworthy here? Besides, this particular complaint is 7 years old. Poster: is this still an issue?
I think you must be unfamiliar with the glibc maintainers during that period. They were hostile to outside contributions, to put it mildly. The only way to fix it would have been to make a fork. Which is what actually happened in the end with eglibc.
A lot of the big distros dropped glibc and switched to eglibc because they didn't want to deal with the glibc maintainers and their refusal to fix things anymore: http://blog.aurel32.net/47