Date: Sat, 4 May 2013 20:42:18 +0400 From: Sergey Kandaurov <pluknet@freebsd.org> To: Andrey Chernov <ache@freebsd.org> Cc: svn-src-stable@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org, svn-src-stable-9@freebsd.org, Jilles Tjoelker <jilles@stack.nl> Subject: Re: svn commit: r250215 - stable/9/lib/libc/locale Message-ID: <CAE-mSOKPjx-tF5gtXXtNUHYraPL-Rd1FPxq5ECw8Nbup=jahng@mail.gmail.com> In-Reply-To: <51851969.6020802@freebsd.org> References: <201305031552.r43FqiPN024580@svn.freebsd.org> <5183E899.4000503@freebsd.org> <CAE-mSO%2BB_p_HCbKwSO-rJ%2BdforcPEfThmOxy%2BKi_1e9zPn3q_w@mail.gmail.com> <20130503195540.GA52657@stack.nl> <CAE-mSOLT6EdaYQheNka%2B%2BNPZRbUFM=kXv6i9k=uRiyQTy1JuuA@mail.gmail.com> <5184ED7E.3040703@freebsd.org> <CAE-mSO%2BJOTcfx1vDbiux8LpikZV0J1ti2HJ0ypCsotfeJ4qKzg@mail.gmail.com> <51851969.6020802@freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On 4 May 2013 18:21, Andrey Chernov <ache@freebsd.org> wrote:
> On 04.05.2013 16:03, Sergey Kandaurov wrote:
>>> BTW, I don't run tests and look in asm code for sure, but it seems
>>> property[0] == p[0] is unneeded because almost every compiler tries to
>>> inline strcmp().
>>
>> Doesn't seem so (in-lining), see below.
>
> Yes, system's GNU cc don't inline strcmp() but inlines memcmp():
> repz
> cmpsb
> I don't have clang nearby right now to test what it does.
I've checked gcc46 and clang3.2, and they behave similarly (poor).
It's worth to note that inlined memcmp didn't help with performance
relative to strcmp().
note2 - it's surprising that only base gcc inlined memcmp. This explains
the difference between base gcc and {gcc46, clang} in the table below.
1 - base gcc 4.2
2 - gcc46
3 - base clang 3.2
a - if (property[0] == p[0] && strcmp(property, p) == 0)
b - if (property[0] == p[0] && memcmp(property, p, *len2) == 0)
c - if (memcmp(property, p, *len2) == 0)
Time spend for 2097152 wctype() calls for each of wctype property
1a 2a 3a 1b 2b 3b 1c 2c 3c
alnum 0.034 0.036 0.034 0.049 0.071 0.073 0.046 0.068 0.069
alpha 0.045 0.049 0.046 0.111 0.156 0.158 0.107 0.153 0.154
blank 0.037 0.041 0.038 0.053 0.075 0.079 0.153 0.224 0.223
cntrl 0.039 0.044 0.042 0.058 0.078 0.081 0.206 0.300 0.301
digit 0.039 0.044 0.043 0.059 0.080 0.085 0.259 0.378 0.378
graph 0.043 0.049 0.050 0.061 0.082 0.087 0.313 0.455 0.455
lower 0.044 0.049 0.051 0.062 0.085 0.090 0.365 0.532 0.533
print 0.048 0.054 0.059 0.067 0.088 0.092 0.419 0.610 0.610
punct 0.060 0.067 0.103 0.127 0.183 0.211 0.477 0.692 0.692
space 0.053 0.059 0.067 0.072 0.092 0.097 0.525 0.764 0.765
upper 0.054 0.059 0.068 0.074 0.094 0.100 0.578 0.841 0.842
xdigit 0.060 0.066 0.077 0.079 0.099 0.106 0.635 0.922 0.985
ideogram 0.068 0.074 0.084 0.087 0.089 0.094 0.695 0.986 0.985
special 0.098 0.104 0.113 0.169 0.210 0.212 0.753 1.116 1.118
phonogram 0.136 0.156 0.187 0.240 0.285 0.325 0.815 1.181 1.183
rune 0.064 0.070 0.087 0.099 0.104 0.113 0.842 1.293 1.283
--
wbr,
pluknet
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CAE-mSOKPjx-tF5gtXXtNUHYraPL-Rd1FPxq5ECw8Nbup=jahng>