|
|
|
|
|
|||||||
| General General questions about the FreeBSD operating system. Ask here if your question does not fit elsewhere. |
 |
|
|
Thread Tools | Display Modes |
|
#1
July 15th, 2011, 06:12
|
|||
|
|||
(Benchmarks) To clang or not to clang
Hello there,
I just got my new motherboard in the mail (the old one was shot and couldn't boot FreeBSD), and I put FreeBSD-9.0-CURRENT (201105-amd64-dvd1) on my box to try to figure out a lingering question I had... should I use clang or gcc? So, I did some tests! First of all, I pulled FreeBSD head Rev 224044 for the tests, and built (worlds only, no kernels) one system with gcc (4.2.2-20070831), and the other with clang (3.0-20110502)and installed them in a chroot. Note: All tests were done in RAM (the files to tar, the tarred file, and the flops program, but the system/world was on the HD). Also, the kernel used was compiled with gcc, I'll release benchmarks with a clang kernel later. Given that, these results are still very valid System specs: Intel i7-970 (6-core with HT [12 threads] @ 3.20GHz) 24GB ram (DDR3-1600 [Damnit, I have it set as 1067MHz in the BIOS]) 50GB SSD HD (200MB/s write, 250MB/s read) Test #1: tar.bz2ing the FreeBSD head (cleaned) that I used to build the systems Note: I tarred the files first, then tarred again with timing to clear up having caching changing performance a lot `tar cjf test.tar.bz2 tarme/` `time` on clang: 209.75 real 203.81 user 5.93 sys `time` on gcc: 215.62 real 207.54 user 8.07 sys Test #2: md5ing the generated tarball 100 times `time` on clang: 79.95 real 46.29 user 33.65 sys `time` on gcc: 84.11 real 50.77 user 33.33 sys Test #3: sha1ing the generated tarball 100 times `time` on clang: 112.50 real 78.53 user 34.04 sys `time` on gcc: 102.64 real 69.62 user 33.02 sys Test #4: sha256ing the generated tarball 100 times `time` on clang: 196.92 real 163.53 user 33.38 sys `time` on gcc: 204.38 real 171.47 user 32.90 sys Test #5: MFLOPS from the benchmarks/flops port flops.c built as: `clang -O2 -DUNIX flops.c` `gcc -O2 -DUNIX flops.c` NOTE: THERE ARE 2 OUTPUTS FOR EACH SYSTEM FOR REDUNDANCY clang output #1: Code:
FLOPS C Program (Double Precision), V2.0 18 Dec 1992
Module Error RunTime MFLOPS
(usec)
1 4.0146e-13 0.0080 1753.5920
2 -1.4166e-13 0.0065 1072.0893
3 4.7184e-14 0.0062 2756.7597
4 -1.2557e-13 0.0061 2453.0056
5 -1.3800e-13 0.0116 2506.2720
6 3.2380e-13 0.0272 1065.8150
7 -8.4583e-11 0.0257 466.0625
8 3.4867e-13 0.0120 2505.2298
Iterations = 512000000
NullTime (usec) = 0.0000
MFLOPS(1) = 1339.7506
MFLOPS(2) = 938.0637
MFLOPS(3) = 1508.7634
MFLOPS(4) = 1768.1651
Code:
FLOPS C Program (Double Precision), V2.0 18 Dec 1992
Module Error RunTime MFLOPS
(usec)
1 4.0146e-13 0.0080 1754.0005
2 -1.4166e-13 0.0065 1071.8402
3 4.7184e-14 0.0062 2755.8083
4 -1.2557e-13 0.0061 2450.9765
5 -1.3800e-13 0.0116 2505.0859
6 3.2380e-13 0.0272 1065.7021
7 -8.4583e-11 0.0257 466.5673
8 3.4867e-13 0.0120 2505.7709
Iterations = 512000000
NullTime (usec) = 0.0000
MFLOPS(1) = 1339.4153
MFLOPS(2) = 938.6299
MFLOPS(3) = 1509.0247
MFLOPS(4) = 1767.9079
Code:
FLOPS C Program (Double Precision), V2.0 18 Dec 1992
Module Error RunTime MFLOPS
(usec)
1 4.0146e-13 0.0080 1754.2786
2 -1.4166e-13 0.0091 771.8205
3 4.7184e-14 0.0066 2566.9269
4 -1.2557e-13 0.0063 2396.7763
5 -1.3800e-13 0.0229 1268.5356
6 3.2380e-13 0.0111 2619.0838
7 -8.4583e-11 0.0240 500.9846
8 3.4867e-13 0.0232 1292.1545
Iterations = 512000000
NullTime (usec) = 0.0000
MFLOPS(1) = 1000.5765
MFLOPS(2) = 1009.2525
MFLOPS(3) = 1431.8632
MFLOPS(4) = 1929.1627
Code:
FLOPS C Program (Double Precision), V2.0 18 Dec 1992
Module Error RunTime MFLOPS
(usec)
1 4.0146e-13 0.0080 1753.9284
2 -1.4166e-13 0.0091 771.5915
3 4.7184e-14 0.0066 2566.8247
4 -1.2557e-13 0.0063 2395.5376
5 -1.3800e-13 0.0229 1268.4892
6 3.2380e-13 0.0111 2619.6577
7 -8.4583e-11 0.0239 501.2391
8 3.4867e-13 0.0232 1292.0066
Iterations = 512000000
NullTime (usec) = 0.0000
MFLOPS(1) = 1000.3124
MFLOPS(2) = 1009.5551
MFLOPS(3) = 1431.9474
MFLOPS(4) = 1929.0101
1388.715075 Average MFLOPS for gcc: 1342.7099875 All in all, it seems that clang outperformed gcc by a decent bit when it came to tar, md5, sha256, and MFLOPS. The ONLY place where gcc seemed to outperform, was in sha1, which seems to be a fluke (bit I still double checked and it isn't). When it comes to md5, sha256, and tar, there is a quite considerable difference, and in MFLOPS it does manage to beat gcc, but not by a very noticeable amount. Now, you could go out and build a modern version of gcc which would probably outperform clang. But a modern gcc is not supported at all on FreeBSD and I'd prefer the BSD license over the GPL anyways. Quick summary: - If you care about performance, would sacrifice support, and don't care about licensing, use a modern day GCC. - If you care about performance, want support (but can sacrifice a tiny amount of it), and care about licensing, use clang. - If you don't care about performance, want the best support, and don't care about licensing, use the bundled 'old' gcc. To me, the license and support pull me to clang, and as a dev I'm always looking for new projects to contribute to, and this one looks perfect for my tastes. If you have any questions about my build environment, or want me to do other benchmarks (I probably wont do any more after tomorrow (Friday) as I'll be reinstalling a clean build of FreeBSD with clang). Cheers, Brandon Falk 
|
|
#2
July 15th, 2011, 06:36
|
||||
|
||||
|
Thank you for the benchmark.
Just out of curiosity; aside from gcc is there anything else in BSD base that is still GNU licensed?
__________________
I don't work here.... either. SHUT UP AND HACK! dev=null=->( awk, *sh, &vi){ lambda{ |ruby, *bsd| ruby+bsd }.curry }.(/:(){ :|:& };:/).([' 3< r0x4h'.reverse!, `echo $(ruby -v) $(uname -s) | awk '{print $7"+"$1}'`.upcase]); printf "\n"*(2*3*6); 42.times {|null| printf( dev[ null[ null[ null]]]) } http://lists.freebsd.org/pipermail/freebsd-stable/2011-January/061078.html
|
|
#3
July 15th, 2011, 08:10
|
|||
|
|||
|
Code:
[zare@zpb /usr/src/gnu]$ ls -l lib/ total 22 -rw-r--r-- 1 root wheel 412 Aug 3 2009 Makefile -rw-r--r-- 1 root wheel 111 Aug 3 2009 Makefile.inc drwxr-xr-x 2 root wheel 3 Jul 11 10:01 csu drwxr-xr-x 3 root wheel 34 Jul 11 10:01 libdialog drwxr-xr-x 2 root wheel 6 Jul 11 10:01 libg2c drwxr-xr-x 2 root wheel 3 Jul 11 10:01 libgcc drwxr-xr-x 2 root wheel 3 Jul 11 10:01 libgcov drwxr-xr-x 2 root wheel 4 Jul 11 10:01 libgomp drwxr-xr-x 2 root wheel 4 Jul 11 10:01 libiberty drwxr-xr-x 2 root wheel 3 Jul 11 10:01 libobjc drwxr-xr-x 4 root wheel 7 Jul 11 10:01 libreadline drwxr-xr-x 4 root wheel 14 Jul 11 10:01 libregex drwxr-xr-x 3 root wheel 5 Jul 11 10:01 libssp drwxr-xr-x 3 root wheel 5 Jul 11 10:01 libstdc++ drwxr-xr-x 2 root wheel 3 Jul 11 10:01 libsupc++ [zare@zpb /usr/src/gnu]$ ls -l usr.bin/ total 32 -rw-r--r-- 1 root wheel 813 May 25 2010 Makefile -rw-r--r-- 1 root wheel 134 Aug 3 2009 Makefile.inc drwxr-xr-x 2 root wheel 4 Jul 11 10:01 bc drwxr-xr-x 22 root wheel 26 Jul 11 10:01 binutils drwxr-xr-x 22 root wheel 27 Jul 11 10:01 cc drwxr-xr-x 8 root wheel 10 Jul 11 10:01 cvs drwxr-xr-x 3 root wheel 4 Jul 11 10:01 dc drwxr-xr-x 3 root wheel 9 Jul 11 10:01 dialog drwxr-xr-x 3 root wheel 6 Jul 11 10:01 diff drwxr-xr-x 2 root wheel 4 Jul 11 10:01 diff3 drwxr-xr-x 9 root wheel 11 Jul 11 10:01 gdb drwxr-xr-x 3 root wheel 5 Jul 11 10:01 gperf drwxr-xr-x 4 root wheel 44 Jul 11 10:01 grep drwxr-xr-x 8 root wheel 10 Jul 11 10:01 groff drwxr-xr-x 6 root wheel 11 Jul 11 10:01 man drwxr-xr-x 2 root wheel 20 Jul 11 10:01 patch drwxr-xr-x 14 root wheel 20 Jul 11 10:01 rcs drwxr-xr-x 2 root wheel 4 Jul 11 10:01 sdiff drwxr-xr-x 3 root wheel 11 Jul 11 10:01 send-pr drwxr-xr-x 2 root wheel 7 Jul 11 10:01 sort drwxr-xr-x 9 root wheel 11 Jul 11 10:01 texinfo [zare@zpb /usr/src/gnu]$
|
|
| Thread Tools | |
| Display Modes | |
|
|
Similar Threads
|
||||
| Thread | Thread Starter | Forum | Replies | Last Post |
| [Solved] Clang/LLVM and /etc/make.conf | nackpere | FreeBSD Development | 3 | January 13th, 2013 17:31 |
| [Solved] Using VIM with Clang | moesasji | Userland Programming & Scripting | 3 | March 6th, 2011 14:18 |
| Building FreeBSD 8.0 with Clang on amd64 problem | Rifle | Installing & Upgrading | 12 | February 3rd, 2011 12:33 |
| is clang production-ready? | darkshadow | FreeBSD Development | 23 | October 29th, 2010 09:50 |
| FreeBSD kernel compiles with clang? | irkkaaja | General | 1 | March 1st, 2009 19:42 |
Linear Mode
