Date: Fri, 24 Jul 2015 15:53:40 -0700 From: Dennis Glatting <freebsd@pki2.com> To: freebsd-questions@freebsd.org Subject: C++ container performance Message-ID: <1437778420.67638.120.camel@pki2.com>
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I have a relatively small program (needs to be smaller for post) where the performance of some STD c++ containers (deque and queue) is more or less twice as slow under clang than gcc. My question is whether I should file something under FreeBSD or llvm? Or maybe this is a known, irrelevant problem? Summary: clang++ 3.4.1 clang++ 3.7.0 g++49 g++5 deque: 0.000890143 0.000646584 0.000367548 0.000365817 root@Tasha# uname -a FreeBSD Tasha 10.2-BETA1 FreeBSD 10.2-BETA1 #0 r285434: Sun Jul 12 16:57:18 PDT 2015 root@Tasha:/disk-2/obj/disk-1/src/sys/SMUNI-FreeBSD10-amd64 amd64 root@Tasha# c++ -O3 -std=c++11 -Wsign-compare -Wall -Wno-uninitialized -fvisibility=hidden -finline -I /usr/local/include main_dc.cc complex deque: size=88 Done: total_t: 44507162167, sec_t: 44.5072, t/ea: 0.000890143 root@Tasha# clang++-devel -O3 -std=c++11 -Wsign-compare -Wall -Wno-uninitialized -fvisibility=hidden -finline -I /usr/local/include main_dc.cc complex deque: size=88 Done: total_t: 32329207134, sec_t: 32.3292, t/ea: 0.000646584 root@Tasha# g++49 -O3 -std=c++11 -Wsign-compare -Wall -Wno-uninitialized -fvisibility=hidden -finline -I /usr/local/include main_dc.cc complex deque: size=120 Done: total_t: 18377396318, sec_t: 18.3774, t/ea: 0.000367548 root@Tasha# g++5 -O3 -std=c++11 -Wsign-compare -Wall -Wno-uninitialized -fvisibility=hidden -finline -I /usr/local/include main_dc.cc complex deque: size=120 Done: total_t: 18290835564, sec_t: 18.2908, t/ea: 0.000365817 root@Tasha# g++6 -O3 -std=c++11 -Wsign-compare -Wall -Wno-uninitialized -fvisibility=hidden -finline -I /usr/local/include main_dc.cc complex deque: size=120 Done: total_t: 18249643758, sec_t: 18.2496, t/ea: 0.000364993
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