Sedat Dilek via llvm-dev
2016-Feb-25 16:13 UTC
[llvm-dev] [LLVM v3.8.0rc3] cmake-2.8.12: Statistics gcc-4.9 VS. clang-3.8
Hi, here some statistics when building LLVM v3.8.0rc3 with CMAKE and GCC v4.9.2 or CLANG v3.8.0rc3 here on my Ubuntu/precise AMD64 system. [ THE GOOD (disc-usage) ] Compiling with clang-3.8 produces smaller binaries VS. gcc-4.9 (approx. 250MiB smaller). Checking with 'wc -l' shows 1893 files in total for both install-dirs. $ cd /opt ; du -s -m llvm-toolchain-3.8.0rc3_* 609 llvm-toolchain-3.8.0rc3_clang-compiled 864 llvm-toolchain-3.8.0rc3_gcc-compiled $ LC_ALL=C wc -l ls-lR_*.txt 1893 ls-lR_clang-compiled.txt 1893 ls-lR_gcc-compiled.txt 3786 total [ THE BAD (build-time) ] Build-time increased approx. 1h from 2 to 3 hours when using CMAKE instead of CONFIGURE/MAKE (logs deleted for LLVM v3.8.0rc2). Building always done with one single parallel-compile-jobs. When using CMAKE $COMPILER does not matter, it's approx. 3 hours build-time. $ cat statistics/3.8.0rc3*/build*.txt -rw-r--r-- 1 wearefam wearefam 138872 Feb 25 10:25 logs/3.8.0rc3_clang-compiled/install-log_llvm-toolchain-3.8.0rc3.txt -rw-r--r-- 1 wearefam wearefam 216544 Feb 25 10:22 logs/3.8.0rc3_clang-compiled/build-log_llvm-toolchain-3.8.0rc3.txt -rw-r--r-- 1 wearefam wearefam 14476 Feb 25 07:29 logs/3.8.0rc3_clang-compiled/configure-log_llvm-toolchain-3.8.0rc3.txt -rw-r--r-- 1 wearefam wearefam 138872 Feb 24 18:55 logs/3.8.0rc3_gcc-compiled/install-log_llvm-toolchain-3.8.0rc3.txt -rw-r--r-- 1 wearefam wearefam 344202 Feb 24 18:45 logs/3.8.0rc3_gcc-compiled/build-log_llvm-toolchain-3.8.0rc3.txt -rw-r--r-- 1 wearefam wearefam 14295 Feb 24 15:53 logs/3.8.0rc3_gcc-compiled/configure-log_llvm-toolchain-3.8.0rc3.txt [ AND THE UGLY ] /me or my attached build-script? I have not tried NINJA with CMAKE v3.x in combinations with parallel-compile-jobs >=1. My Samsung Ultrabook should do 5 compile-jobs in parallel. Hope this helps a bit. Regards, - Sedat - [1] https://en.wikipedia.org/wiki/The_Good,_the_Bad_and_the_Ugly -------------- next part -------------- A non-text attachment was scrubbed... Name: build_llvm-toolchain.sh Type: application/x-sh Size: 3827 bytes Desc: not available URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20160225/fc351060/attachment.sh>
Joerg Sonnenberger via llvm-dev
2016-Feb-25 17:18 UTC
[llvm-dev] [LLVM v3.8.0rc3] cmake-2.8.12: Statistics gcc-4.9 VS. clang-3.8
On Thu, Feb 25, 2016 at 05:13:05PM +0100, Sedat Dilek via llvm-dev wrote:> Build-time increased approx. 1h from 2 to 3 hours when using CMAKE > instead of CONFIGURE/MAKE (logs deleted for LLVM v3.8.0rc2). > Building always done with one single parallel-compile-jobs. > When using CMAKE $COMPILER does not matter, it's approx. 3 hours build-time.Are you sure that you are actually using equivalent settings? cmake vs manual Makefiles should have at most a few percent performance impact for a full build on moderate concurrent load. It should certainly not be a factor of 2 or 3. Joerg