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From: "redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/58999] sizeof ...(T) is very slow than clang
Date: Tue, 05 Nov 2013 12:22:00 -0000	[thread overview]
Message-ID: <bug-58999-4-aIGCFeEdsj@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-58999-4@http.gcc.gnu.org/bugzilla/>

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58999

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> ---
--enable-checking=release makes quite a big difference

$ time ~/gcc/4.x/bin/g++  -std=c++11 -c t.cc -ftime-report

Execution times (seconds)
 phase setup             :   0.00 ( 0%) usr   0.01 ( 2%) sys   0.05 ( 0%) wall 
  1323 kB ( 0%) ggc
 phase parsing           :  12.84 (100%) usr   0.44 (96%) sys  13.31 (99%) wall
1422475 kB (100%) ggc
 phase opt and generate  :   0.00 ( 0%) usr   0.01 ( 2%) sys   0.09 ( 1%) wall 
    42 kB ( 0%) ggc
 phase last asm          :   0.00 ( 0%) usr   0.00 ( 0%) sys   0.01 ( 0%) wall 
     0 kB ( 0%) ggc
 |overload resolution    :   0.03 ( 0%) usr   0.01 ( 2%) sys   0.03 ( 0%) wall 
  1153 kB ( 0%) ggc
 garbage collection      :   0.19 ( 1%) usr   0.00 ( 0%) sys   0.19 ( 1%) wall 
     0 kB ( 0%) ggc
 parser function body    :   0.00 ( 0%) usr   0.00 ( 0%) sys   0.01 ( 0%) wall 
     1 kB ( 0%) ggc
 template instantiation  :  12.65 (99%) usr   0.44 (96%) sys  13.11 (97%) wall
1422149 kB (100%) ggc
 tree gimplify           :   0.00 ( 0%) usr   0.01 ( 2%) sys   0.00 ( 0%) wall 
     0 kB ( 0%) ggc
 tree STMT verifier      :   0.00 ( 0%) usr   0.00 ( 0%) sys   0.01 ( 0%) wall 
     0 kB ( 0%) ggc
 expand                  :   0.00 ( 0%) usr   0.00 ( 0%) sys   0.02 ( 0%) wall 
     1 kB ( 0%) ggc
 LRA non-specific        :   0.00 ( 0%) usr   0.00 ( 0%) sys   0.01 ( 0%) wall 
     0 kB ( 0%) ggc
 shorten branches        :   0.00 ( 0%) usr   0.00 ( 0%) sys   0.02 ( 0%) wall 
     0 kB ( 0%) ggc
 symout                  :   0.00 ( 0%) usr   0.00 ( 0%) sys   0.01 ( 0%) wall 
     0 kB ( 0%) ggc
 rest of compilation     :   0.00 ( 0%) usr   0.00 ( 0%) sys   0.03 ( 0%) wall 
     2 kB ( 0%) ggc
 TOTAL                 :  12.84             0.46            13.50           
1423858 kB
Extra diagnostic checks enabled; compiler may run slowly.
Configure with --enable-checking=release to disable checks.

real    0m14.014s
user    0m12.853s
sys     0m0.528s

$ time ~/gcc/4.x-release/bin/g++  -std=c++11 -c t.cc -ftime-report

Execution times (seconds)
 phase setup             :   0.01 ( 0%) usr   0.00 ( 0%) sys   0.05 ( 1%) wall 
  1374 kB ( 0%) ggc
 phase parsing           :   7.40 (100%) usr   0.28 (100%) sys   7.71 (98%)
wall 1422475 kB (100%) ggc
 phase opt and generate  :   0.00 ( 0%) usr   0.00 ( 0%) sys   0.05 ( 1%) wall 
    42 kB ( 0%) ggc
 phase last asm          :   0.00 ( 0%) usr   0.00 ( 0%) sys   0.01 ( 0%) wall 
     0 kB ( 0%) ggc
 |overload resolution    :   0.06 ( 1%) usr   0.01 ( 4%) sys   0.07 ( 1%) wall 
  1153 kB ( 0%) ggc
 garbage collection      :   0.01 ( 0%) usr   0.00 ( 0%) sys   0.01 ( 0%) wall 
     0 kB ( 0%) ggc
 parser (global)         :   0.00 ( 0%) usr   0.00 ( 0%) sys   0.02 ( 0%) wall 
   309 kB ( 0%) ggc
 template instantiation  :   7.39 (100%) usr   0.28 (100%) sys   7.68 (98%)
wall 1422149 kB (100%) ggc
 expand                  :   0.00 ( 0%) usr   0.00 ( 0%) sys   0.01 ( 0%) wall 
     1 kB ( 0%) ggc
 integrated RA           :   0.00 ( 0%) usr   0.00 ( 0%) sys   0.01 ( 0%) wall 
    24 kB ( 0%) ggc
 shorten branches        :   0.00 ( 0%) usr   0.00 ( 0%) sys   0.01 ( 0%) wall 
     0 kB ( 0%) ggc
 symout                  :   0.00 ( 0%) usr   0.00 ( 0%) sys   0.01 ( 0%) wall 
     0 kB ( 0%) ggc
 rest of compilation     :   0.00 ( 0%) usr   0.00 ( 0%) sys   0.02 ( 0%) wall 
     2 kB ( 0%) ggc
 TOTAL                 :   7.41             0.28             7.83           
1423909 kB

real    0m8.237s
user    0m7.420s
sys     0m0.328s

But it's still orders of magnitude slower than clang


  parent reply	other threads:[~2013-11-05 12:22 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <bug-58999-4@http.gcc.gnu.org/bugzilla/>
2013-11-05  9:08 ` khurshid.normuradov at gmail dot com
2013-11-05 10:51 ` vhaisman at gmail dot com
2013-11-05 11:34 ` redi at gcc dot gnu.org
2013-11-05 12:22 ` redi at gcc dot gnu.org [this message]
2013-11-05 12:57 ` paolo.carlini at oracle dot com

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