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Subject: [Bug c++/46401] New: [4.5/4.6 Regression] very slow compile time with -Wsequence-point
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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46401

           Summary: [4.5/4.6 Regression] very slow compile time with
                    -Wsequence-point
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: zsojka@seznam.cz


Created attachment 22356
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=22356
reduced testcase

Compiler output - 4.4.5:
$ time gcc-4.4.5 -Wsequence-point -c testcase.C
real    0m0.514s
user    0m0.470s
sys     0m0.030s

Compiler output - 4.5.1: (disabled checking)
$ time gcc-4.5.1 -Wsequence-point -c testcase.C

real    4m22.328s
user    4m21.230s
sys     0m0.250s

Compiler output - r166492: (enabled checking)
$ time gcc -Wsequence-point -c testcase.C
real    6m2.734s
user    6m2.090s
sys     0m0.300s

Compiler output - r166492 without -Wsequence-point:
$ time gcc -c testcase.C
real    0m0.699s
user    0m0.520s
sys     0m0.050s

The time needed to analyze sequence points grew a lot in 4.5 for attached
testcase. The problem is more likely to appear since -Wsequence-point is
enabled by -Wall. The reduced testcase is from 'cantor', a KDE application.