Bug 63381 - [5 Regression] Wrong constant folding
Summary: [5 Regression] Wrong constant folding
Status: RESOLVED DUPLICATE of bug 63380
Alias: None
Product: gcc
Classification: Unclassified
Component: tree-optimization (show other bugs)
Version: 5.0
: P3 normal
Target Milestone: 5.0
Assignee: Richard Biener
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2014-09-26 09:47 UTC by Ishiura Lab Compiler Team
Modified: 2014-10-09 08:18 UTC (History)
0 users

See Also:
Host:
Target:
Build:
Known to work:
Known to fail:
Last reconfirmed: 2014-10-02 00:00:00


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Description Ishiura Lab Compiler Team 2014-09-26 09:47:50 UTC
GCC 5.0.0 for x86_64 miscompiles the following code.

   $ cat test.c

    int a = 0, b = 0, c = 0, d, e;
    int
    main (void)
    {
        d = ((20 % (1 != b)) && c) + 2147483647;
        e = 20 % (a >= 0);
        return 0;
    }

   $ x86_64-unknown-linux-gnu-gcc-5.0.0 test.c -Os
   $ ./a.out
   Floating point exception (core dumped)

   $ x86_64-unknown-linux-gnu-gcc-5.0.0 -v
    Using built-in specs.
    COLLECT_GCC=x86_64-unknown-linux-gnu-gcc-5.0.0
    COLLECT_LTO_WRAPPER=/usr/local/x86_64-tools/gcc-
    5.0.0/libexec/gcc/x86_64-unknown-linux-gnu/5.0.0/lto-wrapper
    Target: x86_64-unknown-linux-gnu
    Configured with: /home/orange3/gcc-master/configure --
    prefix=/usr/local/x86_64-tools/gcc-5.0.0/ --with-gmp=/usr/local/gmp-
    5.1.1/ --with-mpfr=/usr/local/mpfr-3.1.2/ --with-mpc=/usr/local/mpc-
    1.0.1/ --disable-multilib --disable-nls --enable-languages=c
    Thread model: posix
    gcc version 5.0.0 20140922 (experimental) (GCC)
Comment 1 Marek Polacek 2014-10-02 14:56:22 UTC
Works with -fno-tree-vrp.  Seems to have started with r211904.
Comment 2 Marek Polacek 2014-10-02 15:00:52 UTC
Ugh, ignore Comment 1, that was for PR63380.
Comment 3 Marek Polacek 2014-10-02 15:07:23 UTC
Actually, Comment 1 applies here as well, so these two could be dups.
Comment 4 Richard Biener 2014-10-06 12:05:15 UTC
Mine.
Comment 5 Richard Biener 2014-10-09 08:18:42 UTC
Patch for 63380 fixes this as well.

*** This bug has been marked as a duplicate of bug 63380 ***