[llvm-bugs] [Bug 30707] New: wrong code at -Os and above on x86_64-linux-gnu (in both 32-bit and 64-bit modes)

via llvm-bugs llvm-bugs at lists.llvm.org
Fri Oct 14 14:54:07 PDT 2016


https://llvm.org/bugs/show_bug.cgi?id=30707

            Bug ID: 30707
           Summary: wrong code at -Os and above on x86_64-linux-gnu (in
                    both 32-bit and 64-bit modes)
           Product: clang
           Version: trunk
          Hardware: PC
                OS: All
            Status: NEW
          Severity: normal
          Priority: P
         Component: -New Bugs
          Assignee: unassignedclangbugs at nondot.org
          Reporter: su at cs.ucdavis.edu
                CC: llvm-bugs at lists.llvm.org
    Classification: Unclassified

$ clang -v
clang version 4.0.0 (trunk 284107)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/local/clang-trunk/bin
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.4
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.4.7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.6.4
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.7.3
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.8
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.8.4
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.9
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.9.3
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.3.0
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.9
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Candidate multilib: x32;@mx32
Selected multilib: .;@m64
$ 
$ clang -O1 small.c; ./a.out
$ clang-3.8 -Os small.c; ./a.out
$ 
$ clang -Os small.c
$ ./a.out
Aborted (core dumped)
$ 


---------------------------------------


static int *b;
int **c = &b, **d = &b, e, f, g;

int main ()
{
  int **h = &b;
  for (; g < 1; g++)
    {
      *c = &e;
      if (!b)
        __builtin_abort (); 
      *h = &f;
    }
  return 0; 
}

-- 
You are receiving this mail because:
You are on the CC list for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-bugs/attachments/20161014/be5158b2/attachment.html>


More information about the llvm-bugs mailing list