[llvm-bugs] [Bug 27804] New: wrong code at -Os and above in 32-bit mode on x86_64-linux-gnu

[via llvm-bugs]

https://llvm.org/bugs/show_bug.cgi?id=27804

            Bug ID: 27804
           Summary: wrong code at -Os and above in 32-bit mode on
                    x86_64-linux-gnu
           Product: clang
           Version: trunk
          Hardware: PC
                OS: All
            Status: NEW
          Severity: normal
          Priority: P
         Component: -New Bugs
          Assignee: unassignedclangbugs at nondot.org
          Reporter: chengniansun at gmail.com
                CC: llvm-bugs at lists.llvm.org
    Classification: Unclassified

The following code is miscompiled by the trunk at -Os, -O2, and -O3 in 32-bit
mode (not in 64-bit mode) on x86_64-linux-gnu. 



$: clang-trunk -v
clang version 3.9.0 (trunk 269748)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/local/bin
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/4.9
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/4.9.3
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/5.3.0
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/4.8.5
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/5.3.0
Found candidate GCC installation:
/usr/local/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.6.3
Found candidate GCC installation:
/usr/local/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.7.4
Found candidate GCC installation:
/usr/local/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.8.2
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-trunk small.c -w -m32 -Os ; ./a.out
Floating point exception (core dumped)
$: clang-trunk small.c -w -m32 -O2 ; ./a.out
Floating point exception (core dumped)
$: clang-trunk small.c -w -m32 -O3 ; ./a.out
Floating point exception (core dumped)
$: clang-trunk small.c -w -m32 -O1 ; ./a.out
l_5906=1
$:
$: cat small.c
volatile short a, g, l = 1;
char b, e;
int c, d, h, i = -7L, k, m;
short f;
short j;
static short fn1() {
  unsigned short n = 4;
  for (; b >= 0; b--)
    ;
  for (;;) {
    int o = ~(e && f && j), p = ~(~(h % ~k ^ e) & b);
    char q = ~(b | e) ^ (p && o ^ j) >> ~i;
    short r = (n & h && q) | ~(o | (e | p)), s = (h && q && j && i % l) * e;
    if (e)
      k = r | b;
    j = s;
    if (!(c >= 0)) {
      h++;
      printf("g_5326=%lld\n", (long long)2);
    }
    a / b &&a;
    short t = ~g;
    n = t;
  L1:
    if (l) {
      printf("l_5906=%lld\n", (long long)l);
      goto L2;
    }
    continue;
  L2:
    if (d)
      goto L1;
    return m;
  }
}

int main() { fn1(); }
$:

-- 
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/20160518/b76413e9/attachment.html>