[llvm-bugs] [Bug 30622] New: wrong code at -Os and above in both 32-bit and 64-bit modes on x86_64-linux-gnu

[via llvm-bugs]

https://llvm.org/bugs/show_bug.cgi?id=30622

            Bug ID: 30622
           Summary: wrong code at -Os and above in both 32-bit and 64-bit
                    modes on x86_64-linux-gnu
           Product: clang
           Version: trunk
          Hardware: PC
                OS: Windows NT
            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

$ clang-trunk -v
clang version 4.0.0 (trunk 283333)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
Found candidate GCC installation: /usr/bin/../lib/gcc/i686-linux-gnu/5
Found candidate GCC installation: /usr/bin/../lib/gcc/i686-linux-gnu/5.3.0
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/4.8
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/4.8.5
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/4.9
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/4.9.3
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/5
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/5.3.0
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/5
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/5.3.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.8
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
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.3.0
Selected GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/4.9
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Candidate multilib: x32;@mx32
Selected multilib: .;@m64
$ clang-trunk -Os small.c ; ./a.out
-3
$ clang-trunk -O1 small.c ; ./a.out
3
$ cat small.c
static int a = -3L, h;
int *b = &a;
int c[3];
char d, e;
char *g = &d;
int **i = &b;
void fn1() {
  int *f = &c[2];
  for (;;) {
    if (e)
      f = 0;
    f == &a ? (void)0 : fn1();
  }
}

int main() {
  if (a)
    *b = 3;
  h = a;
  b = &h;
  *g = **i;
  __builtin_printf("%d\n", d);
  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/20161006/a32de44e/attachment.html>