[llvm-bugs] [Bug 29170] New: wrong code at -Os and above on x86_64-linux-gnu in 32-bit mode

[via llvm-bugs]

https://llvm.org/bugs/show_bug.cgi?id=29170

            Bug ID: 29170
           Summary: wrong code at -Os and above on x86_64-linux-gnu in
                    32-bit mode
           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

This also affects 3.8.0 and 3.8.1, and is a regression from 3.7.x. 

$ clang -v
clang version 4.0.0 (trunk 279924)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/local/clang-trunk/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
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
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.3.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6.1.1
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 -m32 -O1 small.c; ./a.out
0
$ clang-3.7 -m32 -Os small.c; ./a.out
0
$ 
$ clang -m32 -Os small.c; ./a.out
$ clang-3.8.1 -m32 -Os small.c; ./a.out
$ clang-3.8.0 -m32 -Os small.c; ./a.out
$ 


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


int printf (const char *, ...);

int a, b, c = 2, d;
unsigned short e;

char fn1 (int p1)
{
  return p1 ? a / p1 : a;
}

int main ()
{
  e = fn1 (c);
  long long f = ~(~(d | 4294967295) & ~b);
  if (f > e)
    printf ("0\n") ;
  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/20160828/2db5cf20/attachment.html>