[LLVMbugs] [Bug 3294] New: another math bug

[bugzilla-daemon at cs.uiuc.edu]

http://llvm.org/bugs/show_bug.cgi?id=3294

           Summary: another math bug
           Product: new-bugs
           Version: unspecified
          Platform: PC
        OS/Version: Linux
            Status: NEW
          Severity: normal
          Priority: P2
         Component: new bugs
        AssignedTo: unassignedbugs at nondot.org
        ReportedBy: regehr at cs.utah.edu
                CC: llvmbugs at cs.uiuc.edu


This looks a lot like PR 3275 but it is still wrong in r61912 on Ubuntu Hardy
on x86.

LLVM up to and including r59527 gets this right, since then it is wrong.

regehr at john-home:~/volatile/tmp112$ llvm-gcc -O0 small.c -o small
regehr at john-home:~/volatile/tmp112$ ./small
-1
regehr at john-home:~/volatile/tmp112$ llvm-gcc -O1 small.c -o small
regehr at john-home:~/volatile/tmp112$ ./small
10
regehr at john-home:~/volatile/tmp112$ cat small.c
#include <stdio.h>

unsigned g_9;

void func_1 (void);
void func_1 (void)
{
  for (g_9 = 11; g_9 < (unsigned)-8; g_9--)
    {
    }
}

int
main (void)
{
  func_1 ();
  printf ("%d\n", g_9);
  return 0;
}


-- 
Configure bugmail: http://llvm.org/bugs/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.