[LLVMbugs] [Bug 3369] New: math error at all optimization levels

[bugzilla-daemon at cs.uiuc.edu]

http://llvm.org/bugs/show_bug.cgi?id=3369

           Summary: math error at all optimization levels
           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


Using r62644 on Ubuntu Hardy on x86 I get func_1() returning 1 at all
optimization levels.  I believe it should return -1.  The safe mod macro is
just a macroized version of the safe signed mod function from here:

https://www.securecoding.cert.org/confluence/display/seccode/INT32-C.+Ensure+that+operations+on+signed+integers+do+not+result+in+overflow

#include <stdint.h>
#include <stdio.h>

#define safe_mod_macro_int_s_s(si1,si2) \
  (((((int)(si2)) == ((int)0)) || ((((int)(si1)) == (INT32_MIN)) &&
(((int)(si2)) == ((int)-1)))) \
  ? ((int)(si1)) \
  : (((int)(si1)) % ((int)(si2))))

int func_1 (void);
int func_1 (void)
{
  unsigned int l_174 = -7;
  return safe_mod_macro_int_s_s (l_174, 2);
}

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


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