[llvm-bugs] [Bug 35650] New: [mc] Zero divider is not handled for modulo

via llvm-bugs llvm-bugs at lists.llvm.org
Wed Dec 13 08:20:21 PST 2017


https://bugs.llvm.org/show_bug.cgi?id=35650

            Bug ID: 35650
           Summary: [mc] Zero divider is not handled for modulo
           Product: libraries
           Version: trunk
          Hardware: PC
                OS: Windows NT
            Status: NEW
          Severity: enhancement
          Priority: P
         Component: MC
          Assignee: unassignedbugs at nondot.org
          Reporter: i.am.perminov at gmail.com
                CC: artem.tamazov at amd.com, dpreobrazhensky at luxoft.com,
                    llvm-bugs at lists.llvm.org

Zero RHS is handled for DIV, but not for MOD operation which leads to crash if
divider is zero:

bool MCExpr::evaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm,
...
case MCBinaryExpr::Div:
  // Handle division by zero. gas just emits a warning and keeps going,
  // we try to be stricter.
  // FIXME: Currently the caller of this function has no way to understand
  // we're bailing out because of 'division by zero'. Therefore, it will
  // emit a 'expected relocatable expression' error. It would be nice to
  // change this code to emit a better diagnostic.
  if (RHS == 0)
    return false;
  Result = LHS / RHS;
  break;
...
case MCBinaryExpr::Mod:  Result = LHS % RHS; break;

-- 
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/20171213/52737338/attachment.html>


More information about the llvm-bugs mailing list