Roberto Bagnara writes: > Andrew Haley wrote: > > Roberto Bagnara writes: > > > > > > Reading the thread "Autoconf manual's coverage of signed integer > > > overflow & portability" I was horrified to discover about GCC's > > > miscompilation of the remainder expression that causes INT_MIN % -1 > > > to cause a SIGFPE on CPUs of the i386 family. Are there plans to > > > fix this bug (which, to me, looks quite serious)? > > > > No, there aren't. It would make more sense for you to wrap % in some > > code that checks for this, rather than for us to slow down every division > > for this one special case. > > With all due respect, I must say I am shocked. I always thought > (and taught) that we, Free Software people, value standard conformance > and getting things right.
This is a disgreement about interpretation of the langauge in the standard, which is: "The result of the / operator is the quotient from the division of the first operand by the second; the result of the % operator is the remainder. In both operations, if the value of the second operand is zero, the behavior is undefined. When integers are divided, the result of the / operator is the algebraic quotient with any fractional part discarded.87) If the quotient a/b is representable, the expression (a/b)*b + a%b shall equal a." If the quotient a/b is *not* representable, is the behaviour of % well-defined or not? It doesn't say. Andrew.
