Andreas Schwab <[EMAIL PROTECTED]> wrote:
> [EMAIL PROTECTED] (Paul Jarc) writes:
>> result=a*b;
>> if (result/a!=b) { report overflow; }
>
> That won't work, since (signed integer) overflow is undefined in C. A
> compiler is allowed to optimize the condition to false.
Right, operations would hav
[EMAIL PROTECTED] (Paul Jarc) writes:
> Richard Neill <[EMAIL PROTECTED]> wrote:
>> I thought testing for overflow was quite simple?
>> Isn't it just a case of looking at the carry-bit, and seeing whether it
>> gets set?
>
> That's usually how it's done in assembly. In C, it's somewhat more
> co
Richard Neill <[EMAIL PROTECTED]> wrote:
> I thought testing for overflow was quite simple?
> Isn't it just a case of looking at the carry-bit, and seeing whether it
> gets set?
That's usually how it's done in assembly. In C, it's somewhat more
compilcated. For example:
result=a*b;
if (result/a
[EMAIL PROTECTED] (Bob Proulx) wrote:
> On some cpus the result is done one way and on others the result is
> done a different way. It is in these cases where typically POSIX
> would give up and declare it undefined behavior.
Yes, and those are exactly the cases where a message would be helpful,
Bob Proulx wrote:
Andreas Schwab wrote:
Richard Neill <[EMAIL PROTECTED]> writes:
Are you sure this isn't comparable? After all, in both cases, the user has
submitted something to which bash cannot give a sensible answer. In the
integer-overflow case, bash simply returns the wrong answer, wit
Andreas Schwab wrote:
> Richard Neill <[EMAIL PROTECTED]> writes:
> > Are you sure this isn't comparable? After all, in both cases, the user has
> > submitted something to which bash cannot give a sensible answer. In the
> > integer-overflow case, bash simply returns the wrong answer, with no
> > w
Richard Neill <[EMAIL PROTECTED]> writes:
> Are you sure this isn't comparable? After all, in both cases, the user has
> submitted something to which bash cannot give a sensible answer. In the
> integer-overflow case, bash simply returns the wrong answer, with no
> warning.
The answer is not real
