Re: [Full-disclosure] Firefox 2.0.0.7 has a very serious calculation bug

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Not so much it required such a long thread.

On Fri, 28 Sep 2007 15:29:18 -0400 Rodrigo Barbosa
<rodrigob@xxxxxxxxxxxx> wrote:
On Fri, Sep 28, 2007 at 09:09:02PM +0200, Michal Zalewski wrote:
On Sat, 29 Sep 2007, Jimby Sharp wrote:

I don't get the same from C-style double arithmetics. Could
you provide
a sample code that you believe should show the same behavior?

If you don't, it's presumably because the subtraction is
optimized out by
the compiler, or because you printf() with an insufficient
precision in
format spec. The following should do the trick:

volatile double a = 5.2;
volatile double b = 0.1;
main() { printf("%.16lf\n",a-b); }

Confirmed here with:

gcc (GCC) 4.1.1 20070105 (Red Hat 4.1.1-52)

Actually quite interesting.

--
Rodrigo Barbosa
"Quid quid Latine dictum sit, altum viditur"
"Be excellent to each other ..." - Bill & Ted (Wyld Stallyns)
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