Re: [Valgrind-users] Strange behaviour with both 1.9.x and 1.0.x

[Jeremy F. <je...@go...>]

Quoting Sebastian <sc...@nb...>:
> It extracted all functions taking part in this code to extra files and
> ran
> some tests, without successes. The situation is quite simple:
> be_random
> returns one random unsigned int (in %eax), %edx is zeroed out, a 64
> bit
> integer is temporarily created on the stack and the resulting number
> is
> loaded into a double register (fildll).

Well, the behaviour you're seeing is consistent with be_random() returning an
undefined value in %eax.  FP instructions like fildll immediately check the
defined-ness of their values (unlike integer instructions, which only check for
defined-ness when the value is used as a pointer or in a conditional
instruction).  It may be that be_random() has a bug, or it is returning an
undefined value as a result of an undefined input. 

There doesn't seem to be anything wrong with this particular piece of code, or
with Valgrind's behaviour.

     J