[PD-dev] amd64: rsqrt~

[Thomas Grill]

Tim Blechmann schrieb:

>>>The rsqrt bug is not guaranteed to manifest itself because memory
>>>layout decisions made by the compiler may very well hide the bug,
>>>e.g. if the area clobbered by the buffer overflow is left unused.
>>>      
>>>
>>so still not knowing what might happen: it seems to be a buffer
>>overflow that crashes pd as soon as the [rsqrt~]-object is created ?
>>(or the dsp is turned on ??)
>>    
>>
>pd didn't start up ... interrupting the pd process showed that it's in
>the process of filling the rsqrt lookup table ...
>
>matju's guess, that the loop counter has been overridden might be a
>reasonable explanation ... fit's more or less to what i've
>experienced ...
>  
>
it's pretty obvious that 
*(long *)(&f) = l;
must/can be fatal on a 64 bit platform if f is 32 bits and long is 64 bits, no? Some data neighboring f on the stack must suffer from that.

all the best,
Thomas