2 Aug
2012
2 Aug
'12
5:14 p.m.
Hi Martin,
Can I pick your brain on how this works?
My biggest question is why to use the typedef__u32__attribute__ line
inside an inline function. Don't you only have to do this once? If
so, wouldn't you place that line outside the function?
On Thu, Aug 2, 2012 at 7:39 AM, Martin Homuth-Rosemann
<linuxaudio(a)cryptomys.de> wrote:
static inline float daz( float f )
If we remove the "static" scope of this function, could we make a
header and re-use this code efficiently?
{
// define an aliasing type to perform a "reinterpret cast"
typedef __u32 __attribute__ (( __may_alias__ )) u32bit;
if ( *( (u32bit*)&f ) & 0x7F000000 ) // E > 1 : normal.
Is there a 64-bit version of the same? This appears to work with a
32-bit unsigned int as a pointer, meaning that it's applicable to
32-bits. How does a "reinterpret cast" work?
What this does is check the exponent is non-zero, right? Doesn't this
also depend on the mantissa? for example, if the mantissa is 2^24-1
and the exponent is zero, is that number still a denormal?
return f;
else // E <= 1 : zero or _almost_ denormal
// (may become denormal with next operation)
return 0.0;
}
Ciao, Martin
Thanks for the code--any further explanation would be enlightening.
Chuck