Re: [ANN] Lua 5.3.0 (work1) now available

[Ross Bencina <rossb-lists@...>]

On 10/07/2013 11:18 PM, Roberto Ierusalimschy wrote:
> On many (all?) Intel CPUs, long double uses
> 80-bit floats, which have exactly 64 bits in their mantissas. So, they
> count correctly up to 2^64, but after that they lose precision. (Because
> of alignment, the sizeof of a long double usually is larger than 80
> bits.)

Sorry if someone else already pointed this out, but on MSVC at least, 
long double is 64 bits:

"In Win32 programming, however, the long double data type maps to the 
double, 64-bit precision data type."
http://msdn.microsoft.com/en-us/library/9cx8xs15.aspx

Last I checked the Borland compiler had 80 bit long doubles. But since 
this type is only supported on the (legacy) FPU and not in SSE it 
doesn't surprise me that it isn't available in MSVC.

Ross.