real.sizeof

[Iain Buclaw]

On Monday, 5 February 2024 at 16:45:03 UTC, Dom DiSc wrote:
> Why is real.sizeof == 16 on x86-systems?!?
> Its the IEEE 754 extended format: 64bit mantissa + 15bit 
> exponent + sign.
> It should be size 10!
> I mean, alignment may be different, but why wasting so much 
> memory even in arrays?

Padding.

x86 ABI prefers things to be aligned, so on x86 it's 12 bytes, 
x86_64 16 bytes.  In both cases you don't get any extra precision 
over the 80-bits that x87 gives you.