libc requires this to use `long double` which is sometimes the same as
f128, sometimes not.
Also for an unknown reason, aarch64 is getting an invalid result for the
`@mulAdd` behavior test for f128. See #9900.
std: add f128 implementations of fma, frexp, and ilogb. Expose `fmal` in
zig's freestanding libc. This makes `@mulAdd` work correctly for f128.
Fixes a CI regression from yesterday, where I added a usage of f128
`@mulAdd` into the self-hosted compiler.
We already have a LICENSE file that covers the Zig Standard Library. We
no longer need to remind everyone that the license is MIT in every single
file.
Previously this was introduced to clarify the situation for a fork of
Zig that made Zig's LICENSE file harder to find, and replaced it with
their own license that required annual payments to their company.
However that fork now appears to be dead. So there is no need to
reinforce the copyright notice in every single file.
Comparisons with absolute epsilons are usually useful when comparing
numbers to zero, for non-zero numbers it's advised to switch to relative
epsilons instead to obtain meaningful results (check [1] for more
details).
The new API introduces approxEqAbs and approxEqRel, where the former
aliases and deprecated the old `approxEq`, allowing the user to pick the
right tool for the job.
The documentation is meant to guide the user in the choice of the
correct alternative.
[1] https://randomascii.wordpress.com/2012/02/25/comparing-floating-point-numbers-2012-edition/
