* Use macros for more division/array checks
This commit moves over more array accesses to the `i!` macro to avoid
bounds checks when debug assertions are disabled. This is surfaced from
rust-lang/compiler-builtins#360 where recent changes in codegen units
has caused some bounds checks to not get elided in release mode. This
also adds a `div!` macro to work around rust-lang/rust#72751.
* Don't test/bench our shim crate
It's not intended to run all our tests
`AArch64` GCCs exit with an error condition when they encounter any kind of
floating point code if the `nofp` and/or `nosimd` compiler flags have been set.
Therefore, evaluate if those flags are present and set a boolean that causes any
compiler-rt intrinsics that contain floating point source to be excluded for
this target.
This patch prepares https://github.com/rust-lang/rust/pull/68334
The `LICENSE.txt` file should be distributed to crates.io, but it wasn't
due to the `Cargo.toml` entry in the `includes` field being
`LICENSE.txt` with lower-case file extension while the file itself had
an upper-case extension.
* Allow FFI-unsafe warnings for u128/i128
Handle new warnings on nightly, and we shouldn't need to worry about
these with compiler-builtins since this is tied to a particular compiler.
* Clean up crate attributes
* No need for stability marker
* Rustdoc docs not used for this crate
* Remove old build-system related cruft from rustc itself.
* Run `cargo fmt`
Looks like the implementation was not ported correctly. Some negations
were forgotten in a certain branch. Here is the original code in musl
that has the negations:
94cb2ec2a0/src/math/sincosf.c (L66-L67)Resolvesrust-lang/libm#228
As of LLVM 9.0, certain calls to memcmp may be converted to bcmp, which I guess
could save a single subtraction on some architectures. [1]
bcmp is just like memcmp except instead of returning the difference between the
two differing bytes, it returns non-zero instead. As such, memcmp is a valid
implementation of bcmp.
If we care about size, bcmp should just call memcmp.
If we care about speed, we can change bcmp to look like this instead:
```rust
pub unsafe extern "C" fn bcmp(s1: *const u8, s2: *const u8, n: usize) -> i32 {
let mut i = 0;
while i < n {
let a = *s1.offset(i as isize);
let b = *s2.offset(i as isize);
if a != b {
return 1;
}
i += 1;
}
0
}
```
In this PR I do not address any changes which may or may not be needed for arm
aebi as I lack proper test hardware.
[1]: https://releases.llvm.org/9.0.0/docs/ReleaseNotes.html#noteworthy-optimizations
