Joshua Wong dd0620b867 allocate before calling T::default in <Box<T>>::default() ...

The `Box<T: Default>` impl currently calls `T::default()` before allocating
the `Box`.

Most `Default` impls are trivial, which should in theory allow
LLVM to construct `T: Default` directly in the `Box` allocation when calling
`<Box<T>>::default()`.

However, the allocation may fail, which necessitates calling `T's` destructor if it has one.
If the destructor is non-trivial, then LLVM has a hard time proving that it's
sound to elide, which makes it construct `T` on the stack first, and then copy it into the allocation.

Create an uninit `Box` first, and then write `T::default` into it, so that LLVM now only needs to prove
that the `T::default` can't panic, which should be trivial for most `Default` impls.

2024-10-10 09:49:24 -04:00

..

benches

Improve autovectorization of to_lowercase / to_uppercase functions

2024-09-23 11:31:29 +02:00

src

allocate before calling T::default in <Box<T>>::default()

2024-10-10 09:49:24 -04:00

tests

Stabilize const_slice_from_raw_parts_mut

2024-10-01 22:02:19 +02:00

Cargo.toml

Update compiler-builtins to 0.1.133

2024-10-05 21:34:51 -05:00