4ecfdfac51
Optimize `array::IntoIter` `.into_iter()` on arrays was slower than it needed to be (especially compared to slice iterator) since it uses `Range<usize>`, which needs to handle degenerate ranges like `10..4`. This PR adds an internal `IndexRange` type that's like `Range<usize>` but with a safety invariant that means it doesn't need to worry about those cases -- it only handles `start <= end` -- and thus can give LLVM more information to optimize better. I added one simple demonstration of the improvement as a codegen test. (`vec::IntoIter` uses pointers instead of indexes, so doesn't have this problem, but that only works because its elements are boxed. `array::IntoIter` can't use pointers because that would keep it from being movable.) |
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| .. | ||
| alloc | ||
| backtrace@07872f28cd | ||
| core | ||
| panic_abort | ||
| panic_unwind | ||
| portable-simd | ||
| proc_macro | ||
| profiler_builtins | ||
| rtstartup | ||
| rustc-std-workspace-alloc | ||
| rustc-std-workspace-core | ||
| rustc-std-workspace-std | ||
| std | ||
| stdarch@699c093a42 | ||
| test | ||
| unwind | ||