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Jacob Adam
29 lines
954 B
Rust
29 lines
954 B
Rust
//! Regression test for https://github.com/rust-lang/rust/issues/113899.
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//! When indexing into an array of an enum type with spare niches, the compiler
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//! used to emit a superfluous branch checking whether the loaded value was
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//! a niche value. Every element in the array is a valid variant, so this check
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//! is unnecessary and should be optimised away.
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//@ compile-flags: -Copt-level=3
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#![crate_type = "lib"]
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#[derive(Clone, Copy)]
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pub enum Outer {
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A([u8; 8]),
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B([u8; 8]),
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}
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pub struct Error(u8);
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// CHECK-LABEL: @test
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#[no_mangle]
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pub fn test(x: usize) -> Result<Outer, Error> {
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// There should be exactly one comparison: the bounds check on `x`.
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// There must be no second comparison checking the discriminant
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// against the niche value used by `Option<Outer>` (from `get()`).
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// CHECK: icmp ult
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// CHECK-NOT: icmp
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// CHECK: ret void
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[Outer::A([10; 8]), Outer::B([20; 8])].get(x).copied().ok_or(Error(5))
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}
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