47b99485a3
`SimplifyArm` and such are currently in `-Zunsound-mir-opts` and thus weren't running by default, so having something like them for the new desugar shouldn't be necessary for switching.
34 lines
886 B
Rust
34 lines
886 B
Rust
// compile-flags: -C no-prepopulate-passes -O -Z mir-opt-level=3 -Zunsound-mir-opts
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// Ensure that `x?` has no overhead on `Result<T, E>` due to identity `match`es in lowering.
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// This requires inlining to trigger the MIR optimizations in `SimplifyArmIdentity`.
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#![crate_type = "lib"]
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type R = Result<u64, i32>;
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// This was written to the `?` from `try_trait`,
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// but `try_trait_v2` uses a different structure,
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// so the relevant desugar is copied inline
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// in order to keep the test testing the same thing.
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#[no_mangle]
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pub fn try_identity(x: R) -> R {
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// CHECK: start:
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// CHECK-NOT: br {{.*}}
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// CHECK ret void
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let y = match into_result(x) {
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Err(e) => return from_error(From::from(e)),
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Ok(v) => v,
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};
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Ok(y)
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}
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#[inline]
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fn into_result<T, E>(r: Result<T, E>) -> Result<T, E> {
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r
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}
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#[inline]
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fn from_error<T, E>(e: E) -> Result<T, E> {
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Err(e)
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}
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