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Regression test for bad codegen of #[derive(Clone)] on enums #144961

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Regression test for bad codegen of #[derive(Clone)] on enums #144961

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26 changes: 26 additions & 0 deletions tests/codegen-llvm/derive-clone-enum-variants.rs
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Original file line number Diff line number Diff line change
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//! Regression test for bad codegen of `#[derive(Clone)]` on enums.
//! Ensures efficient LLVM IR without unnecessary branches.
//! See <https://github.com/rust-lang/rust/issues/69174>.

//@ compile-flags: -C opt-level=3

#![crate_type = "lib"]

#[derive(Clone)]
pub enum Foo {
A(u8),
B(bool),
}

#[derive(Clone)]
pub enum Bar {
C(Foo),
D(u8),
}

// CHECK-LABEL: @clone_bar
// CHECK-NOT: icmp
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Can you adjust this to specifically check this is just a load + ret? That should be fairly future proof and avoids any regressions if this is something that's more complex but not an icmp.

  %0 = load i16, ptr %b, align 1
  ret i16 %0

#[unsafe(no_mangle)]
pub fn clone_bar(b: &Bar) -> Bar {
b.clone()
}
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