Regression test for const promotion with Option<Ordering> #145651
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Aug 21, 2025
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| //@ compile-flags: -O -Zmir-opt-level=2 -Cdebuginfo=0 | |||
| // EMIT_MIR_FOR_EACH_BIT_WIDTH | |||
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https://rust.godbolt.org/z/EjxqE8WcT
Fixes #139093
Add a regression test to ensure that comparing
Option<Ordering>toSome(Ordering::Equal)does not trigger unnecessary const promotionin MIR.
Previously, inlined constants like
Some(Ordering::Equal)would getpromoted, leading to more complex MIR and redundant LLVM IR checks.
This test verifies that both the direct form and the
let-binding formnow generate equivalent, simplified MIR.
r? cjgillot