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Auto merge of #130561 - lukas-code:perf-normalize-env, r=compiler-errors

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[perf] skip normalizing param env if it is already normalized

If the param env is already normalized after elaboration, then we can skip a bunch of expensive operations.

> [!note]
> This makes it so that outlives predicates are no longer sorted after non-outlives predicates. Surely this won't make a semantic difference.

r? ghost
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bors 2024-09-20 00:19:16 +00:00
commit 5793a9e902
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3
compiler/rustc_trait_selection/src/traits/mod.rs
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@ -409,6 +409,9 @@ pub fn normalize_param_env_or_error<'tcx>(
debug!("normalize_param_env_or_error: elaborated-predicates={:?}", predicates); debug!("normalize_param_env_or_error: elaborated-predicates={:?}", predicates);
let elaborated_env = ty::ParamEnv::new(tcx.mk_clauses(&predicates), unnormalized_env.reveal()); let elaborated_env = ty::ParamEnv::new(tcx.mk_clauses(&predicates), unnormalized_env.reveal());
if !normalize::needs_normalization(&elaborated_env, unnormalized_env.reveal()) {
return elaborated_env;
}
// HACK: we are trying to normalize the param-env inside *itself*. The problem is that // HACK: we are trying to normalize the param-env inside *itself*. The problem is that
// normalization expects its param-env to be already normalized, which means we have // normalization expects its param-env to be already normalized, which means we have