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| author | bors <bors@rust-lang.org> | 2023-10-09 06:00:23 +0000 |
|---|---|---|
| committer | bors <bors@rust-lang.org> | 2023-10-09 06:00:23 +0000 |
| commit | 093b9d5b295d85e144d0ee7da65ea03987214c06 (patch) | |
| tree | 6ef09fdeb0126ffa561738dd1b37a03f9a8e6463 | |
| parent | 1f48cbc3f8dbd393a7e713a0f90d7c6ec72d58ee (diff) | |
| parent | 005ec2e51ce99c6dd5e88c273b3f9b273fdf3f41 (diff) | |
| download | rust-093b9d5b295d85e144d0ee7da65ea03987214c06.tar.gz rust-093b9d5b295d85e144d0ee7da65ea03987214c06.zip | |
Auto merge of #116533 - cjgillot:skip-trivial-mir, r=oli-obk
Do not run optimizations on trivial MIR. Fixes https://github.com/rust-lang/rust/issues/116513 The bug was introduced in https://github.com/rust-lang/rust/pull/110728, which put the check too early in the query chain. cc `@oli-obk` `@ouz-a`
| -rw-r--r-- | compiler/rustc_mir_transform/src/lib.rs | 9 | ||||
| -rw-r--r-- | tests/ui/consts/issue-67696-const-prop-ice.rs | 2 |
2 files changed, 10 insertions, 1 deletions
diff --git a/compiler/rustc_mir_transform/src/lib.rs b/compiler/rustc_mir_transform/src/lib.rs index c0a09b7a761..c42888d8791 100644 --- a/compiler/rustc_mir_transform/src/lib.rs +++ b/compiler/rustc_mir_transform/src/lib.rs @@ -613,6 +613,15 @@ fn inner_optimized_mir(tcx: TyCtxt<'_>, did: LocalDefId) -> Body<'_> { return body; } + // If `mir_drops_elaborated_and_const_checked` found that the current body has unsatisfiable + // predicates, it will shrink the MIR to a single `unreachable` terminator. + // More generally, if MIR is a lone `unreachable`, there is nothing to optimize. + if let TerminatorKind::Unreachable = body.basic_blocks[START_BLOCK].terminator().kind + && body.basic_blocks[START_BLOCK].statements.is_empty() + { + return body; + } + run_optimization_passes(tcx, &mut body); body diff --git a/tests/ui/consts/issue-67696-const-prop-ice.rs b/tests/ui/consts/issue-67696-const-prop-ice.rs index ad52608b3f4..858035190ca 100644 --- a/tests/ui/consts/issue-67696-const-prop-ice.rs +++ b/tests/ui/consts/issue-67696-const-prop-ice.rs @@ -1,5 +1,5 @@ // check-pass -// compile-flags: --emit=mir,link +// compile-flags: --emit=mir,link -Zmir-opt-level=4 // Checks that we don't ICE due to attempting to run const prop // on a function with unsatisifable 'where' clauses |