- // MIR for `foo` before MatchBranchSimplification + // MIR for `foo` after MatchBranchSimplification fn foo(_1: [u8; 16]) -> Option<[u8; 4]> { debug bytes => _1; // in scope 0 at $DIR/issue-75439.rs:5:12: 5:17 let mut _0: std::option::Option<[u8; 4]>; // return place in scope 0 at $DIR/issue-75439.rs:5:32: 5:47 let _2: [u32; 4]; // in scope 0 at $DIR/issue-75439.rs:7:9: 7:15 let mut _3: [u8; 16]; // in scope 0 at $DIR/issue-75439.rs:7:47: 7:52 let mut _5: [u8; 4]; // in scope 0 at $DIR/issue-75439.rs:10:14: 10:38 let mut _6: u32; // in scope 0 at $DIR/issue-75439.rs:10:33: 10:35 scope 1 { debug dwords => _2; // in scope 1 at $DIR/issue-75439.rs:7:9: 7:15 scope 3 { debug ip => _4; // in scope 3 at $DIR/issue-75439.rs:9:27: 9:29 let _4: u32; // in scope 3 at $DIR/issue-75439.rs:9:27: 9:29 scope 4 { } } } scope 2 { } bb0: { StorageLive(_2); // scope 0 at $DIR/issue-75439.rs:7:9: 7:15 StorageLive(_3); // scope 2 at $DIR/issue-75439.rs:7:47: 7:52 _3 = _1; // scope 2 at $DIR/issue-75439.rs:7:47: 7:52 _2 = transmute::<[u8; 16], [u32; 4]>(move _3) -> bb1; // scope 2 at $DIR/issue-75439.rs:7:37: 7:53 // mir::Constant // + span: $DIR/issue-75439.rs:7:37: 7:46 // + literal: Const { ty: unsafe extern "rust-intrinsic" fn([u8; 16]) -> [u32; 4] {transmute::<[u8; 16], [u32; 4]>}, val: Value() } } bb1: { StorageDead(_3); // scope 2 at $DIR/issue-75439.rs:7:52: 7:53 switchInt(_2[0 of 4]) -> [0_u32: bb2, otherwise: bb8]; // scope 3 at $DIR/issue-75439.rs:9:12: 9:30 } bb2: { switchInt(_2[1 of 4]) -> [0_u32: bb3, otherwise: bb8]; // scope 3 at $DIR/issue-75439.rs:9:12: 9:30 } bb3: { switchInt(_2[2 of 4]) -> [0_u32: bb5, 4294901760_u32: bb6, otherwise: bb8]; // scope 3 at $DIR/issue-75439.rs:9:12: 9:30 } bb4: { StorageLive(_5); // scope 3 at $DIR/issue-75439.rs:10:14: 10:38 StorageLive(_6); // scope 4 at $DIR/issue-75439.rs:10:33: 10:35 _6 = _4; // scope 4 at $DIR/issue-75439.rs:10:33: 10:35 _5 = transmute::(move _6) -> bb7; // scope 4 at $DIR/issue-75439.rs:10:23: 10:36 // mir::Constant // + span: $DIR/issue-75439.rs:10:23: 10:32 // + literal: Const { ty: unsafe extern "rust-intrinsic" fn(u32) -> [u8; 4] {transmute::}, val: Value() } } bb5: { StorageLive(_4); // scope 3 at $DIR/issue-75439.rs:9:27: 9:29 _4 = _2[3 of 4]; // scope 3 at $DIR/issue-75439.rs:9:27: 9:29 goto -> bb4; // scope 3 at $DIR/issue-75439.rs:9:12: 9:30 } bb6: { StorageLive(_4); // scope 3 at $DIR/issue-75439.rs:9:27: 9:29 _4 = _2[3 of 4]; // scope 3 at $DIR/issue-75439.rs:9:27: 9:29 goto -> bb4; // scope 3 at $DIR/issue-75439.rs:9:12: 9:30 } bb7: { StorageDead(_6); // scope 4 at $DIR/issue-75439.rs:10:35: 10:36 Deinit(_0); // scope 3 at $DIR/issue-75439.rs:10:9: 10:39 ((_0 as Some).0: [u8; 4]) = move _5; // scope 3 at $DIR/issue-75439.rs:10:9: 10:39 discriminant(_0) = 1; // scope 3 at $DIR/issue-75439.rs:10:9: 10:39 StorageDead(_5); // scope 3 at $DIR/issue-75439.rs:10:38: 10:39 StorageDead(_4); // scope 1 at $DIR/issue-75439.rs:11:5: 11:6 goto -> bb9; // scope 1 at $DIR/issue-75439.rs:9:5: 13:6 } bb8: { Deinit(_0); // scope 1 at $DIR/issue-75439.rs:12:9: 12:13 discriminant(_0) = 0; // scope 1 at $DIR/issue-75439.rs:12:9: 12:13 goto -> bb9; // scope 1 at $DIR/issue-75439.rs:9:5: 13:6 } bb9: { StorageDead(_2); // scope 0 at $DIR/issue-75439.rs:14:1: 14:2 return; // scope 0 at $DIR/issue-75439.rs:14:2: 14:2 } }