diff options
6 files changed, 80 insertions, 85 deletions
diff --git a/compiler/rustc_mir_transform/src/simplify_branches.rs b/compiler/rustc_mir_transform/src/simplify_branches.rs index b508cd1c9cc..1f0e605c3b8 100644 --- a/compiler/rustc_mir_transform/src/simplify_branches.rs +++ b/compiler/rustc_mir_transform/src/simplify_branches.rs @@ -16,8 +16,25 @@ impl<'tcx> MirPass<'tcx> for SimplifyConstCondition { } fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { + trace!("Running SimplifyConstCondition on {:?}", body.source); let param_env = tcx.param_env_reveal_all_normalized(body.source.def_id()); - for block in body.basic_blocks_mut() { + 'blocks: for block in body.basic_blocks_mut() { + for stmt in block.statements.iter_mut() { + if let StatementKind::Intrinsic(box ref intrinsic) = stmt.kind + && let NonDivergingIntrinsic::Assume(discr) = intrinsic + && let Operand::Constant(ref c) = discr + && let Some(constant) = c.const_.try_eval_bool(tcx, param_env) + { + if constant { + stmt.make_nop(); + } else { + block.statements.clear(); + block.terminator_mut().kind = TerminatorKind::Unreachable; + continue 'blocks; + } + } + } + let terminator = block.terminator_mut(); terminator.kind = match terminator.kind { TerminatorKind::SwitchInt { diff --git a/tests/mir-opt/inline/unwrap_unchecked.unwrap_unchecked.Inline.panic-abort.diff b/tests/mir-opt/inline/unwrap_unchecked.unwrap_unchecked.Inline.panic-abort.diff index 14a8b22657f..4ca7a2c4294 100644 --- a/tests/mir-opt/inline/unwrap_unchecked.unwrap_unchecked.Inline.panic-abort.diff +++ b/tests/mir-opt/inline/unwrap_unchecked.unwrap_unchecked.Inline.panic-abort.diff @@ -9,6 +9,8 @@ + debug self => _2; + let mut _3: &std::option::Option<T>; + let mut _4: isize; ++ let mut _5: bool; ++ let mut _6: bool; + scope 2 { + debug val => _0; + } @@ -16,7 +18,6 @@ + scope 5 (inlined unreachable_unchecked) { + scope 6 { + scope 7 (inlined unreachable_unchecked::runtime) { -+ let _5: !; + } + } + } @@ -30,24 +31,20 @@ StorageLive(_2); _2 = move _1; - _0 = Option::<T>::unwrap_unchecked(move _2) -> [return: bb1, unwind unreachable]; +- } +- +- bb1: { + StorageLive(_3); + StorageLive(_4); + StorageLive(_5); ++ StorageLive(_6); + _4 = discriminant(_2); -+ switchInt(move _4) -> [0: bb1, 1: bb3, otherwise: bb2]; - } - - bb1: { -+ assume(const false); -+ _5 = core::panicking::panic_nounwind(const "unsafe precondition(s) violated: hint::unreachable_unchecked must never be reached") -> unwind unreachable; -+ } -+ -+ bb2: { -+ unreachable; -+ } -+ -+ bb3: { ++ _5 = Ne(_4, const 0_isize); ++ assume(move _5); ++ _6 = Eq(_4, const 1_isize); ++ assume(move _6); + _0 = move ((_2 as Some).0: T); ++ StorageDead(_6); + StorageDead(_5); + StorageDead(_4); + StorageDead(_3); diff --git a/tests/mir-opt/inline/unwrap_unchecked.unwrap_unchecked.Inline.panic-unwind.diff b/tests/mir-opt/inline/unwrap_unchecked.unwrap_unchecked.Inline.panic-unwind.diff index a6901ca0892..caabb7ea463 100644 --- a/tests/mir-opt/inline/unwrap_unchecked.unwrap_unchecked.Inline.panic-unwind.diff +++ b/tests/mir-opt/inline/unwrap_unchecked.unwrap_unchecked.Inline.panic-unwind.diff @@ -9,6 +9,8 @@ + debug self => _2; + let mut _3: &std::option::Option<T>; + let mut _4: isize; ++ let mut _5: bool; ++ let mut _6: bool; + scope 2 { + debug val => _0; + } @@ -16,7 +18,6 @@ + scope 5 (inlined unreachable_unchecked) { + scope 6 { + scope 7 (inlined unreachable_unchecked::runtime) { -+ let _5: !; + } + } + } @@ -30,33 +31,29 @@ StorageLive(_2); _2 = move _1; - _0 = Option::<T>::unwrap_unchecked(move _2) -> [return: bb1, unwind: bb2]; +- } +- +- bb1: { + StorageLive(_3); + StorageLive(_4); + StorageLive(_5); ++ StorageLive(_6); + _4 = discriminant(_2); -+ switchInt(move _4) -> [0: bb1, 1: bb3, otherwise: bb2]; - } - - bb1: { -- StorageDead(_2); -- return; -+ assume(const false); -+ _5 = core::panicking::panic_nounwind(const "unsafe precondition(s) violated: hint::unreachable_unchecked must never be reached") -> unwind unreachable; - } - -- bb2 (cleanup): { -- resume; -+ bb2: { -+ unreachable; -+ } -+ -+ bb3: { ++ _5 = Ne(_4, const 0_isize); ++ assume(move _5); ++ _6 = Eq(_4, const 1_isize); ++ assume(move _6); + _0 = move ((_2 as Some).0: T); ++ StorageDead(_6); + StorageDead(_5); + StorageDead(_4); + StorageDead(_3); -+ StorageDead(_2); -+ return; + StorageDead(_2); + return; +- } +- +- bb2 (cleanup): { +- resume; } } diff --git a/tests/mir-opt/inline/unwrap_unchecked.unwrap_unchecked.PreCodegen.after.panic-abort.mir b/tests/mir-opt/inline/unwrap_unchecked.unwrap_unchecked.PreCodegen.after.panic-abort.mir index 37a2d28e0c4..521266925e0 100644 --- a/tests/mir-opt/inline/unwrap_unchecked.unwrap_unchecked.PreCodegen.after.panic-abort.mir +++ b/tests/mir-opt/inline/unwrap_unchecked.unwrap_unchecked.PreCodegen.after.panic-abort.mir @@ -6,7 +6,9 @@ fn unwrap_unchecked(_1: Option<T>) -> T { scope 1 (inlined #[track_caller] Option::<T>::unwrap_unchecked) { debug self => _1; let mut _2: isize; - let mut _4: &std::option::Option<T>; + let mut _3: bool; + let mut _4: bool; + let mut _5: &std::option::Option<T>; scope 2 { debug val => _0; } @@ -14,36 +16,30 @@ fn unwrap_unchecked(_1: Option<T>) -> T { scope 5 (inlined unreachable_unchecked) { scope 6 { scope 7 (inlined unreachable_unchecked::runtime) { - let _3: !; } } } } scope 4 (inlined Option::<T>::is_some) { - debug self => _4; + debug self => _5; } } bb0: { - StorageLive(_4); + StorageLive(_5); StorageLive(_2); + StorageLive(_3); + StorageLive(_4); _2 = discriminant(_1); - switchInt(move _2) -> [0: bb1, 1: bb2, otherwise: bb3]; - } - - bb1: { - assume(const false); - _3 = core::panicking::panic_nounwind(const "unsafe precondition(s) violated: hint::unreachable_unchecked must never be reached") -> unwind unreachable; - } - - bb2: { + _3 = Ne(_2, const 0_isize); + assume(move _3); + _4 = Eq(_2, const 1_isize); + assume(move _4); _0 = move ((_1 as Some).0: T); - StorageDead(_2); StorageDead(_4); + StorageDead(_3); + StorageDead(_2); + StorageDead(_5); return; } - - bb3: { - unreachable; - } } diff --git a/tests/mir-opt/inline/unwrap_unchecked.unwrap_unchecked.PreCodegen.after.panic-unwind.mir b/tests/mir-opt/inline/unwrap_unchecked.unwrap_unchecked.PreCodegen.after.panic-unwind.mir index 37a2d28e0c4..521266925e0 100644 --- a/tests/mir-opt/inline/unwrap_unchecked.unwrap_unchecked.PreCodegen.after.panic-unwind.mir +++ b/tests/mir-opt/inline/unwrap_unchecked.unwrap_unchecked.PreCodegen.after.panic-unwind.mir @@ -6,7 +6,9 @@ fn unwrap_unchecked(_1: Option<T>) -> T { scope 1 (inlined #[track_caller] Option::<T>::unwrap_unchecked) { debug self => _1; let mut _2: isize; - let mut _4: &std::option::Option<T>; + let mut _3: bool; + let mut _4: bool; + let mut _5: &std::option::Option<T>; scope 2 { debug val => _0; } @@ -14,36 +16,30 @@ fn unwrap_unchecked(_1: Option<T>) -> T { scope 5 (inlined unreachable_unchecked) { scope 6 { scope 7 (inlined unreachable_unchecked::runtime) { - let _3: !; } } } } scope 4 (inlined Option::<T>::is_some) { - debug self => _4; + debug self => _5; } } bb0: { - StorageLive(_4); + StorageLive(_5); StorageLive(_2); + StorageLive(_3); + StorageLive(_4); _2 = discriminant(_1); - switchInt(move _2) -> [0: bb1, 1: bb2, otherwise: bb3]; - } - - bb1: { - assume(const false); - _3 = core::panicking::panic_nounwind(const "unsafe precondition(s) violated: hint::unreachable_unchecked must never be reached") -> unwind unreachable; - } - - bb2: { + _3 = Ne(_2, const 0_isize); + assume(move _3); + _4 = Eq(_2, const 1_isize); + assume(move _4); _0 = move ((_1 as Some).0: T); - StorageDead(_2); StorageDead(_4); + StorageDead(_3); + StorageDead(_2); + StorageDead(_5); return; } - - bb3: { - unreachable; - } } diff --git a/tests/mir-opt/pre-codegen/duplicate_switch_targets.ub_if_b.PreCodegen.after.mir b/tests/mir-opt/pre-codegen/duplicate_switch_targets.ub_if_b.PreCodegen.after.mir index d5d5253a8b7..fe7beadc818 100644 --- a/tests/mir-opt/pre-codegen/duplicate_switch_targets.ub_if_b.PreCodegen.after.mir +++ b/tests/mir-opt/pre-codegen/duplicate_switch_targets.ub_if_b.PreCodegen.after.mir @@ -4,30 +4,22 @@ fn ub_if_b(_1: Thing) -> Thing { debug t => _1; let mut _0: Thing; let mut _2: isize; + let mut _3: bool; + let mut _4: bool; scope 1 (inlined unreachable_unchecked) { scope 2 { scope 3 (inlined unreachable_unchecked::runtime) { - let _3: !; } } } bb0: { _2 = discriminant(_1); - switchInt(move _2) -> [0: bb1, 1: bb2, otherwise: bb3]; - } - - bb1: { + _3 = Ne(_2, const 1_isize); + assume(move _3); + _4 = Eq(_2, const 0_isize); + assume(move _4); _0 = move _1; return; } - - bb2: { - assume(const false); - _3 = core::panicking::panic_nounwind(const "unsafe precondition(s) violated: hint::unreachable_unchecked must never be reached") -> unwind unreachable; - } - - bb3: { - unreachable; - } } |