diff --git a/compiler/rustc_mir_transform/src/dataflow_const_prop.rs b/compiler/rustc_mir_transform/src/dataflow_const_prop.rs index d4c9163b571..29fc3a1be37 100644 --- a/compiler/rustc_mir_transform/src/dataflow_const_prop.rs +++ b/compiler/rustc_mir_transform/src/dataflow_const_prop.rs @@ -9,7 +9,7 @@ use rustc_hir::def::DefKind; use rustc_middle::mir::visit::{MutVisitor, Visitor}; use rustc_middle::mir::*; use rustc_middle::ty::layout::TyAndLayout; -use rustc_middle::ty::{self, Ty, TyCtxt}; +use rustc_middle::ty::{self, ScalarInt, Ty, TyCtxt}; use rustc_mir_dataflow::value_analysis::{ Map, State, TrackElem, ValueAnalysis, ValueAnalysisWrapper, ValueOrPlace, }; @@ -58,9 +58,13 @@ impl<'tcx> MirPass<'tcx> for DataflowConstProp { .in_scope(|| analysis.wrap().into_engine(tcx, body).iterate_to_fixpoint()); // Collect results and patch the body afterwards. - let mut visitor = CollectAndPatch::new(tcx); + let mut visitor = CollectAndPatch::new(tcx, &body.local_decls); debug_span!("collect").in_scope(|| results.visit_reachable_with(body, &mut visitor)); - debug_span!("patch").in_scope(|| visitor.visit_body(body)); + debug_span!("patch").in_scope(|| { + for (block, bbdata) in body.basic_blocks.as_mut_preserves_cfg().iter_enumerated_mut() { + visitor.visit_basic_block_data(block, bbdata); + } + }) } } @@ -73,7 +77,7 @@ struct ConstAnalysis<'a, 'tcx> { } impl<'tcx> ValueAnalysis<'tcx> for ConstAnalysis<'_, 'tcx> { - type Value = FlatSet>; + type Value = FlatSet; const NAME: &'static str = "ConstAnalysis"; @@ -172,9 +176,7 @@ impl<'tcx> ValueAnalysis<'tcx> for ConstAnalysis<'_, 'tcx> { if let Some(overflow_target) = overflow_target { let overflow = match overflow { FlatSet::Top => FlatSet::Top, - FlatSet::Elem(overflow) => { - self.wrap_scalar(Scalar::from_bool(overflow), self.tcx.types.bool) - } + FlatSet::Elem(overflow) => FlatSet::Elem(overflow.into()), FlatSet::Bottom => FlatSet::Bottom, }; // We have flooded `target` earlier. @@ -209,7 +211,7 @@ impl<'tcx> ValueAnalysis<'tcx> for ConstAnalysis<'_, 'tcx> { } _ => unreachable!(), } - .map(|result| ValueOrPlace::Value(self.wrap_immediate(result, *ty))) + .map(|result| ValueOrPlace::Value(self.wrap_immediate(result))) .unwrap_or(ValueOrPlace::TOP), _ => ValueOrPlace::TOP, }, @@ -242,9 +244,8 @@ impl<'tcx> ValueAnalysis<'tcx> for ConstAnalysis<'_, 'tcx> { constant .literal .eval(self.tcx, self.param_env) - .try_to_scalar() - .map(|value| FlatSet::Elem(ScalarTy(value, constant.ty()))) - .unwrap_or(FlatSet::Top) + .try_to_scalar_int() + .map_or(FlatSet::Top, FlatSet::Elem) } fn handle_switch_int<'mir>( @@ -261,9 +262,8 @@ impl<'tcx> ValueAnalysis<'tcx> for ConstAnalysis<'_, 'tcx> { // We are branching on uninitialized data, this is UB, treat it as unreachable. // This allows the set of visited edges to grow monotonically with the lattice. FlatSet::Bottom => TerminatorEdges::None, - FlatSet::Elem(ScalarTy(scalar, _)) => { - let int = scalar.assert_int(); - let choice = int.assert_bits(int.size()); + FlatSet::Elem(scalar) => { + let choice = scalar.assert_bits(scalar.size()); TerminatorEdges::Single(targets.target_for_value(choice)) } FlatSet::Top => TerminatorEdges::SwitchInt { discr, targets }, @@ -271,16 +271,6 @@ impl<'tcx> ValueAnalysis<'tcx> for ConstAnalysis<'_, 'tcx> { } } -#[derive(Clone, PartialEq, Eq)] -struct ScalarTy<'tcx>(Scalar, Ty<'tcx>); - -impl<'tcx> std::fmt::Debug for ScalarTy<'tcx> { - fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { - // This is used for dataflow visualization, so we return something more concise. - std::fmt::Display::fmt(&ConstantKind::Val(ConstValue::Scalar(self.0), self.1), f) - } -} - impl<'a, 'tcx> ConstAnalysis<'a, 'tcx> { pub fn new(tcx: TyCtxt<'tcx>, body: &'a Body<'tcx>, map: Map) -> Self { let param_env = tcx.param_env_reveal_all_normalized(body.source.def_id()); @@ -295,17 +285,19 @@ impl<'a, 'tcx> ConstAnalysis<'a, 'tcx> { fn binary_op( &self, - state: &mut State>>, + state: &mut State>, op: BinOp, left: &Operand<'tcx>, right: &Operand<'tcx>, - ) -> (FlatSet>, FlatSet) { + ) -> (FlatSet, FlatSet) { let left = self.eval_operand(left, state); let right = self.eval_operand(right, state); match (left, right) { (FlatSet::Elem(left), FlatSet::Elem(right)) => { match self.ecx.overflowing_binary_op(op, &left, &right) { - Ok((val, overflow, ty)) => (self.wrap_scalar(val, ty), FlatSet::Elem(overflow)), + Ok((Scalar::Int(val), overflow, _)) => { + (FlatSet::Elem(val), FlatSet::Elem(overflow)) + } _ => (FlatSet::Top, FlatSet::Top), } } @@ -320,7 +312,7 @@ impl<'a, 'tcx> ConstAnalysis<'a, 'tcx> { fn eval_operand( &self, op: &Operand<'tcx>, - state: &mut State>>, + state: &mut State>, ) -> FlatSet> { let value = match self.handle_operand(op, state) { ValueOrPlace::Value(value) => value, @@ -328,76 +320,76 @@ impl<'a, 'tcx> ConstAnalysis<'a, 'tcx> { }; match value { FlatSet::Top => FlatSet::Top, - FlatSet::Elem(ScalarTy(scalar, ty)) => self - .tcx - .layout_of(self.param_env.and(ty)) - .map(|layout| FlatSet::Elem(ImmTy::from_scalar(scalar, layout))) - .unwrap_or(FlatSet::Top), + FlatSet::Elem(scalar) => { + let ty = op.ty(self.local_decls, self.tcx); + self.tcx + .layout_of(self.param_env.and(ty)) + .map(|layout| FlatSet::Elem(ImmTy::from_scalar(scalar.into(), layout))) + .unwrap_or(FlatSet::Top) + } FlatSet::Bottom => FlatSet::Bottom, } } - fn eval_discriminant( - &self, - enum_ty: Ty<'tcx>, - variant_index: VariantIdx, - ) -> Option> { + fn eval_discriminant(&self, enum_ty: Ty<'tcx>, variant_index: VariantIdx) -> Option { if !enum_ty.is_enum() { return None; } let discr = enum_ty.discriminant_for_variant(self.tcx, variant_index)?; let discr_layout = self.tcx.layout_of(self.param_env.and(discr.ty)).ok()?; - let discr_value = Scalar::try_from_uint(discr.val, discr_layout.size)?; - Some(ScalarTy(discr_value, discr.ty)) + let discr_value = ScalarInt::try_from_uint(discr.val, discr_layout.size)?; + Some(discr_value) } - fn wrap_scalar(&self, scalar: Scalar, ty: Ty<'tcx>) -> FlatSet> { - FlatSet::Elem(ScalarTy(scalar, ty)) - } - - fn wrap_immediate(&self, imm: Immediate, ty: Ty<'tcx>) -> FlatSet> { + fn wrap_immediate(&self, imm: Immediate) -> FlatSet { match imm { - Immediate::Scalar(scalar) => self.wrap_scalar(scalar, ty), + Immediate::Scalar(Scalar::Int(scalar)) => FlatSet::Elem(scalar), _ => FlatSet::Top, } } - fn wrap_immty(&self, val: ImmTy<'tcx>) -> FlatSet> { - self.wrap_immediate(*val, val.layout.ty) + fn wrap_immty(&self, val: ImmTy<'tcx>) -> FlatSet { + self.wrap_immediate(*val) } } -struct CollectAndPatch<'tcx> { +struct CollectAndPatch<'tcx, 'locals> { tcx: TyCtxt<'tcx>, + local_decls: &'locals LocalDecls<'tcx>, /// For a given MIR location, this stores the values of the operands used by that location. In /// particular, this is before the effect, such that the operands of `_1 = _1 + _2` are /// properly captured. (This may become UB soon, but it is currently emitted even by safe code.) - before_effect: FxHashMap<(Location, Place<'tcx>), ScalarTy<'tcx>>, + before_effect: FxHashMap<(Location, Place<'tcx>), ScalarInt>, /// Stores the assigned values for assignments where the Rvalue is constant. - assignments: FxHashMap>, + assignments: FxHashMap, } -impl<'tcx> CollectAndPatch<'tcx> { - fn new(tcx: TyCtxt<'tcx>) -> Self { - Self { tcx, before_effect: FxHashMap::default(), assignments: FxHashMap::default() } +impl<'tcx, 'locals> CollectAndPatch<'tcx, 'locals> { + fn new(tcx: TyCtxt<'tcx>, local_decls: &'locals LocalDecls<'tcx>) -> Self { + Self { + tcx, + local_decls, + before_effect: FxHashMap::default(), + assignments: FxHashMap::default(), + } } - fn make_operand(&self, scalar: ScalarTy<'tcx>) -> Operand<'tcx> { + fn make_operand(&self, scalar: ScalarInt, ty: Ty<'tcx>) -> Operand<'tcx> { Operand::Constant(Box::new(Constant { span: DUMMY_SP, user_ty: None, - literal: ConstantKind::Val(ConstValue::Scalar(scalar.0), scalar.1), + literal: ConstantKind::Val(ConstValue::Scalar(scalar.into()), ty), })) } } impl<'mir, 'tcx> ResultsVisitor<'mir, 'tcx, Results<'tcx, ValueAnalysisWrapper>>> - for CollectAndPatch<'tcx> + for CollectAndPatch<'tcx, '_> { - type FlowState = State>>; + type FlowState = State>; fn visit_statement_before_primary_effect( &mut self, @@ -453,8 +445,8 @@ impl<'mir, 'tcx> } } -impl<'tcx> MutVisitor<'tcx> for CollectAndPatch<'tcx> { - fn tcx<'a>(&'a self) -> TyCtxt<'tcx> { +impl<'tcx> MutVisitor<'tcx> for CollectAndPatch<'tcx, '_> { + fn tcx(&self) -> TyCtxt<'tcx> { self.tcx } @@ -462,7 +454,8 @@ impl<'tcx> MutVisitor<'tcx> for CollectAndPatch<'tcx> { if let Some(value) = self.assignments.get(&location) { match &mut statement.kind { StatementKind::Assign(box (_, rvalue)) => { - *rvalue = Rvalue::Use(self.make_operand(value.clone())); + let ty = rvalue.ty(self.local_decls, self.tcx); + *rvalue = Rvalue::Use(self.make_operand(*value, ty)); } _ => bug!("found assignment info for non-assign statement"), } @@ -475,21 +468,22 @@ impl<'tcx> MutVisitor<'tcx> for CollectAndPatch<'tcx> { match operand { Operand::Copy(place) | Operand::Move(place) => { if let Some(value) = self.before_effect.get(&(location, *place)) { - *operand = self.make_operand(value.clone()); + let ty = place.ty(self.local_decls, self.tcx).ty; + *operand = self.make_operand(*value, ty); } } - _ => (), + Operand::Constant(_) => {} } } } -struct OperandCollector<'tcx, 'map, 'a> { - state: &'a State>>, - visitor: &'a mut CollectAndPatch<'tcx>, +struct OperandCollector<'tcx, 'map, 'locals, 'a> { + state: &'a State>, + visitor: &'a mut CollectAndPatch<'tcx, 'locals>, map: &'map Map, } -impl<'tcx, 'map, 'a> Visitor<'tcx> for OperandCollector<'tcx, 'map, 'a> { +impl<'tcx> Visitor<'tcx> for OperandCollector<'tcx, '_, '_, '_> { fn visit_operand(&mut self, operand: &Operand<'tcx>, location: Location) { match operand { Operand::Copy(place) | Operand::Move(place) => { @@ -572,7 +566,7 @@ impl<'mir, 'tcx: 'mir> rustc_const_eval::interpret::Machine<'mir, 'tcx> for Dumm _bin_op: BinOp, _left: &rustc_const_eval::interpret::ImmTy<'tcx, Self::Provenance>, _right: &rustc_const_eval::interpret::ImmTy<'tcx, Self::Provenance>, - ) -> interpret::InterpResult<'tcx, (interpret::Scalar, bool, Ty<'tcx>)> { + ) -> interpret::InterpResult<'tcx, (Scalar, bool, Ty<'tcx>)> { throw_unsup!(Unsupported("".into())) }