diff options
Diffstat (limited to 'compiler/rustc_mir_transform')
| -rw-r--r-- | compiler/rustc_mir_transform/src/dataflow_const_prop.rs | 38 | ||||
| -rw-r--r-- | compiler/rustc_mir_transform/src/gvn.rs | 77 | ||||
| -rw-r--r-- | compiler/rustc_mir_transform/src/known_panics_lint.rs | 15 | ||||
| -rw-r--r-- | compiler/rustc_mir_transform/src/promote_consts.rs | 4 | ||||
| -rw-r--r-- | compiler/rustc_mir_transform/src/validate.rs | 8 |
5 files changed, 40 insertions, 102 deletions
diff --git a/compiler/rustc_mir_transform/src/dataflow_const_prop.rs b/compiler/rustc_mir_transform/src/dataflow_const_prop.rs index fe53de31f75..5c984984d3c 100644 --- a/compiler/rustc_mir_transform/src/dataflow_const_prop.rs +++ b/compiler/rustc_mir_transform/src/dataflow_const_prop.rs @@ -412,18 +412,6 @@ impl<'a, 'tcx> ConstAnalysis<'a, 'tcx> { state: &mut State<FlatSet<Scalar>>, ) -> ValueOrPlace<FlatSet<Scalar>> { let val = match rvalue { - Rvalue::Len(place) => { - let place_ty = place.ty(self.local_decls, self.tcx); - if let ty::Array(_, len) = place_ty.ty.kind() { - Const::Ty(self.tcx.types.usize, *len) - .try_eval_scalar(self.tcx, self.typing_env) - .map_or(FlatSet::Top, FlatSet::Elem) - } else if let [ProjectionElem::Deref] = place.projection[..] { - state.get_len(place.local.into(), &self.map) - } else { - FlatSet::Top - } - } Rvalue::Cast(CastKind::IntToInt | CastKind::IntToFloat, operand, ty) => { let Ok(layout) = self.tcx.layout_of(self.typing_env.as_query_input(*ty)) else { return ValueOrPlace::Value(FlatSet::Top); @@ -465,15 +453,23 @@ impl<'a, 'tcx> ConstAnalysis<'a, 'tcx> { let (val, _overflow) = self.binary_op(state, *op, left, right); val } - Rvalue::UnaryOp(op, operand) => match self.eval_operand(operand, state) { - FlatSet::Elem(value) => self - .ecx - .unary_op(*op, &value) - .discard_err() - .map_or(FlatSet::Top, |val| self.wrap_immediate(*val)), - FlatSet::Bottom => FlatSet::Bottom, - FlatSet::Top => FlatSet::Top, - }, + Rvalue::UnaryOp(op, operand) => { + if let UnOp::PtrMetadata = op + && let Some(place) = operand.place() + && let Some(len) = self.map.find_len(place.as_ref()) + { + return ValueOrPlace::Place(len); + } + match self.eval_operand(operand, state) { + FlatSet::Elem(value) => self + .ecx + .unary_op(*op, &value) + .discard_err() + .map_or(FlatSet::Top, |val| self.wrap_immediate(*val)), + FlatSet::Bottom => FlatSet::Bottom, + FlatSet::Top => FlatSet::Top, + } + } Rvalue::NullaryOp(null_op, ty) => { let Ok(layout) = self.tcx.layout_of(self.typing_env.as_query_input(*ty)) else { return ValueOrPlace::Value(FlatSet::Top); diff --git a/compiler/rustc_mir_transform/src/gvn.rs b/compiler/rustc_mir_transform/src/gvn.rs index bf6aa800d20..30e68a3f650 100644 --- a/compiler/rustc_mir_transform/src/gvn.rs +++ b/compiler/rustc_mir_transform/src/gvn.rs @@ -200,8 +200,6 @@ enum Value<'tcx> { Projection(VnIndex, ProjectionElem<VnIndex, ()>), /// Discriminant of the given value. Discriminant(VnIndex), - /// Length of an array or slice. - Len(VnIndex), // Operations. NullaryOp(NullOp<'tcx>, Ty<'tcx>), @@ -477,11 +475,6 @@ impl<'body, 'tcx> VnState<'body, 'tcx> { self.ecx.discriminant_for_variant(base.layout.ty, variant).discard_err()?; discr_value.into() } - Len(slice) => { - let slice = self.evaluated[slice].as_ref()?; - let len = slice.len(&self.ecx).discard_err()?; - ImmTy::from_uint(len, ty).into() - } NullaryOp(null_op, arg_ty) => { let arg_layout = self.ecx.layout_of(arg_ty).ok()?; if let NullOp::SizeOf | NullOp::AlignOf = null_op @@ -841,7 +834,6 @@ impl<'body, 'tcx> VnState<'body, 'tcx> { } // Operations. - Rvalue::Len(ref mut place) => return self.simplify_len(place, location), Rvalue::Cast(ref mut kind, ref mut value, to) => { return self.simplify_cast(kind, value, to, location); } @@ -1049,7 +1041,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> { if op == UnOp::PtrMetadata { let mut was_updated = false; loop { - match self.get(arg_index) { + arg_index = match self.get(arg_index) { // Pointer casts that preserve metadata, such as // `*const [i32]` <-> `*mut [i32]` <-> `*mut [f32]`. // It's critical that this not eliminate cases like @@ -1061,9 +1053,19 @@ impl<'body, 'tcx> VnState<'body, 'tcx> { Value::Cast { kind: CastKind::PtrToPtr, value: inner } if self.pointers_have_same_metadata(self.ty(*inner), arg_ty) => { - arg_index = *inner; - was_updated = true; - continue; + *inner + } + + // We have an unsizing cast, which assigns the length to wide pointer metadata. + Value::Cast { + kind: CastKind::PointerCoercion(ty::adjustment::PointerCoercion::Unsize, _), + value: from, + } if let Some(from) = self.ty(*from).builtin_deref(true) + && let ty::Array(_, len) = from.kind() + && let Some(to) = self.ty(arg_index).builtin_deref(true) + && let ty::Slice(..) = to.kind() => + { + return Some(self.insert_constant(Const::Ty(self.tcx.types.usize, *len))); } // `&mut *p`, `&raw *p`, etc don't change metadata. @@ -1072,18 +1074,16 @@ impl<'body, 'tcx> VnState<'body, 'tcx> { place.as_ref() && let Some(local_index) = self.locals[local] => { - arg_index = local_index; - was_updated = true; - continue; + local_index } - _ => { - if was_updated && let Some(op) = self.try_as_operand(arg_index, location) { - *arg_op = op; - } - break; - } - } + _ => break, + }; + was_updated = true; + } + + if was_updated && let Some(op) = self.try_as_operand(arg_index, location) { + *arg_op = op; } } @@ -1407,39 +1407,6 @@ impl<'body, 'tcx> VnState<'body, 'tcx> { Some(self.insert(to, Value::Cast { kind, value })) } - fn simplify_len(&mut self, place: &mut Place<'tcx>, location: Location) -> Option<VnIndex> { - // Trivial case: we are fetching a statically known length. - let place_ty = place.ty(self.local_decls, self.tcx).ty; - if let ty::Array(_, len) = place_ty.kind() { - return Some(self.insert_constant(Const::Ty(self.tcx.types.usize, *len))); - } - - let mut inner = self.simplify_place_value(place, location)?; - - // The length information is stored in the wide pointer. - // Reborrowing copies length information from one pointer to the other. - while let Value::Address { place: borrowed, .. } = self.get(inner) - && let [PlaceElem::Deref] = borrowed.projection[..] - && let Some(borrowed) = self.locals[borrowed.local] - { - inner = borrowed; - } - - // We have an unsizing cast, which assigns the length to wide pointer metadata. - if let Value::Cast { kind, value: from } = self.get(inner) - && let CastKind::PointerCoercion(ty::adjustment::PointerCoercion::Unsize, _) = kind - && let Some(from) = self.ty(*from).builtin_deref(true) - && let ty::Array(_, len) = from.kind() - && let Some(to) = self.ty(inner).builtin_deref(true) - && let ty::Slice(..) = to.kind() - { - return Some(self.insert_constant(Const::Ty(self.tcx.types.usize, *len))); - } - - // Fallback: a symbolic `Len`. - Some(self.insert(self.tcx.types.usize, Value::Len(inner))) - } - fn pointers_have_same_metadata(&self, left_ptr_ty: Ty<'tcx>, right_ptr_ty: Ty<'tcx>) -> bool { let left_meta_ty = left_ptr_ty.pointee_metadata_ty_or_projection(self.tcx); let right_meta_ty = right_ptr_ty.pointee_metadata_ty_or_projection(self.tcx); diff --git a/compiler/rustc_mir_transform/src/known_panics_lint.rs b/compiler/rustc_mir_transform/src/known_panics_lint.rs index 481c7941909..aaacc5866a2 100644 --- a/compiler/rustc_mir_transform/src/known_panics_lint.rs +++ b/compiler/rustc_mir_transform/src/known_panics_lint.rs @@ -441,7 +441,6 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> { | Rvalue::Use(..) | Rvalue::CopyForDeref(..) | Rvalue::Repeat(..) - | Rvalue::Len(..) | Rvalue::Cast(..) | Rvalue::ShallowInitBox(..) | Rvalue::Discriminant(..) @@ -604,20 +603,6 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> { return None; } - Len(place) => { - let len = if let ty::Array(_, n) = place.ty(self.local_decls(), self.tcx).ty.kind() - { - n.try_to_target_usize(self.tcx)? - } else { - match self.get_const(place)? { - Value::Immediate(src) => src.len(&self.ecx).discard_err()?, - Value::Aggregate { fields, .. } => fields.len() as u64, - Value::Uninit => return None, - } - }; - ImmTy::from_scalar(Scalar::from_target_usize(len, self), layout).into() - } - Ref(..) | RawPtr(..) => return None, NullaryOp(ref null_op, ty) => { diff --git a/compiler/rustc_mir_transform/src/promote_consts.rs b/compiler/rustc_mir_transform/src/promote_consts.rs index 9ea2eb4f25d..a0b0c8c990f 100644 --- a/compiler/rustc_mir_transform/src/promote_consts.rs +++ b/compiler/rustc_mir_transform/src/promote_consts.rs @@ -437,9 +437,7 @@ impl<'tcx> Validator<'_, 'tcx> { self.validate_operand(op)? } - Rvalue::Discriminant(place) | Rvalue::Len(place) => { - self.validate_place(place.as_ref())? - } + Rvalue::Discriminant(place) => self.validate_place(place.as_ref())?, Rvalue::ThreadLocalRef(_) => return Err(Unpromotable), diff --git a/compiler/rustc_mir_transform/src/validate.rs b/compiler/rustc_mir_transform/src/validate.rs index 99e4782e470..c8a9a88dc3f 100644 --- a/compiler/rustc_mir_transform/src/validate.rs +++ b/compiler/rustc_mir_transform/src/validate.rs @@ -1064,14 +1064,6 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> { } } Rvalue::Ref(..) => {} - Rvalue::Len(p) => { - let pty = p.ty(&self.body.local_decls, self.tcx).ty; - check_kinds!( - pty, - "Cannot compute length of non-array type {:?}", - ty::Array(..) | ty::Slice(..) - ); - } Rvalue::BinaryOp(op, vals) => { use BinOp::*; let a = vals.0.ty(&self.body.local_decls, self.tcx); |