diff --git a/compiler/rustc_codegen_ssa/src/mir/analyze.rs b/compiler/rustc_codegen_ssa/src/mir/analyze.rs index 6d6465dd798b..b9a6d3af4451 100644 --- a/compiler/rustc_codegen_ssa/src/mir/analyze.rs +++ b/compiler/rustc_codegen_ssa/src/mir/analyze.rs @@ -170,11 +170,6 @@ impl<'a, 'b, 'tcx, Bx: BuilderMethods<'b, 'tcx>> Visitor<'tcx> for LocalAnalyzer if let Some(local) = place.as_local() { self.define(local, DefLocation::Assignment(location)); - if self.locals[local] != LocalKind::Memory { - if !self.fx.rvalue_creates_operand(rvalue) { - self.locals[local] = LocalKind::Memory; - } - } } else { self.visit_place(place, PlaceContext::MutatingUse(MutatingUseContext::Store), location); } diff --git a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs index 4c080de2b31e..e9d37517c5ff 100644 --- a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs +++ b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs @@ -180,7 +180,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { } _ => { - assert!(self.rvalue_creates_operand(rvalue)); let temp = self.codegen_rvalue_operand(bx, rvalue); temp.val.store(bx, dest); } @@ -218,11 +217,8 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { /// Transmutes an `OperandValue` to another `OperandValue`. /// - /// This is supported only for cases where [`Self::rvalue_creates_operand`] - /// returns `true`, and will ICE otherwise. (In particular, anything that - /// would need to `alloca` in order to return a `PlaceValue` will ICE, - /// expecting those to go via [`Self::codegen_transmute`] instead where - /// the destination place is already allocated.) + /// This is supported for all cases where the `cast` type is SSA, + /// but for non-ZSTs with [`abi::BackendRepr::Memory`] it ICEs. pub(crate) fn codegen_transmute_operand( &mut self, bx: &mut Bx, @@ -379,8 +375,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { bx: &mut Bx, rvalue: &mir::Rvalue<'tcx>, ) -> OperandRef<'tcx, Bx::Value> { - assert!(self.rvalue_creates_operand(rvalue), "cannot codegen {rvalue:?} to operand",); - match *rvalue { mir::Rvalue::Cast(ref kind, ref source, mir_cast_ty) => { let operand = self.codegen_operand(bx, source); @@ -706,8 +700,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { let ty = self.monomorphize(ty); let layout = self.cx.layout_of(ty); - // `rvalue_creates_operand` has arranged that we only get here if - // we can build the aggregate immediate from the field immediates. let mut builder = OperandRefBuilder::new(layout); for (field_idx, field) in fields.iter_enumerated() { let op = self.codegen_operand(bx, field); @@ -1008,38 +1000,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { OperandValue::Pair(val, of) } - - /// Returns `true` if the `rvalue` can be computed into an [`OperandRef`], - /// rather than needing a full `PlaceRef` for the assignment destination. - /// - /// This is used by the [`super::analyze`] code to decide which MIR locals - /// can stay as SSA values (as opposed to generating `alloca` slots for them). - /// As such, some paths here return `true` even where the specific rvalue - /// will not actually take the operand path because the result type is such - /// that it always gets an `alloca`, but where it's not worth re-checking the - /// layout in this code when the right thing will happen anyway. - pub(crate) fn rvalue_creates_operand(&self, rvalue: &mir::Rvalue<'tcx>) -> bool { - match *rvalue { - mir::Rvalue::Ref(..) | - mir::Rvalue::CopyForDeref(..) | - mir::Rvalue::RawPtr(..) | - mir::Rvalue::Len(..) | - mir::Rvalue::Cast(..) | // (*) - mir::Rvalue::ShallowInitBox(..) | // (*) - mir::Rvalue::BinaryOp(..) | - mir::Rvalue::UnaryOp(..) | - mir::Rvalue::Discriminant(..) | - mir::Rvalue::NullaryOp(..) | - mir::Rvalue::ThreadLocalRef(_) | - mir::Rvalue::Use(..) | - mir::Rvalue::Repeat(..) | // (*) - mir::Rvalue::Aggregate(..) | // (*) - mir::Rvalue::WrapUnsafeBinder(..) => // (*) - true, - } - - // (*) this is only true if the type is suitable - } } /// Transmutes a single scalar value `imm` from `from_scalar` to `to_scalar`.