diff options
Diffstat (limited to 'compiler/rustc_codegen_ssa/src/mir')
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/mir/block.rs | 15 | ||||
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/mir/intrinsic.rs | 15 | ||||
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/mir/operand.rs | 47 | ||||
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/mir/place.rs | 87 | ||||
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/mir/rvalue.rs | 52 |
5 files changed, 115 insertions, 101 deletions
diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs index d36972d0d86..ba6aad51316 100644 --- a/compiler/rustc_codegen_ssa/src/mir/block.rs +++ b/compiler/rustc_codegen_ssa/src/mir/block.rs @@ -1454,9 +1454,9 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { Some(pointee_align) => cmp::max(pointee_align, arg.layout.align.abi), None => arg.layout.align.abi, }; - let scratch = PlaceRef::alloca_aligned(bx, arg.layout, required_align); - op.val.store(bx, scratch); - (scratch.val.llval, scratch.val.align, true) + let scratch = PlaceValue::alloca(bx, arg.layout.size, required_align); + op.val.store(bx, scratch.with_type(arg.layout)); + (scratch.llval, scratch.align, true) } PassMode::Cast { .. } => { let scratch = PlaceRef::alloca(bx, arg.layout); @@ -1475,10 +1475,9 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { // For `foo(packed.large_field)`, and types with <4 byte alignment on x86, // alignment requirements may be higher than the type's alignment, so copy // to a higher-aligned alloca. - let scratch = PlaceRef::alloca_aligned(bx, arg.layout, required_align); - let op_place = PlaceRef { val: op_place_val, layout: op.layout }; - bx.typed_place_copy(scratch, op_place); - (scratch.val.llval, scratch.val.align, true) + let scratch = PlaceValue::alloca(bx, arg.layout.size, required_align); + bx.typed_place_copy(scratch, op_place_val, op.layout); + (scratch.llval, scratch.align, true) } else { (op_place_val.llval, op_place_val.align, true) } @@ -1567,7 +1566,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { if place_val.llextra.is_some() { bug!("closure arguments must be sized"); } - let tuple_ptr = PlaceRef { val: place_val, layout: tuple.layout }; + let tuple_ptr = place_val.with_type(tuple.layout); for i in 0..tuple.layout.fields.count() { let field_ptr = tuple_ptr.project_field(bx, i); let field = bx.load_operand(field_ptr); diff --git a/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs b/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs index 2e008460798..f88deaa7abc 100644 --- a/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs +++ b/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs @@ -1,4 +1,4 @@ -use super::operand::{OperandRef, OperandValue}; +use super::operand::OperandRef; use super::place::PlaceRef; use super::FunctionCx; use crate::errors; @@ -93,9 +93,10 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { // into the (unoptimized) direct swapping implementation, so we disable it. || bx.sess().target.arch == "spirv" { - let x_place = PlaceRef::new_sized(args[0].immediate(), pointee_layout); - let y_place = PlaceRef::new_sized(args[1].immediate(), pointee_layout); - bx.typed_place_swap(x_place, y_place); + let align = pointee_layout.align.abi; + let x_place = args[0].val.deref(align); + let y_place = args[1].val.deref(align); + bx.typed_place_swap(x_place, y_place, pointee_layout); return Ok(()); } } @@ -113,15 +114,13 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { sym::va_end => bx.va_end(args[0].immediate()), sym::size_of_val => { let tp_ty = fn_args.type_at(0); - let meta = - if let OperandValue::Pair(_, meta) = args[0].val { Some(meta) } else { None }; + let (_, meta) = args[0].val.pointer_parts(); let (llsize, _) = size_of_val::size_and_align_of_dst(bx, tp_ty, meta); llsize } sym::min_align_of_val => { let tp_ty = fn_args.type_at(0); - let meta = - if let OperandValue::Pair(_, meta) = args[0].val { Some(meta) } else { None }; + let (_, meta) = args[0].val.pointer_parts(); let (_, llalign) = size_of_val::size_and_align_of_dst(bx, tp_ty, meta); llalign } diff --git a/compiler/rustc_codegen_ssa/src/mir/operand.rs b/compiler/rustc_codegen_ssa/src/mir/operand.rs index 0479dd11ed0..e1c584e8ed5 100644 --- a/compiler/rustc_codegen_ssa/src/mir/operand.rs +++ b/compiler/rustc_codegen_ssa/src/mir/operand.rs @@ -61,7 +61,7 @@ pub enum OperandValue<V> { ZeroSized, } -impl<V> OperandValue<V> { +impl<V: CodegenObject> OperandValue<V> { /// If this is ZeroSized/Immediate/Pair, return an array of the 0/1/2 values. /// If this is Ref, return the place. #[inline] @@ -86,6 +86,30 @@ impl<V> OperandValue<V> { }; OperandValue::Pair(a, b) } + + /// Treat this value as a pointer and return the data pointer and + /// optional metadata as backend values. + /// + /// If you're making a place, use [`Self::deref`] instead. + pub fn pointer_parts(self) -> (V, Option<V>) { + match self { + OperandValue::Immediate(llptr) => (llptr, None), + OperandValue::Pair(llptr, llextra) => (llptr, Some(llextra)), + _ => bug!("OperandValue cannot be a pointer: {self:?}"), + } + } + + /// Treat this value as a pointer and return the place to which it points. + /// + /// The pointer immediate doesn't inherently know its alignment, + /// so you need to pass it in. If you want to get it from a type's ABI + /// alignment, then maybe you want [`OperandRef::deref`] instead. + /// + /// This is the inverse of [`PlaceValue::address`]. + pub fn deref(self, align: Align) -> PlaceValue<V> { + let (llval, llextra) = self.pointer_parts(); + PlaceValue { llval, llextra, align } + } } /// An `OperandRef` is an "SSA" reference to a Rust value, along with @@ -235,6 +259,15 @@ impl<'a, 'tcx, V: CodegenObject> OperandRef<'tcx, V> { } } + /// Asserts that this operand is a pointer (or reference) and returns + /// the place to which it points. (This requires no code to be emitted + /// as we represent places using the pointer to the place.) + /// + /// This uses [`Ty::builtin_deref`] to include the type of the place and + /// assumes the place is aligned to the pointee's usual ABI alignment. + /// + /// If you don't need the type, see [`OperandValue::pointer_parts`] + /// or [`OperandValue::deref`]. pub fn deref<Cx: LayoutTypeMethods<'tcx>>(self, cx: &Cx) -> PlaceRef<'tcx, V> { if self.layout.ty.is_box() { // Derefer should have removed all Box derefs @@ -247,15 +280,8 @@ impl<'a, 'tcx, V: CodegenObject> OperandRef<'tcx, V> { .builtin_deref(true) .unwrap_or_else(|| bug!("deref of non-pointer {:?}", self)); - let (llptr, llextra) = match self.val { - OperandValue::Immediate(llptr) => (llptr, None), - OperandValue::Pair(llptr, llextra) => (llptr, Some(llextra)), - OperandValue::Ref(..) => bug!("Deref of by-Ref operand {:?}", self), - OperandValue::ZeroSized => bug!("Deref of ZST operand {:?}", self), - }; let layout = cx.layout_of(projected_ty); - let val = PlaceValue { llval: llptr, llextra, align: layout.align.abi }; - PlaceRef { val, layout } + self.val.deref(layout.align.abi).with_type(layout) } /// If this operand is a `Pair`, we return an aggregate with the two values. @@ -448,8 +474,7 @@ impl<'a, 'tcx, V: CodegenObject> OperandValue<V> { if val.llextra.is_some() { bug!("cannot directly store unsized values"); } - let source_place = PlaceRef { val, layout: dest.layout }; - bx.typed_place_copy_with_flags(dest, source_place, flags); + bx.typed_place_copy_with_flags(dest.val, val, dest.layout, flags); } OperandValue::Immediate(s) => { let val = bx.from_immediate(s); diff --git a/compiler/rustc_codegen_ssa/src/mir/place.rs b/compiler/rustc_codegen_ssa/src/mir/place.rs index 870a105c61d..971ac2defdc 100644 --- a/compiler/rustc_codegen_ssa/src/mir/place.rs +++ b/compiler/rustc_codegen_ssa/src/mir/place.rs @@ -10,12 +10,15 @@ use rustc_middle::mir; use rustc_middle::mir::tcx::PlaceTy; use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf, TyAndLayout}; use rustc_middle::ty::{self, Ty}; -use rustc_target::abi::{Align, FieldsShape, Int, Pointer, TagEncoding}; +use rustc_target::abi::{Align, FieldsShape, Int, Pointer, Size, TagEncoding}; use rustc_target::abi::{VariantIdx, Variants}; /// The location and extra runtime properties of the place. /// /// Typically found in a [`PlaceRef`] or an [`OperandValue::Ref`]. +/// +/// As a location in memory, this has no specific type. If you want to +/// load or store it using a typed operation, use [`Self::with_type`]. #[derive(Copy, Clone, Debug)] pub struct PlaceValue<V> { /// A pointer to the contents of the place. @@ -35,6 +38,41 @@ impl<V: CodegenObject> PlaceValue<V> { pub fn new_sized(llval: V, align: Align) -> PlaceValue<V> { PlaceValue { llval, llextra: None, align } } + + /// Allocates a stack slot in the function for a value + /// of the specified size and alignment. + /// + /// The allocation itself is untyped. + pub fn alloca<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx, Value = V>>( + bx: &mut Bx, + size: Size, + align: Align, + ) -> PlaceValue<V> { + let llval = bx.alloca(size, align); + PlaceValue::new_sized(llval, align) + } + + /// Creates a `PlaceRef` to this location with the given type. + pub fn with_type<'tcx>(self, layout: TyAndLayout<'tcx>) -> PlaceRef<'tcx, V> { + debug_assert!( + layout.is_unsized() || layout.abi.is_uninhabited() || self.llextra.is_none(), + "Had pointer metadata {:?} for sized type {layout:?}", + self.llextra, + ); + PlaceRef { val: self, layout } + } + + /// Gets the pointer to this place as an [`OperandValue::Immediate`] + /// or, for those needing metadata, an [`OperandValue::Pair`]. + /// + /// This is the inverse of [`OperandValue::deref`]. + pub fn address(self) -> OperandValue<V> { + if let Some(llextra) = self.llextra { + OperandValue::Pair(self.llval, llextra) + } else { + OperandValue::Immediate(self.llval) + } + } } #[derive(Copy, Clone, Debug)] @@ -52,9 +90,7 @@ pub struct PlaceRef<'tcx, V> { impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> { pub fn new_sized(llval: V, layout: TyAndLayout<'tcx>) -> PlaceRef<'tcx, V> { - assert!(layout.is_sized()); - let val = PlaceValue::new_sized(llval, layout.align.abi); - PlaceRef { val, layout } + PlaceRef::new_sized_aligned(llval, layout, layout.align.abi) } pub fn new_sized_aligned( @@ -63,8 +99,7 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> { align: Align, ) -> PlaceRef<'tcx, V> { assert!(layout.is_sized()); - let val = PlaceValue::new_sized(llval, align); - PlaceRef { val, layout } + PlaceValue::new_sized(llval, align).with_type(layout) } // FIXME(eddyb) pass something else for the name so no work is done @@ -73,17 +108,8 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> { bx: &mut Bx, layout: TyAndLayout<'tcx>, ) -> Self { - Self::alloca_aligned(bx, layout, layout.align.abi) - } - - pub fn alloca_aligned<Bx: BuilderMethods<'a, 'tcx, Value = V>>( - bx: &mut Bx, - layout: TyAndLayout<'tcx>, - align: Align, - ) -> Self { assert!(layout.is_sized(), "tried to statically allocate unsized place"); - let tmp = bx.alloca(layout.size, align); - Self::new_sized_aligned(tmp, layout, align) + PlaceValue::alloca(bx, layout.size, layout.align.abi).with_type(layout) } /// Returns a place for an indirect reference to an unsized place. @@ -132,18 +158,12 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> { } else { bx.inbounds_ptradd(self.val.llval, bx.const_usize(offset.bytes())) }; - PlaceRef { - val: PlaceValue { + let val = PlaceValue { llval, - llextra: if bx.cx().type_has_metadata(field.ty) { - self.val.llextra - } else { - None - }, + llextra: if bx.cx().type_has_metadata(field.ty) { self.val.llextra } else { None }, align: effective_field_align, - }, - layout: field, - } + }; + val.with_type(field) }; // Simple cases, which don't need DST adjustment: @@ -198,7 +218,7 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> { let ptr = bx.inbounds_ptradd(self.val.llval, offset); let val = PlaceValue { llval: ptr, llextra: self.val.llextra, align: effective_field_align }; - PlaceRef { val, layout: field } + val.with_type(field) } /// Obtain the actual discriminant of a value. @@ -387,18 +407,13 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> { layout.size }; - PlaceRef { - val: PlaceValue { - llval: bx.inbounds_gep( + let llval = bx.inbounds_gep( bx.cx().backend_type(self.layout), self.val.llval, &[bx.cx().const_usize(0), llindex], - ), - llextra: None, - align: self.val.align.restrict_for_offset(offset), - }, - layout, - } + ); + let align = self.val.align.restrict_for_offset(offset); + PlaceValue::new_sized(llval, align).with_type(layout) } pub fn project_downcast<Bx: BuilderMethods<'a, 'tcx, Value = V>>( diff --git a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs index 2976ca14c92..e47a8198736 100644 --- a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs +++ b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs @@ -74,8 +74,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { if val.llextra.is_some() { bug!("unsized coercion on an unsized rvalue"); } - let source = PlaceRef { val, layout: operand.layout }; - base::coerce_unsized_into(bx, source, dest); + base::coerce_unsized_into(bx, val.with_type(operand.layout), dest); } OperandValue::ZeroSized => { bug!("unsized coercion on a ZST rvalue"); @@ -184,10 +183,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { OperandValue::Immediate(..) | OperandValue::Pair(..) => { // When we have immediate(s), the alignment of the source is irrelevant, // so we can store them using the destination's alignment. - src.val.store( - bx, - PlaceRef::new_sized_aligned(dst.val.llval, src.layout, dst.val.align), - ); + src.val.store(bx, dst.val.with_type(src.layout)); } } } @@ -225,8 +221,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { OperandValue::Ref(source_place_val) => { debug_assert_eq!(source_place_val.llextra, None); debug_assert!(matches!(operand_kind, OperandValueKind::Ref)); - let fake_place = PlaceRef { val: source_place_val, layout: cast }; - Some(bx.load_operand(fake_place).val) + Some(bx.load_operand(source_place_val.with_type(cast)).val) } OperandValue::ZeroSized => { let OperandValueKind::ZeroSized = operand_kind else { @@ -452,23 +447,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { } mir::CastKind::PointerCoercion(PointerCoercion::Unsize) => { assert!(bx.cx().is_backend_scalar_pair(cast)); - let (lldata, llextra) = match operand.val { - OperandValue::Pair(lldata, llextra) => { - // unsize from a fat pointer -- this is a - // "trait-object-to-supertrait" coercion. - (lldata, Some(llextra)) - } - OperandValue::Immediate(lldata) => { - // "standard" unsize - (lldata, None) - } - OperandValue::Ref(..) => { - bug!("by-ref operand {:?} in `codegen_rvalue_operand`", operand); - } - OperandValue::ZeroSized => { - bug!("zero-sized operand {:?} in `codegen_rvalue_operand`", operand); - } - }; + let (lldata, llextra) = operand.val.pointer_parts(); let (lldata, llextra) = base::unsize_ptr(bx, lldata, operand.layout.ty, cast.ty, llextra); OperandValue::Pair(lldata, llextra) @@ -489,12 +468,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { } } mir::CastKind::DynStar => { - let (lldata, llextra) = match operand.val { - OperandValue::Ref(..) => todo!(), - OperandValue::Immediate(v) => (v, None), - OperandValue::Pair(v, l) => (v, Some(l)), - OperandValue::ZeroSized => bug!("ZST -- which is not PointerLike -- in DynStar"), - }; + let (lldata, llextra) = operand.val.pointer_parts(); let (lldata, llextra) = base::cast_to_dyn_star(bx, lldata, operand.layout, cast.ty, llextra); OperandValue::Pair(lldata, llextra) @@ -812,16 +786,18 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { mk_ptr_ty: impl FnOnce(TyCtxt<'tcx>, Ty<'tcx>) -> Ty<'tcx>, ) -> OperandRef<'tcx, Bx::Value> { let cg_place = self.codegen_place(bx, place.as_ref()); + let val = cg_place.val.address(); let ty = cg_place.layout.ty; - - // Note: places are indirect, so storing the `llval` into the - // destination effectively creates a reference. - let val = if !bx.cx().type_has_metadata(ty) { - OperandValue::Immediate(cg_place.val.llval) + debug_assert!( + if bx.cx().type_has_metadata(ty) { + matches!(val, OperandValue::Pair(..)) } else { - OperandValue::Pair(cg_place.val.llval, cg_place.val.llextra.unwrap()) - }; + matches!(val, OperandValue::Immediate(..)) + }, + "Address of place was unexpectedly {val:?} for pointee type {ty:?}", + ); + OperandRef { val, layout: self.cx.layout_of(mk_ptr_ty(self.cx.tcx(), ty)) } } |