diff options
Diffstat (limited to 'compiler/rustc_codegen_ssa/src/mir/operand.rs')
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/mir/operand.rs | 131 |
1 files changed, 67 insertions, 64 deletions
diff --git a/compiler/rustc_codegen_ssa/src/mir/operand.rs b/compiler/rustc_codegen_ssa/src/mir/operand.rs index 9ca7d4f8f00..461cf1b8acd 100644 --- a/compiler/rustc_codegen_ssa/src/mir/operand.rs +++ b/compiler/rustc_codegen_ssa/src/mir/operand.rs @@ -1,15 +1,14 @@ -use std::assert_matches::assert_matches; use std::fmt; use arrayvec::ArrayVec; use either::Either; use rustc_abi as abi; use rustc_abi::{Align, BackendRepr, Size}; -use rustc_middle::bug; use rustc_middle::mir::interpret::{Pointer, Scalar, alloc_range}; use rustc_middle::mir::{self, ConstValue}; use rustc_middle::ty::Ty; use rustc_middle::ty::layout::{LayoutOf, TyAndLayout}; +use rustc_middle::{bug, span_bug}; use tracing::debug; use super::place::{PlaceRef, PlaceValue}; @@ -352,79 +351,83 @@ impl<'a, 'tcx, V: CodegenObject> OperandRef<'tcx, V> { pub(crate) fn extract_field<Bx: BuilderMethods<'a, 'tcx, Value = V>>( &self, + fx: &mut FunctionCx<'a, 'tcx, Bx>, bx: &mut Bx, i: usize, ) -> Self { let field = self.layout.field(bx.cx(), i); let offset = self.layout.fields.offset(i); - let mut val = match (self.val, self.layout.backend_repr) { - // If the field is ZST, it has no data. - _ if field.is_zst() => OperandValue::ZeroSized, - - // Newtype of a scalar, scalar pair or vector. - (OperandValue::Immediate(_) | OperandValue::Pair(..), _) - if field.size == self.layout.size => + if !bx.is_backend_ref(self.layout) && bx.is_backend_ref(field) { + if let BackendRepr::Vector { count, .. } = self.layout.backend_repr + && let BackendRepr::Memory { sized: true } = field.backend_repr + && count.is_power_of_two() { - assert_eq!(offset.bytes(), 0); - self.val + assert_eq!(field.size, self.layout.size); + // This is being deprecated, but for now stdarch still needs it for + // Newtype vector of array, e.g. #[repr(simd)] struct S([i32; 4]); + let place = PlaceRef::alloca(bx, field); + self.val.store(bx, place.val.with_type(self.layout)); + return bx.load_operand(place); + } else { + // Part of https://github.com/rust-lang/compiler-team/issues/838 + bug!("Non-ref type {self:?} cannot project to ref field type {field:?}"); } + } - // Extract a scalar component from a pair. - (OperandValue::Pair(a_llval, b_llval), BackendRepr::ScalarPair(a, b)) => { - if offset.bytes() == 0 { - assert_eq!(field.size, a.size(bx.cx())); - OperandValue::Immediate(a_llval) - } else { - assert_eq!(offset, a.size(bx.cx()).align_to(b.align(bx.cx()).abi)); - assert_eq!(field.size, b.size(bx.cx())); - OperandValue::Immediate(b_llval) + let val = if field.is_zst() { + OperandValue::ZeroSized + } else if field.size == self.layout.size { + assert_eq!(offset.bytes(), 0); + fx.codegen_transmute_operand(bx, *self, field).unwrap_or_else(|| { + bug!( + "Expected `codegen_transmute_operand` to handle equal-size \ + field {i:?} projection from {self:?} to {field:?}" + ) + }) + } else { + let (in_scalar, imm) = match (self.val, self.layout.backend_repr) { + // Extract a scalar component from a pair. + (OperandValue::Pair(a_llval, b_llval), BackendRepr::ScalarPair(a, b)) => { + if offset.bytes() == 0 { + assert_eq!(field.size, a.size(bx.cx())); + (Some(a), a_llval) + } else { + assert_eq!(offset, a.size(bx.cx()).align_to(b.align(bx.cx()).abi)); + assert_eq!(field.size, b.size(bx.cx())); + (Some(b), b_llval) + } } - } - - // `#[repr(simd)]` types are also immediate. - (OperandValue::Immediate(llval), BackendRepr::Vector { .. }) => { - OperandValue::Immediate(bx.extract_element(llval, bx.cx().const_usize(i as u64))) - } - _ => bug!("OperandRef::extract_field({:?}): not applicable", self), + _ => { + span_bug!(fx.mir.span, "OperandRef::extract_field({:?}): not applicable", self) + } + }; + OperandValue::Immediate(match field.backend_repr { + BackendRepr::Vector { .. } => imm, + BackendRepr::Scalar(out_scalar) => { + let Some(in_scalar) = in_scalar else { + span_bug!( + fx.mir.span, + "OperandRef::extract_field({:?}): missing input scalar for output scalar", + self + ) + }; + if in_scalar != out_scalar { + // If the backend and backend_immediate types might differ, + // flip back to the backend type then to the new immediate. + // This avoids nop truncations, but still handles things like + // Bools in union fields needs to be truncated. + let backend = bx.from_immediate(imm); + bx.to_immediate_scalar(backend, out_scalar) + } else { + imm + } + } + BackendRepr::ScalarPair(_, _) | BackendRepr::Memory { .. } => bug!(), + }) }; - match (&mut val, field.backend_repr) { - (OperandValue::ZeroSized, _) => {} - ( - OperandValue::Immediate(llval), - BackendRepr::Scalar(_) | BackendRepr::ScalarPair(..) | BackendRepr::Vector { .. }, - ) => { - // Bools in union fields needs to be truncated. - *llval = bx.to_immediate(*llval, field); - } - (OperandValue::Pair(a, b), BackendRepr::ScalarPair(a_abi, b_abi)) => { - // Bools in union fields needs to be truncated. - *a = bx.to_immediate_scalar(*a, a_abi); - *b = bx.to_immediate_scalar(*b, b_abi); - } - // Newtype vector of array, e.g. #[repr(simd)] struct S([i32; 4]); - (OperandValue::Immediate(llval), BackendRepr::Memory { sized: true }) => { - assert_matches!(self.layout.backend_repr, BackendRepr::Vector { .. }); - - let llfield_ty = bx.cx().backend_type(field); - - // Can't bitcast an aggregate, so round trip through memory. - let llptr = bx.alloca(field.size, field.align.abi); - bx.store(*llval, llptr, field.align.abi); - *llval = bx.load(llfield_ty, llptr, field.align.abi); - } - ( - OperandValue::Immediate(_), - BackendRepr::Uninhabited | BackendRepr::Memory { sized: false }, - ) => { - bug!() - } - (OperandValue::Pair(..), _) => bug!(), - (OperandValue::Ref(..), _) => bug!(), - } - OperandRef { val, layout: field } } } @@ -581,13 +584,13 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { // Moves out of scalar and scalar pair fields are trivial. for elem in place_ref.projection.iter() { match elem { - mir::ProjectionElem::Field(ref f, _) => { + mir::ProjectionElem::Field(f, _) => { assert!( !o.layout.ty.is_any_ptr(), "Bad PlaceRef: destructing pointers should use cast/PtrMetadata, \ but tried to access field {f:?} of pointer {o:?}", ); - o = o.extract_field(bx, f.index()); + o = o.extract_field(self, bx, f.index()); } mir::ProjectionElem::Index(_) | mir::ProjectionElem::ConstantIndex { .. } => { |