From 6f9cfd694d67ad24af6c7e2235a2da5d22918df0 Mon Sep 17 00:00:00 2001 From: Scott McMurray Date: Sat, 15 Feb 2025 16:07:18 -0800 Subject: [PATCH] Rework `OperandRef::extract_field` to stop calling `to_immediate_scalar` on things which are already immediates That means it stops trying to truncate things that are already `i1`s. --- compiler/rustc_codegen_gcc/src/builder.rs | 12 +- .../rustc_codegen_gcc/src/intrinsic/mod.rs | 11 +- compiler/rustc_codegen_llvm/src/builder.rs | 10 +- compiler/rustc_codegen_ssa/src/mir/block.rs | 10 +- compiler/rustc_codegen_ssa/src/mir/operand.rs | 131 +++++++++--------- compiler/rustc_codegen_ssa/src/mir/rvalue.rs | 4 +- .../rustc_codegen_ssa/src/traits/builder.rs | 9 +- .../simd/project-to-simd-array-field.rs | 31 +++++ tests/crashes/project-to-simd-array-field.rs | 33 +++++ 9 files changed, 164 insertions(+), 87 deletions(-) create mode 100644 tests/codegen/simd/project-to-simd-array-field.rs create mode 100644 tests/crashes/project-to-simd-array-field.rs diff --git a/compiler/rustc_codegen_gcc/src/builder.rs b/compiler/rustc_codegen_gcc/src/builder.rs index 76846692459d5..c8b7616e64509 100644 --- a/compiler/rustc_codegen_gcc/src/builder.rs +++ b/compiler/rustc_codegen_gcc/src/builder.rs @@ -989,10 +989,14 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> { OperandValue::Ref(place.val) } else if place.layout.is_gcc_immediate() { let load = self.load(place.layout.gcc_type(self), place.val.llval, place.val.align); - if let abi::BackendRepr::Scalar(ref scalar) = place.layout.backend_repr { - scalar_load_metadata(self, load, scalar); - } - OperandValue::Immediate(self.to_immediate(load, place.layout)) + OperandValue::Immediate( + if let abi::BackendRepr::Scalar(ref scalar) = place.layout.backend_repr { + scalar_load_metadata(self, load, scalar); + self.to_immediate_scalar(load, *scalar) + } else { + load + }, + ) } else if let abi::BackendRepr::ScalarPair(ref a, ref b) = place.layout.backend_repr { let b_offset = a.size(self).align_to(b.align(self).abi); diff --git a/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs b/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs index a1123fafe2f30..5322b731d8bb5 100644 --- a/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs +++ b/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs @@ -9,7 +9,7 @@ use gccjit::FunctionType; use gccjit::{ComparisonOp, Function, RValue, ToRValue, Type, UnaryOp}; #[cfg(feature = "master")] use rustc_abi::ExternAbi; -use rustc_abi::HasDataLayout; +use rustc_abi::{BackendRepr, HasDataLayout}; use rustc_codegen_ssa::MemFlags; use rustc_codegen_ssa::base::wants_msvc_seh; use rustc_codegen_ssa::common::IntPredicate; @@ -181,14 +181,19 @@ impl<'a, 'gcc, 'tcx> IntrinsicCallBuilderMethods<'tcx> for Builder<'a, 'gcc, 'tc sym::volatile_load | sym::unaligned_volatile_load => { let tp_ty = fn_args.type_at(0); let ptr = args[0].immediate(); + let layout = self.layout_of(tp_ty); let load = if let PassMode::Cast { cast: ref ty, pad_i32: _ } = fn_abi.ret.mode { let gcc_ty = ty.gcc_type(self); self.volatile_load(gcc_ty, ptr) } else { - self.volatile_load(self.layout_of(tp_ty).gcc_type(self), ptr) + self.volatile_load(layout.gcc_type(self), ptr) }; // TODO(antoyo): set alignment. - self.to_immediate(load, self.layout_of(tp_ty)) + if let BackendRepr::Scalar(scalar) = layout.backend_repr { + self.to_immediate_scalar(load, scalar) + } else { + load + } } sym::volatile_store => { let dst = args[0].deref(self.cx()); diff --git a/compiler/rustc_codegen_llvm/src/builder.rs b/compiler/rustc_codegen_llvm/src/builder.rs index 5d1a133e80821..e1609e31c0707 100644 --- a/compiler/rustc_codegen_llvm/src/builder.rs +++ b/compiler/rustc_codegen_llvm/src/builder.rs @@ -746,10 +746,12 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> { let load = self.load(llty, place.val.llval, place.val.align); if let abi::BackendRepr::Scalar(scalar) = place.layout.backend_repr { scalar_load_metadata(self, load, scalar, place.layout, Size::ZERO); + self.to_immediate_scalar(load, scalar) + } else { + load } - load }); - OperandValue::Immediate(self.to_immediate(llval, place.layout)) + OperandValue::Immediate(llval) } else if let abi::BackendRepr::ScalarPair(a, b) = place.layout.backend_repr { let b_offset = a.size(self).align_to(b.align(self).abi); @@ -943,6 +945,8 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> { } fn unchecked_utrunc(&mut self, val: &'ll Value, dest_ty: &'ll Type) -> &'ll Value { + debug_assert_ne!(self.val_ty(val), dest_ty); + let trunc = self.trunc(val, dest_ty); if llvm_util::get_version() >= (19, 0, 0) { unsafe { @@ -955,6 +959,8 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> { } fn unchecked_strunc(&mut self, val: &'ll Value, dest_ty: &'ll Type) -> &'ll Value { + debug_assert_ne!(self.val_ty(val), dest_ty); + let trunc = self.trunc(val, dest_ty); if llvm_util::get_version() >= (19, 0, 0) { unsafe { diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs index 616d748a2995a..0620f08fc731b 100644 --- a/compiler/rustc_codegen_ssa/src/mir/block.rs +++ b/compiler/rustc_codegen_ssa/src/mir/block.rs @@ -1040,7 +1040,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { let (idx, _) = op.layout.non_1zst_field(bx).expect( "not exactly one non-1-ZST field in a `DispatchFromDyn` type", ); - op = op.extract_field(bx, idx); + op = op.extract_field(self, bx, idx); } // Now that we have `*dyn Trait` or `&dyn Trait`, split it up into its @@ -1072,7 +1072,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { let (idx, _) = op.layout.non_1zst_field(bx).expect( "not exactly one non-1-ZST field in a `DispatchFromDyn` type", ); - op = op.extract_field(bx, idx); + op = op.extract_field(self, bx, idx); } // Make sure that we've actually unwrapped the rcvr down @@ -1572,9 +1572,9 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { if scalar.is_bool() { bx.range_metadata(llval, WrappingRange { start: 0, end: 1 }); } + // We store bools as `i8` so we need to truncate to `i1`. + llval = bx.to_immediate_scalar(llval, scalar); } - // We store bools as `i8` so we need to truncate to `i1`. - llval = bx.to_immediate(llval, arg.layout); } } @@ -1604,7 +1604,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { } else { // If the tuple is immediate, the elements are as well. for i in 0..tuple.layout.fields.count() { - let op = tuple.extract_field(bx, i); + let op = tuple.extract_field(self, bx, i); self.codegen_argument(bx, op, llargs, &args[i]); } } diff --git a/compiler/rustc_codegen_ssa/src/mir/operand.rs b/compiler/rustc_codegen_ssa/src/mir/operand.rs index 9ca7d4f8f0047..958a52a2cb1dc 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>( &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 => - { - assert_eq!(offset.bytes(), 0); - self.val + let val = if field.is_zst() { + OperandValue::ZeroSized + } else if field.size == self.layout.size { + assert_eq!(offset.bytes(), 0); + if let Some(field_val) = fx.codegen_transmute_operand(bx, *self, field) { + field_val + } else { + // we have to go through memory for things like + // 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)); + bx.load_operand(place).val } - - // 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) + } 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))) - } + // `#[repr(simd)]` types are also immediate. + (OperandValue::Immediate(llval), BackendRepr::Vector { .. }) => { + (None, 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::Memory { sized: true } => { + span_bug!( + fx.mir.span, + "Projecting into a simd type with padding doesn't work; \ + See ", + ); + } + BackendRepr::Uninhabited + | BackendRepr::ScalarPair(_, _) + | BackendRepr::Memory { sized: false } => 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 } } } @@ -587,7 +590,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { "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 { .. } => { diff --git a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs index 4c5b183cfe92a..daa4fa90ed704 100644 --- a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs +++ b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs @@ -231,7 +231,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { /// /// Returns `None` for cases that can't work in that framework, such as for /// `Immediate`->`Ref` that needs an `alloc` to get the location. - fn codegen_transmute_operand( + pub(crate) fn codegen_transmute_operand( &mut self, bx: &mut Bx, operand: OperandRef<'tcx, Bx::Value>, @@ -260,6 +260,8 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { OperandValue::Ref(source_place_val) => { assert_eq!(source_place_val.llextra, None); assert_matches!(operand_kind, OperandValueKind::Ref); + // The existing alignment is part of `source_place_val`, + // so that alignment will be used, not `cast`'s. Some(bx.load_operand(source_place_val.with_type(cast)).val) } OperandValue::ZeroSized => { diff --git a/compiler/rustc_codegen_ssa/src/traits/builder.rs b/compiler/rustc_codegen_ssa/src/traits/builder.rs index 345db31302265..2b00ba01946e5 100644 --- a/compiler/rustc_codegen_ssa/src/traits/builder.rs +++ b/compiler/rustc_codegen_ssa/src/traits/builder.rs @@ -1,7 +1,7 @@ use std::assert_matches::assert_matches; use std::ops::Deref; -use rustc_abi::{Align, BackendRepr, Scalar, Size, WrappingRange}; +use rustc_abi::{Align, Scalar, Size, WrappingRange}; use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrs; use rustc_middle::ty::layout::{FnAbiOf, LayoutOf, TyAndLayout}; use rustc_middle::ty::{Instance, Ty}; @@ -223,13 +223,6 @@ pub trait BuilderMethods<'a, 'tcx>: ) -> (Self::Value, Self::Value); fn from_immediate(&mut self, val: Self::Value) -> Self::Value; - fn to_immediate(&mut self, val: Self::Value, layout: TyAndLayout<'_>) -> Self::Value { - if let BackendRepr::Scalar(scalar) = layout.backend_repr { - self.to_immediate_scalar(val, scalar) - } else { - val - } - } fn to_immediate_scalar(&mut self, val: Self::Value, scalar: Scalar) -> Self::Value; fn alloca(&mut self, size: Size, align: Align) -> Self::Value; diff --git a/tests/codegen/simd/project-to-simd-array-field.rs b/tests/codegen/simd/project-to-simd-array-field.rs new file mode 100644 index 0000000000000..29fab64063363 --- /dev/null +++ b/tests/codegen/simd/project-to-simd-array-field.rs @@ -0,0 +1,31 @@ +//@compile-flags: -Copt-level=3 + +#![crate_type = "lib"] +#![feature(repr_simd, core_intrinsics)] + +#[allow(non_camel_case_types)] +#[derive(Clone, Copy)] +#[repr(simd)] +struct i32x4([i32; 4]); + +#[inline(always)] +fn to_array4(a: i32x4) -> [i32; 4] { + a.0 +} + +// CHECK-LABEL: simd_add_self_then_return_array( +// CHECK-SAME: ptr{{.+}}sret{{.+}}%[[RET:.+]], +// CHECK-SAME: ptr{{.+}}%a) +#[no_mangle] +pub fn simd_add_self_then_return_array(a: &i32x4) -> [i32; 4] { + // It would be nice to just ban `.0` into simd types, + // but until we do this has to keep working. + // See also + + // CHECK: %[[T1:.+]] = load <4 x i32>, ptr %a + // CHECK: %[[T2:.+]] = shl <4 x i32> %[[T1]], {{splat \(i32 1\)|}} + // CHECK: store <4 x i32> %[[T2]], ptr %[[RET]] + let a = *a; + let b = unsafe { core::intrinsics::simd::simd_add(a, a) }; + to_array4(b) +} diff --git a/tests/crashes/project-to-simd-array-field.rs b/tests/crashes/project-to-simd-array-field.rs new file mode 100644 index 0000000000000..6dc916c41dbd5 --- /dev/null +++ b/tests/crashes/project-to-simd-array-field.rs @@ -0,0 +1,33 @@ +//@ known-bug: #137108 +//@compile-flags: -Copt-level=3 + +// If you fix this, put it in the corresponding codegen test, +// not in a UI test like the readme says. + +#![crate_type = "lib"] + +#![feature(repr_simd, core_intrinsics)] + +#[allow(non_camel_case_types)] +#[derive(Clone, Copy)] +#[repr(simd)] +struct i32x3([i32; 3]); + +const _: () = { assert!(size_of::() == 16) }; + +#[inline(always)] +fn to_array3(a: i32x3) -> [i32; 3] { + a.0 +} + +// CHECK-LABEL: simd_add_self_then_return_array_packed( +// CHECK-SAME: ptr{{.+}}sret{{.+}}%[[RET:.+]], +// CHECK-SAME: ptr{{.+}}%a) +#[no_mangle] +pub fn simd_add_self_then_return_array_packed(a: i32x3) -> [i32; 3] { + // CHECK: %[[T1:.+]] = load <3 x i32>, ptr %a + // CHECK: %[[T2:.+]] = shl <3 x i32> %[[T1]], + // CHECK: store <3 x i32> %[[T2]], ptr %[[RET]] + let b = unsafe { core::intrinsics::simd::simd_add(a, a) }; + to_array3(b) +}