From 0fde82fb97a23c84d95b48d8acad0e035ade0dcf Mon Sep 17 00:00:00 2001 From: Ralf Jung Date: Sat, 26 Aug 2023 08:34:56 +0200 Subject: [PATCH 1/4] codegen_llvm/llvm_type: avoid matching on the Rust type --- compiler/rustc_codegen_llvm/src/type_of.rs | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/compiler/rustc_codegen_llvm/src/type_of.rs b/compiler/rustc_codegen_llvm/src/type_of.rs index 2be7bce115dd8..c2645d680b395 100644 --- a/compiler/rustc_codegen_llvm/src/type_of.rs +++ b/compiler/rustc_codegen_llvm/src/type_of.rs @@ -3,7 +3,7 @@ use crate::context::TypeLowering; use crate::type_::Type; use rustc_codegen_ssa::traits::*; use rustc_middle::bug; -use rustc_middle::ty::layout::{FnAbiOf, LayoutOf, TyAndLayout}; +use rustc_middle::ty::layout::{LayoutOf, TyAndLayout}; use rustc_middle::ty::print::{with_no_trimmed_paths, with_no_visible_paths}; use rustc_middle::ty::{self, Ty, TypeVisitableExt}; use rustc_target::abi::HasDataLayout; @@ -215,20 +215,16 @@ impl<'tcx> LayoutLlvmExt<'tcx> for TyAndLayout<'tcx> { /// of that field's type - this is useful for taking the address of /// that field and ensuring the struct has the right alignment. fn llvm_type<'a>(&self, cx: &CodegenCx<'a, 'tcx>) -> &'a Type { + // This must produce the same result for `repr(transparent)` wrappers as for the inner type! + // In other words, this should generally not look at the type at all, but only at the + // layout. if let Abi::Scalar(scalar) = self.abi { // Use a different cache for scalars because pointers to DSTs // can be either fat or thin (data pointers of fat pointers). if let Some(&llty) = cx.scalar_lltypes.borrow().get(&self.ty) { return llty; } - let llty = match *self.ty.kind() { - ty::Ref(..) | ty::RawPtr(_) => cx.type_ptr(), - ty::Adt(def, _) if def.is_box() => cx.type_ptr(), - ty::FnPtr(sig) => { - cx.fn_ptr_backend_type(cx.fn_abi_of_fn_ptr(sig, ty::List::empty())) - } - _ => self.scalar_llvm_type_at(cx, scalar), - }; + let llty = self.scalar_llvm_type_at(cx, scalar); cx.scalar_lltypes.borrow_mut().insert(self.ty, llty); return llty; } From dc70fb65283622a256f9c122d64ed3936425b0b3 Mon Sep 17 00:00:00 2001 From: Ralf Jung Date: Mon, 28 Aug 2023 16:35:00 +0200 Subject: [PATCH 2/4] also avoid matching on the type in scalar_pair_element_llvm_type --- compiler/rustc_codegen_llvm/src/type_of.rs | 24 +++------------------- 1 file changed, 3 insertions(+), 21 deletions(-) diff --git a/compiler/rustc_codegen_llvm/src/type_of.rs b/compiler/rustc_codegen_llvm/src/type_of.rs index c2645d680b395..81cafdc98c45c 100644 --- a/compiler/rustc_codegen_llvm/src/type_of.rs +++ b/compiler/rustc_codegen_llvm/src/type_of.rs @@ -299,27 +299,9 @@ impl<'tcx> LayoutLlvmExt<'tcx> for TyAndLayout<'tcx> { index: usize, immediate: bool, ) -> &'a Type { - // HACK(eddyb) special-case fat pointers until LLVM removes - // pointee types, to avoid bitcasting every `OperandRef::deref`. - match *self.ty.kind() { - ty::Ref(..) | ty::RawPtr(_) => { - return self.field(cx, index).llvm_type(cx); - } - // only wide pointer boxes are handled as pointers - // thin pointer boxes with scalar allocators are handled by the general logic below - ty::Adt(def, args) if def.is_box() && cx.layout_of(args.type_at(1)).is_zst() => { - let ptr_ty = Ty::new_mut_ptr(cx.tcx, self.ty.boxed_ty()); - return cx.layout_of(ptr_ty).scalar_pair_element_llvm_type(cx, index, immediate); - } - // `dyn* Trait` has the same ABI as `*mut dyn Trait` - ty::Dynamic(bounds, region, ty::DynStar) => { - let ptr_ty = - Ty::new_mut_ptr(cx.tcx, Ty::new_dynamic(cx.tcx, bounds, region, ty::Dyn)); - return cx.layout_of(ptr_ty).scalar_pair_element_llvm_type(cx, index, immediate); - } - _ => {} - } - + // This must produce the same result for `repr(transparent)` wrappers as for the inner type! + // In other words, this should generally not look at the type at all, but only at the + // layout. let Abi::ScalarPair(a, b) = self.abi else { bug!("TyAndLayout::scalar_pair_element_llty({:?}): not applicable", self); }; From 99d76a4027fd296118b0e3b55cd4c05a34cf9c08 Mon Sep 17 00:00:00 2001 From: Ralf Jung Date: Mon, 28 Aug 2023 16:35:22 +0200 Subject: [PATCH 3/4] carry out the same changes in the gcc backend --- compiler/rustc_codegen_gcc/src/type_of.rs | 34 +++++------------------ 1 file changed, 7 insertions(+), 27 deletions(-) diff --git a/compiler/rustc_codegen_gcc/src/type_of.rs b/compiler/rustc_codegen_gcc/src/type_of.rs index 84d5783851273..bb5f561ebc367 100644 --- a/compiler/rustc_codegen_gcc/src/type_of.rs +++ b/compiler/rustc_codegen_gcc/src/type_of.rs @@ -182,23 +182,16 @@ impl<'tcx> LayoutGccExt<'tcx> for TyAndLayout<'tcx> { /// of that field's type - this is useful for taking the address of /// that field and ensuring the struct has the right alignment. fn gcc_type<'gcc>(&self, cx: &CodegenCx<'gcc, 'tcx>) -> Type<'gcc> { + // This must produce the same result for `repr(transparent)` wrappers as for the inner type! + // In other words, this should generally not look at the type at all, but only at the + // layout. if let Abi::Scalar(ref scalar) = self.abi { // Use a different cache for scalars because pointers to DSTs // can be either fat or thin (data pointers of fat pointers). if let Some(&ty) = cx.scalar_types.borrow().get(&self.ty) { return ty; } - let ty = - match *self.ty.kind() { - ty::Ref(_, ty, _) | ty::RawPtr(ty::TypeAndMut { ty, .. }) => { - cx.type_ptr_to(cx.layout_of(ty).gcc_type(cx)) - } - ty::Adt(def, _) if def.is_box() => { - cx.type_ptr_to(cx.layout_of(self.ty.boxed_ty()).gcc_type(cx)) - } - ty::FnPtr(sig) => cx.fn_ptr_backend_type(&cx.fn_abi_of_fn_ptr(sig, ty::List::empty())), - _ => self.scalar_gcc_type_at(cx, scalar, Size::ZERO), - }; + let ty = self.scalar_gcc_type_at(cx, scalar, Size::ZERO); cx.scalar_types.borrow_mut().insert(self.ty, ty); return ty; } @@ -273,22 +266,9 @@ impl<'tcx> LayoutGccExt<'tcx> for TyAndLayout<'tcx> { } fn scalar_pair_element_gcc_type<'gcc>(&self, cx: &CodegenCx<'gcc, 'tcx>, index: usize, immediate: bool) -> Type<'gcc> { - // TODO(antoyo): remove llvm hack: - // HACK(eddyb) special-case fat pointers until LLVM removes - // pointee types, to avoid bitcasting every `OperandRef::deref`. - match self.ty.kind() { - ty::Ref(..) | ty::RawPtr(_) => { - return self.field(cx, index).gcc_type(cx); - } - // only wide pointer boxes are handled as pointers - // thin pointer boxes with scalar allocators are handled by the general logic below - ty::Adt(def, args) if def.is_box() && cx.layout_of(args.type_at(1)).is_zst() => { - let ptr_ty = Ty::new_mut_ptr(cx.tcx,self.ty.boxed_ty()); - return cx.layout_of(ptr_ty).scalar_pair_element_gcc_type(cx, index, immediate); - } - _ => {} - } - + // This must produce the same result for `repr(transparent)` wrappers as for the inner type! + // In other words, this should generally not look at the type at all, but only at the + // layout. let (a, b) = match self.abi { Abi::ScalarPair(ref a, ref b) => (a, b), _ => bug!("TyAndLayout::scalar_pair_element_llty({:?}): not applicable", self), From 9b9cb51a407e46e555afa1c2ec80ced185ad5395 Mon Sep 17 00:00:00 2001 From: Ralf Jung Date: Mon, 28 Aug 2023 18:21:16 +0200 Subject: [PATCH 4/4] remove an unused argument it was already unused before, but due to the recursion the compiler did not realize --- compiler/rustc_codegen_gcc/src/abi.rs | 4 ++-- compiler/rustc_codegen_gcc/src/builder.rs | 2 +- compiler/rustc_codegen_gcc/src/type_of.rs | 14 +++++++------- 3 files changed, 10 insertions(+), 10 deletions(-) diff --git a/compiler/rustc_codegen_gcc/src/abi.rs b/compiler/rustc_codegen_gcc/src/abi.rs index 6fb1cbfad8cd3..377dc753f688a 100644 --- a/compiler/rustc_codegen_gcc/src/abi.rs +++ b/compiler/rustc_codegen_gcc/src/abi.rs @@ -125,8 +125,8 @@ impl<'gcc, 'tcx> FnAbiGccExt<'gcc, 'tcx> for FnAbi<'tcx, Ty<'tcx>> { PassMode::Ignore => continue, PassMode::Direct(_) => arg.layout.immediate_gcc_type(cx), PassMode::Pair(..) => { - argument_tys.push(arg.layout.scalar_pair_element_gcc_type(cx, 0, true)); - argument_tys.push(arg.layout.scalar_pair_element_gcc_type(cx, 1, true)); + argument_tys.push(arg.layout.scalar_pair_element_gcc_type(cx, 0)); + argument_tys.push(arg.layout.scalar_pair_element_gcc_type(cx, 1)); continue; } PassMode::Indirect { extra_attrs: Some(_), .. } => { diff --git a/compiler/rustc_codegen_gcc/src/builder.rs b/compiler/rustc_codegen_gcc/src/builder.rs index 0b1f2fe6a87d9..308cb04cac3d5 100644 --- a/compiler/rustc_codegen_gcc/src/builder.rs +++ b/compiler/rustc_codegen_gcc/src/builder.rs @@ -821,7 +821,7 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> { let mut load = |i, scalar: &abi::Scalar, align| { let llptr = self.struct_gep(pair_type, place.llval, i as u64); - let llty = place.layout.scalar_pair_element_gcc_type(self, i, false); + let llty = place.layout.scalar_pair_element_gcc_type(self, i); let load = self.load(llty, llptr, align); scalar_load_metadata(self, load, scalar); if scalar.is_bool() { self.trunc(load, self.type_i1()) } else { load } diff --git a/compiler/rustc_codegen_gcc/src/type_of.rs b/compiler/rustc_codegen_gcc/src/type_of.rs index bb5f561ebc367..cc467801bebad 100644 --- a/compiler/rustc_codegen_gcc/src/type_of.rs +++ b/compiler/rustc_codegen_gcc/src/type_of.rs @@ -4,7 +4,7 @@ use gccjit::{Struct, Type}; use crate::rustc_codegen_ssa::traits::{BaseTypeMethods, DerivedTypeMethods, LayoutTypeMethods}; use rustc_middle::bug; use rustc_middle::ty::{self, Ty, TypeVisitableExt}; -use rustc_middle::ty::layout::{FnAbiOf, LayoutOf, TyAndLayout}; +use rustc_middle::ty::layout::{LayoutOf, TyAndLayout}; use rustc_middle::ty::print::with_no_trimmed_paths; use rustc_target::abi::{self, Abi, Align, F32, F64, FieldsShape, Int, Integer, Pointer, PointeeInfo, Size, TyAbiInterface, Variants}; use rustc_target::abi::call::{CastTarget, FnAbi, Reg}; @@ -74,8 +74,8 @@ fn uncached_gcc_type<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, layout: TyAndLayout Abi::ScalarPair(..) => { return cx.type_struct( &[ - layout.scalar_pair_element_gcc_type(cx, 0, false), - layout.scalar_pair_element_gcc_type(cx, 1, false), + layout.scalar_pair_element_gcc_type(cx, 0), + layout.scalar_pair_element_gcc_type(cx, 1), ], false, ); @@ -150,7 +150,7 @@ pub trait LayoutGccExt<'tcx> { fn gcc_type<'gcc>(&self, cx: &CodegenCx<'gcc, 'tcx>) -> Type<'gcc>; fn immediate_gcc_type<'gcc>(&self, cx: &CodegenCx<'gcc, 'tcx>) -> Type<'gcc>; fn scalar_gcc_type_at<'gcc>(&self, cx: &CodegenCx<'gcc, 'tcx>, scalar: &abi::Scalar, offset: Size) -> Type<'gcc>; - fn scalar_pair_element_gcc_type<'gcc>(&self, cx: &CodegenCx<'gcc, 'tcx>, index: usize, immediate: bool) -> Type<'gcc>; + fn scalar_pair_element_gcc_type<'gcc>(&self, cx: &CodegenCx<'gcc, 'tcx>, index: usize) -> Type<'gcc>; fn gcc_field_index(&self, index: usize) -> u64; fn pointee_info_at<'gcc>(&self, cx: &CodegenCx<'gcc, 'tcx>, offset: Size) -> Option; } @@ -265,7 +265,7 @@ impl<'tcx> LayoutGccExt<'tcx> for TyAndLayout<'tcx> { } } - fn scalar_pair_element_gcc_type<'gcc>(&self, cx: &CodegenCx<'gcc, 'tcx>, index: usize, immediate: bool) -> Type<'gcc> { + fn scalar_pair_element_gcc_type<'gcc>(&self, cx: &CodegenCx<'gcc, 'tcx>, index: usize) -> Type<'gcc> { // This must produce the same result for `repr(transparent)` wrappers as for the inner type! // In other words, this should generally not look at the type at all, but only at the // layout. @@ -347,8 +347,8 @@ impl<'gcc, 'tcx> LayoutTypeMethods<'tcx> for CodegenCx<'gcc, 'tcx> { layout.gcc_field_index(index) } - fn scalar_pair_element_backend_type(&self, layout: TyAndLayout<'tcx>, index: usize, immediate: bool) -> Type<'gcc> { - layout.scalar_pair_element_gcc_type(self, index, immediate) + fn scalar_pair_element_backend_type(&self, layout: TyAndLayout<'tcx>, index: usize, _immediate: bool) -> Type<'gcc> { + layout.scalar_pair_element_gcc_type(self, index) } fn cast_backend_type(&self, ty: &CastTarget) -> Type<'gcc> {