Auto merge of rust-lang#121728 - tgross35:f16-f128-step1-ty-updates, r=compiler-errors

Add stubs in IR and ABI for `f16` and `f128`

This is the very first step toward the changes in rust-lang#114607 and the [`f16` and `f128` RFC](https://rust-lang.github.io/rfcs/3453-f16-and-f128.html). It adds the types to `rustc_type_ir::FloatTy` and `rustc_abi::Primitive`, and just propagates those out as `unimplemented!` stubs where necessary.

These types do not parse yet so there is no feature gate, and it should be okay to use `unimplemented!`.

The next steps will probably be AST support with parsing and the feature gate.

r? `@compiler-errors`
cc `@Nilstrieb` suggested breaking the PR up in rust-lang#120645 (comment)

Author: bors

compiler/rustc_abi/src/lib.rs

@@ -171,8 +171,10 @@ pub struct TargetDataLayout {
     pub i32_align: AbiAndPrefAlign,
     pub i64_align: AbiAndPrefAlign,
     pub i128_align: AbiAndPrefAlign,
+    pub f16_align: AbiAndPrefAlign,
     pub f32_align: AbiAndPrefAlign,
     pub f64_align: AbiAndPrefAlign,
+    pub f128_align: AbiAndPrefAlign,
     pub pointer_size: Size,
     pub pointer_align: AbiAndPrefAlign,
     pub aggregate_align: AbiAndPrefAlign,
@@ -200,8 +202,10 @@ impl Default for TargetDataLayout {
             i32_align: AbiAndPrefAlign::new(align(32)),
             i64_align: AbiAndPrefAlign { abi: align(32), pref: align(64) },
             i128_align: AbiAndPrefAlign { abi: align(32), pref: align(64) },
+            f16_align: AbiAndPrefAlign::new(align(16)),
             f32_align: AbiAndPrefAlign::new(align(32)),
             f64_align: AbiAndPrefAlign::new(align(64)),
+            f128_align: AbiAndPrefAlign::new(align(128)),
             pointer_size: Size::from_bits(64),
             pointer_align: AbiAndPrefAlign::new(align(64)),
             aggregate_align: AbiAndPrefAlign { abi: align(0), pref: align(64) },
@@ -281,8 +285,10 @@ impl TargetDataLayout {
                     dl.instruction_address_space = parse_address_space(&p[1..], "P")?
                 }
                 ["a", ref a @ ..] => dl.aggregate_align = parse_align(a, "a")?,
+                ["f16", ref a @ ..] => dl.f16_align = parse_align(a, "f16")?,
                 ["f32", ref a @ ..] => dl.f32_align = parse_align(a, "f32")?,
                 ["f64", ref a @ ..] => dl.f64_align = parse_align(a, "f64")?,
+                ["f128", ref a @ ..] => dl.f128_align = parse_align(a, "f128")?,
                 // FIXME(erikdesjardins): we should be parsing nonzero address spaces
                 // this will require replacing TargetDataLayout::{pointer_size,pointer_align}
                 // with e.g. `fn pointer_size_in(AddressSpace)`
@@ -919,8 +925,10 @@ pub enum Primitive {
     /// a negative integer passed by zero-extension will appear positive in
     /// the callee, and most operations on it will produce the wrong values.
     Int(Integer, bool),
+    F16,
     F32,
     F64,
+    F128,
     Pointer(AddressSpace),
 }
 
@@ -931,8 +939,10 @@ impl Primitive {
 
         match self {
             Int(i, _) => i.size(),
+            F16 => Size::from_bits(16),
             F32 => Size::from_bits(32),
             F64 => Size::from_bits(64),
+            F128 => Size::from_bits(128),
             // FIXME(erikdesjardins): ignoring address space is technically wrong, pointers in
             // different address spaces can have different sizes
             // (but TargetDataLayout doesn't currently parse that part of the DL string)
@@ -946,8 +956,10 @@ impl Primitive {
 
         match self {
             Int(i, _) => i.align(dl),
+            F16 => dl.f16_align,
             F32 => dl.f32_align,
             F64 => dl.f64_align,
+            F128 => dl.f128_align,
             // FIXME(erikdesjardins): ignoring address space is technically wrong, pointers in
             // different address spaces can have different alignments
             // (but TargetDataLayout doesn't currently parse that part of the DL string)

compiler/rustc_codegen_cranelift/src/common.rs

@@ -33,8 +33,10 @@ pub(crate) fn scalar_to_clif_type(tcx: TyCtxt<'_>, scalar: Scalar) -> Type {
             Integer::I64 => types::I64,
             Integer::I128 => types::I128,
         },
+        Primitive::F16 => unimplemented!("f16_f128"),
         Primitive::F32 => types::F32,
         Primitive::F64 => types::F64,
+        Primitive::F128 => unimplemented!("f16_f128"),
         // FIXME(erikdesjardins): handle non-default addrspace ptr sizes
         Primitive::Pointer(_) => pointer_ty(tcx),
     }
@@ -61,8 +63,10 @@ fn clif_type_from_ty<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Option<types::Typ
         },
         ty::Char => types::I32,
         ty::Float(size) => match size {
+            FloatTy::F16 => unimplemented!("f16_f128"),
             FloatTy::F32 => types::F32,
             FloatTy::F64 => types::F64,
+            FloatTy::F128 => unimplemented!("f16_f128"),
         },
         ty::FnPtr(_) => pointer_ty(tcx),
         ty::RawPtr(TypeAndMut { ty: pointee_ty, mutbl: _ }) | ty::Ref(_, pointee_ty, _) => {

compiler/rustc_codegen_gcc/src/type_.rs

@@ -83,8 +83,10 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
 
     pub fn type_float_from_ty(&self, t: ty::FloatTy) -> Type<'gcc> {
         match t {
+            ty::FloatTy::F16 => self.type_f16(),
             ty::FloatTy::F32 => self.type_f32(),
             ty::FloatTy::F64 => self.type_f64(),
+            ty::FloatTy::F128 => self.type_f128(),
         }
     }
 }
@@ -118,13 +120,21 @@ impl<'gcc, 'tcx> BaseTypeMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
         self.isize_type
     }
 
+    fn type_f16(&self) -> Type<'gcc> {
+        unimplemented!("f16_f128")
+    }
+    
     fn type_f32(&self) -> Type<'gcc> {
         self.float_type
     }
 
     fn type_f64(&self) -> Type<'gcc> {
         self.double_type
     }
+    
+    fn type_f128(&self) -> Type<'gcc> {
+        unimplemented!("f16_f128")
+    }
 
     fn type_func(&self, params: &[Type<'gcc>], return_type: Type<'gcc>) -> Type<'gcc> {
         self.context.new_function_pointer_type(None, return_type, params, false)

compiler/rustc_codegen_gcc/src/type_of.rs

@@ -6,7 +6,7 @@ use rustc_middle::bug;
 use rustc_middle::ty::{self, Ty, TypeVisitableExt};
 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::{self, Abi, Align, F16, F128, F32, F64, FieldsShape, Int, Integer, Pointer, PointeeInfo, Size, TyAbiInterface, Variants};
 use rustc_target::abi::call::{CastTarget, FnAbi, Reg};
 
 use crate::abi::{FnAbiGcc, FnAbiGccExt, GccType};
@@ -257,8 +257,10 @@ impl<'tcx> LayoutGccExt<'tcx> for TyAndLayout<'tcx> {
         match scalar.primitive() {
             Int(i, true) => cx.type_from_integer(i),
             Int(i, false) => cx.type_from_unsigned_integer(i),
+            F16 => cx.type_f16(),
             F32 => cx.type_f32(),
             F64 => cx.type_f64(),
+            F128 => cx.type_f128(),
             Pointer(address_space) => {
                 // If we know the alignment, pick something better than i8.
                 let pointee =

compiler/rustc_codegen_llvm/src/builder.rs

@@ -568,7 +568,7 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
                         }
                     }
                 }
-                abi::F32 | abi::F64 => {}
+                abi::F16 | abi::F32 | abi::F64 | abi::F128 => {}
             }
         }
 

compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs

@@ -695,9 +695,13 @@ impl MsvcBasicName for ty::UintTy {
 
 impl MsvcBasicName for ty::FloatTy {
     fn msvc_basic_name(self) -> &'static str {
+        // FIXME: f16 and f128 have no MSVE representation. We could improve the debuginfo.
+        // See: <https://github.com/rust-lang/rust/pull/114607/files#r1454683264>
         match self {
+            ty::FloatTy::F16 => "half",
             ty::FloatTy::F32 => "float",
             ty::FloatTy::F64 => "double",
+            ty::FloatTy::F128 => "fp128",
         }
     }
 }

compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs

@@ -122,8 +122,10 @@ fn tag_base_type<'ll, 'tcx>(
             // Niche tags are always normalized to unsized integers of the correct size.
             match tag.primitive() {
                 Primitive::Int(t, _) => t,
+                Primitive::F16 => Integer::I16,
                 Primitive::F32 => Integer::I32,
                 Primitive::F64 => Integer::I64,
+                Primitive::F128 => Integer::I128,
                 // FIXME(erikdesjardins): handle non-default addrspace ptr sizes
                 Primitive::Pointer(_) => {
                     // If the niche is the NULL value of a reference, then `discr_enum_ty` will be

compiler/rustc_codegen_llvm/src/intrinsic.rs

@@ -163,11 +163,15 @@ impl<'ll, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'_, 'll, 'tcx> {
                                     emit_va_arg(self, args[0], ret_ty)
                                 }
                             }
+                            Primitive::F16 => bug!("the va_arg intrinsic does not work with `f16`"),
                             Primitive::F64 | Primitive::Pointer(_) => {
                                 emit_va_arg(self, args[0], ret_ty)
                             }
                             // `va_arg` should never be used with the return type f32.
                             Primitive::F32 => bug!("the va_arg intrinsic does not work with `f32`"),
+                            Primitive::F128 => {
+                                bug!("the va_arg intrinsic does not work with `f128`")
+                            }
                         }
                     }
                     _ => bug!("the va_arg intrinsic does not work with non-scalar types"),

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -858,8 +858,10 @@ extern "C" {
     pub fn LLVMGetIntTypeWidth(IntegerTy: &Type) -> c_uint;
 
     // Operations on real types
+    pub fn LLVMHalfTypeInContext(C: &Context) -> &Type;
     pub fn LLVMFloatTypeInContext(C: &Context) -> &Type;
     pub fn LLVMDoubleTypeInContext(C: &Context) -> &Type;
+    pub fn LLVMFP128TypeInContext(C: &Context) -> &Type;
 
     // Operations on function types
     pub fn LLVMFunctionType<'a>(

compiler/rustc_codegen_llvm/src/type_.rs

@@ -107,8 +107,10 @@ impl<'ll> CodegenCx<'ll, '_> {
 
     pub(crate) fn type_float_from_ty(&self, t: ty::FloatTy) -> &'ll Type {
         match t {
+            ty::FloatTy::F16 => self.type_f16(),
             ty::FloatTy::F32 => self.type_f32(),
             ty::FloatTy::F64 => self.type_f64(),
+            ty::FloatTy::F128 => self.type_f128(),
         }
     }
 
@@ -156,6 +158,10 @@ impl<'ll, 'tcx> BaseTypeMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         self.isize_ty
     }
 
+    fn type_f16(&self) -> &'ll Type {
+        unsafe { llvm::LLVMHalfTypeInContext(self.llcx) }
+    }
+
     fn type_f32(&self) -> &'ll Type {
         unsafe { llvm::LLVMFloatTypeInContext(self.llcx) }
     }
@@ -164,6 +170,10 @@ impl<'ll, 'tcx> BaseTypeMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         unsafe { llvm::LLVMDoubleTypeInContext(self.llcx) }
     }
 
+    fn type_f128(&self) -> &'ll Type {
+        unsafe { llvm::LLVMFP128TypeInContext(self.llcx) }
+    }
+
     fn type_func(&self, args: &[&'ll Type], ret: &'ll Type) -> &'ll Type {
         unsafe { llvm::LLVMFunctionType(ret, args.as_ptr(), args.len() as c_uint, False) }
     }
@@ -195,7 +205,7 @@ impl<'ll, 'tcx> BaseTypeMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         match self.type_kind(ty) {
             TypeKind::Array | TypeKind::Vector => unsafe { llvm::LLVMGetElementType(ty) },
             TypeKind::Pointer => bug!("element_type is not supported for opaque pointers"),
-            other => bug!("element_type called on unsupported type {:?}", other),
+            other => bug!("element_type called on unsupported type {other:?}"),
         }
     }
 
@@ -205,11 +215,12 @@ impl<'ll, 'tcx> BaseTypeMethods<'tcx> for CodegenCx<'ll, 'tcx> {
 
     fn float_width(&self, ty: &'ll Type) -> usize {
         match self.type_kind(ty) {
+            TypeKind::Half => 16,
             TypeKind::Float => 32,
             TypeKind::Double => 64,
             TypeKind::X86_FP80 => 80,
             TypeKind::FP128 | TypeKind::PPC_FP128 => 128,
-            _ => bug!("llvm_float_width called on a non-float type"),
+            other => bug!("llvm_float_width called on a non-float type {other:?}"),
         }
     }
 

compiler/rustc_codegen_llvm/src/type_of.rs

@@ -8,7 +8,7 @@ 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;
 use rustc_target::abi::{Abi, Align, FieldsShape};
-use rustc_target::abi::{Int, Pointer, F32, F64};
+use rustc_target::abi::{Int, Pointer, F128, F16, F32, F64};
 use rustc_target::abi::{Scalar, Size, Variants};
 use smallvec::{smallvec, SmallVec};
 
@@ -291,8 +291,10 @@ impl<'tcx> LayoutLlvmExt<'tcx> for TyAndLayout<'tcx> {
     fn scalar_llvm_type_at<'a>(&self, cx: &CodegenCx<'a, 'tcx>, scalar: Scalar) -> &'a Type {
         match scalar.primitive() {
             Int(i, _) => cx.type_from_integer(i),
+            F16 => cx.type_f16(),
             F32 => cx.type_f32(),
             F64 => cx.type_f64(),
+            F128 => cx.type_f128(),
             Pointer(address_space) => cx.type_ptr_ext(address_space),
         }
     }

compiler/rustc_codegen_ssa/src/mir/rvalue.rs

@@ -303,15 +303,17 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         self.assume_scalar_range(bx, imm, from_scalar, from_backend_ty);
 
         imm = match (from_scalar.primitive(), to_scalar.primitive()) {
-            (Int(..) | F32 | F64, Int(..) | F32 | F64) => bx.bitcast(imm, to_backend_ty),
+            (Int(..) | F16 | F32 | F64 | F128, Int(..) | F16 | F32 | F64 | F128) => {
+                bx.bitcast(imm, to_backend_ty)
+            }
             (Pointer(..), Pointer(..)) => bx.pointercast(imm, to_backend_ty),
             (Int(..), Pointer(..)) => bx.inttoptr(imm, to_backend_ty),
             (Pointer(..), Int(..)) => bx.ptrtoint(imm, to_backend_ty),
-            (F32 | F64, Pointer(..)) => {
+            (F16 | F32 | F64 | F128, Pointer(..)) => {
                 let int_imm = bx.bitcast(imm, bx.cx().type_isize());
                 bx.inttoptr(int_imm, to_backend_ty)
             }
-            (Pointer(..), F32 | F64) => {
+            (Pointer(..), F16 | F32 | F64 | F128) => {
                 let int_imm = bx.ptrtoint(imm, bx.cx().type_isize());
                 bx.bitcast(int_imm, to_backend_ty)
             }

compiler/rustc_codegen_ssa/src/traits/type_.rs

@@ -19,8 +19,10 @@ pub trait BaseTypeMethods<'tcx>: Backend<'tcx> {
     fn type_i128(&self) -> Self::Type;
     fn type_isize(&self) -> Self::Type;
 
+    fn type_f16(&self) -> Self::Type;
     fn type_f32(&self) -> Self::Type;
     fn type_f64(&self) -> Self::Type;
+    fn type_f128(&self) -> Self::Type;
 
     fn type_array(&self, ty: Self::Type, len: u64) -> Self::Type;
     fn type_func(&self, args: &[Self::Type], ret: Self::Type) -> Self::Type;

compiler/rustc_const_eval/src/interpret/operator.rs

@@ -389,12 +389,14 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 let left = left.to_scalar();
                 let right = right.to_scalar();
                 Ok(match fty {
+                    FloatTy::F16 => unimplemented!("f16_f128"),
                     FloatTy::F32 => {
                         self.binary_float_op(bin_op, layout, left.to_f32()?, right.to_f32()?)
                     }
                     FloatTy::F64 => {
                         self.binary_float_op(bin_op, layout, left.to_f64()?, right.to_f64()?)
                     }
+                    FloatTy::F128 => unimplemented!("f16_f128"),
                 })
             }
             _ if left.layout.ty.is_integral() => {

compiler/rustc_lint/src/types.rs

@@ -561,8 +561,10 @@ fn lint_literal<'tcx>(
         ty::Float(t) => {
             let is_infinite = match lit.node {
                 ast::LitKind::Float(v, _) => match t {
+                    ty::FloatTy::F16 => unimplemented!("f16_f128"),
                     ty::FloatTy::F32 => v.as_str().parse().map(f32::is_infinite),
                     ty::FloatTy::F64 => v.as_str().parse().map(f64::is_infinite),
+                    ty::FloatTy::F128 => unimplemented!("f16_f128"),
                 },
                 _ => bug!(),
             };

compiler/rustc_middle/src/ty/context.rs

@@ -335,8 +335,10 @@ pub struct CommonTypes<'tcx> {
     pub u32: Ty<'tcx>,
     pub u64: Ty<'tcx>,
     pub u128: Ty<'tcx>,
+    pub f16: Ty<'tcx>,
     pub f32: Ty<'tcx>,
     pub f64: Ty<'tcx>,
+    pub f128: Ty<'tcx>,
     pub str_: Ty<'tcx>,
     pub never: Ty<'tcx>,
     pub self_param: Ty<'tcx>,
@@ -416,8 +418,10 @@ impl<'tcx> CommonTypes<'tcx> {
             u32: mk(Uint(ty::UintTy::U32)),
             u64: mk(Uint(ty::UintTy::U64)),
             u128: mk(Uint(ty::UintTy::U128)),
+            f16: mk(Float(ty::FloatTy::F16)),
             f32: mk(Float(ty::FloatTy::F32)),
             f64: mk(Float(ty::FloatTy::F64)),
+            f128: mk(Float(ty::FloatTy::F128)),
             str_: mk(Str),
             self_param: mk(ty::Param(ty::ParamTy { index: 0, name: kw::SelfUpper })),
 

compiler/rustc_middle/src/ty/layout.rs

@@ -116,8 +116,10 @@ impl Primitive {
     fn to_ty<'tcx>(&self, tcx: TyCtxt<'tcx>) -> Ty<'tcx> {
         match *self {
             Int(i, signed) => i.to_ty(tcx, signed),
+            F16 => tcx.types.f16,
             F32 => tcx.types.f32,
             F64 => tcx.types.f64,
+            F128 => tcx.types.f128,
             // FIXME(erikdesjardins): handle non-default addrspace ptr sizes
             Pointer(_) => Ty::new_mut_ptr(tcx, Ty::new_unit(tcx)),
         }
@@ -134,7 +136,7 @@ impl Primitive {
                 let signed = false;
                 tcx.data_layout().ptr_sized_integer().to_ty(tcx, signed)
             }
-            F32 | F64 => bug!("floats do not have an int type"),
+            F16 | F32 | F64 | F128 => bug!("floats do not have an int type"),
         }
     }
 }

compiler/rustc_middle/src/ty/sty.rs

@@ -1580,8 +1580,10 @@ impl<'tcx> Ty<'tcx> {
     pub fn new_float(tcx: TyCtxt<'tcx>, f: ty::FloatTy) -> Ty<'tcx> {
         use ty::FloatTy::*;
         match f {
+            F16 => tcx.types.f16,
             F32 => tcx.types.f32,
             F64 => tcx.types.f64,
+            F128 => tcx.types.f128,
         }
     }
 
@@ -2539,8 +2541,10 @@ impl<'tcx> Ty<'tcx> {
             ty::Bool => Some(sym::bool),
             ty::Char => Some(sym::char),
             ty::Float(f) => match f {
+                ty::FloatTy::F16 => Some(sym::f16),
                 ty::FloatTy::F32 => Some(sym::f32),
                 ty::FloatTy::F64 => Some(sym::f64),
+                ty::FloatTy::F128 => Some(sym::f128),
             },
             ty::Int(f) => match f {
                 ty::IntTy::Isize => Some(sym::isize),