diff --git a/compiler/rustc_abi/src/lib.rs b/compiler/rustc_abi/src/lib.rs
index 297dbf89029..34529e0a086 100644
--- a/compiler/rustc_abi/src/lib.rs
+++ b/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)
diff --git a/compiler/rustc_codegen_cranelift/src/common.rs b/compiler/rustc_codegen_cranelift/src/common.rs
index 1e37825b548..e35ec4fe1c7 100644
--- a/compiler/rustc_codegen_cranelift/src/common.rs
+++ b/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, _) => {
diff --git a/compiler/rustc_codegen_gcc/src/type_.rs b/compiler/rustc_codegen_gcc/src/type_.rs
index 7a89fe81d38..7e5aa1c1766 100644
--- a/compiler/rustc_codegen_gcc/src/type_.rs
+++ b/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(),
         }
     }
 }
@@ -118,6 +120,10 @@ 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
     }
@@ -125,6 +131,10 @@ impl<'gcc, 'tcx> BaseTypeMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
     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)
diff --git a/compiler/rustc_codegen_gcc/src/type_of.rs b/compiler/rustc_codegen_gcc/src/type_of.rs
index 25149b80201..62136d24a2c 100644
--- a/compiler/rustc_codegen_gcc/src/type_of.rs
+++ b/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 =
diff --git a/compiler/rustc_codegen_llvm/src/builder.rs b/compiler/rustc_codegen_llvm/src/builder.rs
index 8cab2a3f27c..2110e62a9c4 100644
--- a/compiler/rustc_codegen_llvm/src/builder.rs
+++ b/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 => {}
             }
         }
 
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
index f961cd2d00b..045b6d2b651 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
+++ b/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",
         }
     }
 }
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs
index 7f671d1d061..657e9ce998f 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs
+++ b/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
diff --git a/compiler/rustc_codegen_llvm/src/intrinsic.rs b/compiler/rustc_codegen_llvm/src/intrinsic.rs
index e5de2f78376..1d4ab866cb3 100644
--- a/compiler/rustc_codegen_llvm/src/intrinsic.rs
+++ b/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"),
diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
index 70fc7a66bcd..3c20b579349 100644
--- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
+++ b/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>(
diff --git a/compiler/rustc_codegen_llvm/src/type_.rs b/compiler/rustc_codegen_llvm/src/type_.rs
index 447c4ed1f0c..8f180bab3df 100644
--- a/compiler/rustc_codegen_llvm/src/type_.rs
+++ b/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:?}"),
         }
     }
 
diff --git a/compiler/rustc_codegen_llvm/src/type_of.rs b/compiler/rustc_codegen_llvm/src/type_of.rs
index 219c7025311..369dcfb7b8f 100644
--- a/compiler/rustc_codegen_llvm/src/type_of.rs
+++ b/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),
         }
     }
diff --git a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs
index 5c6060a7159..f7ff36c0467 100644
--- a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs
+++ b/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)
             }
diff --git a/compiler/rustc_codegen_ssa/src/traits/type_.rs b/compiler/rustc_codegen_ssa/src/traits/type_.rs
index b1fde8e4d86..505ce5a61ff 100644
--- a/compiler/rustc_codegen_ssa/src/traits/type_.rs
+++ b/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;
diff --git a/compiler/rustc_const_eval/src/interpret/operator.rs b/compiler/rustc_const_eval/src/interpret/operator.rs
index eef15425764..475c533077a 100644
--- a/compiler/rustc_const_eval/src/interpret/operator.rs
+++ b/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() => {
diff --git a/compiler/rustc_lint/src/types.rs b/compiler/rustc_lint/src/types.rs
index 2ea891ce04d..a87e2410b3d 100644
--- a/compiler/rustc_lint/src/types.rs
+++ b/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!(),
             };
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index c6359dae1ab..b2a7f5599b6 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/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 })),
 
diff --git a/compiler/rustc_middle/src/ty/layout.rs b/compiler/rustc_middle/src/ty/layout.rs
index 62d5a8fa4df..529d847bfb0 100644
--- a/compiler/rustc_middle/src/ty/layout.rs
+++ b/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"),
         }
     }
 }
diff --git a/compiler/rustc_middle/src/ty/sty.rs b/compiler/rustc_middle/src/ty/sty.rs
index 06be8191dc4..53690cc5811 100644
--- a/compiler/rustc_middle/src/ty/sty.rs
+++ b/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),
diff --git a/compiler/rustc_mir_build/src/build/mod.rs b/compiler/rustc_mir_build/src/build/mod.rs
index 2b1a9fef360..294b27def16 100644
--- a/compiler/rustc_mir_build/src/build/mod.rs
+++ b/compiler/rustc_mir_build/src/build/mod.rs
@@ -1053,6 +1053,7 @@ pub(crate) fn parse_float_into_scalar(
 ) -> Option<Scalar> {
     let num = num.as_str();
     match float_ty {
+        ty::FloatTy::F16 => unimplemented!("f16_f128"),
         ty::FloatTy::F32 => {
             let Ok(rust_f) = num.parse::<f32>() else { return None };
             let mut f = num
@@ -1099,6 +1100,7 @@ pub(crate) fn parse_float_into_scalar(
 
             Some(Scalar::from_f64(f))
         }
+        ty::FloatTy::F128 => unimplemented!("f16_f128"),
     }
 }
 
diff --git a/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs b/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs
index 09727f9b71b..ce39aff69cb 100644
--- a/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs
+++ b/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs
@@ -442,8 +442,10 @@ impl<'tcx> ConstToPat<'tcx> {
             ty::Float(flt) => {
                 let v = cv.unwrap_leaf();
                 let is_nan = match flt {
+                    ty::FloatTy::F16 => unimplemented!("f16_f128"),
                     ty::FloatTy::F32 => v.try_to_f32().unwrap().is_nan(),
                     ty::FloatTy::F64 => v.try_to_f64().unwrap().is_nan(),
+                    ty::FloatTy::F128 => unimplemented!("f16_f128"),
                 };
                 if is_nan {
                     // NaNs are not ever equal to anything so they make no sense as patterns.
diff --git a/compiler/rustc_pattern_analysis/src/rustc.rs b/compiler/rustc_pattern_analysis/src/rustc.rs
index 7a0562e12f1..f8839b0b590 100644
--- a/compiler/rustc_pattern_analysis/src/rustc.rs
+++ b/compiler/rustc_pattern_analysis/src/rustc.rs
@@ -604,6 +604,7 @@ impl<'p, 'tcx: 'p> RustcMatchCheckCtxt<'p, 'tcx> {
                         let lo = lo.as_finite().map(|c| c.eval_bits(cx.tcx, cx.param_env));
                         let hi = hi.as_finite().map(|c| c.eval_bits(cx.tcx, cx.param_env));
                         match fty {
+                            ty::FloatTy::F16 => unimplemented!("f16_f128"),
                             ty::FloatTy::F32 => {
                                 use rustc_apfloat::ieee::Single;
                                 let lo = lo.map(Single::from_bits).unwrap_or(-Single::INFINITY);
@@ -616,6 +617,7 @@ impl<'p, 'tcx: 'p> RustcMatchCheckCtxt<'p, 'tcx> {
                                 let hi = hi.map(Double::from_bits).unwrap_or(Double::INFINITY);
                                 F64Range(lo, hi, end)
                             }
+                            ty::FloatTy::F128 => unimplemented!("f16_f128"),
                         }
                     }
                     _ => bug!("invalid type for range pattern: {}", ty.inner()),
diff --git a/compiler/rustc_smir/src/rustc_smir/convert/ty.rs b/compiler/rustc_smir/src/rustc_smir/convert/ty.rs
index a066b9ed3aa..84c6cbf178b 100644
--- a/compiler/rustc_smir/src/rustc_smir/convert/ty.rs
+++ b/compiler/rustc_smir/src/rustc_smir/convert/ty.rs
@@ -297,8 +297,10 @@ impl<'tcx> Stable<'tcx> for ty::FloatTy {
 
     fn stable(&self, _: &mut Tables<'_>) -> Self::T {
         match self {
+            ty::FloatTy::F16 => unimplemented!("f16_f128"),
             ty::FloatTy::F32 => FloatTy::F32,
             ty::FloatTy::F64 => FloatTy::F64,
+            ty::FloatTy::F128 => unimplemented!("f16_f128"),
         }
     }
 }
diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs
index 4d8475bef54..2e86a8bd581 100644
--- a/compiler/rustc_span/src/symbol.rs
+++ b/compiler/rustc_span/src/symbol.rs
@@ -758,6 +758,8 @@ symbols! {
         external,
         external_doc,
         f,
+        f128,
+        f16,
         f16c_target_feature,
         f32,
         f32_legacy_const_digits,
diff --git a/compiler/rustc_symbol_mangling/src/typeid/typeid_itanium_cxx_abi.rs b/compiler/rustc_symbol_mangling/src/typeid/typeid_itanium_cxx_abi.rs
index 42d9b519c14..b5b3aa27060 100644
--- a/compiler/rustc_symbol_mangling/src/typeid/typeid_itanium_cxx_abi.rs
+++ b/compiler/rustc_symbol_mangling/src/typeid/typeid_itanium_cxx_abi.rs
@@ -470,8 +470,10 @@ fn encode_ty<'tcx>(
         // (See https://rust-lang.github.io/unsafe-code-guidelines/layout/scalars.html#fixed-width-floating-point-types.)
         ty::Float(float_ty) => {
             typeid.push(match float_ty {
+                FloatTy::F16 => unimplemented!("f16_f128"),
                 FloatTy::F32 => 'f',
                 FloatTy::F64 => 'd',
+                FloatTy::F128 => unimplemented!("f16_f128"),
             });
         }
 
diff --git a/compiler/rustc_target/src/abi/call/loongarch.rs b/compiler/rustc_target/src/abi/call/loongarch.rs
index 647b6500c52..35d4b331cb4 100644
--- a/compiler/rustc_target/src/abi/call/loongarch.rs
+++ b/compiler/rustc_target/src/abi/call/loongarch.rs
@@ -59,7 +59,7 @@ where
                     _ => return Err(CannotUseFpConv),
                 }
             }
-            abi::F32 | abi::F64 => {
+            abi::F16 | abi::F32 | abi::F64 | abi::F128 => {
                 if arg_layout.size.bits() > flen {
                     return Err(CannotUseFpConv);
                 }
diff --git a/compiler/rustc_target/src/abi/call/mod.rs b/compiler/rustc_target/src/abi/call/mod.rs
index db721212f8e..66177d551ba 100644
--- a/compiler/rustc_target/src/abi/call/mod.rs
+++ b/compiler/rustc_target/src/abi/call/mod.rs
@@ -412,7 +412,7 @@ impl<'a, Ty> TyAndLayout<'a, Ty> {
             Abi::Scalar(scalar) => {
                 let kind = match scalar.primitive() {
                     abi::Int(..) | abi::Pointer(_) => RegKind::Integer,
-                    abi::F32 | abi::F64 => RegKind::Float,
+                    abi::F16 | abi::F32 | abi::F64 | abi::F128 => RegKind::Float,
                 };
                 Ok(HomogeneousAggregate::Homogeneous(Reg { kind, size: self.size }))
             }
diff --git a/compiler/rustc_target/src/abi/call/riscv.rs b/compiler/rustc_target/src/abi/call/riscv.rs
index cbde234d34c..6a38496dc57 100644
--- a/compiler/rustc_target/src/abi/call/riscv.rs
+++ b/compiler/rustc_target/src/abi/call/riscv.rs
@@ -65,7 +65,7 @@ where
                     _ => return Err(CannotUseFpConv),
                 }
             }
-            abi::F32 | abi::F64 => {
+            abi::F16 | abi::F32 | abi::F64 | abi::F128 => {
                 if arg_layout.size.bits() > flen {
                     return Err(CannotUseFpConv);
                 }
diff --git a/compiler/rustc_target/src/abi/call/x86_64.rs b/compiler/rustc_target/src/abi/call/x86_64.rs
index 6c34585a11b..2eb50cc8dea 100644
--- a/compiler/rustc_target/src/abi/call/x86_64.rs
+++ b/compiler/rustc_target/src/abi/call/x86_64.rs
@@ -51,7 +51,7 @@ where
 
             Abi::Scalar(scalar) => match scalar.primitive() {
                 abi::Int(..) | abi::Pointer(_) => Class::Int,
-                abi::F32 | abi::F64 => Class::Sse,
+                abi::F16 | abi::F32 | abi::F64 | abi::F128 => Class::Sse,
             },
 
             Abi::Vector { .. } => Class::Sse,
diff --git a/compiler/rustc_trait_selection/src/solve/assembly/mod.rs b/compiler/rustc_trait_selection/src/solve/assembly/mod.rs
index 4c4cd2af779..3be53a6591d 100644
--- a/compiler/rustc_trait_selection/src/solve/assembly/mod.rs
+++ b/compiler/rustc_trait_selection/src/solve/assembly/mod.rs
@@ -394,10 +394,12 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
 
             ty::Infer(ty::FloatVar(_)) => {
                 // This causes a compiler error if any new float kinds are added.
-                let (ty::FloatTy::F32 | ty::FloatTy::F64);
+                let (ty::FloatTy::F16 | ty::FloatTy::F32 | ty::FloatTy::F64 | ty::FloatTy::F128);
                 let possible_floats = [
+                    SimplifiedType::Float(ty::FloatTy::F16),
                     SimplifiedType::Float(ty::FloatTy::F32),
                     SimplifiedType::Float(ty::FloatTy::F64),
+                    SimplifiedType::Float(ty::FloatTy::F128),
                 ];
 
                 for simp in possible_floats {
diff --git a/compiler/rustc_ty_utils/src/layout.rs b/compiler/rustc_ty_utils/src/layout.rs
index b00330d335e..e32179d56d1 100644
--- a/compiler/rustc_ty_utils/src/layout.rs
+++ b/compiler/rustc_ty_utils/src/layout.rs
@@ -141,8 +141,10 @@ fn layout_of_uncached<'tcx>(
         ty::Int(ity) => scalar(Int(Integer::from_int_ty(dl, ity), true)),
         ty::Uint(ity) => scalar(Int(Integer::from_uint_ty(dl, ity), false)),
         ty::Float(fty) => scalar(match fty {
+            ty::FloatTy::F16 => F16,
             ty::FloatTy::F32 => F32,
             ty::FloatTy::F64 => F64,
+            ty::FloatTy::F128 => F128,
         }),
         ty::FnPtr(_) => {
             let mut ptr = scalar_unit(Pointer(dl.instruction_address_space));
diff --git a/compiler/rustc_type_ir/src/ty_kind.rs b/compiler/rustc_type_ir/src/ty_kind.rs
index a4d67169bc7..00f49a07f9d 100644
--- a/compiler/rustc_type_ir/src/ty_kind.rs
+++ b/compiler/rustc_type_ir/src/ty_kind.rs
@@ -550,22 +550,28 @@ impl UintTy {
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
 #[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_NoContext))]
 pub enum FloatTy {
+    F16,
     F32,
     F64,
+    F128,
 }
 
 impl FloatTy {
     pub fn name_str(self) -> &'static str {
         match self {
+            FloatTy::F16 => "f16",
             FloatTy::F32 => "f32",
             FloatTy::F64 => "f64",
+            FloatTy::F128 => "f128",
         }
     }
 
     pub fn bit_width(self) -> u64 {
         match self {
+            FloatTy::F16 => 16,
             FloatTy::F32 => 32,
             FloatTy::F64 => 64,
+            FloatTy::F128 => 128,
         }
     }
 }
diff --git a/src/librustdoc/clean/types.rs b/src/librustdoc/clean/types.rs
index 30cadfe7dac..1707b514ef8 100644
--- a/src/librustdoc/clean/types.rs
+++ b/src/librustdoc/clean/types.rs
@@ -1743,8 +1743,10 @@ pub(crate) enum PrimitiveType {
     U32,
     U64,
     U128,
+    F16,
     F32,
     F64,
+    F128,
     Char,
     Bool,
     Str,
@@ -1890,8 +1892,10 @@ impl PrimitiveType {
             U32 => sym::u32,
             U64 => sym::u64,
             U128 => sym::u128,
+            F16 => sym::f16,
             F32 => sym::f32,
             F64 => sym::f64,
+            F128 => sym::f128,
             Str => sym::str,
             Bool => sym::bool,
             Char => sym::char,
@@ -2008,8 +2012,10 @@ impl From<ty::UintTy> for PrimitiveType {
 impl From<ty::FloatTy> for PrimitiveType {
     fn from(float_ty: ty::FloatTy) -> PrimitiveType {
         match float_ty {
+            ty::FloatTy::F16 => PrimitiveType::F16,
             ty::FloatTy::F32 => PrimitiveType::F32,
             ty::FloatTy::F64 => PrimitiveType::F64,
+            ty::FloatTy::F128 => PrimitiveType::F128,
         }
     }
 }
diff --git a/src/tools/clippy/clippy_lints/src/float_literal.rs b/src/tools/clippy/clippy_lints/src/float_literal.rs
index 38a16c5c8b0..cffca952e47 100644
--- a/src/tools/clippy/clippy_lints/src/float_literal.rs
+++ b/src/tools/clippy/clippy_lints/src/float_literal.rs
@@ -81,6 +81,7 @@ impl<'tcx> LateLintPass<'tcx> for FloatLiteral {
                 LitFloatType::Unsuffixed => None,
             };
             let (is_whole, is_inf, mut float_str) = match fty {
+                FloatTy::F16 => unimplemented!("f16_f128"),
                 FloatTy::F32 => {
                     let value = sym_str.parse::<f32>().unwrap();
 
@@ -91,6 +92,7 @@ impl<'tcx> LateLintPass<'tcx> for FloatLiteral {
 
                     (value.fract() == 0.0, value.is_infinite(), formatter.format(value))
                 },
+                FloatTy::F128 => unimplemented!("f16_f128"),
             };
 
             if is_inf {
@@ -135,8 +137,10 @@ impl<'tcx> LateLintPass<'tcx> for FloatLiteral {
 #[must_use]
 fn max_digits(fty: FloatTy) -> u32 {
     match fty {
+        FloatTy::F16 => unimplemented!("f16_f128"),
         FloatTy::F32 => f32::DIGITS,
         FloatTy::F64 => f64::DIGITS,
+        FloatTy::F128 => unimplemented!("f16_f128"),
     }
 }
 
diff --git a/src/tools/clippy/clippy_utils/src/consts.rs b/src/tools/clippy/clippy_utils/src/consts.rs
index 79c691992a8..1f2b2d54efd 100644
--- a/src/tools/clippy/clippy_utils/src/consts.rs
+++ b/src/tools/clippy/clippy_utils/src/consts.rs
@@ -778,8 +778,10 @@ pub fn mir_to_const<'tcx>(lcx: &LateContext<'tcx>, result: mir::Const<'tcx>) ->
                 let range = alloc_range(offset + size * idx, size);
                 let val = alloc.read_scalar(&lcx.tcx, range, /* read_provenance */ false).ok()?;
                 res.push(match flt {
+                    FloatTy::F16 => unimplemented!("f16_f128"),
                     FloatTy::F32 => Constant::F32(f32::from_bits(val.to_u32().ok()?)),
                     FloatTy::F64 => Constant::F64(f64::from_bits(val.to_u64().ok()?)),
+                    FloatTy::F128 => unimplemented!("f16_f128"),
                 });
             }
             Some(Constant::Vec(res))
diff --git a/src/tools/miri/src/shims/intrinsics/simd.rs b/src/tools/miri/src/shims/intrinsics/simd.rs
index ca8773cac14..bb18fba5c98 100644
--- a/src/tools/miri/src/shims/intrinsics/simd.rs
+++ b/src/tools/miri/src/shims/intrinsics/simd.rs
@@ -83,8 +83,10 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                             let op = op.to_scalar();
                             // "Bitwise" operation, no NaN adjustments
                             match float_ty {
+                                FloatTy::F16 => unimplemented!("f16_f128"),
                                 FloatTy::F32 => Scalar::from_f32(op.to_f32()?.abs()),
                                 FloatTy::F64 => Scalar::from_f64(op.to_f64()?.abs()),
+                                FloatTy::F128 => unimplemented!("f16_f128"),
                             }
                         }
                         Op::Sqrt => {
@@ -93,6 +95,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                             };
                             // FIXME using host floats
                             match float_ty {
+                                FloatTy::F16 => unimplemented!("f16_f128"),
                                 FloatTy::F32 => {
                                     let f = op.to_scalar().to_f32()?;
                                     let res = f.to_host().sqrt().to_soft();
@@ -105,6 +108,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                                     let res = this.adjust_nan(res, &[f]);
                                     Scalar::from(res)
                                 }
+                                FloatTy::F128 => unimplemented!("f16_f128"),
                             }
                         }
                         Op::Round(rounding) => {
@@ -112,6 +116,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                                 span_bug!(this.cur_span(), "{} operand is not a float", intrinsic_name)
                             };
                             match float_ty {
+                                FloatTy::F16 => unimplemented!("f16_f128"),
                                 FloatTy::F32 => {
                                     let f = op.to_scalar().to_f32()?;
                                     let res = f.round_to_integral(rounding).value;
@@ -124,6 +129,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                                     let res = this.adjust_nan(res, &[f]);
                                     Scalar::from_f64(res)
                                 }
+                                FloatTy::F128 => unimplemented!("f16_f128"),
                             }
                         }
                         Op::Numeric(name) => {
@@ -267,6 +273,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                         span_bug!(this.cur_span(), "{} operand is not a float", intrinsic_name)
                     };
                     let val = match float_ty {
+                        FloatTy::F16 => unimplemented!("f16_f128"),
                         FloatTy::F32 => {
                             let a = a.to_f32()?;
                             let b = b.to_f32()?;
@@ -283,6 +290,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                             let res = this.adjust_nan(res, &[a, b, c]);
                             Scalar::from(res)
                         }
+                        FloatTy::F128 => unimplemented!("f16_f128"),
                     };
                     this.write_scalar(val, &dest)?;
                 }
@@ -724,6 +732,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         let left = left.to_scalar();
         let right = right.to_scalar();
         Ok(match float_ty {
+            FloatTy::F16 => unimplemented!("f16_f128"),
             FloatTy::F32 => {
                 let left = left.to_f32()?;
                 let right = right.to_f32()?;
@@ -744,6 +753,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 let res = this.adjust_nan(res, &[left, right]);
                 Scalar::from_f64(res)
             }
+            FloatTy::F128 => unimplemented!("f16_f128"),
         })
     }
 }
diff --git a/tests/ui/parser/f16-f128.rs b/tests/ui/parser/f16-f128.rs
new file mode 100644
index 00000000000..4f31dccce3c
--- /dev/null
+++ b/tests/ui/parser/f16-f128.rs
@@ -0,0 +1,37 @@
+// Make sure we don't ICE while incrementally adding f16 and f128 support
+
+mod f16_checks {
+    const A: f16 = 10.0; //~ ERROR cannot find type `f16` in this scope
+
+    pub fn main() {
+        let a: f16 = 100.0; //~ ERROR cannot find type `f16` in this scope
+        let b = 0.0f16; //~ ERROR invalid width `16` for float literal
+
+        foo(1.23);
+    }
+
+    fn foo(a: f16) {} //~ ERROR cannot find type `f16` in this scope
+
+    struct Bar {
+        a: f16, //~ ERROR cannot find type `f16` in this scope
+    }
+}
+
+mod f128_checks {
+    const A: f128 = 10.0; //~ ERROR cannot find type `f128` in this scope
+
+    pub fn main() {
+        let a: f128 = 100.0; //~ ERROR cannot find type `f128` in this scope
+        let b = 0.0f128; //~ ERROR invalid width `128` for float literal
+
+        foo(1.23);
+    }
+
+    fn foo(a: f128) {} //~ ERROR cannot find type `f128` in this scope
+
+    struct Bar {
+        a: f128, //~ ERROR cannot find type `f128` in this scope
+    }
+}
+
+fn main() {}
diff --git a/tests/ui/parser/f16-f128.stderr b/tests/ui/parser/f16-f128.stderr
new file mode 100644
index 00000000000..d3f2227acd7
--- /dev/null
+++ b/tests/ui/parser/f16-f128.stderr
@@ -0,0 +1,67 @@
+error[E0412]: cannot find type `f16` in this scope
+  --> $DIR/f16-f128.rs:4:14
+   |
+LL |     const A: f16 = 10.0;
+   |              ^^^ help: a builtin type with a similar name exists: `i16`
+
+error[E0412]: cannot find type `f16` in this scope
+  --> $DIR/f16-f128.rs:7:16
+   |
+LL |         let a: f16 = 100.0;
+   |                ^^^ help: a builtin type with a similar name exists: `i16`
+
+error[E0412]: cannot find type `f16` in this scope
+  --> $DIR/f16-f128.rs:13:15
+   |
+LL |     fn foo(a: f16) {}
+   |               ^^^ help: a builtin type with a similar name exists: `i16`
+
+error[E0412]: cannot find type `f16` in this scope
+  --> $DIR/f16-f128.rs:16:12
+   |
+LL |         a: f16,
+   |            ^^^ help: a builtin type with a similar name exists: `i16`
+
+error[E0412]: cannot find type `f128` in this scope
+  --> $DIR/f16-f128.rs:21:14
+   |
+LL |     const A: f128 = 10.0;
+   |              ^^^^ help: a builtin type with a similar name exists: `i128`
+
+error[E0412]: cannot find type `f128` in this scope
+  --> $DIR/f16-f128.rs:24:16
+   |
+LL |         let a: f128 = 100.0;
+   |                ^^^^ help: a builtin type with a similar name exists: `i128`
+
+error[E0412]: cannot find type `f128` in this scope
+  --> $DIR/f16-f128.rs:30:15
+   |
+LL |     fn foo(a: f128) {}
+   |               ^^^^ help: a builtin type with a similar name exists: `i128`
+
+error[E0412]: cannot find type `f128` in this scope
+  --> $DIR/f16-f128.rs:33:12
+   |
+LL |         a: f128,
+   |            ^^^^ help: a builtin type with a similar name exists: `i128`
+
+error: invalid width `16` for float literal
+  --> $DIR/f16-f128.rs:8:17
+   |
+LL |         let b = 0.0f16;
+   |                 ^^^^^^
+   |
+   = help: valid widths are 32 and 64
+
+error: invalid width `128` for float literal
+  --> $DIR/f16-f128.rs:25:17
+   |
+LL |         let b = 0.0f128;
+   |                 ^^^^^^^
+   |
+   = help: valid widths are 32 and 64
+
+error: aborting due to 10 previous errors
+
+For more information about this error, try `rustc --explain E0412`.