Auto merge of #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 https://github.com/rust-lang/rust/pull/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 https://github.com/rust-lang/rust/pull/120645#issuecomment-1925900572

2 files changed, 7 insertions, 3 deletions

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;