Add support for fmaf16

Author: antoyo

src/intrinsic/mod.rs

@@ -16,8 +16,9 @@ use rustc_codegen_ssa::mir::place::{PlaceRef, PlaceValue};
 use rustc_codegen_ssa::traits::{
     ArgAbiBuilderMethods, BuilderMethods, ConstCodegenMethods, IntrinsicCallBuilderMethods,
 };
+use rustc_codegen_ssa::traits::BaseTypeCodegenMethods;
 #[cfg(feature = "master")]
-use rustc_codegen_ssa::traits::{BaseTypeCodegenMethods, MiscCodegenMethods};
+use rustc_codegen_ssa::traits::MiscCodegenMethods;
 use rustc_middle::bug;
 #[cfg(feature = "master")]
 use rustc_middle::ty::layout::{FnAbiOf, HasTyCtxt};
@@ -139,6 +140,17 @@ impl<'a, 'gcc, 'tcx> IntrinsicCallBuilderMethods<'tcx> for Builder<'a, 'gcc, 'tc
                     &args.iter().map(|arg| arg.immediate()).collect::<Vec<_>>(),
                 )
             }
+            sym::fmaf16 => {
+                let func = self.cx.context.get_builtin_function("fmaf");
+                let args: Vec<_> = args
+                    .iter()
+                    .map(|arg| {
+                        self.cx.context.new_cast(self.location, arg.immediate(), self.cx.type_f32())
+                    })
+                    .collect();
+                let result = self.cx.context.new_call(self.location, func, &args);
+                self.cx.context.new_cast(self.location, result, self.cx.type_f16())
+            }
             sym::is_val_statically_known => {
                 let a = args[0].immediate();
                 let builtin = self.context.get_builtin_function("__builtin_constant_p");