[libc-commits] [libc] [libc][math][c++23] Add bfloat16 support in LLVM libc (PR #144463)

[via libc-commits]

================
@@ -26,9 +26,20 @@ LIBC_INLINE constexpr cpp::enable_if_t<cpp::is_floating_point_v<OutType> &&
                                            cpp::is_floating_point_v<InType>,
                                        OutType>
 cast(InType x) {
-#if defined(LIBC_TYPES_HAS_FLOAT16) && !defined(__LIBC_USE_FLOAT16_CONVERSION)
-  if constexpr (cpp::is_same_v<OutType, float16> ||
-                cpp::is_same_v<InType, float16>) {
+
+  // no need to cast to the same type
+  if constexpr (cpp::is_same_v<InType, OutType>) {
+    return x;
+  }
+
+  // bfloat16 is always defined (for now)
+  if constexpr (cpp::is_same_v<OutType, bfloat16> ||
+                cpp::is_same_v<InType, bfloat16>
+#if (defined(LIBC_TYPES_HAS_FLOAT16) && !defined(__LIBC_USE_FLOAT16_CONVERSION))
+                || cpp::is_same_v<InType, float16> ||
+                cpp::is_same_v<InType, float16>
----------------
overmighty wrote:

```suggestion
                || cpp::is_same_v<OutType, float16> ||
                cpp::is_same_v<InType, float16>
```

https://github.com/llvm/llvm-project/pull/144463