[libc-commits] [libc] [libc][math][c23] Add {ldexp, scalbn, scalbln}f16 C23 math functions (PR #94797)

[via libc-commits]

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@@ -183,6 +184,10 @@ template <size_t Bits> struct DyadicFloat {
     return r;
   }
 
+  LIBC_INLINE explicit constexpr operator float16() const {
+    return static_cast<float16>(static_cast<float>(*this));
+  }
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overmighty wrote:

By the way, they're the same inputs for which the test was initially failing before the `DyadicFloat<16>` change, which made me add `operator float16()`. So the incorrect result (in this specific case at least) still comes from this path:

```cpp
      return multiply_add(d_lo, T(round_and_sticky), d_hi * scale_up_factor) *
             scale_down_factor;
```
https://github.com/llvm/llvm-project/blob/main/libc/src/__support/FPUtil/dyadic_float.h#L160-L161

https://github.com/llvm/llvm-project/pull/94797