[libcxx-commits] [libcxx] [libc++][math] Fix undue overflowing of `std::hypot(x, y, z)` (PR #93350)

[Louis Dionne via libcxx-commits]

================
@@ -41,6 +46,83 @@ inline _LIBCPP_HIDE_FROM_ABI typename __promote<_A1, _A2>::type hypot(_A1 __x, _
   return __math::hypot((__result_type)__x, (__result_type)__y);
 }
 
+#if _LIBCPP_STD_VER >= 17
+template <class _Real>
+struct __hypot_factors {
+  _Real __threshold;
+  _Real __scale_xyz;
+  _Real __scale_M;
+};
+
+// returns [underflow_factors, overflow_factors]
+template <class _Real>
+std::array<__hypot_factors<_Real>, 2> __create_factors() {
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ldionne wrote:

```suggestion
_LIBCPP_HIDE_FROM_ABI array<__hypot_factors<_Real>, 2> __create_factors() {
```

https://github.com/llvm/llvm-project/pull/93350