perf(math): inline measured high-low arithmetic call boundaries

src/fesa/math/high_low_arithmetic.h

@@ -55,7 +55,13 @@ inline bool IsFinite(HighLow value) {
   return IsFiniteBinary64(value.high) && IsFiniteBinary64(value.low);
 }
 /// @brief Recovers the exact error of supported finite binary64 addition.
-inline HighLow TwoSum(double left, double right) {
+/// @note Requests local expansion at the measured MSVC x64 call boundary.
+#if defined(_MSC_VER) && defined(_M_X64)
+__forceinline
+#else
+inline
+#endif
+HighLow TwoSum(double left, double right) {
   const double sum = left + right;
   const double bridge = sum - left;
   const double restored_left = sum - bridge;
@@ -105,7 +111,13 @@ inline HighLow Subtract(HighLow left, HighLow right) {
 }
 /// @brief Returns the exponent of the least nonzero binary64 significand bit.
 /// @pre value is finite and nonzero; gradual underflow is enabled.
-inline int LowestBitExponent(double value) {
+/// @note Keeps the small integer search inside its measured MSVC x64 caller.
+#if defined(_MSC_VER) && defined(_M_X64)
+__forceinline
+#else
+inline
+#endif
+int LowestBitExponent(double value) {
   static_assert(sizeof(double) == sizeof(std::uint64_t) &&
                 std::numeric_limits<double>::is_iec559 &&
                 std::numeric_limits<double>::digits == 53);