diff --git a/libstdc++-v3/src/c++17/fast_float/fast_float.h b/libstdc++-v3/src/c++17/fast_float/fast_float.h index 7551c4f89ef7..3da58f2850ce 100644 --- a/libstdc++-v3/src/c++17/fast_float/fast_float.h +++ b/libstdc++-v3/src/c++17/fast_float/fast_float.h @@ -275,7 +275,8 @@ fastfloat_really_inline value128 full_multiplication(uint64_t a, // But MinGW on ARM64 doesn't have native support for 64-bit multiplications answer.high = __umulh(a, b); answer.low = a * b; -#elif defined(FASTFLOAT_32BIT) || (defined(_WIN64) && !defined(__clang__)) +#elif defined(FASTFLOAT_32BIT) || \ + (defined(_WIN64) && !defined(__clang__) && !defined(_M_ARM64)) answer.low = _umul128(a, b, &answer.high); // _umul128 not available on ARM64 #elif defined(FASTFLOAT_64BIT) __uint128_t r = ((__uint128_t)a) * b;