This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.
double. You should be able to just replace every usage of jsdouble with double in your code.
jsdouble is a C floating-point number type. It is defined to be a 64-bit, IEEE 754 compliant type. See ECMA 262-3 §8.5. Arithmetic on
Implementation note: SpiderMonkey has had several bugs involving details of floating-point arithmetic on various platforms. Controlling the behavior of floating-point arithmetic is very architecture- and system-specific, and can be hard to get right. Help in the form of test cases, commentary, and patches is always appreciated.