Some x87 FPU source range restrictions are not regarded by the Jit yet

[PeterK]

When looking into the Intel Vol2 instruction set manual I was just remembered that some x87 FPU instructions have limitations for the valid range of the source operands, which is not handled by the Jit code yet. It would make many functions a lot more complex, if all operands were checked and reduced to the supported range. Just one example, FSIN:

This instruction calculates the sine of the source operand in register ST(0) and stores the result in ST(0). The source operand must be given in radians and must be within the range -2^63 to +2^63.

If the source operand is outside the acceptable range, the C2 flag in the FPU status word is set, and the value in register ST(0) remains unchanged. The instruction does not raise an exception when the source operand is out of range. It is up to the program to check the C2 flag for out of range conditions. Source values outside the range -2^63 to +2^63 can be reduced to the range of the instruction by subtracting an appropriate integer multiple of 2*Pi or by using the FPREM instruction with a divisor of 2*Pi.

The Amiga Programmers Reference Manual says:

If the source operand is not in the range of [–2*Pi ... +2*Pi], the argument is reduced to within that range before the sine is calculated.

No idea, if it's worth to support values out of range?

Update:
Thought about it last night: No, it's not worth to care about larger operands. Even with a 63 bit mantissa you are losing all the remaining exactness if you multiply it with more than 2^63. So, you would start dealing with integer numbers and that's like pointing to random spots on the 2*Pi circle. I think it won't get exact anymore when you reduce the number with FPREM(2*Pi, x). Or what's the trick behind Intel's suggestion? I don't get it. I guess, the reduction only makes it possible to get pointless results instead of nothing.