math: Sin returns value not in [-1, 1] for very large values #7110
Description
by zhuwl08:
I'm using go version go1.2 darwin/amd64, but the issue still exists in the latest go src. Here is the demo code: http://play.golang.org/p/K4Fc8ts24u {{{ a := 387001390666326231482368.000000 fmt.Printf("Sin(a) = %e\n", math.Sin(a)) }}} The output is {{{ Sin(a) = 6.944847e+296 }}} I know that for a large float, it's hard to get the accurate value for math.Sin, but I expected that the return value should be in range [-1, 1], at least, which I rely on to produce a reasonable value for other input.