## Tests for various features of IEC60559 doubles.
## Most of these are optional, so this is a sloppy test.

# Goes to denormal (aka subnormal) numbers at -708.4
exp(c(-745:-740, -730, -720, -710:-705))

# goes to subnormal numbers at -308, to zero at ca 5e-324.
10^-(324:307)
2^-(1022:1075)

# And because most libm pow() functions special-case integer powers.
10^-(324:307-0.01)/10^0.01

# IEC60559 mandates this, but C99/C11 do not.
# Mingw-w64 did not do so in v 2.0.1
x <- 0*(-1) # negative zero
sqrt(x)
sprintf("%g, rt = %g, .^2 = %g", x, sqrt(x), x^2)
identical(x, sqrt(x))