shithub: mc

ref: f2e8e641bf8ee06fa5128c522b151a7f4d9d003b
dir: /lib/math/test/atan-impl.myr/

use std
use math
use testr

const main = {
	math.fptrap(false)
	testr.run([
		[.name="atan-01", .fn = atan01], /* atan, flt32 */
		[.name="atan-02", .fn = atan02], /* atan, flt64 */
		[.name="atan-03", .fn = atan03], /* atan2, flt32 */
		[.name="atan-04", .fn = atan04], /* atan2, flt64 */
		[.name="atan-05", .fn = atan05], /* off-by-1-ulp quarantine */
		[.name="atan-06", .fn = atan06], /* exhaustively test C */
		[.name="atan-07", .fn = atan07], /* NaN handling */
	][:])
}

const same32 = {a, b
	if a == b
		-> true
	;;

	if std.isnan(std.flt32frombits(a)) && std.isnan(std.flt32frombits(b))
		-> true
	;;

	-> false
}

const same64 = {a, b
	if a == b
		-> true
	;;

	if std.isnan(std.flt64frombits(a)) && std.isnan(std.flt64frombits(b))
		-> true
	;;

	-> false
}

const atan01 = {c
	var inputs : (uint32, uint32)[:] = [
		(0x00000000, 0x00000000),
		(0xec0c0000, 0xbfc90fdb),
		(0xd30d0000, 0xbfc90fdb),
		(0x4c120000, 0x3fc90fda),
		(0x0c010000, 0x0c010000),
		(0xc0070000, 0xbf9065b4),
	][:]

	for (x, y) : inputs
		var xf : flt32 = std.flt32frombits(x)
		var yf : flt32 = std.flt32frombits(y)
		var a1f : flt32 = math.atan(xf)
		var a2f : flt32 = math.atan2(xf, 1.0)
		var a1u : uint32 = std.flt32bits(a1f)
		var a2u : uint32 = std.flt32bits(a2f)
		testr.check(c, same32(a1u, a2u),
			"atan(0x{b=16,w=8,p=0}) = 0x{b=16,w=8,p=0}, but atan2(0x{b=16,w=8,p=0}, 1.0) = 0x{b=16,w=8,p=0}",
			x, a1u, x, a2u)

		testr.check(c, same32(a1u, y),
			"atan(0x{b=16,w=8,p=0}) = 0x{b=16,w=8,p=0}, should be 0x{b=16,w=8,p=0}",
			x, a1u, y)
	;;
}

const atan02 = {c
}

const atan03 = {c
}

const atan04 = {c
}

const atan05 = {c
}

const atan06 = {c
}

const atan07 = {c
	testr.check(c, std.isnan(math.atan(std.flt64nan())), "atan(NaN64) should be NaN")
	testr.check(c, std.isnan(math.atan(std.flt32nan())), "atan(NaN32) should be NaN")

	testr.check(c, std.isnan(math.atan2(std.flt64nan(), 3.0)), "atan2(NaN64, 3.0) should be NaN")
	testr.check(c, std.isnan(math.atan2(std.flt32nan(), -2.0)), "atan2(NaN32, -2.0) should be NaN")
	testr.check(c, std.isnan(math.atan2(6.0, std.flt64nan())), "atan2(6.0, NaN64) should be NaN")
	testr.check(c, std.isnan(math.atan2(4.0, std.flt32nan())), "atan2(4.0, NaN32) should be NaN")
}