1.global atan2
 2.type atan2,@function
 3atan2:
 4	fldl 4(%esp)
 5	fldl 12(%esp)
 6	fpatan
 7	fstpl 4(%esp)
 8	fldl 4(%esp)
 9	mov 8(%esp),%eax
10	add %eax,%eax
11	cmp $0x00200000,%eax
12	jae 1f
13		# subnormal x, return x with underflow
14	fsts 4(%esp)
151:	ret