github.com/afumu/libc@v0.0.6/musl/src/math/i386/atanf.s (about)

     1  .global atanf
     2  .type atanf,@function
     3  atanf:
     4  	flds 4(%esp)
     5  	mov 4(%esp),%eax
     6  	add %eax,%eax
     7  	cmp $0x01000000,%eax
     8  	jb 1f
     9  	fld1
    10  	fpatan
    11  	fstps 4(%esp)
    12  	flds 4(%esp)
    13  	ret
    14  		# subnormal x, return x with underflow
    15  1:	fld %st(0)
    16  	fmul %st(1)
    17  	fstps 4(%esp)
    18  	ret