forked from KolibriOS/kolibrios
24 lines
582 B
NASM
24 lines
582 B
NASM
|
|
||
|
|
format ELF
|
||
|
|
include '../proc32.inc'
|
||
|
|
section '.text' executable
|
||
|
|
|
||
|
|
public acos_ as "acos"
|
||
|
|
|
||
|
|
acos_:
|
||
|
|
|
||
|
|
; acos(x) = atan(sqrt((1-x*x)/(x*x)))
|
||
|
|
|
||
|
|
fld qword[esp+4]
|
||
|
|
fld st0 ;Duplicate X on tos.
|
||
|
|
fmul st0, st1 ;Compute X**2.
|
||
|
|
fld st0 ;Duplicate X**2 on tos.
|
||
|
|
fld1 ;Compute 1-X**2.
|
||
|
|
fsub st0, st1
|
||
|
|
fdiv st0, st1 ;Compute (1-x**2)/X**2.
|
||
|
|
fsqrt ;Compute sqrt((1-X**2)/X**2).
|
||
|
|
fld1 ;To compute full arctangent.
|
||
|
|
fpatan ;Compute atan of the above.
|
||
|
|
ret
|
||
|
|
|