jedi-academy/codemp/unix/ftol.nasm
2013-04-04 17:35:38 -05:00

131 lines
2.1 KiB
NASM

;
; qftol -- fast floating point to long conversion.
;
segment .data
temp dd 0.0
fpucw dd 0
; Precision Control Field , 2 bits / 0x0300
; PC24 0x0000 Single precision (24 bits).
; PC53 0x0200 Double precision (53 bits).
; PC64 0x0300 Extended precision (64 bits).
; Rounding Control Field, 2 bits / 0x0C00
; RCN 0x0000 Rounding to nearest (even).
; RCD 0x0400 Rounding down (directed, minus).
; RCU 0x0800 Rounding up (directed plus).
; RC0 0x0C00 Rounding towards zero (chop mode).
; rounding towards nearest (even)
cw027F dd 0x027F ; double precision
cw037F dd 0x037F ; extended precision
; rounding towards zero (chop mode)
cw0E7F dd 0x0E7F ; double precision
cw0F7F dd 0x0F7F ; extended precision
segment .text
;
; int qftol( void ) - default control word
;
global qftol
qftol:
fistp dword [temp]
mov eax, [temp]
ret
;
; int qftol027F( void ) - DirectX FPU
;
global qftol027F
qftol027F:
fnstcw [fpucw]
fldcw [cw027F]
fistp dword [temp]
fldcw [fpucw]
mov eax, [temp]
ret
;
; int qftol037F( void ) - Linux FPU
;
global qftol037F
qftol037F:
fnstcw [fpucw]
fldcw [cw037F]
fistp dword [temp]
fldcw [fpucw]
mov eax, [temp]
ret
;
; int qftol0F7F( void ) - ANSI
;
global qftol0F7F
qftol0F7F:
fnstcw [fpucw]
fldcw [cw0F7F]
fistp dword [temp]
fldcw [fpucw]
mov eax, [temp]
ret
;
; int qftol0E7F( void )
;
global qftol0E7F
qftol0E7F:
fnstcw [fpucw]
fldcw [cw0E7F]
fistp dword [temp]
fldcw [fpucw]
mov eax, [temp]
ret
;
; long Q_ftol( float q )
;
global Q_ftol
Q_ftol:
fld dword [esp+4]
fistp dword [temp]
mov eax, [temp]
ret
;
; long qftol0F7F( float q ) - Linux FPU
;
global Q_ftol0F7F
Q_ftol0F7F:
fnstcw [fpucw]
fld dword [esp+4]
fldcw [cw0F7F]
fistp dword [temp]
fldcw [fpucw]
mov eax, [temp]
ret