[mirror_ubuntu-artful-kernel.git] / arch / h8300 / lib / mulsi3.S

;
; mulsi3 for H8/300H - based on Renesas SH implementation
;
; by Toshiyasu Morita
;
; Old code:
;
; 16b * 16b = 372 states (worst case)
; 32b * 32b = 724 states (worst case)
;
; New code:
;
; 16b * 16b =  48 states
; 16b * 32b =  72 states
; 32b * 32b =  92 states
;

	.global __mulsi3
__mulsi3:
	mov.w	r1,r2   ; ( 2 states) b * d
	mulxu	r0,er2  ; (22 states)

	mov.w	e0,r3   ; ( 2 states) a * d
	beq	L_skip1 ; ( 4 states)
	mulxu	r1,er3  ; (22 states)
	add.w	r3,e2   ; ( 2 states)

L_skip1:
	mov.w	e1,r3   ; ( 2 states) c * b
	beq	L_skip2 ; ( 4 states)
	mulxu	r0,er3  ; (22 states)
	add.w	r3,e2   ; ( 2 states)

L_skip2:
	mov.l	er2,er0	; ( 2 states)
	rts		; (10 states)

	.end
Commit	Line	Data
a71a29de YS	1	;
	2	; mulsi3 for H8/300H - based on Renesas SH implementation
	3	;
	4	; by Toshiyasu Morita
	5	;
	6	; Old code:
	7	;
	8	; 16b * 16b = 372 states (worst case)
	9	; 32b * 32b = 724 states (worst case)
	10	;
	11	; New code:
	12	;
	13	; 16b * 16b = 48 states
	14	; 16b * 32b = 72 states
	15	; 32b * 32b = 92 states
	16	;
	17
	18	.global __mulsi3
	19	__mulsi3:
	20	mov.w r1,r2 ; ( 2 states) b * d
	21	mulxu r0,er2 ; (22 states)
	22
	23	mov.w e0,r3 ; ( 2 states) a * d
	24	beq L_skip1 ; ( 4 states)
	25	mulxu r1,er3 ; (22 states)
	26	add.w r3,e2 ; ( 2 states)
	27
	28	L_skip1:
	29	mov.w e1,r3 ; ( 2 states) c * b
	30	beq L_skip2 ; ( 4 states)
	31	mulxu r0,er3 ; (22 states)
	32	add.w r3,e2 ; ( 2 states)
	33
	34	L_skip2:
	35	mov.l er2,er0 ; ( 2 states)
	36	rts ; (10 states)
	37
	38	.end