1/*
2 * linux/arch/alpha/lib/memset.S
3 *
4 * This is an efficient (and small) implementation of the C library "memset()"
5 * function for the alpha.
6 *
7 *	(C) Copyright 1996 Linus Torvalds
8 *
9 * This routine is "moral-ware": you are free to use it any way you wish, and
10 * the only obligation I put on you is a moral one: if you make any improvements
11 * to the routine, please send me your improvements for me to use similarly.
12 *
13 * The scheduling comments are according to the EV5 documentation (and done by
14 * hand, so they might well be incorrect, please do tell me about it..)
15 */
16
17	.set noat
18	.set noreorder
19.text
20	.globl memset
21	.globl __memset
22	.globl __memsetw
23	.globl __constant_c_memset
24	.ent __memset
25.align 5
26__memset:
27	.frame $30,0,$26,0
28	.prologue 0
29
30	and $17,255,$1		/* E1 */
31	insbl $17,1,$17		/* .. E0 */
32	bis $17,$1,$17		/* E0 (p-c latency, next cycle) */
33	sll $17,16,$1		/* E1 (p-c latency, next cycle) */
34
35	bis $17,$1,$17		/* E0 (p-c latency, next cycle) */
36	sll $17,32,$1		/* E1 (p-c latency, next cycle) */
37	bis $17,$1,$17		/* E0 (p-c latency, next cycle) */
38	ldq_u $31,0($30)	/* .. E1 */
39
40.align 5
41__constant_c_memset:
42	addq $18,$16,$6		/* E0 */
43	bis $16,$16,$0		/* .. E1 */
44	xor $16,$6,$1		/* E0 */
45	ble $18,end		/* .. E1 */
46
47	bic $1,7,$1		/* E0 */
48	beq $1,within_one_quad	/* .. E1 (note EV5 zero-latency forwarding) */
49	and $16,7,$3		/* E0 */
50	beq $3,aligned		/* .. E1 (note EV5 zero-latency forwarding) */
51
52	ldq_u $4,0($16)		/* E0 */
53	bis $16,$16,$5		/* .. E1 */
54	insql $17,$16,$2	/* E0 */
55	subq $3,8,$3		/* .. E1 */
56
57	addq $18,$3,$18		/* E0	$18 is new count ($3 is negative) */
58	mskql $4,$16,$4		/* .. E1 (and possible load stall) */
59	subq $16,$3,$16		/* E0 	$16 is new aligned destination */
60	bis $2,$4,$1		/* .. E1 */
61
62	bis $31,$31,$31		/* E0 */
63	ldq_u $31,0($30)	/* .. E1 */
64	stq_u $1,0($5)		/* E0 */
65	bis $31,$31,$31		/* .. E1 */
66
67.align 4
68aligned:
69	sra $18,3,$3		/* E0 */
70	and $18,7,$18		/* .. E1 */
71	bis $16,$16,$5		/* E0 */
72	beq $3,no_quad		/* .. E1 */
73
74.align 3
75loop:
76	stq $17,0($5)		/* E0 */
77	subq $3,1,$3		/* .. E1 */
78	addq $5,8,$5		/* E0 */
79	bne $3,loop		/* .. E1 */
80
81no_quad:
82	bis $31,$31,$31		/* E0 */
83	beq $18,end		/* .. E1 */
84	ldq $7,0($5)		/* E0 */
85	mskqh $7,$6,$2		/* .. E1 (and load stall) */
86
87	insqh $17,$6,$4		/* E0 */
88	bis $2,$4,$1		/* .. E1 */
89	stq $1,0($5)		/* E0 */
90	ret $31,($26),1		/* .. E1 */
91
92.align 3
93within_one_quad:
94	ldq_u $1,0($16)		/* E0 */
95	insql $17,$16,$2	/* E1 */
96	mskql $1,$16,$4		/* E0 (after load stall) */
97	bis $2,$4,$2		/* E0 */
98
99	mskql $2,$6,$4		/* E0 */
100	mskqh $1,$6,$2		/* .. E1 */
101	bis $2,$4,$1		/* E0 */
102	stq_u $1,0($16)		/* E0 */
103
104end:
105	ret $31,($26),1		/* E1 */
106	.end __memset
107
108	.align 5
109	.ent __memsetw
110__memsetw:
111	.prologue 0
112
113	inswl $17,0,$1		/* E0 */
114	inswl $17,2,$2		/* E0 */
115	inswl $17,4,$3		/* E0 */
116	or $1,$2,$1		/* .. E1 */
117	inswl $17,6,$4		/* E0 */
118	or $1,$3,$1		/* .. E1 */
119	or $1,$4,$17		/* E0 */
120	br __constant_c_memset	/* .. E1 */
121
122	.end __memsetw
123
124memset = __memset
125