1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * linux/arch/alpha/lib/memset.S
4 *
5 * This is an efficient (and small) implementation of the C library "memset()"
6 * function for the alpha.
7 *
8 *	(C) Copyright 1996 Linus Torvalds
9 *
10 * This routine is "moral-ware": you are free to use it any way you wish, and
11 * the only obligation I put on you is a moral one: if you make any improvements
12 * to the routine, please send me your improvements for me to use similarly.
13 *
14 * The scheduling comments are according to the EV5 documentation (and done by
15 * hand, so they might well be incorrect, please do tell me about it..)
16 */
17#include <linux/export.h>
18	.set noat
19	.set noreorder
20.text
21	.globl memset
22	.globl __memset
23	.globl ___memset
24	.globl __memset16
25	.globl __constant_c_memset
26
27	.ent ___memset
28.align 5
29___memset:
30	.frame $30,0,$26,0
31	.prologue 0
32
33	and $17,255,$1		/* E1 */
34	insbl $17,1,$17		/* .. E0 */
35	bis $17,$1,$17		/* E0 (p-c latency, next cycle) */
36	sll $17,16,$1		/* E1 (p-c latency, next cycle) */
37
38	bis $17,$1,$17		/* E0 (p-c latency, next cycle) */
39	sll $17,32,$1		/* E1 (p-c latency, next cycle) */
40	bis $17,$1,$17		/* E0 (p-c latency, next cycle) */
41	ldq_u $31,0($30)	/* .. E1 */
42
43.align 5
44__constant_c_memset:
45	addq $18,$16,$6		/* E0 */
46	bis $16,$16,$0		/* .. E1 */
47	xor $16,$6,$1		/* E0 */
48	ble $18,end		/* .. E1 */
49
50	bic $1,7,$1		/* E0 */
51	beq $1,within_one_quad	/* .. E1 (note EV5 zero-latency forwarding) */
52	and $16,7,$3		/* E0 */
53	beq $3,aligned		/* .. E1 (note EV5 zero-latency forwarding) */
54
55	ldq_u $4,0($16)		/* E0 */
56	bis $16,$16,$5		/* .. E1 */
57	insql $17,$16,$2	/* E0 */
58	subq $3,8,$3		/* .. E1 */
59
60	addq $18,$3,$18		/* E0	$18 is new count ($3 is negative) */
61	mskql $4,$16,$4		/* .. E1 (and possible load stall) */
62	subq $16,$3,$16		/* E0 	$16 is new aligned destination */
63	bis $2,$4,$1		/* .. E1 */
64
65	bis $31,$31,$31		/* E0 */
66	ldq_u $31,0($30)	/* .. E1 */
67	stq_u $1,0($5)		/* E0 */
68	bis $31,$31,$31		/* .. E1 */
69
70.align 4
71aligned:
72	sra $18,3,$3		/* E0 */
73	and $18,7,$18		/* .. E1 */
74	bis $16,$16,$5		/* E0 */
75	beq $3,no_quad		/* .. E1 */
76
77.align 3
78loop:
79	stq $17,0($5)		/* E0 */
80	subq $3,1,$3		/* .. E1 */
81	addq $5,8,$5		/* E0 */
82	bne $3,loop		/* .. E1 */
83
84no_quad:
85	bis $31,$31,$31		/* E0 */
86	beq $18,end		/* .. E1 */
87	ldq $7,0($5)		/* E0 */
88	mskqh $7,$6,$2		/* .. E1 (and load stall) */
89
90	insqh $17,$6,$4		/* E0 */
91	bis $2,$4,$1		/* .. E1 */
92	stq $1,0($5)		/* E0 */
93	ret $31,($26),1		/* .. E1 */
94
95.align 3
96within_one_quad:
97	ldq_u $1,0($16)		/* E0 */
98	insql $17,$16,$2	/* E1 */
99	mskql $1,$16,$4		/* E0 (after load stall) */
100	bis $2,$4,$2		/* E0 */
101
102	mskql $2,$6,$4		/* E0 */
103	mskqh $1,$6,$2		/* .. E1 */
104	bis $2,$4,$1		/* E0 */
105	stq_u $1,0($16)		/* E0 */
106
107end:
108	ret $31,($26),1		/* E1 */
109	.end ___memset
110EXPORT_SYMBOL(___memset)
111EXPORT_SYMBOL(__constant_c_memset)
112
113	.align 5
114	.ent __memset16
115__memset16:
116	.prologue 0
117
118	inswl $17,0,$1		/* E0 */
119	inswl $17,2,$2		/* E0 */
120	inswl $17,4,$3		/* E0 */
121	or $1,$2,$1		/* .. E1 */
122	inswl $17,6,$4		/* E0 */
123	or $1,$3,$1		/* .. E1 */
124	or $1,$4,$17		/* E0 */
125	br __constant_c_memset	/* .. E1 */
126
127	.end __memset16
128EXPORT_SYMBOL(__memset16)
129
130memset = ___memset
131__memset = ___memset
132	EXPORT_SYMBOL(memset)
133	EXPORT_SYMBOL(__memset)
134