1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * "memset" implementation for SH4
  4 *
  5 * Copyright (C) 1999  Niibe Yutaka
  6 * Copyright (c) 2009  STMicroelectronics Limited
  7 * Author: Stuart Menefy <stuart.menefy:st.com>
  8 */
  9
 10/*
 11 *            void *memset(void *s, int c, size_t n);
 12 */
 13
 14#include <linux/linkage.h>
 15
 16ENTRY(memset)
 17	mov	#12,r0
 18	add	r6,r4
 19	cmp/gt	r6,r0
 20	bt/s	40f		! if it's too small, set a byte at once
 21	 mov	r4,r0
 22	and	#3,r0
 23	cmp/eq	#0,r0
 24	bt/s	2f		! It's aligned
 25	 sub	r0,r6
 261:
 27	dt	r0
 28	bf/s	1b
 29	 mov.b	r5,@-r4
 302:				! make VVVV
 31	extu.b	r5,r5
 32	swap.b	r5,r0		!   V0
 33	or	r0,r5		!   VV
 34	swap.w	r5,r0		! VV00
 35	or	r0,r5		! VVVV
 36
 37	! Check if enough bytes need to be copied to be worth the big loop
 38	mov	#0x40, r0	! (MT)
 39	cmp/gt	r6,r0		! (MT)  64 > len => slow loop
 40
 41	bt/s	22f
 42	 mov	r6,r0
 43
 44	! align the dst to the cache block size if necessary
 45	mov	r4, r3
 46	mov	#~(0x1f), r1
 47
 48	and	r3, r1
 49	cmp/eq	r3, r1
 50
 51	bt/s	11f		! dst is already aligned
 52	 sub	r1, r3		! r3-r1 -> r3
 53	shlr2	r3		! number of loops
 54
 5510:	mov.l	r5,@-r4
 56	dt	r3
 57	bf/s	10b
 58	 add	#-4, r6
 59
 6011:	! dst is 32byte aligned
 61	mov	r6,r2
 62	mov	#-5,r0
 63	shld	r0,r2		! number of loops
 64
 65	add	#-32, r4
 66	mov	r5, r0
 6712:
 68	movca.l	r0,@r4
 69	mov.l	r5,@(4, r4)
 70	mov.l	r5,@(8, r4)
 71	mov.l	r5,@(12,r4)
 72	mov.l	r5,@(16,r4)
 73	mov.l	r5,@(20,r4)
 74	add	#-0x20, r6
 75	mov.l	r5,@(24,r4)
 76	dt	r2
 77	mov.l	r5,@(28,r4)
 78	bf/s	12b
 79	 add	#-32, r4
 80
 81	add	#32, r4
 82	mov	#8, r0
 83	cmp/ge	r0, r6
 84	bf	40f
 85
 86	mov	r6,r0
 8722:
 88	shlr2	r0
 89	shlr	r0		! r0 = r6 >> 3
 903:
 91	dt	r0
 92	mov.l	r5,@-r4		! set 8-byte at once
 93	bf/s	3b
 94	 mov.l	r5,@-r4
 95	!
 96	mov	#7,r0
 97	and	r0,r6
 98
 99	! fill bytes (length may be zero)
10040:	tst	r6,r6
101	bt	5f
1024:
103	dt	r6
104	bf/s	4b
105	 mov.b	r5,@-r4
1065:
107	rts
108	 mov	r4,r0