1/*
  2 *  linux/arch/arm/lib/memset.S
  3 *
  4 *  Copyright (C) 1995-2000 Russell King
  5 *
  6 * This program is free software; you can redistribute it and/or modify
  7 * it under the terms of the GNU General Public License version 2 as
  8 * published by the Free Software Foundation.
  9 *
 10 *  ASM optimised string functions
 11 */
 12#include <linux/linkage.h>
 13#include <asm/assembler.h>
 14
 15	.text
 16	.align	5
 
 
 
 
 
 
 
 
 
 
 
 
 
 17
 18ENTRY(memset)
 19	ands	r3, r0, #3		@ 1 unaligned?
 20	mov	ip, r0			@ preserve r0 as return value
 21	bne	6f			@ 1
 22/*
 23 * we know that the pointer in ip is aligned to a word boundary.
 24 */
 251:	orr	r1, r1, r1, lsl #8
 26	orr	r1, r1, r1, lsl #16
 27	mov	r3, r1
 28	cmp	r2, #16
 29	blt	4f
 30
 31#if ! CALGN(1)+0
 32
 33/*
 34 * We need 2 extra registers for this loop - use r8 and the LR
 
 35 */
 36	stmfd	sp!, {r8, lr}
 37	mov	r8, r1
 38	mov	lr, r1
 39
 402:	subs	r2, r2, #64
 41	stmgeia	ip!, {r1, r3, r8, lr}	@ 64 bytes at a time.
 42	stmgeia	ip!, {r1, r3, r8, lr}
 43	stmgeia	ip!, {r1, r3, r8, lr}
 44	stmgeia	ip!, {r1, r3, r8, lr}
 45	bgt	2b
 46	ldmeqfd	sp!, {r8, pc}		@ Now <64 bytes to go.
 47/*
 48 * No need to correct the count; we're only testing bits from now on
 49 */
 50	tst	r2, #32
 51	stmneia	ip!, {r1, r3, r8, lr}
 52	stmneia	ip!, {r1, r3, r8, lr}
 53	tst	r2, #16
 54	stmneia	ip!, {r1, r3, r8, lr}
 55	ldmfd	sp!, {r8, lr}
 56
 57#else
 58
 59/*
 60 * This version aligns the destination pointer in order to write
 61 * whole cache lines at once.
 62 */
 63
 64	stmfd	sp!, {r4-r8, lr}
 65	mov	r4, r1
 66	mov	r5, r1
 67	mov	r6, r1
 68	mov	r7, r1
 69	mov	r8, r1
 70	mov	lr, r1
 71
 72	cmp	r2, #96
 73	tstgt	ip, #31
 74	ble	3f
 75
 76	and	r8, ip, #31
 77	rsb	r8, r8, #32
 78	sub	r2, r2, r8
 79	movs	r8, r8, lsl #(32 - 4)
 80	stmcsia	ip!, {r4, r5, r6, r7}
 81	stmmiia	ip!, {r4, r5}
 82	tst	r8, #(1 << 30)
 83	mov	r8, r1
 84	strne	r1, [ip], #4
 85
 863:	subs	r2, r2, #64
 87	stmgeia	ip!, {r1, r3-r8, lr}
 88	stmgeia	ip!, {r1, r3-r8, lr}
 89	bgt	3b
 90	ldmeqfd	sp!, {r4-r8, pc}
 91
 92	tst	r2, #32
 93	stmneia	ip!, {r1, r3-r8, lr}
 94	tst	r2, #16
 95	stmneia	ip!, {r4-r7}
 96	ldmfd	sp!, {r4-r8, lr}
 97
 98#endif
 99
1004:	tst	r2, #8
101	stmneia	ip!, {r1, r3}
102	tst	r2, #4
103	strne	r1, [ip], #4
104/*
105 * When we get here, we've got less than 4 bytes to zero.  We
106 * may have an unaligned pointer as well.
107 */
1085:	tst	r2, #2
109	strneb	r1, [ip], #1
110	strneb	r1, [ip], #1
111	tst	r2, #1
112	strneb	r1, [ip], #1
113	mov	pc, lr
114
1156:	subs	r2, r2, #4		@ 1 do we have enough
116	blt	5b			@ 1 bytes to align with?
117	cmp	r3, #2			@ 1
118	strltb	r1, [ip], #1		@ 1
119	strleb	r1, [ip], #1		@ 1
120	strb	r1, [ip], #1		@ 1
121	add	r2, r2, r3		@ 1 (r2 = r2 - (4 - r3))
122	b	1b
123ENDPROC(memset)

  1/*
  2 *  linux/arch/arm/lib/memset.S
  3 *
  4 *  Copyright (C) 1995-2000 Russell King
  5 *
  6 * This program is free software; you can redistribute it and/or modify
  7 * it under the terms of the GNU General Public License version 2 as
  8 * published by the Free Software Foundation.
  9 *
 10 *  ASM optimised string functions
 11 */
 12#include <linux/linkage.h>
 13#include <asm/assembler.h>
 14
 15	.text
 16	.align	5
 17	.word	0
 18
 191:	subs	r2, r2, #4		@ 1 do we have enough
 20	blt	5f			@ 1 bytes to align with?
 21	cmp	r3, #2			@ 1
 22	strltb	r1, [r0], #1		@ 1
 23	strleb	r1, [r0], #1		@ 1
 24	strb	r1, [r0], #1		@ 1
 25	add	r2, r2, r3		@ 1 (r2 = r2 - (4 - r3))
 26/*
 27 * The pointer is now aligned and the length is adjusted.  Try doing the
 28 * memset again.
 29 */
 30
 31ENTRY(memset)
 32	ands	r3, r0, #3		@ 1 unaligned?
 33	bne	1b			@ 1
 
 34/*
 35 * we know that the pointer in r0 is aligned to a word boundary.
 36 */
 37	orr	r1, r1, r1, lsl #8
 38	orr	r1, r1, r1, lsl #16
 39	mov	r3, r1
 40	cmp	r2, #16
 41	blt	4f
 42
 43#if ! CALGN(1)+0
 44
 45/*
 46 * We need an extra register for this loop - save the return address and
 47 * use the LR
 48 */
 49	str	lr, [sp, #-4]!
 50	mov	ip, r1
 51	mov	lr, r1
 52
 532:	subs	r2, r2, #64
 54	stmgeia	r0!, {r1, r3, ip, lr}	@ 64 bytes at a time.
 55	stmgeia	r0!, {r1, r3, ip, lr}
 56	stmgeia	r0!, {r1, r3, ip, lr}
 57	stmgeia	r0!, {r1, r3, ip, lr}
 58	bgt	2b
 59	ldmeqfd	sp!, {pc}		@ Now <64 bytes to go.
 60/*
 61 * No need to correct the count; we're only testing bits from now on
 62 */
 63	tst	r2, #32
 64	stmneia	r0!, {r1, r3, ip, lr}
 65	stmneia	r0!, {r1, r3, ip, lr}
 66	tst	r2, #16
 67	stmneia	r0!, {r1, r3, ip, lr}
 68	ldr	lr, [sp], #4
 69
 70#else
 71
 72/*
 73 * This version aligns the destination pointer in order to write
 74 * whole cache lines at once.
 75 */
 76
 77	stmfd	sp!, {r4-r7, lr}
 78	mov	r4, r1
 79	mov	r5, r1
 80	mov	r6, r1
 81	mov	r7, r1
 82	mov	ip, r1
 83	mov	lr, r1
 84
 85	cmp	r2, #96
 86	tstgt	r0, #31
 87	ble	3f
 88
 89	and	ip, r0, #31
 90	rsb	ip, ip, #32
 91	sub	r2, r2, ip
 92	movs	ip, ip, lsl #(32 - 4)
 93	stmcsia	r0!, {r4, r5, r6, r7}
 94	stmmiia	r0!, {r4, r5}
 95	tst	ip, #(1 << 30)
 96	mov	ip, r1
 97	strne	r1, [r0], #4
 98
 993:	subs	r2, r2, #64
100	stmgeia	r0!, {r1, r3-r7, ip, lr}
101	stmgeia	r0!, {r1, r3-r7, ip, lr}
102	bgt	3b
103	ldmeqfd	sp!, {r4-r7, pc}
104
105	tst	r2, #32
106	stmneia	r0!, {r1, r3-r7, ip, lr}
107	tst	r2, #16
108	stmneia	r0!, {r4-r7}
109	ldmfd	sp!, {r4-r7, lr}
110
111#endif
112
1134:	tst	r2, #8
114	stmneia	r0!, {r1, r3}
115	tst	r2, #4
116	strne	r1, [r0], #4
117/*
118 * When we get here, we've got less than 4 bytes to zero.  We
119 * may have an unaligned pointer as well.
120 */
1215:	tst	r2, #2
122	strneb	r1, [r0], #1
123	strneb	r1, [r0], #1
124	tst	r2, #1
125	strneb	r1, [r0], #1
126	mov	pc, lr
 
 
 
 
 
 
 
 
 
127ENDPROC(memset)