xref: /rk3399_rockchip-uboot/arch/arc/lib/strcpy-700.S (revision 1ad6364eeb4f578e423081d1748e8a3fdf1ab01d)
1*22723828SAlexey Brodkin/*
2*22723828SAlexey Brodkin * Copyright (C) 2004, 2007-2010, 2011-2014 Synopsys, Inc. All rights reserved.
3*22723828SAlexey Brodkin *
4*22723828SAlexey Brodkin * SPDX-License-Identifier:	GPL-2.0+
5*22723828SAlexey Brodkin */
6*22723828SAlexey Brodkin
7*22723828SAlexey Brodkin/*
8*22723828SAlexey Brodkin * If dst and src are 4 byte aligned, copy 8 bytes at a time.
9*22723828SAlexey Brodkin * If the src is 4, but not 8 byte aligned, we first read 4 bytes to get
10*22723828SAlexey Brodkin * it 8 byte aligned.  Thus, we can do a little read-ahead, without
11*22723828SAlexey Brodkin * dereferencing a cache line that we should not touch.
12*22723828SAlexey Brodkin * Note that short and long instructions have been scheduled to avoid
13*22723828SAlexey Brodkin * branch stalls.
14*22723828SAlexey Brodkin * The beq_s to r3z could be made unaligned & long to avoid a stall
15*22723828SAlexey Brodkin * there, but it is not likely to be taken often, and it would also be likely
16*22723828SAlexey Brodkin * to cost an unaligned mispredict at the next call.
17*22723828SAlexey Brodkin */
18*22723828SAlexey Brodkin
19*22723828SAlexey Brodkin.global strcpy
20*22723828SAlexey Brodkin.align 4
21*22723828SAlexey Brodkinstrcpy:
22*22723828SAlexey Brodkin	or	%r2, %r0, %r1
23*22723828SAlexey Brodkin	bmsk_s	%r2, %r2, 1
24*22723828SAlexey Brodkin	brne.d	%r2, 0, charloop
25*22723828SAlexey Brodkin	mov_s	%r10, %r0
26*22723828SAlexey Brodkin	ld_s	%r3, [%r1, 0]
27*22723828SAlexey Brodkin	mov	%r8, 0x01010101
28*22723828SAlexey Brodkin	bbit0.d	%r1, 2, loop_start
29*22723828SAlexey Brodkin	ror	%r12, %r8
30*22723828SAlexey Brodkin	sub	%r2, %r3, %r8
31*22723828SAlexey Brodkin	bic_s	%r2, %r2, %r3
32*22723828SAlexey Brodkin	tst_s	%r2,%r12
33*22723828SAlexey Brodkin	bne	r3z
34*22723828SAlexey Brodkin	mov_s	%r4,%r3
35*22723828SAlexey Brodkin	.balign 4
36*22723828SAlexey Brodkinloop:
37*22723828SAlexey Brodkin	ld.a	%r3, [%r1, 4]
38*22723828SAlexey Brodkin	st.ab	%r4, [%r10, 4]
39*22723828SAlexey Brodkinloop_start:
40*22723828SAlexey Brodkin	ld.a	%r4, [%r1, 4]
41*22723828SAlexey Brodkin	sub	%r2, %r3, %r8
42*22723828SAlexey Brodkin	bic_s	%r2, %r2, %r3
43*22723828SAlexey Brodkin	tst_s	%r2, %r12
44*22723828SAlexey Brodkin	bne_s	r3z
45*22723828SAlexey Brodkin	st.ab	%r3, [%r10, 4]
46*22723828SAlexey Brodkin	sub	%r2, %r4, %r8
47*22723828SAlexey Brodkin	bic	%r2, %r2, %r4
48*22723828SAlexey Brodkin	tst	%r2, %r12
49*22723828SAlexey Brodkin	beq	loop
50*22723828SAlexey Brodkin	mov_s	%r3, %r4
51*22723828SAlexey Brodkin#ifdef __LITTLE_ENDIAN__
52*22723828SAlexey Brodkinr3z:	bmsk.f	%r1, %r3, 7
53*22723828SAlexey Brodkin	lsr_s	%r3, %r3, 8
54*22723828SAlexey Brodkin#else /* __BIG_ENDIAN__ */
55*22723828SAlexey Brodkinr3z:	lsr.f	%r1, %r3, 24
56*22723828SAlexey Brodkin	asl_s	%r3, %r3, 8
57*22723828SAlexey Brodkin#endif /* _ENDIAN__ */
58*22723828SAlexey Brodkin	bne.d	r3z
59*22723828SAlexey Brodkin	stb.ab	%r1, [%r10, 1]
60*22723828SAlexey Brodkin	j_s	[%blink]
61*22723828SAlexey Brodkin
62*22723828SAlexey Brodkin	.balign	4
63*22723828SAlexey Brodkincharloop:
64*22723828SAlexey Brodkin	ldb.ab	%r3, [%r1, 1]
65*22723828SAlexey Brodkin	brne.d	%r3, 0, charloop
66*22723828SAlexey Brodkin	stb.ab	%r3, [%r10, 1]
67*22723828SAlexey Brodkin	j	[%blink]
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