| Alexey Brodkin | b628c01 | 2014-02-04 12:56:15 +0400 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2004, 2007-2010, 2011-2014 Synopsys, Inc. All rights reserved. |
| 3 | * |
| 4 | * SPDX-License-Identifier: GPL-2.0+ |
| 5 | */ |
| 6 | |
| 7 | /* |
| 8 | * If dst and src are 4 byte aligned, copy 8 bytes at a time. |
| 9 | * If the src is 4, but not 8 byte aligned, we first read 4 bytes to get |
| 10 | * it 8 byte aligned. Thus, we can do a little read-ahead, without |
| 11 | * dereferencing a cache line that we should not touch. |
| 12 | * Note that short and long instructions have been scheduled to avoid |
| 13 | * branch stalls. |
| 14 | * The beq_s to r3z could be made unaligned & long to avoid a stall |
| 15 | * there, but it is not likely to be taken often, and it would also be likely |
| 16 | * to cost an unaligned mispredict at the next call. |
| 17 | */ |
| 18 | |
| 19 | .global strcpy |
| 20 | .align 4 |
| 21 | strcpy: |
| 22 | or %r2, %r0, %r1 |
| 23 | bmsk_s %r2, %r2, 1 |
| 24 | brne.d %r2, 0, charloop |
| 25 | mov_s %r10, %r0 |
| 26 | ld_s %r3, [%r1, 0] |
| 27 | mov %r8, 0x01010101 |
| 28 | bbit0.d %r1, 2, loop_start |
| 29 | ror %r12, %r8 |
| 30 | sub %r2, %r3, %r8 |
| 31 | bic_s %r2, %r2, %r3 |
| 32 | tst_s %r2,%r12 |
| 33 | bne r3z |
| 34 | mov_s %r4,%r3 |
| 35 | .balign 4 |
| 36 | loop: |
| 37 | ld.a %r3, [%r1, 4] |
| 38 | st.ab %r4, [%r10, 4] |
| 39 | loop_start: |
| 40 | ld.a %r4, [%r1, 4] |
| 41 | sub %r2, %r3, %r8 |
| 42 | bic_s %r2, %r2, %r3 |
| 43 | tst_s %r2, %r12 |
| 44 | bne_s r3z |
| 45 | st.ab %r3, [%r10, 4] |
| 46 | sub %r2, %r4, %r8 |
| 47 | bic %r2, %r2, %r4 |
| 48 | tst %r2, %r12 |
| 49 | beq loop |
| 50 | mov_s %r3, %r4 |
| 51 | #ifdef __LITTLE_ENDIAN__ |
| 52 | r3z: bmsk.f %r1, %r3, 7 |
| 53 | lsr_s %r3, %r3, 8 |
| 54 | #else /* __BIG_ENDIAN__ */ |
| 55 | r3z: lsr.f %r1, %r3, 24 |
| 56 | asl_s %r3, %r3, 8 |
| 57 | #endif /* _ENDIAN__ */ |
| 58 | bne.d r3z |
| 59 | stb.ab %r1, [%r10, 1] |
| 60 | j_s [%blink] |
| 61 | |
| 62 | .balign 4 |
| 63 | charloop: |
| 64 | ldb.ab %r3, [%r1, 1] |
| 65 | brne.d %r3, 0, charloop |
| 66 | stb.ab %r3, [%r10, 1] |
| 67 | j [%blink] |