diff options
Diffstat (limited to 'sysdeps/arm/armv6/strcpy.S')
| -rw-r--r-- | sysdeps/arm/armv6/strcpy.S | 218 |
1 files changed, 0 insertions, 218 deletions
diff --git a/sysdeps/arm/armv6/strcpy.S b/sysdeps/arm/armv6/strcpy.S deleted file mode 100644 index 1b98dbce30..0000000000 --- a/sysdeps/arm/armv6/strcpy.S +++ /dev/null @@ -1,218 +0,0 @@ -/* strcpy -- copy a nul-terminated string. - Copyright (C) 2013-2017 Free Software Foundation, Inc. - This file is part of the GNU C Library. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library. If not, see - <http://www.gnu.org/licenses/>. */ - -#include <sysdep.h> - -/* Endian independent macros for shifting bytes within registers. */ -#ifdef __ARMEB__ -#define lsh_gt lsr -#define lsh_ls lsl -#else -#define lsh_gt lsl -#define lsh_ls lsr -#endif - - .syntax unified - .text - -ENTRY (__stpcpy) - @ Signal stpcpy with NULL in IP. - mov ip, #0 - b 0f -END (__stpcpy) - -weak_alias (__stpcpy, stpcpy) -libc_hidden_def (__stpcpy) -libc_hidden_builtin_def (stpcpy) - -ENTRY (strcpy) - @ Signal strcpy with DEST in IP. - mov ip, r0 -0: - pld [r0, #0] - pld [r1, #0] - - @ To cater to long strings, we want 8 byte alignment in the source. - @ To cater to small strings, we don't want to start that right away. - @ Loop up to 16 times, less whatever it takes to reach alignment. - and r3, r1, #7 - rsb r3, r3, #16 - - @ Loop until we find ... -1: ldrb r2, [r1], #1 - subs r3, r3, #1 @ ... the alignment point - strb r2, [r0], #1 - it ne - cmpne r2, #0 @ ... or EOS - bne 1b - - @ Disambiguate the exit possibilites above - cmp r2, #0 @ Found EOS - beq .Lreturn - - @ Load the next two words asap - ldrd r2, r3, [r1], #8 - pld [r0, #64] - pld [r1, #64] - - @ For longer strings, we actaully need a stack frame. - push { r4, r5, r6, r7 } - cfi_adjust_cfa_offset (16) - cfi_rel_offset (r4, 0) - cfi_rel_offset (r5, 4) - cfi_rel_offset (r6, 8) - cfi_rel_offset (r7, 12) - - @ Subtracting (unsigned saturating) from 1 for any byte means result - @ of 1 for any byte that was originally zero and 0 otherwise. - @ Therefore we consider the lsb of each byte the "found" bit. -#ifdef ARCH_HAS_T2 - movw r7, #0x0101 - tst r0, #3 @ Test alignment of DEST - movt r7, #0x0101 -#else - ldr r7, =0x01010101 - tst r0, #3 -#endif - bne .Lunaligned - - @ So now source (r1) is aligned to 8, and dest (r0) is aligned to 4. - @ Loop, reading 8 bytes at a time, searching for EOS. - .balign 16 -2: uqsub8 r4, r7, r2 @ Find EOS - uqsub8 r5, r7, r3 - pld [r1, #128] - cmp r4, #0 @ EOS in first word? - pld [r0, #128] - bne 3f - str r2, [r0], #4 - cmp r5, #0 @ EOS in second word? - bne 4f - str r3, [r0], #4 - ldrd r2, r3, [r1], #8 - b 2b - -3: sub r1, r1, #4 @ backup to first word -4: sub r1, r1, #4 @ backup to second word - - @ ... then finish up any tail a byte at a time. - @ Note that we generally back up and re-read source bytes, - @ but we'll not re-write dest bytes. -.Lbyte_loop: - ldrb r2, [r1], #1 - cmp r2, #0 - strb r2, [r0], #1 - bne .Lbyte_loop - - pop { r4, r5, r6, r7 } - cfi_remember_state - cfi_adjust_cfa_offset (-16) - cfi_restore (r4) - cfi_restore (r5) - cfi_restore (r6) - cfi_restore (r7) - -.Lreturn: - cmp ip, #0 @ Was this strcpy or stpcpy? - ite eq - subeq r0, r0, #1 @ stpcpy: undo post-inc from store - movne r0, ip @ strcpy: return original dest - bx lr - -.Lunaligned: - cfi_restore_state - @ Here, source is aligned to 8, but the destination is not word - @ aligned. Therefore we have to shift the data in order to be - @ able to perform aligned word stores. - - @ Find out which misalignment we're dealing with. - tst r0, #1 - beq .Lunaligned2 - tst r0, #2 - bne .Lunaligned3 - @ Fallthru to .Lunaligned1. - -.macro unaligned_copy unalign - @ Prologue to unaligned loop. Seed shifted non-zero bytes. - uqsub8 r4, r7, r2 @ Find EOS - uqsub8 r5, r7, r3 - cmp r4, #0 @ EOS in first word? - it ne - subne r1, r1, #8 - bne .Lbyte_loop -#ifdef __ARMEB__ - rev r2, r2 @ Byte stores below need LE data -#endif - @ Store a few bytes from the first word. - @ At the same time we align r0 and shift out bytes from r2. -.rept 4-\unalign - strb r2, [r0], #1 - lsr r2, r2, #8 -.endr -#ifdef __ARMEB__ - rev r2, r2 @ Undo previous rev -#endif - @ Rotated unaligned copy loop. The tail of the prologue is - @ shared with the loop itself. - .balign 8 -1: cmp r5, #0 @ EOS in second word? - bne 4f - @ Combine first and second words - orr r2, r2, r3, lsh_gt #(\unalign*8) - @ Save leftover bytes from the two words - lsh_ls r6, r3, #((4-\unalign)*8) - str r2, [r0], #4 - @ The "real" start of the unaligned copy loop. - ldrd r2, r3, [r1], #8 @ Load 8 more bytes - uqsub8 r4, r7, r2 @ Find EOS - pld [r1, #128] - uqsub8 r5, r7, r3 - pld [r0, #128] - cmp r4, #0 @ EOS in first word? - bne 3f - @ Combine the leftover and the first word - orr r6, r6, r2, lsh_gt #(\unalign*8) - @ Discard used bytes from the first word. - lsh_ls r2, r2, #((4-\unalign)*8) - str r6, [r0], #4 - b 1b - @ Found EOS in one of the words; adjust backward -3: sub r1, r1, #4 - mov r2, r6 -4: sub r1, r1, #4 - @ And store the remaining bytes from the leftover -#ifdef __ARMEB__ - rev r2, r2 -#endif -.rept \unalign - strb r2, [r0], #1 - lsr r2, r2, #8 -.endr - b .Lbyte_loop -.endm - -.Lunaligned1: - unaligned_copy 1 -.Lunaligned2: - unaligned_copy 2 -.Lunaligned3: - unaligned_copy 3 - -END (strcpy) - -libc_hidden_builtin_def (strcpy) |