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Diffstat (limited to 'sysdeps/arm/armv6/strrchr.S')
| -rw-r--r-- | sysdeps/arm/armv6/strrchr.S | 129 |
1 files changed, 0 insertions, 129 deletions
diff --git a/sysdeps/arm/armv6/strrchr.S b/sysdeps/arm/armv6/strrchr.S deleted file mode 100644 index e6eea01816..0000000000 --- a/sysdeps/arm/armv6/strrchr.S +++ /dev/null @@ -1,129 +0,0 @@ -/* strrchr -- find the last occurence of C in 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> - - .syntax unified - .text - -ENTRY (strrchr) - @ r0 = start of string - @ r1 = character to match - @ returns NULL for no match, or a pointer to the match - - mov r3, r0 - mov r0, #0 - uxtb r1, r1 - - @ Loop a few times until we're aligned. - tst r3, #7 - beq 2f -1: ldrb r2, [r3], #1 - cmp r2, r1 @ Find the character - it eq - subeq r0, r3, #1 - cmp r2, #0 @ Find EOS - it eq - bxeq lr - tst r3, #7 @ Find the aligment point - bne 1b - - @ So now we're aligned. Now we actually need a stack frame. -2: 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) - - orr r1, r1, r1, lsl #8 @ Replicate C to all bytes -#ifdef ARCH_HAS_T2 - movw ip, #0x0101 - movt ip, #0x0101 -#else - ldr ip, =0x01010101 -#endif - orr r1, r1, r1, lsl #16 - mov r2, #0 @ No found bits yet - - @ Loop searching for EOS and C, 8 bytes at a time. - @ Any time we find a match in a word, we copy the address of - @ the word to r0, and the found bits to r2. -3: ldrd r4, r5, [r3], #8 - @ Subtracting (unsigned saturating) from 1 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. - uqsub8 r6, ip, r4 @ Find EOS - uqsub8 r7, ip, r5 - eor r4, r4, r1 @ Convert C bytes to 0 - eor r5, r5, r1 - uqsub8 r4, ip, r4 @ Find C - uqsub8 r5, ip, r5 - cmp r6, #0 @ Found EOS, first word - bne 4f - cmp r4, #0 @ Handle C, first word - itt ne - subne r0, r3, #8 - movne r2, r4 - cmp r7, #0 @ Found EOS, second word - bne 5f - cmp r5, #0 @ Handle C, second word - itt ne - subne r0, r3, #4 - movne r2, r5 - b 3b - - @ Found EOS in second word; fold to first word. -5: add r3, r3, #4 @ Dec pointer to 2nd word, with below - mov r4, r5 @ Overwrite first word C found - mov r6, r7 @ Overwrite first word EOS found - - @ Found EOS. Zap found C after EOS. -4: sub r3, r3, #8 @ Decrement pointer to first word -#ifdef __ARMEB__ - @ Byte swap to be congruent with LE, which is easier from here on. - rev r6, r6 @ Byte swap found EOS, - rev r4, r4 @ ... this found C - rev r2, r2 @ ... prev found C -#endif - sub r7, r6, #1 @ Toggle EOS lsb and below - eor r6, r6, r7 @ All bits below and including lsb - ands r4, r4, r6 @ Zap C above EOS - itt ne - movne r2, r4 @ Copy to result, if still non-zero - movne r0, r3 - - pop { r4, r5, r6, r7 } - cfi_adjust_cfa_offset (-16) - cfi_restore (r4) - cfi_restore (r5) - cfi_restore (r6) - cfi_restore (r7) - - @ Adjust the result pointer if we found a word containing C. - cmp r2, #0 - clz r2, r2 @ Find the bit offset of the last C - itt ne - rsbne r2, r2, #32 @ Convert to a count from the right - addne r0, r0, r2, lsr #3 @ Convert to byte offset and add. - bx lr - -END (strrchr) - -weak_alias (strrchr, rindex) -libc_hidden_builtin_def (strrchr) |