diff options
Diffstat (limited to 'sysdeps/powerpc/powerpc32/power7/strnlen.S')
| -rw-r--r-- | sysdeps/powerpc/powerpc32/power7/strnlen.S | 176 |
1 files changed, 0 insertions, 176 deletions
diff --git a/sysdeps/powerpc/powerpc32/power7/strnlen.S b/sysdeps/powerpc/powerpc32/power7/strnlen.S deleted file mode 100644 index 6019d5be5b..0000000000 --- a/sysdeps/powerpc/powerpc32/power7/strnlen.S +++ /dev/null @@ -1,176 +0,0 @@ -/* Optimized strnlen implementation for PowerPC32/POWER7 using cmpb insn. - Copyright (C) 2010-2017 Free Software Foundation, Inc. - Contributed by Luis Machado <luisgpm@br.ibm.com>. - 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> - -/* int [r3] strnlen (char *s [r3], int size [r4]) */ - .machine power7 -ENTRY (__strnlen) - CALL_MCOUNT - dcbt 0,r3 - clrrwi r8,r3,2 /* Align the address to word boundary. */ - add r7,r3,r4 /* Calculate the last acceptable address. */ - cmplwi r4,16 - li r0,0 /* Word with null chars. */ - addi r7,r7,-1 - ble L(small_range) - - rlwinm r6,r3,3,27,28 /* Calculate padding. */ - lwz r12,0(r8) /* Load word from memory. */ - cmpb r10,r12,r0 /* Check for null bytes in DWORD1. */ -#ifdef __LITTLE_ENDIAN__ - srw r10,r10,r6 - slw r10,r10,r6 -#else - slw r10,r10,r6 - srw r10,r10,r6 -#endif - cmplwi cr7,r10,0 /* If r10 == 0, no null's have been found. */ - bne cr7,L(done) - - clrrwi r7,r7,2 /* Address of last word. */ - mtcrf 0x01,r8 - /* Are we now aligned to a doubleword boundary? If so, skip to - the main loop. Otherwise, go through the alignment code. */ - - bt 29,L(loop_setup) - - /* Handle WORD2 of pair. */ - lwzu r12,4(r8) - cmpb r10,r12,r0 - cmplwi cr7,r10,0 - bne cr7,L(done) - -L(loop_setup): - /* The last word we want to read in the loop below is the one - containing the last byte of the string, ie. the word at - (s + size - 1) & ~3, or r7. The first word read is at - r8 + 4, we read 2 * cnt words, so the last word read will - be at r8 + 4 + 8 * cnt - 4. Solving for cnt gives - cnt = (r7 - r8) / 8 */ - sub r5,r7,r8 - srwi r6,r5,3 /* Number of loop iterations. */ - mtctr r6 /* Setup the counter. */ - - /* Main loop to look for the null byte in the string. Since - it's a small loop (< 8 instructions), align it to 32-bytes. */ - .p2align 5 -L(loop): - /* Load two words, compare and merge in a - single register for speed. This is an attempt - to speed up the null-checking process for bigger strings. */ - - lwz r12,4(r8) - lwzu r11,8(r8) - cmpb r10,r12,r0 - cmpb r9,r11,r0 - or r5,r9,r10 /* Merge everything in one word. */ - cmplwi cr7,r5,0 - bne cr7,L(found) - bdnz L(loop) - - /* We may have one more word to read. */ - cmplw cr6,r8,r7 - beq cr6,L(end_max) - - lwzu r12,4(r8) - cmpb r10,r12,r0 - cmplwi cr6,r10,0 - bne cr6,L(done) - -L(end_max): - mr r3,r4 - blr - - /* OK, one (or both) of the words contains a null byte. Check - the first word and decrement the address in case the first - word really contains a null byte. */ - .align 4 -L(found): - cmplwi cr6,r10,0 - addi r8,r8,-4 - bne cr6,L(done) - - /* The null byte must be in the second word. Adjust the address - again and move the result of cmpb to r10 so we can calculate the - length. */ - - mr r10,r9 - addi r8,r8,4 - - /* r10 has the output of the cmpb instruction, that is, it contains - 0xff in the same position as the null byte in the original - word from the string. Use that to calculate the length. - We need to make sure the null char is *before* the end of the - range. */ -L(done): -#ifdef __LITTLE_ENDIAN__ - addi r0,r10,-1 - andc r0,r0,r10 - popcntw r0,r0 -#else - cntlzw r0,r10 /* Count leading zeros before the match. */ -#endif - sub r3,r8,r3 - srwi r0,r0,3 /* Convert leading/trailing zeros to bytes. */ - add r3,r3,r0 /* Length until the match. */ - cmplw r3,r4 - blelr - mr r3,r4 - blr - -/* Deals with size <= 16. */ - .align 4 -L(small_range): - cmplwi r4,0 - beq L(end_max) - - clrrwi r7,r7,2 /* Address of last word. */ - - rlwinm r6,r3,3,27,28 /* Calculate padding. */ - lwz r12,0(r8) /* Load word from memory. */ - cmpb r10,r12,r0 /* Check for null bytes in WORD1. */ -#ifdef __LITTLE_ENDIAN__ - srw r10,r10,r6 - slw r10,r10,r6 -#else - slw r10,r10,r6 - srw r10,r10,r6 -#endif - cmplwi cr7,r10,0 - bne cr7,L(done) - - cmplw r8,r7 - beq L(end_max) - - .p2align 5 -L(loop_small): - lwzu r12,4(r8) - cmpb r10,r12,r0 - cmplwi cr6,r10,0 - bne cr6,L(done) - cmplw r8,r7 - bne L(loop_small) - mr r3,r4 - blr - -END (__strnlen) -libc_hidden_def (__strnlen) -weak_alias (__strnlen, strnlen) -libc_hidden_builtin_def (strnlen) |