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Diffstat (limited to 'newlib/libc/machine/i960/strlen.S')
| -rw-r--r-- | newlib/libc/machine/i960/strlen.S | 117 |
1 files changed, 0 insertions, 117 deletions
diff --git a/newlib/libc/machine/i960/strlen.S b/newlib/libc/machine/i960/strlen.S deleted file mode 100644 index dfbeec2..0000000 --- a/newlib/libc/machine/i960/strlen.S +++ /dev/null @@ -1,117 +0,0 @@ -/******************************************************************************* - * - * Copyright (c) 1993 Intel Corporation - * - * Intel hereby grants you permission to copy, modify, and distribute this - * software and its documentation. Intel grants this permission provided - * that the above copyright notice appears in all copies and that both the - * copyright notice and this permission notice appear in supporting - * documentation. In addition, Intel grants this permission provided that - * you prominently mark as "not part of the original" any modifications - * made to this software or documentation, and that the name of Intel - * Corporation not be used in advertising or publicity pertaining to - * distribution of the software or the documentation without specific, - * written prior permission. - * - * Intel Corporation provides this AS IS, WITHOUT ANY WARRANTY, EXPRESS OR - * IMPLIED, INCLUDING, WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY - * OR FITNESS FOR A PARTICULAR PURPOSE. Intel makes no guarantee or - * representations regarding the use of, or the results of the use of, - * the software and documentation in terms of correctness, accuracy, - * reliability, currentness, or otherwise; and you rely on the software, - * documentation and results solely at your own risk. - * - * IN NO EVENT SHALL INTEL BE LIABLE FOR ANY LOSS OF USE, LOSS OF BUSINESS, - * LOSS OF PROFITS, INDIRECT, INCIDENTAL, SPECIAL OR CONSEQUENTIAL DAMAGES - * OF ANY KIND. IN NO EVENT SHALL INTEL'S TOTAL LIABILITY EXCEED THE SUM - * PAID TO INTEL FOR THE PRODUCT LICENSED HEREUNDER. - * - ******************************************************************************/ - - .file "strlen.s" -#ifdef __PIC - .pic -#endif -#ifdef __PID - .pid -#endif - -/* - * (c) copyright 1988,1993 Intel Corp., all rights reserved - */ - -/* - procedure strlen (optimized assembler version for the 80960K series) - - src_addr = strlen (src_addr) - - return the number of bytes that precede the null byte in the - string pointed to by src_addr. - - Undefined behavior will occur if the end of the source string (i.e. - the terminating null byte) is in the last four words of the program's - allocated memory space. This is so because strlen fetches ahead - several words. Disallowing the fetch ahead would impose a severe - performance penalty. - - Strategy: - - Fetch the source array by long-words and scanbyte the words for the - null byte until found. Examine the word in which the null byte is - found, to determine its actual position, and return the length. - - Tactics: - - 1) Do NOT try to fetch the words in a word aligned manner because, - in my judgement, the performance degradation experienced due to - non-aligned accesses does NOT outweigh the time and complexity added - by the preamble that would be necessary to assure alignment. This - is supported by the intuition that many source strings will be word - aligned to begin with. -*/ - - .globl _strlen - .globl __strlen - .leafproc _strlen, __strlen - .align 2 -_strlen: -#ifndef __PIC - lda Lrett,g14 -#else - lda Lrett-(.+8)(ip),g14 -#endif -__strlen: - - mov g14,g13 # preserve return address - ldl (g0),g4 # fetch first two words - addo 8,g0,g2 # post-increment src word pointer - lda 0xff,g3 # byte extraction mask - - -Lsearch_for_word_with_null_byte: - scanbyte 0,g4 # check for null byte - mov g5,g7 # copy second word - bo.f Lsearch_for_null # branch if null found - scanbyte 0,g7 # check for null byte - ldl (g2),g4 # fetch next pair of word of src - addo 8,g2,g2 # post-increment src word pointer - bno Lsearch_for_word_with_null_byte # branch if null not found yet - - subo 4,g2,g2 # back up the byte pointer - mov g7,g4 # move word with null to search word -Lsearch_for_null: - subo 9,g2,g2 # back up the byte pointer -Lsearch_for_null.a: - and g4,g3,g14 # extract byte - cmpo 0,g14 # is it null? - addo 1,g2,g2 # bump src byte ptr - shro 8,g4,g4 # shift word to position next byte - bne Lsearch_for_null.a - -Lexit_code: - subo g0,g2,g0 # calculate string length - bx (g13) # g0 = addr of src; g14 = 0 -Lrett: - ret - -/* end of strlen */ |