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+/*******************************************************************************
+ *
+ * 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 "strcpy.s"
+#ifdef __PIC
+ .pic
+#endif
+#ifdef __PID
+ .pid
+#endif
+/*
+ * (c) copyright 1988,1993 Intel Corp., all rights reserved
+ */
+/*
+ procedure strcpy (optimized assembler version for the 80960K series)
+ procedure strcat (optimized assembler version for the 80960K series)
+
+ dest_addr = strcpy (dest_addr, src_addr)
+
+ copy the null terminated string pointed to by src_addr to
+ the string space pointed to by dest_addr. Return the original
+ dest_addr.
+
+ This routine will fail if the source and destination string
+ overlap (in particular, if the end of the source is overlapped
+ by the beginning of the destination). The behavior is undefined.
+ This is acceptable according to the draft C standard.
+
+ Undefined behavior will also occur if the end of the source string
+ (i.e. the terminating null byte) is in the last two words of the
+ program's allocated memory space. This is so because strcpy fetches
+ ahead. Disallowing the fetch ahead would impose a severe performance
+ penalty.
+
+ Strategy:
+
+ Fetch the source string and store the destination string by words
+ until the null byte is encountered. When the word with the null
+ byte is reached, store it by bytes up through the null byte only.
+
+ Tactics:
+
+ 1) Do NOT try to fetch and store 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 and convoluted body that would be necessary to assure
+ alignment. This is supported by the intuition that most source and
+ destination strings will be word aligned to begin with.
+
+
+ procedure strcat
+
+ dest_addr = strcat (dest_addr, src_addr)
+
+ Appends the string pointed to by src_addr to the string pointed
+ to by dest_addr. The first character of the source string is
+ copied to the location initially occupied by the trailing null
+ byte of the destination string. Thereafter, characters are copied
+ from the source to the destination up thru the null byte that
+ trails the source string.
+
+ See the strcpy routine, above, for its caveats, as they apply here too.
+
+ Strategy:
+
+ Skip to the end (null byte) of the destination string, and then drop
+ into the strcpy code.
+
+ Tactics:
+
+ Skipping to the null byte is Ldone by reading the destination string
+ in long-words and scanbyte'ing them, then examining the bytes of the
+ word that contains the null byte, until the address of the null byte is
+ known. Then we drop into the strcpy routine. It is probable (approx.
+ three out of four times) that the destination string as strcpy sees
+ it will NOT be word aligned (i.e. that the null byte won't be the
+ last byte of a word). But it is not worth the complication to that
+ routine to force word aligned memory accesses to be gaurenteed.
+*/
+ .globl _strcpy, _strcat
+ .globl __strcpy, __strcat
+ .leafproc _strcpy,__strcpy
+ .leafproc _strcat,__strcat
+ .align 2
+_strcat:
+#ifndef __PIC
+ lda Lrett,g14
+#else
+ lda Lrett-(.+8)(ip),g14
+#endif
+__strcat:
+ 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,g5 # back up the byte pointer
+Lsearch_for_null.a:
+ and g4,g3,g6 # extract byte
+ cmpo 0,g6 # is it null?
+ addo 1,g5,g5 # bump src byte ptr
+ shro 8,g4,g4 # shift word to position next byte
+ bne Lsearch_for_null.a
+ b Lend_of_dest_found
+
+_strcpy:
+#ifndef __PIC
+ lda Lrett,g14
+#else
+ lda Lrett-(.+8)(ip),g14
+#endif
+__strcpy:
+ mov g0, g5
+Lend_of_dest_found:
+ ld (g1), g2 # fetch first word of source
+ mov g14,g6 # preserve return address
+ lda 0xff, g3 # byte extraction mask = 0xff;
+Lwloop: # word copying loop
+ addo 4, g1, g1 # post-increment source ptr
+ scanbyte 0, g2 # does source word contain null byte?
+ mov g2, g4 # save a copy of the source word
+ be Lcloop # branch if null present
+ ld (g1), g2 # pre-fetch next word of source
+ st g4, (g5) # store current word
+ addo 4, g5, g5 # post-increment dest ptr
+ b Lwloop
+
+Lcloop: # character copying loop
+ and g3, g4, g14 # extract next char
+ shro 8, g4, g4 # position word for next byte extraction
+ cmpo 0, g14 # is it null?
+ stob g14, (g5) # store the byte
+ addo 1, g5, g5 # post-increment dest ptr
+ bne Lcloop # quit if null encountered
+
+ bx (g6) # g0 = dest string address; g14 = 0
+Lrett:
+ ret