svn commit: trunk/uClibc/libc/string: cris
ricardw at uclibc.org
ricardw at uclibc.org
Mon Nov 12 12:08:32 UTC 2007
Author: ricardw
Date: 2007-11-12 04:08:31 -0800 (Mon, 12 Nov 2007)
New Revision: 20410
Log:
CRIS/CRISv32 architecture specific memcpy, memmove and memset.
Added:
trunk/uClibc/libc/string/cris/
trunk/uClibc/libc/string/cris/memcopy.h
trunk/uClibc/libc/string/cris/memcpy.c
trunk/uClibc/libc/string/cris/memmove.c
trunk/uClibc/libc/string/cris/memset.c
Changeset:
Property changes on: trunk/uClibc/libc/string/cris
___________________________________________________________________
Name: svn:ignore
+ *.os
Added: trunk/uClibc/libc/string/cris/memcopy.h
===================================================================
--- trunk/uClibc/libc/string/cris/memcopy.h (rev 0)
+++ trunk/uClibc/libc/string/cris/memcopy.h 2007-11-12 12:08:31 UTC (rev 20410)
@@ -0,0 +1,62 @@
+/* Copyright (C) 2001 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ Modified for use in uClibc (C) 2007 Axis Communications AB.
+ Minimal modifications: include path name and #undef of WORD_COPY_FWD/BWD
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Library General Public License as
+ published by the Free Software Foundation; either version 2 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
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If not,
+ write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+#include "../generic/memcopy.h"
+
+/* We override the word-copying macros, partly because misalignment in one
+ pointer isn't cause for a special function, partly because we want to
+ get rid of all the static functions in generic/memcopy.c; these macros
+ are only used in memmove.c since we have arch-specific mempcpy, memcpy and
+ memset. */
+
+#undef OP_T_THRES
+#define OP_T_THRES OPSIZ
+
+#undef WORD_COPY_FWD
+#define WORD_COPY_FWD(dst_bp, src_bp, nbytes_left, nbytes) \
+ do \
+ { \
+ unsigned long enddst_bp = dst_bp + nbytes - (nbytes % OPSIZ); \
+ nbytes_left = (nbytes % OPSIZ); \
+ while (dst_bp < (unsigned long) enddst_bp) \
+ { \
+ op_t x = *(op_t *) src_bp; \
+ src_bp += sizeof x; \
+ *(op_t *) dst_bp = x; \
+ dst_bp += sizeof x; \
+ } \
+ } while (0)
+
+#undef WORD_COPY_BWD
+#define WORD_COPY_BWD(dst_bp, src_bp, nbytes_left, nbytes) \
+ do \
+ { \
+ unsigned long enddst_bp = dst_bp - nbytes + (nbytes % OPSIZ); \
+ nbytes_left = (nbytes % OPSIZ); \
+ while (dst_bp > enddst_bp) \
+ { \
+ op_t x; \
+ src_bp -= sizeof x; \
+ x = *(op_t *) src_bp; \
+ dst_bp -= sizeof x; \
+ *(op_t *) dst_bp = x; \
+ } \
+ } while (0)
Added: trunk/uClibc/libc/string/cris/memcpy.c
===================================================================
--- trunk/uClibc/libc/string/cris/memcpy.c (rev 0)
+++ trunk/uClibc/libc/string/cris/memcpy.c 2007-11-12 12:08:31 UTC (rev 20410)
@@ -0,0 +1,264 @@
+/* Copyright (C) 2001, 2003 Free Software Foundation, Inc.
+ Copyright (C) 1994, 1995, 2000 Axis Communications AB.
+
+ 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 Library General Public License as
+ published by the Free Software Foundation; either version 2 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
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If not,
+ write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+/*#************************************************************************#*/
+/*#-------------------------------------------------------------------------*/
+/*# */
+/*# FUNCTION NAME: memcpy() */
+/*# */
+/*# PARAMETERS: void* dst; Destination address. */
+/*# void* src; Source address. */
+/*# int len; Number of bytes to copy. */
+/*# */
+/*# RETURNS: dst. */
+/*# */
+/*# DESCRIPTION: Copies len bytes of memory from src to dst. No guarantees */
+/*# about copying of overlapping memory areas. This routine is */
+/*# very sensitive to compiler changes in register allocation. */
+/*# Should really be rewritten to avoid this problem. */
+/*# */
+/*#-------------------------------------------------------------------------*/
+/*# */
+/*# HISTORY */
+/*# */
+/*# DATE NAME CHANGES */
+/*# ---- ---- ------- */
+/*# 941007 Kenny R Creation */
+/*# 941011 Kenny R Lots of optimizations and inlining. */
+/*# 941129 Ulf A Adapted for use in libc. */
+/*# 950216 HP N==0 forgotten if non-aligned src/dst. */
+/*# Added some optimizations. */
+/*# 001025 HP Make src and dst char *. Align dst to */
+/*# dword, not just word-if-both-src-and-dst- */
+/*# are-misaligned. */
+/*# 070806 RW Modified for uClibc */
+/*# (__arch_v32 -> __CONFIG_CRISV32__, */
+/*# include features.h to reach it.) */
+/*# */
+/*#-------------------------------------------------------------------------*/
+
+#include <features.h>
+
+#ifdef __CONFIG_CRISV32__
+/* For CRISv32, movem is very cheap. */
+#define MEMCPY_BLOCK_THRESHOLD (44)
+#else
+/* Break even between movem and move16 is at 38.7*2, but modulo 44. */
+#define MEMCPY_BLOCK_THRESHOLD (44*2)
+#endif
+
+void *memcpy(void *, const void *, unsigned int);
+
+libc_hidden_proto(memcpy)
+void *memcpy(void *pdst,
+ const void *psrc,
+ unsigned int pn)
+{
+ /* Ok. Now we want the parameters put in special registers.
+ Make sure the compiler is able to make something useful of this.
+ As it is now: r10 -> r13; r11 -> r11 (nop); r12 -> r12 (nop).
+
+ If gcc was allright, it really would need no temporaries, and no
+ stack space to save stuff on. */
+
+#ifndef MEMPCPY
+ register void *return_dst __asm__ ("r10") = pdst;
+#else
+ /* FIXME: Use R10 for something. */
+# define return_dst dst
+#endif
+
+ register char *dst __asm__ ("r13") = pdst;
+ register char *src __asm__ ("r11") = (char *) psrc;
+ register int n __asm__ ("r12") = pn;
+
+
+ /* When src is aligned but not dst, this makes a few extra needless
+ cycles. I believe it would take as many to check that the
+ re-alignment was unnecessary. */
+ if (((unsigned long) dst & 3) != 0
+ /* Don't align if we wouldn't copy more than a few bytes; so we
+ don't have to check further for overflows. */
+ && n >= 3)
+ {
+ if ((unsigned long) dst & 1)
+ {
+ n--;
+ *(char*)dst = *(char*)src;
+ src++;
+ dst++;
+ }
+
+ if ((unsigned long) dst & 2)
+ {
+ n -= 2;
+ *(short*)dst = *(short*)src;
+ src += 2;
+ dst += 2;
+ }
+ }
+
+ /* Decide which copying method to use. */
+ if (n >= MEMCPY_BLOCK_THRESHOLD)
+ {
+ /* For large copies we use 'movem' */
+
+ /* It is not optimal to tell the compiler about clobbering any
+ registers; that will move the saving/restoring of those registers
+ to the function prologue/epilogue, and make non-movem sizes
+ suboptimal.
+
+ This method is not foolproof; it assumes that the "register asm"
+ declarations at the beginning of the function really are used
+ here (beware: they may be moved to temporary registers).
+ This way, we do not have to save/move the registers around into
+ temporaries; we can safely use them straight away. */
+ __asm__ volatile ("\
+ .syntax no_register_prefix \n\
+ \n\
+ ;; Check that the register asm declaration got right. \n\
+ ;; The GCC manual explicitly says TRT will happen. \n\
+ .ifnc %0-%1-%2,$r13-$r11-$r12 \n\
+ .err \n\
+ .endif \n\
+ \n\
+ ;; Save the registers we'll use in the movem process \n\
+ ;; on the stack. \n\
+ subq 11*4,sp \n\
+ movem r10,[sp] \n\
+ \n\
+ ;; Now we've got this: \n\
+ ;; r11 - src \n\
+ ;; r13 - dst \n\
+ ;; r12 - n \n\
+ \n\
+ ;; Update n for the first loop \n\
+ subq 44,r12 \n\
+0: \n\
+ movem [r11+],r10 \n\
+ subq 44,r12 \n\
+ bge 0b \n\
+ movem r10,[r13+] \n\
+ \n\
+ addq 44,r12 ;; compensate for last loop underflowing n \n\
+ \n\
+ ;; Restore registers from stack \n\
+ movem [sp+],r10"
+
+ /* Outputs */ : "=r" (dst), "=r" (src), "=r" (n)
+ /* Inputs */ : "0" (dst), "1" (src), "2" (n));
+ }
+
+ /* Either we directly starts copying, using dword copying
+ in a loop, or we copy as much as possible with 'movem'
+ and then the last block (<44 bytes) is copied here.
+ This will work since 'movem' will have updated src,dst,n. */
+
+ while ( n >= 16 )
+ {
+ *((long*)dst)++ = *((long*)src)++;
+ *((long*)dst)++ = *((long*)src)++;
+ *((long*)dst)++ = *((long*)src)++;
+ *((long*)dst)++ = *((long*)src)++;
+ n -= 16;
+ }
+
+ /* A switch() is definitely the fastest although it takes a LOT of code.
+ * Particularly if you inline code this.
+ */
+ switch (n)
+ {
+ case 0:
+ break;
+ case 1:
+ *((char*)dst)++ = *((char*)src)++;
+ break;
+ case 2:
+ *((short*)dst)++ = *((short*)src)++;
+ break;
+ case 3:
+ *((short*)dst)++ = *((short*)src)++;
+ *((char*)dst)++ = *((char*)src)++;
+ break;
+ case 4:
+ *((long*)dst)++ = *((long*)src)++;
+ break;
+ case 5:
+ *((long*)dst)++ = *((long*)src)++;
+ *((char*)dst)++ = *((char*)src)++;
+ break;
+ case 6:
+ *((long*)dst)++ = *((long*)src)++;
+ *((short*)dst)++ = *((short*)src)++;
+ break;
+ case 7:
+ *((long*)dst)++ = *((long*)src)++;
+ *((short*)dst)++ = *((short*)src)++;
+ *((char*)dst)++ = *((char*)src)++;
+ break;
+ case 8:
+ *((long*)dst)++ = *((long*)src)++;
+ *((long*)dst)++ = *((long*)src)++;
+ break;
+ case 9:
+ *((long*)dst)++ = *((long*)src)++;
+ *((long*)dst)++ = *((long*)src)++;
+ *((char*)dst)++ = *((char*)src)++;
+ break;
+ case 10:
+ *((long*)dst)++ = *((long*)src)++;
+ *((long*)dst)++ = *((long*)src)++;
+ *((short*)dst)++ = *((short*)src)++;
+ break;
+ case 11:
+ *((long*)dst)++ = *((long*)src)++;
+ *((long*)dst)++ = *((long*)src)++;
+ *((short*)dst)++ = *((short*)src)++;
+ *((char*)dst)++ = *((char*)src)++;
+ break;
+ case 12:
+ *((long*)dst)++ = *((long*)src)++;
+ *((long*)dst)++ = *((long*)src)++;
+ *((long*)dst)++ = *((long*)src)++;
+ break;
+ case 13:
+ *((long*)dst)++ = *((long*)src)++;
+ *((long*)dst)++ = *((long*)src)++;
+ *((long*)dst)++ = *((long*)src)++;
+ *((char*)dst)++ = *((char*)src)++;
+ break;
+ case 14:
+ *((long*)dst)++ = *((long*)src)++;
+ *((long*)dst)++ = *((long*)src)++;
+ *((long*)dst)++ = *((long*)src)++;
+ *((short*)dst)++ = *((short*)src)++;
+ break;
+ case 15:
+ *((long*)dst)++ = *((long*)src)++;
+ *((long*)dst)++ = *((long*)src)++;
+ *((long*)dst)++ = *((long*)src)++;
+ *((short*)dst)++ = *((short*)src)++;
+ *((char*)dst)++ = *((char*)src)++;
+ break;
+ }
+
+ return return_dst; /* destination pointer. */
+} /* memcpy() */
+libc_hidden_def(memcpy)
Added: trunk/uClibc/libc/string/cris/memmove.c
===================================================================
--- trunk/uClibc/libc/string/cris/memmove.c (rev 0)
+++ trunk/uClibc/libc/string/cris/memmove.c 2007-11-12 12:08:31 UTC (rev 20410)
@@ -0,0 +1,101 @@
+/* Taken from generic/memmove.c; trivially modified to work with
+ arch-specific memcopy.h for Cris.
+
+ Copy memory to memory until the specified number of bytes
+ has been copied. Overlap is handled correctly.
+ Copyright (C) 1991, 1995, 1996, 1997, 2003 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Torbjorn Granlund (tege at sics.se).
+
+ 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, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <string.h>
+
+#include "memcopy.h"
+#include "../generic/pagecopy.h"
+
+libc_hidden_proto(memmove)
+void *memmove (void *dest, const void *src, size_t len)
+{
+ unsigned long int dstp = (long int) dest;
+ unsigned long int srcp = (long int) src;
+
+ /* This test makes the forward copying code be used whenever possible.
+ Reduces the working set. */
+ if (dstp - srcp >= len) /* *Unsigned* compare! */
+ {
+#if 1
+#warning REMINDER: Cris arch-opt memmove assumes memcpy does forward copying!
+ memcpy(dest, src, len);
+#else
+ /* Copy from the beginning to the end. */
+
+ /* If there not too few bytes to copy, use word copy. */
+ if (len >= OP_T_THRES)
+ {
+ /* Copy just a few bytes to make DSTP aligned. */
+ len -= (-dstp) % OPSIZ;
+ BYTE_COPY_FWD (dstp, srcp, (-dstp) % OPSIZ);
+
+ /* Copy whole pages from SRCP to DSTP by virtual address
+ manipulation, as much as possible. */
+
+ PAGE_COPY_FWD_MAYBE (dstp, srcp, len, len);
+
+ /* Copy from SRCP to DSTP taking advantage of the known
+ alignment of DSTP. Number of bytes remaining is put
+ in the third argument, i.e. in LEN. This number may
+ vary from machine to machine. */
+
+ WORD_COPY_FWD (dstp, srcp, len, len);
+
+ /* Fall out and copy the tail. */
+ }
+
+ /* There are just a few bytes to copy. Use byte memory operations. */
+ BYTE_COPY_FWD (dstp, srcp, len);
+#endif
+ }
+ else
+ {
+ /* Copy from the end to the beginning. */
+ srcp += len;
+ dstp += len;
+
+ /* If there not too few bytes to copy, use word copy. */
+ if (len >= OP_T_THRES)
+ {
+ /* Copy just a few bytes to make DSTP aligned. */
+ len -= dstp % OPSIZ;
+ BYTE_COPY_BWD (dstp, srcp, dstp % OPSIZ);
+
+ /* Copy from SRCP to DSTP taking advantage of the known
+ alignment of DSTP. Number of bytes remaining is put
+ in the third argument, i.e. in LEN. This number may
+ vary from machine to machine. */
+
+ WORD_COPY_BWD (dstp, srcp, len, len);
+
+ /* Fall out and copy the tail. */
+ }
+
+ /* There are just a few bytes to copy. Use byte memory operations. */
+ BYTE_COPY_BWD (dstp, srcp, len);
+ }
+
+ return (dest);
+}
+libc_hidden_def(memmove)
Added: trunk/uClibc/libc/string/cris/memset.c
===================================================================
--- trunk/uClibc/libc/string/cris/memset.c (rev 0)
+++ trunk/uClibc/libc/string/cris/memset.c 2007-11-12 12:08:31 UTC (rev 20410)
@@ -0,0 +1,271 @@
+/* Copyright (C) 2001, 2003 Free Software Foundation, Inc.
+ Copyright (C) 1999, 2000 Axis Communications AB.
+
+ 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 Library General Public License as
+ published by the Free Software Foundation; either version 2 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
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If not,
+ write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+/*#************************************************************************#*/
+/*#-------------------------------------------------------------------------*/
+/*# */
+/*# FUNCTION NAME: memset() */
+/*# */
+/*# PARAMETERS: void* dst; Destination address. */
+/*# int c; Value of byte to write. */
+/*# int len; Number of bytes to write. */
+/*# */
+/*# RETURNS: dst. */
+/*# */
+/*# DESCRIPTION: Sets the memory dst of length len bytes to c, as standard. */
+/*# Framework taken from memcpy. This routine is */
+/*# very sensitive to compiler changes in register allocation. */
+/*# Should really be rewritten to avoid this problem. */
+/*# */
+/*#-------------------------------------------------------------------------*/
+/*# */
+/*# HISTORY */
+/*# */
+/*# DATE NAME CHANGES */
+/*# ---- ---- ------- */
+/*# 990713 HP Tired of watching this function (or */
+/*# really, the nonoptimized generic */
+/*# implementation) take up 90% of simulator */
+/*# output. Measurements needed. */
+/*# */
+/*#-------------------------------------------------------------------------*/
+
+/* No, there's no macro saying 12*4, since it is "hard" to get it into
+ the asm in a good way. Thus better to expose the problem everywhere.
+ */
+
+/* Assuming 1 cycle per dword written or read (ok, not really true), and
+ one per instruction, then 43+3*(n/48-1) <= 24+24*(n/48-1)
+ so n >= 45.7; n >= 0.9; we win on the first full 48-byte block to set. */
+
+#define ZERO_BLOCK_SIZE (1*12*4)
+
+void *memset(void *, int, unsigned long);
+
+libc_hidden_proto(memset)
+void *memset(void *pdst,
+ int c,
+ unsigned long plen)
+{
+ /* Ok. Now we want the parameters put in special registers.
+ Make sure the compiler is able to make something useful of this. */
+
+ register char *return_dst __asm__ ("r10") = pdst;
+ register long n __asm__ ("r12") = plen;
+ register int lc __asm__ ("r11") = c;
+
+ /* Most apps use memset sanely. Only those memsetting about 3..4
+ bytes or less get penalized compared to the generic implementation
+ - and that's not really sane use. */
+
+ /* Ugh. This is fragile at best. Check with newer GCC releases, if
+ they compile cascaded "x |= x << 8" sanely! */
+ __asm__("movu.b %0,$r13 \n\
+ lslq 8,$r13 \n\
+ move.b %0,$r13 \n\
+ move.d $r13,%0 \n\
+ lslq 16,$r13 \n\
+ or.d $r13,%0"
+ : "=r" (lc) : "0" (lc) : "r13");
+
+ {
+ register char *dst __asm__ ("r13") = pdst;
+
+ if (((unsigned long) pdst & 3) != 0
+ /* Oops! n=0 must be a legal call, regardless of alignment. */
+ && n >= 3)
+ {
+ if ((unsigned long)dst & 1)
+ {
+ *dst = (char) lc;
+ n--;
+ dst++;
+ }
+
+ if ((unsigned long)dst & 2)
+ {
+ *(short *)dst = lc;
+ n -= 2;
+ dst += 2;
+ }
+ }
+
+ /* Now the fun part. For the threshold value of this, check the equation
+ above. */
+ /* Decide which copying method to use. */
+ if (n >= ZERO_BLOCK_SIZE)
+ {
+ /* For large copies we use 'movem' */
+
+ /* It is not optimal to tell the compiler about clobbering any
+ registers; that will move the saving/restoring of those registers
+ to the function prologue/epilogue, and make non-movem sizes
+ suboptimal.
+
+ This method is not foolproof; it assumes that the "asm reg"
+ declarations at the beginning of the function really are used
+ here (beware: they may be moved to temporary registers).
+ This way, we do not have to save/move the registers around into
+ temporaries; we can safely use them straight away. */
+ __asm__ volatile (" \n\
+ .syntax no_register_prefix \n\
+ \n\
+ ;; Check that the register asm declaration got right. \n\
+ ;; The GCC manual explicitly says there's no warranty for that (too). \n\
+ .ifnc %0-%1-%4,$r13-$r12-$r11 \n\
+ .err \n\
+ .endif \n\
+ \n\
+ ;; Save the registers we'll clobber in the movem process \n\
+ ;; on the stack. Don't mention them to gcc, it will only be \n\
+ ;; upset. \n\
+ subq 11*4,sp \n\
+ movem r10,[sp] \n\
+ \n\
+ move.d r11,r0 \n\
+ move.d r11,r1 \n\
+ move.d r11,r2 \n\
+ move.d r11,r3 \n\
+ move.d r11,r4 \n\
+ move.d r11,r5 \n\
+ move.d r11,r6 \n\
+ move.d r11,r7 \n\
+ move.d r11,r8 \n\
+ move.d r11,r9 \n\
+ move.d r11,r10 \n\
+ \n\
+ ;; Now we've got this: \n\
+ ;; r13 - dst \n\
+ ;; r12 - n \n\
+ \n\
+ ;; Update n for the first loop \n\
+ subq 12*4,r12 \n\
+0: \n\
+ subq 12*4,r12 \n\
+ bge 0b \n\
+ movem r11,[r13+] \n\
+ \n\
+ addq 12*4,r12 ;; compensate for last loop underflowing n \n\
+ \n\
+ ;; Restore registers from stack \n\
+ movem [sp+],r10"
+
+ /* Outputs */ : "=r" (dst), "=r" (n)
+ /* Inputs */ : "0" (dst), "1" (n), "r" (lc));
+
+ }
+
+ /* Either we directly starts copying, using dword copying
+ in a loop, or we copy as much as possible with 'movem'
+ and then the last block (<44 bytes) is copied here.
+ This will work since 'movem' will have updated src,dst,n. */
+
+ while ( n >= 16 )
+ {
+ *((long*)dst)++ = lc;
+ *((long*)dst)++ = lc;
+ *((long*)dst)++ = lc;
+ *((long*)dst)++ = lc;
+ n -= 16;
+ }
+
+ /* A switch() is definitely the fastest although it takes a LOT of code.
+ * Particularly if you inline code this.
+ */
+ switch (n)
+ {
+ case 0:
+ break;
+ case 1:
+ *(char*)dst = (char) lc;
+ break;
+ case 2:
+ *(short*)dst = (short) lc;
+ break;
+ case 3:
+ *((short*)dst)++ = (short) lc;
+ *(char*)dst = (char) lc;
+ break;
+ case 4:
+ *((long*)dst)++ = lc;
+ break;
+ case 5:
+ *((long*)dst)++ = lc;
+ *(char*)dst = (char) lc;
+ break;
+ case 6:
+ *((long*)dst)++ = lc;
+ *(short*)dst = (short) lc;
+ break;
+ case 7:
+ *((long*)dst)++ = lc;
+ *((short*)dst)++ = (short) lc;
+ *(char*)dst = (char) lc;
+ break;
+ case 8:
+ *((long*)dst)++ = lc;
+ *((long*)dst)++ = lc;
+ break;
+ case 9:
+ *((long*)dst)++ = lc;
+ *((long*)dst)++ = lc;
+ *(char*)dst = (char) lc;
+ break;
+ case 10:
+ *((long*)dst)++ = lc;
+ *((long*)dst)++ = lc;
+ *(short*)dst = (short) lc;
+ break;
+ case 11:
+ *((long*)dst)++ = lc;
+ *((long*)dst)++ = lc;
+ *((short*)dst)++ = (short) lc;
+ *(char*)dst = (char) lc;
+ break;
+ case 12:
+ *((long*)dst)++ = lc;
+ *((long*)dst)++ = lc;
+ *((long*)dst)++ = lc;
+ break;
+ case 13:
+ *((long*)dst)++ = lc;
+ *((long*)dst)++ = lc;
+ *((long*)dst)++ = lc;
+ *(char*)dst = (char) lc;
+ break;
+ case 14:
+ *((long*)dst)++ = lc;
+ *((long*)dst)++ = lc;
+ *((long*)dst)++ = lc;
+ *(short*)dst = (short) lc;
+ break;
+ case 15:
+ *((long*)dst)++ = lc;
+ *((long*)dst)++ = lc;
+ *((long*)dst)++ = lc;
+ *((short*)dst)++ = (short) lc;
+ *(char*)dst = (char) lc;
+ break;
+ }
+ }
+
+ return return_dst; /* destination pointer. */
+} /* memset() */
+libc_hidden_def(memset)
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