From c08b07bc9bff10988100653d280e8afe428249f7 Mon Sep 17 00:00:00 2001 From: Ricard Wanderlof Date: Mon, 12 Nov 2007 12:08:31 +0000 Subject: CRIS/CRISv32 architecture specific memcpy, memmove and memset. --- libc/string/cris/memcpy.c | 264 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 264 insertions(+) create mode 100644 libc/string/cris/memcpy.c (limited to 'libc/string/cris/memcpy.c') diff --git a/libc/string/cris/memcpy.c b/libc/string/cris/memcpy.c new file mode 100644 index 000000000..a85108109 --- /dev/null +++ b/libc/string/cris/memcpy.c @@ -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 + +#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) -- cgit v1.2.3