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/memset.c | 271 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 271 insertions(+) create mode 100644 libc/string/cris/memset.c (limited to 'libc/string/cris/memset.c') diff --git a/libc/string/cris/memset.c b/libc/string/cris/memset.c new file mode 100644 index 000000000..7e71bc50f --- /dev/null +++ b/libc/string/cris/memset.c @@ -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) -- cgit v1.2.3