-/*#************************************************************************#*/
-/*#-------------------------------------------------------------------------*/
-/*# */
-/*# 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. */
-/*# */
-/*#-------------------------------------------------------------------------*/
-
-#include <linux/types.h>
-
-void *memcpy(void *pdst,
- const void *psrc,
- size_t pn)
+/* A memcpy for CRIS.
+ Copyright (C) 1994-2005 Axis Communications.
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions
+ are met:
+
+ 1. Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+
+ 2. Neither the name of Axis Communications nor the names of its
+ contributors may be used to endorse or promote products derived
+ from this software without specific prior written permission.
+
+ THIS SOFTWARE IS PROVIDED BY AXIS COMMUNICATIONS AND ITS CONTRIBUTORS
+ ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL AXIS
+ COMMUNICATIONS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ POSSIBILITY OF SUCH DAMAGE. */
+
+/* FIXME: This file should really only be used for reference, as the
+ result is somewhat depending on gcc generating what we expect rather
+ than what we describe. An assembly file should be used instead. */
+
+#include <stddef.h>
+
+/* Break even between movem and move16 is really at 38.7 * 2, but
+ modulo 44, so up to the next multiple of 44, we use ordinary code. */
+#define MEMCPY_BY_BLOCK_THRESHOLD (44 * 2)
+
+/* No name ambiguities in this file. */
+__asm__ (".syntax no_register_prefix");
+
+void *
+memcpy(void *pdst, const void *psrc, size_t pn)
{
- /* Ok. Now we want the parameters put in special registers.
+ /* 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).
+ As it is now: r10 -> r13; r11 -> r11 (nop); r12 -> r12 (nop).
- If gcc was alright, it really would need no temporaries, and no
- stack space to save stuff on. */
+ If gcc was allright, it really would need no temporaries, and no
+ stack space to save stuff on. */
register void *return_dst __asm__ ("r10") = pdst;
- register char *dst __asm__ ("r13") = pdst;
- register const char *src __asm__ ("r11") = psrc;
+ register unsigned char *dst __asm__ ("r13") = pdst;
+ register unsigned const char *src __asm__ ("r11") = 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. */
&& n >= 3)
{
if ((unsigned long) dst & 1)
- {
- n--;
- *(char*)dst = *(char*)src;
- src++;
- dst++;
- }
+ {
+ n--;
+ *dst = *src;
+ src++;
+ dst++;
+ }
if ((unsigned long) dst & 2)
- {
- n -= 2;
- *(short*)dst = *(short*)src;
- src += 2;
- dst += 2;
- }
+ {
+ n -= 2;
+ *(short *) dst = *(short *) src;
+ src += 2;
+ dst += 2;
+ }
}
- /* Decide which copying method to use. */
- if (n >= 44*2) /* Break even between movem and
- move16 is at 38.7*2, but modulo 44. */
- {
- /* 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.
-
- If you want to check that the allocation was right; then
- check the equalities in the first comment. It should say
- "r13=r13, r11=r11, r12=r12" */
- __asm__ volatile ("\n\
- ;; Check that the following is true (same register names on \n\
- ;; both sides of equal sign, as in r8=r8): \n\
- ;; %0=r13, %1=r11, %2=r12 \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\
+ /* Decide which copying method to use. */
+ if (n >= MEMCPY_BY_BLOCK_THRESHOLD)
+ {
+ /* 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. */
+ __asm__ volatile
+ ("\
+ ;; GCC does promise correct register allocations, but let's \n\
+ ;; make sure it keeps its promises. \n\
+ .ifnc %0-%1-%2,$r13-$r11-$r12 \n\
+ .error \"GCC reg alloc bug: %0-%1-%4 != $r13-$r12-$r11\" \n\
+ .endif \n\
+ \n\
+ ;; Save the registers we'll use in the movem process \n\
+ ;; on the stack. \n\
+ subq 11*4,sp \n\
+ movem r10,[sp] \n\
\n\
- ;; Now we've got this: \n\
- ;; r11 - src \n\
- ;; r13 - dst \n\
- ;; r12 - n \n\
+ ;; Now we've got this: \n\
+ ;; r11 - src \n\
+ ;; r13 - dst \n\
+ ;; r12 - n \n\
\n\
- ;; Update n for the first loop \n\
- subq 44,$r12 \n\
+ ;; 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\
+"
+#ifdef __arch_common_v10_v32
+ /* Cater to branch offset difference between v32 and v10. We
+ assume the branch below has an 8-bit offset. */
+" setf\n"
+#endif
+" movem [r11+],r10 \n\
+ subq 44,r12 \n\
+ bge 0b \n\
+ movem r10,[r13+] \n\
\n\
- addq 44,$r12 ;; compensate for last loop underflowing n \n\
+ ;; Compensate for last loop underflowing n. \n\
+ addq 44,r12 \n\
\n\
- ;; Restore registers from stack \n\
- movem [$sp+],$r10"
+ ;; Restore registers from stack. \n\
+ movem [sp+],r10"
- /* Outputs */ : "=r" (dst), "=r" (src), "=r" (n)
- /* Inputs */ : "0" (dst), "1" (src), "2" (n));
-
- }
+ /* Outputs. */
+ : "=r" (dst), "=r" (src), "=r" (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. */
+ /* Inputs. */
+ : "0" (dst), "1" (src), "2" (n));
+ }
- while ( n >= 16 )
- {
- *((long*)dst)++ = *((long*)src)++;
- *((long*)dst)++ = *((long*)src)++;
- *((long*)dst)++ = *((long*)src)++;
- *((long*)dst)++ = *((long*)src)++;
- n -= 16;
- }
+ while (n >= 16)
+ {
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+
+ 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;
+ *dst = *src;
break;
+
case 2:
- *(short*)dst = *(short*)src;
+ *(short *) dst = *(short *) src;
break;
+
case 3:
- *((short*)dst)++ = *((short*)src)++;
- *(char*)dst = *(char*)src;
+ *(short *) dst = *(short *) src; dst += 2; src += 2;
+ *dst = *src;
break;
+
case 4:
- *((long*)dst)++ = *((long*)src)++;
+ *(long *) dst = *(long *) src;
break;
+
case 5:
- *((long*)dst)++ = *((long*)src)++;
- *(char*)dst = *(char*)src;
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *dst = *src;
break;
+
case 6:
- *((long*)dst)++ = *((long*)src)++;
- *(short*)dst = *(short*)src;
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *(short *) dst = *(short *) src;
break;
+
case 7:
- *((long*)dst)++ = *((long*)src)++;
- *((short*)dst)++ = *((short*)src)++;
- *(char*)dst = *(char*)src;
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *(short *) dst = *(short *) src; dst += 2; src += 2;
+ *dst = *src;
break;
+
case 8:
- *((long*)dst)++ = *((long*)src)++;
- *((long*)dst)++ = *((long*)src)++;
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *(long *) dst = *(long *) src;
break;
+
case 9:
- *((long*)dst)++ = *((long*)src)++;
- *((long*)dst)++ = *((long*)src)++;
- *(char*)dst = *(char*)src;
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *dst = *src;
break;
+
case 10:
- *((long*)dst)++ = *((long*)src)++;
- *((long*)dst)++ = *((long*)src)++;
- *(short*)dst = *(short*)src;
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *(short *) dst = *(short *) src;
break;
+
case 11:
- *((long*)dst)++ = *((long*)src)++;
- *((long*)dst)++ = *((long*)src)++;
- *((short*)dst)++ = *((short*)src)++;
- *(char*)dst = *(char*)src;
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *(short *) dst = *(short *) src; dst += 2; src += 2;
+ *dst = *src;
break;
+
case 12:
- *((long*)dst)++ = *((long*)src)++;
- *((long*)dst)++ = *((long*)src)++;
- *((long*)dst)++ = *((long*)src)++;
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *(long *) dst = *(long *) src;
break;
+
case 13:
- *((long*)dst)++ = *((long*)src)++;
- *((long*)dst)++ = *((long*)src)++;
- *((long*)dst)++ = *((long*)src)++;
- *(char*)dst = *(char*)src;
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *dst = *src;
break;
+
case 14:
- *((long*)dst)++ = *((long*)src)++;
- *((long*)dst)++ = *((long*)src)++;
- *((long*)dst)++ = *((long*)src)++;
- *(short*)dst = *(short*)src;
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *(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;
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *(short *) dst = *(short *) src; dst += 2; src += 2;
+ *dst = *src;
break;
- }
+ }
- return return_dst; /* destination pointer. */
-} /* memcpy() */
+ return return_dst;
+}
git.samba.org / sfrench / cifs-2.6.git / blobdiff