--- /dev/null
+/* 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)
+{
+ /* 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. */
+
+ register void *return_dst __asm__ ("r10") = pdst;
+ 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. */
+ 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--;
+ *dst = *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_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\
+ \n\
+ ;; Update n for the first loop. \n\
+ subq 44,r12 \n\
+0: \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\
+ ;; Compensate for last loop underflowing n. \n\
+ addq 44,r12 \n\
+ \n\
+ ;; Restore registers from stack. \n\
+ movem [sp+],r10"
+
+ /* Outputs. */
+ : "=r" (dst), "=r" (src), "=r" (n)
+
+ /* Inputs. */
+ : "0" (dst), "1" (src), "2" (n));
+ }
+
+ 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;
+ }
+
+ switch (n)
+ {
+ case 0:
+ break;
+
+ case 1:
+ *dst = *src;
+ break;
+
+ case 2:
+ *(short *) dst = *(short *) src;
+ break;
+
+ case 3:
+ *(short *) dst = *(short *) src; dst += 2; src += 2;
+ *dst = *src;
+ break;
+
+ case 4:
+ *(long *) dst = *(long *) src;
+ break;
+
+ case 5:
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *dst = *src;
+ break;
+
+ case 6:
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *(short *) dst = *(short *) src;
+ break;
+
+ case 7:
+ *(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; dst += 4; src += 4;
+ *(long *) dst = *(long *) src;
+ break;
+
+ case 9:
+ *(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; dst += 4; src += 4;
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *(short *) dst = *(short *) src;
+ break;
+
+ case 11:
+ *(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; dst += 4; src += 4;
+ *(long *) dst = *(long *) src; dst += 4; src += 4;
+ *(long *) dst = *(long *) src;
+ break;
+
+ case 13:
+ *(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; 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; 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;
+}
Code Review / kvmfornfv.git / blobdiff