+++ /dev/null
-/* A memset for CRIS.
- Copyright (C) 1999-2005 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. */
-
-/* Note the multiple occurrence of the expression "12*4", including the
- asm. It is hard to get it into the asm in a good way. Thus better to
- expose the problem everywhere: no macro. */
-
-/* Assuming one cycle per dword written or read (ok, not really true; the
- world is not ideal), and one cycle 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 MEMSET_BY_BLOCK_THRESHOLD (1 * 48)
-
-/* No name ambiguities in this file. */
-__asm__ (".syntax no_register_prefix");
-
-void *memset(void *pdst, int c, unsigned int plen)
-{
- /* Now we want the parameters in special registers. Make sure the
- compiler does something usable with this. */
-
- register char *return_dst __asm__ ("r10") = pdst;
- register int n __asm__ ("r12") = plen;
- register int lc __asm__ ("r11") = c;
-
- /* Most apps use memset sanely. Memsetting about 3..4 bytes or less get
- penalized here compared to the generic implementation. */
-
- /* This is fragile performancewise at best. Check with newer GCC
- releases, if they compile cascaded "x |= x << 8" to sane code. */
- __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) /* Inputs. */
- : "0" (lc) /* Outputs. */
- : "r13"); /* Trash. */
-
- {
- register char *dst __asm__ ("r13") = pdst;
-
- if (((unsigned long) pdst & 3) != 0
- /* Oops! n = 0 must be a valid 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;
- }
- }
-
- /* Decide which setting method to use. */
- if (n >= MEMSET_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-block sizes
- suboptimal. */
- __asm__ volatile
- ("\
- ;; GCC does promise correct register allocations, but let's \n\
- ;; make sure it keeps its promises. \n\
- .ifnc %0-%1-%4,$r13-$r12-$r11 \n\
- .error \"GCC reg alloc bug: %0-%1-%4 != $r13-$r12-$r11\" \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\
-"
-#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
-" subq 12*4,r12 \n\
- bge 0b \n\
- movem r11,[r13+] \n\
- \n\
- ;; Compensate for last loop underflowing n. \n\
- addq 12*4,r12 \n\
- \n\
- ;; Restore registers from stack. \n\
- movem [sp+],r10"
-
- /* Outputs. */
- : "=r" (dst), "=r" (n)
-
- /* Inputs. */
- : "0" (dst), "1" (n), "r" (lc));
- }
-
- /* An ad-hoc unroll, used for 4*12-1..16 bytes. */
- while (n >= 16)
- {
- *(long *) dst = lc; dst += 4;
- *(long *) dst = lc; dst += 4;
- *(long *) dst = lc; dst += 4;
- *(long *) dst = lc; dst += 4;
- n -= 16;
- }
-
- switch (n)
- {
- case 0:
- break;
-
- case 1:
- *dst = (char) lc;
- break;
-
- case 2:
- *(short *) dst = (short) lc;
- break;
-
- case 3:
- *(short *) dst = (short) lc; dst += 2;
- *dst = (char) lc;
- break;
-
- case 4:
- *(long *) dst = lc;
- break;
-
- case 5:
- *(long *) dst = lc; dst += 4;
- *dst = (char) lc;
- break;
-
- case 6:
- *(long *) dst = lc; dst += 4;
- *(short *) dst = (short) lc;
- break;
-
- case 7:
- *(long *) dst = lc; dst += 4;
- *(short *) dst = (short) lc; dst += 2;
- *dst = (char) lc;
- break;
-
- case 8:
- *(long *) dst = lc; dst += 4;
- *(long *) dst = lc;
- break;
-
- case 9:
- *(long *) dst = lc; dst += 4;
- *(long *) dst = lc; dst += 4;
- *dst = (char) lc;
- break;
-
- case 10:
- *(long *) dst = lc; dst += 4;
- *(long *) dst = lc; dst += 4;
- *(short *) dst = (short) lc;
- break;
-
- case 11:
- *(long *) dst = lc; dst += 4;
- *(long *) dst = lc; dst += 4;
- *(short *) dst = (short) lc; dst += 2;
- *dst = (char) lc;
- break;
-
- case 12:
- *(long *) dst = lc; dst += 4;
- *(long *) dst = lc; dst += 4;
- *(long *) dst = lc;
- break;
-
- case 13:
- *(long *) dst = lc; dst += 4;
- *(long *) dst = lc; dst += 4;
- *(long *) dst = lc; dst += 4;
- *dst = (char) lc;
- break;
-
- case 14:
- *(long *) dst = lc; dst += 4;
- *(long *) dst = lc; dst += 4;
- *(long *) dst = lc; dst += 4;
- *(short *) dst = (short) lc;
- break;
-
- case 15:
- *(long *) dst = lc; dst += 4;
- *(long *) dst = lc; dst += 4;
- *(long *) dst = lc; dst += 4;
- *(short *) dst = (short) lc; dst += 2;
- *dst = (char) lc;
- break;
- }
- }
-
- return return_dst;
-}
git.samba.org / sfrench / cifs-2.6.git / blobdiff