260 lines
7.3 KiB
C
260 lines
7.3 KiB
C
|
/* 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;
|
||
|
|
}
|