diff options
Diffstat (limited to 'sys/lib/libkern/arch/m68k/bcmp.S')
| -rw-r--r-- | sys/lib/libkern/arch/m68k/bcmp.S | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/sys/lib/libkern/arch/m68k/bcmp.S b/sys/lib/libkern/arch/m68k/bcmp.S new file mode 100644 index 00000000000..6b5d6c88d40 --- /dev/null +++ b/sys/lib/libkern/arch/m68k/bcmp.S @@ -0,0 +1,91 @@ +/*- + * Copyright (c) 1990 The Regents of the University of California. + * All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * the Systems Programming Group of the University of Utah Computer + * Science Department. + * + * 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. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University 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 THE REGENTS AND 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 THE REGENTS OR 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. + */ + +#if defined(LIBC_SCCS) && !defined(lint) + .text + /*.asciz "from: @(#)bcmp.s 5.1 (Berkeley) 5/12/90"*/ + .asciz "$Id: bcmp.S,v 1.1 1995/10/18 08:52:52 deraadt Exp $" +#endif /* LIBC_SCCS and not lint */ + +/* bcmp(s1, s2, n) */ + +#include "DEFS.h" + +/* + * This is probably not the best we can do, but it is still 2-10 times + * faster than the C version in the portable gen directory. + * + * Things that might help: + * - longword align when possible (only on the 68020) + * - use nested DBcc instructions or use one and limit size to 64K + */ +ENTRY(bcmp) + movl sp@(4),a0 | string 1 + movl sp@(8),a1 | string 2 + movl sp@(12),d0 | length + beq bcdone | if zero, nothing to do + movl a0,d1 + btst #0,d1 | string 1 address odd? + beq bceven | no, skip alignment + cmpmb a0@+,a1@+ | yes, compare a byte + bne bcnoteq | not equal, return non-zero + subql #1,d0 | adjust count + beq bcdone | count 0, reutrn zero +bceven: + movl a1,d1 + btst #0,d1 | string 2 address odd? + bne bcbloop | yes, no hope for alignment, compare bytes + movl d0,d1 | no, both even + lsrl #2,d1 | convert count to longword count + beq bcbloop | count 0, skip longword loop +bclloop: + cmpml a0@+,a1@+ | compare a longword + bne bcnoteq | not equal, return non-zero + subql #1,d1 | adjust count + bne bclloop | still more, keep comparing + andl #3,d0 | what remains + beq bcdone | nothing, all done +bcbloop: + cmpmb a0@+,a1@+ | compare a byte + bne bcnoteq | not equal, return non-zero + subql #1,d0 | adjust count + bne bcbloop | still more, keep going + rts +bcnoteq: + moveq #1,d0 +bcdone: + rts |