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Diffstat (limited to 'newlib/libc/machine/microblaze/strcmp.c')
| -rw-r--r-- | newlib/libc/machine/microblaze/strcmp.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/newlib/libc/machine/microblaze/strcmp.c b/newlib/libc/machine/microblaze/strcmp.c new file mode 100644 index 000000000..dbac3878f --- /dev/null +++ b/newlib/libc/machine/microblaze/strcmp.c @@ -0,0 +1,195 @@ +/* Copyright (c) 2009 Xilinx, Inc. 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 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. Neither the name of Xilinx 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 COPYRIGHT HOLDER 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 COPYRIGHT + HOLDER 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. + + +FUNCTION + <<strcmp>>---character string compare + +INDEX + strcmp + +ANSI_SYNOPSIS + #include <string.h> + int strcmp(const char *<[a]>, const char *<[b]>); + +TRAD_SYNOPSIS + #include <string.h> + int strcmp(<[a]>, <[b]>) + char *<[a]>; + char *<[b]>; + +DESCRIPTION + <<strcmp>> compares the string at <[a]> to + the string at <[b]>. + +RETURNS + If <<*<[a]>>> sorts lexicographically after <<*<[b]>>>, + <<strcmp>> returns a number greater than zero. If the two + strings match, <<strcmp>> returns zero. If <<*<[a]>>> + sorts lexicographically before <<*<[b]>>>, <<strcmp>> returns a + number less than zero. + +PORTABILITY +<<strcmp>> is ANSI C. + +<<strcmp>> requires no supporting OS subroutines. + +QUICKREF + strcmp ansi pure +*/ + +#include <string.h> +#include <limits.h> + +/* Nonzero if either X or Y is not aligned on a "long" boundary. */ +#define UNALIGNED(X, Y) \ + (((long)X & (sizeof (long) - 1)) | ((long)Y & (sizeof (long) - 1))) + +/* DETECTNULL returns nonzero if (long)X contains a NULL byte. */ +#if LONG_MAX == 2147483647L +#define DETECTNULL(X) (((X) - 0x01010101) & ~(X) & 0x80808080) +#else +#if LONG_MAX == 9223372036854775807L +#define DETECTNULL(X) (((X) - 0x0101010101010101) & ~(X) & 0x8080808080808080) +#else +#error long int is not a 32bit or 64bit type. +#endif +#endif + +#ifndef DETECTNULL +#error long int is not a 32bit or 64bit byte +#endif + +int +_DEFUN (strcmp, (s1, s2), + _CONST char *s1 _AND + _CONST char *s2) +{ + +#ifndef HAVE_HW_PCMP + +#if defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__) + while (*s1 != '\0' && *s1 == *s2) + { + s1++; + s2++; + } + + return (*(unsigned char *) s1) - (*(unsigned char *) s2); +#else + unsigned long *a1; + unsigned long *a2; + + /* If s1 or s2 are unaligned, then compare bytes. */ + if (!UNALIGNED (s1, s2)) + { + /* If s1 and s2 are word-aligned, compare them a word at a time. */ + a1 = (unsigned long*)s1; + a2 = (unsigned long*)s2; + while (*a1 == *a2) + { + /* To get here, *a1 == *a2, thus if we find a null in *a1, + then the strings must be equal, so return zero. */ + if (DETECTNULL (*a1)) + return 0; + + a1++; + a2++; + } + + /* A difference was detected in last few bytes of s1, so search bytewise */ + s1 = (char*)a1; + s2 = (char*)a2; + } + + while (*s1 != '\0' && *s1 == *s2) + { + s1++; + s2++; + } + return (*(unsigned char *) s1) - (*(unsigned char *) s2); +#endif /* not PREFER_SIZE_OVER_SPEED */ + +#else + + asm volatile (" \n\ + or r9, r0, r0 /* Index register */ \n\ +check_alignment: \n\ + andi r3, r5, 3 \n\ + andi r4, r6, 3 \n\ + bnei r3, try_align_args \n\ + bnei r4, regular_strcmp /* At this point we don't have a choice */ \n\ +cmp_loop: \n\ + lw r3, r5, r9 \n\ + lw r4, r6, r9 \n\ + pcmpbf r7, r3, r0 /* See if there is Null byte */ \n\ + bnei r7, end_cmp_loop /* IF yes (r7 > 0) use byte compares in end_cmp_loop */ \n\ + cmpu r7, r4, r3 /* ELSE compare whole word */ \n\ + bnei r7, end_cmp \n\ + brid cmp_loop \n\ + addik r9, r9, 4 /* delay slot */ \n\ +end_cmp_loop: \n\ + lbu r3, r5, r9 /* byte compare loop */ \n\ + lbu r4, r6, r9 \n\ + cmpu r7, r4, r3 /* Compare bytes */ \n\ + bnei r7, end_cmp_early \n\ + bneid r3, end_cmp_loop /* If reached null on one string, terminate */ \n\ + addik r9, r9, 1 /* delay slot */ \n\ +end_cmp_early: \n\ + rtsd r15, 8 \n\ + or r3, r0, r7 \n\ +try_align_args: \n\ + xor r7, r4, r3 \n\ + bnei r7, regular_strcmp /* cannot align args */ \n\ + rsubik r10, r3, 4 /* Number of initial bytes to align */ \n\ +align_loop: \n\ + lbu r3, r5, r9 \n\ + lbu r4, r6, r9 \n\ + cmpu r7, r4, r3 \n\ + bnei r7, end_cmp \n\ + beqi r3, end_cmp \n\ + addik r10, r10, -1 \n\ + beqid r10, cmp_loop \n\ + addik r9, r9, 1 \n\ + bri align_loop \n\ +regular_strcmp: \n\ + lbu r3, r5, r9 \n\ + lbu r4, r6, r9 \n\ + cmpu r7, r4, r3 \n\ + bnei r7, end_cmp \n\ + beqi r3, end_cmp \n\ + brid regular_strcmp \n\ + addik r9, r9, 1 \n\ +end_cmp: \n\ + rtsd r15, 8 \n\ + or r3, r0, r7 /* Return strcmp result */"); + +#endif /* ! HAVE_HW_PCMP */ +} + |