X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fmemcmp.c;h=ecba1288df947111e23b80a3a162674749404689;hb=5191b3546cfb6c163228c23f214e325ddf60d46f;hp=9f864d1e1053fe182f922dd3eba47aa90d9699e5;hpb=a97855187e28a1a97bf2cad6ab42d71346ccd39a;p=gnulib.git diff --git a/lib/memcmp.c b/lib/memcmp.c index 9f864d1e1..ecba1288d 100644 --- a/lib/memcmp.c +++ b/lib/memcmp.c @@ -1,12 +1,14 @@ -/* Copyright (C) 1991, 1993, 1995, 1997 Free Software Foundation, Inc. +/* Copyright (C) 1991, 1993, 1995, 1997-1998, 2003, 2006, 2009-2013 Free + Software Foundation, Inc. + Contributed by Torbjorn Granlund (tege@sics.se). NOTE: The canonical source of this file is maintained with the GNU C Library. Bugs can be reported to bug-glibc@prep.ai.mit.edu. - This program is free software; you can redistribute it and/or modify it + This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the - Free Software Foundation; either version 2, or (at your option) any + Free Software Foundation; either version 3 of the License, or any later version. This program is distributed in the hope that it will be useful, @@ -15,53 +17,39 @@ GNU General Public License for more details. You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, - USA. */ + along with this program. If not, see . */ -#ifdef HAVE_CONFIG_H -# include "config.h" +#ifndef _LIBC +# include #endif -#undef __ptr_t -#if defined __cplusplus || (defined __STDC__ && __STDC__) -# define __ptr_t void * -#else /* Not C++ or ANSI C. */ -# undef const -# define const -# define __ptr_t char * -#endif /* C++ or ANSI C. */ - -#ifndef __P -# if defined __GNUC__ || (defined __STDC__ && __STDC__) -# define __P(args) args -# else -# define __P(args) () -# endif /* GCC. */ -#endif /* Not __P. */ +#include -#if defined HAVE_STRING_H || defined _LIBC -# include -#endif +#include #undef memcmp #ifdef _LIBC # include +# include + +# if __BYTE_ORDER == __BIG_ENDIAN +# define WORDS_BIGENDIAN +# endif -#else /* Not in the GNU C library. */ +#else /* Not in the GNU C library. */ # include /* Type to use for aligned memory operations. This should normally be the biggest type supported by a single load and store. Must be an unsigned type. */ -# define op_t unsigned long int -# define OPSIZ (sizeof(op_t)) +# define op_t unsigned long int +# define OPSIZ (sizeof(op_t)) /* Threshold value for when to enter the unrolled loops. */ -# define OP_T_THRES 16 +# define OP_T_THRES 16 /* Type to use for unaligned operations. */ typedef unsigned char byte; @@ -72,12 +60,12 @@ typedef unsigned char byte; # define MERGE(w0, sh_1, w1, sh_2) (((w0) << (sh_1)) | ((w1) >> (sh_2))) # endif -#endif /* In the GNU C library. */ +#endif /* In the GNU C library. */ #ifdef WORDS_BIGENDIAN # define CMP_LT_OR_GT(a, b) ((a) > (b) ? 1 : -1) #else -# define CMP_LT_OR_GT(a, b) memcmp_bytes ((a), (b)) +# define CMP_LT_OR_GT(a, b) memcmp_bytes (a, b) #endif /* BE VERY CAREFUL IF YOU CHANGE THIS CODE! */ @@ -98,23 +86,20 @@ typedef unsigned char byte; A and B are known to be different. This is needed only on little-endian machines. */ -static int memcmp_bytes __P((op_t, op_t)); - # ifdef __GNUC__ __inline # endif static int -memcmp_bytes (a, b) - op_t a, b; +memcmp_bytes (op_t a, op_t b) { - long int srcp1 = (long int) &a; - long int srcp2 = (long int) &b; + const byte *srcp1 = (const byte *) &a; + const byte *srcp2 = (const byte *) &b; op_t a0, b0; do { - a0 = ((byte *) srcp1)[0]; - b0 = ((byte *) srcp2)[0]; + a0 = srcp1[0]; + b0 = srcp2[0]; srcp1 += 1; srcp2 += 1; } @@ -123,19 +108,14 @@ memcmp_bytes (a, b) } #endif -static int memcmp_common_alignment __P((long, long, size_t)); - -/* memcmp_common_alignment -- Compare blocks at SRCP1 and SRCP2 with LEN `op_t' +/* memcmp_common_alignment -- Compare blocks at SRCP1 and SRCP2 with LEN 'op_t' objects (not LEN bytes!). Both SRCP1 and SRCP2 should be aligned for - memory operations on `op_t's. */ -#ifdef __GNUC__ + memory operations on 'op_t's. */ +#ifdef __GNUC__ __inline #endif static int -memcmp_common_alignment (srcp1, srcp2, len) - long int srcp1; - long int srcp2; - size_t len; +memcmp_common_alignment (uintptr_t srcp1, uintptr_t srcp2, size_t len) { op_t a0, a1; op_t b0, b1; @@ -159,7 +139,7 @@ memcmp_common_alignment (srcp1, srcp2, len) goto do2; case 0: if (OP_T_THRES <= 3 * OPSIZ && len == 0) - return 0; + return 0; a0 = ((op_t *) srcp1)[0]; b0 = ((op_t *) srcp2)[0]; goto do3; @@ -170,7 +150,7 @@ memcmp_common_alignment (srcp1, srcp2, len) srcp2 += OPSIZ; len -= 1; if (OP_T_THRES <= 3 * OPSIZ && len == 0) - goto do0; + goto do0; /* Fall through. */ } @@ -179,25 +159,25 @@ memcmp_common_alignment (srcp1, srcp2, len) a0 = ((op_t *) srcp1)[0]; b0 = ((op_t *) srcp2)[0]; if (a1 != b1) - return CMP_LT_OR_GT (a1, b1); + return CMP_LT_OR_GT (a1, b1); do3: a1 = ((op_t *) srcp1)[1]; b1 = ((op_t *) srcp2)[1]; if (a0 != b0) - return CMP_LT_OR_GT (a0, b0); + return CMP_LT_OR_GT (a0, b0); do2: a0 = ((op_t *) srcp1)[2]; b0 = ((op_t *) srcp2)[2]; if (a1 != b1) - return CMP_LT_OR_GT (a1, b1); + return CMP_LT_OR_GT (a1, b1); do1: a1 = ((op_t *) srcp1)[3]; b1 = ((op_t *) srcp2)[3]; if (a0 != b0) - return CMP_LT_OR_GT (a0, b0); + return CMP_LT_OR_GT (a0, b0); srcp1 += 4 * OPSIZ; srcp2 += 4 * OPSIZ; @@ -213,19 +193,14 @@ memcmp_common_alignment (srcp1, srcp2, len) return 0; } -static int memcmp_not_common_alignment __P((long, long, size_t)); - /* memcmp_not_common_alignment -- Compare blocks at SRCP1 and SRCP2 with LEN - `op_t' objects (not LEN bytes!). SRCP2 should be aligned for memory - operations on `op_t', but SRCP1 *should be unaligned*. */ -#ifdef __GNUC__ + 'op_t' objects (not LEN bytes!). SRCP2 should be aligned for memory + operations on 'op_t', but SRCP1 *should be unaligned*. */ +#ifdef __GNUC__ __inline #endif static int -memcmp_not_common_alignment (srcp1, srcp2, len) - long int srcp1; - long int srcp2; - size_t len; +memcmp_not_common_alignment (uintptr_t srcp1, uintptr_t srcp2, size_t len) { op_t a0, a1, a2, a3; op_t b0, b1, b2, b3; @@ -238,7 +213,7 @@ memcmp_not_common_alignment (srcp1, srcp2, len) shl = 8 * (srcp1 % OPSIZ); shr = 8 * OPSIZ - shl; - /* Make SRCP1 aligned by rounding it down to the beginning of the `op_t' + /* Make SRCP1 aligned by rounding it down to the beginning of the 'op_t' it points in the middle of. */ srcp1 &= -OPSIZ; @@ -262,7 +237,7 @@ memcmp_not_common_alignment (srcp1, srcp2, len) goto do2; case 0: if (OP_T_THRES <= 3 * OPSIZ && len == 0) - return 0; + return 0; a3 = ((op_t *) srcp1)[0]; a0 = ((op_t *) srcp1)[1]; b0 = ((op_t *) srcp2)[0]; @@ -276,7 +251,7 @@ memcmp_not_common_alignment (srcp1, srcp2, len) srcp2 += 1 * OPSIZ; len -= 1; if (OP_T_THRES <= 3 * OPSIZ && len == 0) - goto do0; + goto do0; /* Fall through. */ } @@ -284,30 +259,30 @@ memcmp_not_common_alignment (srcp1, srcp2, len) { a0 = ((op_t *) srcp1)[0]; b0 = ((op_t *) srcp2)[0]; - x = MERGE(a2, shl, a3, shr); + x = MERGE (a2, shl, a3, shr); if (x != b3) - return CMP_LT_OR_GT (x, b3); + return CMP_LT_OR_GT (x, b3); do3: a1 = ((op_t *) srcp1)[1]; b1 = ((op_t *) srcp2)[1]; - x = MERGE(a3, shl, a0, shr); + x = MERGE (a3, shl, a0, shr); if (x != b0) - return CMP_LT_OR_GT (x, b0); + return CMP_LT_OR_GT (x, b0); do2: a2 = ((op_t *) srcp1)[2]; b2 = ((op_t *) srcp2)[2]; - x = MERGE(a0, shl, a1, shr); + x = MERGE (a0, shl, a1, shr); if (x != b1) - return CMP_LT_OR_GT (x, b1); + return CMP_LT_OR_GT (x, b1); do1: a3 = ((op_t *) srcp1)[3]; b3 = ((op_t *) srcp2)[3]; - x = MERGE(a1, shl, a2, shr); + x = MERGE (a1, shl, a2, shr); if (x != b2) - return CMP_LT_OR_GT (x, b2); + return CMP_LT_OR_GT (x, b2); srcp1 += 4 * OPSIZ; srcp2 += 4 * OPSIZ; @@ -318,50 +293,47 @@ memcmp_not_common_alignment (srcp1, srcp2, len) /* This is the right position for do0. Please don't move it into the loop. */ do0: - x = MERGE(a2, shl, a3, shr); + x = MERGE (a2, shl, a3, shr); if (x != b3) return CMP_LT_OR_GT (x, b3); return 0; } int -memcmp (s1, s2, len) - const __ptr_t s1; - const __ptr_t s2; - size_t len; +rpl_memcmp (const void *s1, const void *s2, size_t len) { op_t a0; op_t b0; - long int srcp1 = (long int) s1; - long int srcp2 = (long int) s2; + uintptr_t srcp1 = (uintptr_t) s1; + uintptr_t srcp2 = (uintptr_t) s2; op_t res; if (len >= OP_T_THRES) { /* There are at least some bytes to compare. No need to test - for LEN == 0 in this alignment loop. */ + for LEN == 0 in this alignment loop. */ while (srcp2 % OPSIZ != 0) - { - a0 = ((byte *) srcp1)[0]; - b0 = ((byte *) srcp2)[0]; - srcp1 += 1; - srcp2 += 1; - res = a0 - b0; - if (res != 0) - return res; - len -= 1; - } - - /* SRCP2 is now aligned for memory operations on `op_t'. - SRCP1 alignment determines if we can do a simple, - aligned compare or need to shuffle bits. */ + { + a0 = ((byte *) srcp1)[0]; + b0 = ((byte *) srcp2)[0]; + srcp1 += 1; + srcp2 += 1; + res = a0 - b0; + if (res != 0) + return res; + len -= 1; + } + + /* SRCP2 is now aligned for memory operations on 'op_t'. + SRCP1 alignment determines if we can do a simple, + aligned compare or need to shuffle bits. */ if (srcp1 % OPSIZ == 0) - res = memcmp_common_alignment (srcp1, srcp2, len / OPSIZ); + res = memcmp_common_alignment (srcp1, srcp2, len / OPSIZ); else - res = memcmp_not_common_alignment (srcp1, srcp2, len / OPSIZ); + res = memcmp_not_common_alignment (srcp1, srcp2, len / OPSIZ); if (res != 0) - return res; + return res; /* Number of bytes remaining in the interval [0..OPSIZ-1]. */ srcp1 += len & -OPSIZ; @@ -378,7 +350,7 @@ memcmp (s1, s2, len) srcp2 += 1; res = a0 - b0; if (res != 0) - return res; + return res; len -= 1; }