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Diffstat (limited to 'include/haproxy/intops.h')
-rw-r--r-- | include/haproxy/intops.h | 495 |
1 files changed, 495 insertions, 0 deletions
diff --git a/include/haproxy/intops.h b/include/haproxy/intops.h new file mode 100644 index 0000000..34010cc --- /dev/null +++ b/include/haproxy/intops.h @@ -0,0 +1,495 @@ +/* + * include/haproxy/intops.h + * Functions for integer operations. + * + * Copyright (C) 2020 Willy Tarreau - w@1wt.eu + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation, version 2.1 + * exclusively. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA +*/ + +#ifndef _HAPROXY_INTOPS_H +#define _HAPROXY_INTOPS_H + +#include <haproxy/api.h> + +/* exported functions, mostly integer parsing */ +/* rounds <i> down to the closest value having max 2 digits */ +unsigned int round_2dig(unsigned int i); +unsigned int full_hash(unsigned int a); +int varint_bytes(uint64_t v); +unsigned int read_uint(const char **s, const char *end); +long long read_int64(const char **s, const char *end); +unsigned long long read_uint64(const char **s, const char *end); +unsigned int str2ui(const char *s); +unsigned int str2uic(const char *s); +unsigned int strl2ui(const char *s, int len); +unsigned int strl2uic(const char *s, int len); +int strl2ic(const char *s, int len); +int strl2irc(const char *s, int len, int *ret); +int strl2llrc(const char *s, int len, long long *ret); +int strl2llrc_dotted(const char *text, int len, long long *ret); +unsigned int mask_find_rank_bit(unsigned int r, unsigned long m); +unsigned int mask_find_rank_bit_fast(unsigned int r, unsigned long m, + unsigned long a, unsigned long b, + unsigned long c, unsigned long d); +void mask_prep_rank_map(unsigned long m, + unsigned long *a, unsigned long *b, + unsigned long *c, unsigned long *d); +int one_among_mask(unsigned long v, int bit); + + +/* Multiply the two 32-bit operands and shift the 64-bit result right 32 bits. + * This is used to compute fixed ratios by setting one of the operands to + * (2^32*ratio). + */ +static inline unsigned int mul32hi(unsigned int a, unsigned int b) +{ + return ((unsigned long long)a * b + a) >> 32; +} + +/* gcc does not know when it can safely divide 64 bits by 32 bits. Use this + * function when you know for sure that the result fits in 32 bits, because + * it is optimal on x86 and on 64bit processors. + */ +static inline unsigned int div64_32(unsigned long long o1, unsigned int o2) +{ + unsigned long long result; +#ifdef __i386__ + asm("divl %2" + : "=A" (result) + : "A"(o1), "rm"(o2)); +#else + result = o1 / o2; +#endif + return result; +} + +/* rotate left a 64-bit integer by <bits:[0-5]> bits */ +static inline uint64_t rotl64(uint64_t v, uint8_t bits) +{ +#if !defined(__ARM_ARCH_8A) && !defined(__x86_64__) + bits &= 63; +#endif + v = (v << bits) | (v >> (-bits & 63)); + return v; +} + +/* rotate right a 64-bit integer by <bits:[0-5]> bits */ +static inline uint64_t rotr64(uint64_t v, uint8_t bits) +{ +#if !defined(__ARM_ARCH_8A) && !defined(__x86_64__) + bits &= 63; +#endif + v = (v >> bits) | (v << (-bits & 63)); + return v; +} + +/* Simple popcountl implementation. It returns the number of ones in a word. + * Described here : https://graphics.stanford.edu/~seander/bithacks.html + */ +static inline unsigned int my_popcountl(unsigned long a) +{ + a = a - ((a >> 1) & ~0UL/3); + a = (a & ~0UL/15*3) + ((a >> 2) & ~0UL/15*3); + a = (a + (a >> 4)) & ~0UL/255*15; + return (unsigned long)(a * (~0UL/255)) >> (sizeof(unsigned long) - 1) * 8; +} + +/* returns non-zero if <a> has at least 2 bits set */ +static inline unsigned long atleast2(unsigned long a) +{ + return a & (a - 1); +} + +/* Simple ffs implementation. It returns the position of the lowest bit set to + * one, starting at 1. It is illegal to call it with a==0 (undefined result). + */ +static inline unsigned int my_ffsl(unsigned long a) +{ + unsigned long cnt; + +#if defined(__x86_64__) + __asm__("bsf %1,%0\n" : "=r" (cnt) : "rm" (a)); + cnt++; +#else + + cnt = 1; +#if LONG_MAX > 0x7FFFFFFFL /* 64bits */ + if (!(a & 0xFFFFFFFFUL)) { + a >>= 32; + cnt += 32; + } +#endif + if (!(a & 0XFFFFU)) { + a >>= 16; + cnt += 16; + } + if (!(a & 0XFF)) { + a >>= 8; + cnt += 8; + } + if (!(a & 0xf)) { + a >>= 4; + cnt += 4; + } + if (!(a & 0x3)) { + a >>= 2; + cnt += 2; + } + if (!(a & 0x1)) { + cnt += 1; + } +#endif /* x86_64 */ + + return cnt; +} + +/* Simple fls implementation. It returns the position of the highest bit set to + * one, starting at 1. It is illegal to call it with a==0 (undefined result). + */ +static inline unsigned int my_flsl(unsigned long a) +{ + unsigned long cnt; + +#if defined(__x86_64__) + __asm__("bsr %1,%0\n" : "=r" (cnt) : "rm" (a)); + cnt++; +#else + + cnt = 1; +#if LONG_MAX > 0x7FFFFFFFUL /* 64bits */ + if (a & 0xFFFFFFFF00000000UL) { + a >>= 32; + cnt += 32; + } +#endif + if (a & 0XFFFF0000U) { + a >>= 16; + cnt += 16; + } + if (a & 0XFF00) { + a >>= 8; + cnt += 8; + } + if (a & 0xf0) { + a >>= 4; + cnt += 4; + } + if (a & 0xc) { + a >>= 2; + cnt += 2; + } + if (a & 0x2) { + cnt += 1; + } +#endif /* x86_64 */ + + return cnt; +} + +/* Build a word with the <bits> lower bits set (reverse of my_popcountl) */ +static inline unsigned long nbits(int bits) +{ + if (--bits < 0) + return 0; + else + return (2UL << bits) - 1; +} + +/* Turns 64-bit value <a> from host byte order to network byte order. + * The principle consists in letting the compiler detect we're playing + * with a union and simplify most or all operations. The asm-optimized + * htonl() version involving bswap (x86) / rev (arm) / other is a single + * operation on little endian, or a NOP on big-endian. In both cases, + * this lets the compiler "see" that we're rebuilding a 64-bit word from + * two 32-bit quantities that fit into a 32-bit register. In big endian, + * the whole code is optimized out. In little endian, with a decent compiler, + * a few bswap and 2 shifts are left, which is the minimum acceptable. + */ +static inline unsigned long long my_htonll(unsigned long long a) +{ +#if defined(__x86_64__) + __asm__ volatile("bswapq %0" : "=r"(a) : "0"(a)); + return a; +#else + union { + struct { + unsigned int w1; + unsigned int w2; + } by32; + unsigned long long by64; + } w = { .by64 = a }; + return ((unsigned long long)htonl(w.by32.w1) << 32) | htonl(w.by32.w2); +#endif +} + +/* Turns 64-bit value <a> from network byte order to host byte order. */ +static inline unsigned long long my_ntohll(unsigned long long a) +{ + return my_htonll(a); +} + +/* sets bit <bit> into map <map>, which must be long-aligned */ +static inline void ha_bit_set(unsigned long bit, long *map) +{ + map[bit / (8 * sizeof(*map))] |= 1UL << (bit & (8 * sizeof(*map) - 1)); +} + +/* clears bit <bit> from map <map>, which must be long-aligned */ +static inline void ha_bit_clr(unsigned long bit, long *map) +{ + map[bit / (8 * sizeof(*map))] &= ~(1UL << (bit & (8 * sizeof(*map) - 1))); +} + +/* flips bit <bit> from map <map>, which must be long-aligned */ +static inline void ha_bit_flip(unsigned long bit, long *map) +{ + map[bit / (8 * sizeof(*map))] ^= 1UL << (bit & (8 * sizeof(*map) - 1)); +} + +/* returns non-zero if bit <bit> from map <map> is set, otherwise 0 */ +static inline int ha_bit_test(unsigned long bit, const long *map) +{ + return !!(map[bit / (8 * sizeof(*map))] & 1UL << (bit & (8 * sizeof(*map) - 1))); +} + +/* hash a 32-bit integer to another 32-bit integer. This code may be large when + * inlined, use full_hash() instead. + */ +static inline unsigned int __full_hash(unsigned int a) +{ + /* This function is one of Bob Jenkins' full avalanche hashing + * functions, which when provides quite a good distribution for little + * input variations. The result is quite suited to fit over a 32-bit + * space with enough variations so that a randomly picked number falls + * equally before any server position. + * Check http://burtleburtle.net/bob/hash/integer.html for more info. + */ + a = (a+0x7ed55d16) + (a<<12); + a = (a^0xc761c23c) ^ (a>>19); + a = (a+0x165667b1) + (a<<5); + a = (a+0xd3a2646c) ^ (a<<9); + a = (a+0xfd7046c5) + (a<<3); + a = (a^0xb55a4f09) ^ (a>>16); + + /* ensure values are better spread all around the tree by multiplying + * by a large prime close to 3/4 of the tree. + */ + return a * 3221225473U; +} + +/* + * Return integer equivalent of character <c> for a hex digit (0-9, a-f, A-F), + * otherwise -1. This compact form helps gcc produce efficient code. + */ +static inline int hex2i(int c) +{ + if ((unsigned char)(c -= '0') > 9) { + if ((unsigned char)(c -= 'A' - '0') > 5 && + (unsigned char)(c -= 'a' - 'A') > 5) + c = -11; + c += 10; + } + return c; +} + +/* This one is 6 times faster than strtoul() on athlon, but does + * no check at all. + */ +static inline unsigned int __str2ui(const char *s) +{ + unsigned int i = 0; + while (*s) { + i = i * 10 - '0'; + i += (unsigned char)*s++; + } + return i; +} + +/* This one is 5 times faster than strtoul() on athlon with checks. + * It returns the value of the number composed of all valid digits read. + */ +static inline unsigned int __str2uic(const char *s) +{ + unsigned int i = 0; + unsigned int j; + + while (1) { + j = (*s++) - '0'; + if (j > 9) + break; + i *= 10; + i += j; + } + return i; +} + +/* This one is 28 times faster than strtoul() on athlon, but does + * no check at all! + */ +static inline unsigned int __strl2ui(const char *s, int len) +{ + unsigned int i = 0; + + while (len-- > 0) { + i = i * 10 - '0'; + i += (unsigned char)*s++; + } + return i; +} + +/* This one is 7 times faster than strtoul() on athlon with checks. + * It returns the value of the number composed of all valid digits read. + */ +static inline unsigned int __strl2uic(const char *s, int len) +{ + unsigned int i = 0; + unsigned int j, k; + + while (len-- > 0) { + j = (*s++) - '0'; + k = i * 10; + if (j > 9) + break; + i = k + j; + } + return i; +} + +/* This function reads an unsigned integer from the string pointed to by <s> + * and returns it. The <s> pointer is adjusted to point to the first unread + * char. The function automatically stops at <end>. + */ +static inline unsigned int __read_uint(const char **s, const char *end) +{ + const char *ptr = *s; + unsigned int i = 0; + unsigned int j, k; + + while (ptr < end) { + j = *ptr - '0'; + k = i * 10; + if (j > 9) + break; + i = k + j; + ptr++; + } + *s = ptr; + return i; +} + +/* returns the number of bytes needed to encode <v> as a varint. Be careful, use + * it only with constants as it generates a large code (typ. 180 bytes). Use the + * varint_bytes() version instead in case of doubt. + */ +static inline int __varint_bytes(uint64_t v) +{ + switch (v) { + case 0x0000000000000000ULL ... 0x00000000000000efULL: return 1; + case 0x00000000000000f0ULL ... 0x00000000000008efULL: return 2; + case 0x00000000000008f0ULL ... 0x00000000000408efULL: return 3; + case 0x00000000000408f0ULL ... 0x00000000020408efULL: return 4; + case 0x00000000020408f0ULL ... 0x00000001020408efULL: return 5; + case 0x00000001020408f0ULL ... 0x00000081020408efULL: return 6; + case 0x00000081020408f0ULL ... 0x00004081020408efULL: return 7; + case 0x00004081020408f0ULL ... 0x00204081020408efULL: return 8; + case 0x00204081020408f0ULL ... 0x10204081020408efULL: return 9; + default: return 10; + } +} + +/* Encode the integer <i> into a varint (variable-length integer). The encoded + * value is copied in <*buf>. Here is the encoding format: + * + * 0 <= X < 240 : 1 byte (7.875 bits) [ XXXX XXXX ] + * 240 <= X < 2288 : 2 bytes (11 bits) [ 1111 XXXX ] [ 0XXX XXXX ] + * 2288 <= X < 264432 : 3 bytes (18 bits) [ 1111 XXXX ] [ 1XXX XXXX ] [ 0XXX XXXX ] + * 264432 <= X < 33818864 : 4 bytes (25 bits) [ 1111 XXXX ] [ 1XXX XXXX ]*2 [ 0XXX XXXX ] + * 33818864 <= X < 4328786160 : 5 bytes (32 bits) [ 1111 XXXX ] [ 1XXX XXXX ]*3 [ 0XXX XXXX ] + * ... + * + * On success, it returns the number of written bytes and <*buf> is moved after + * the encoded value. Otherwise, it returns -1. */ +static inline int encode_varint(uint64_t i, char **buf, char *end) +{ + unsigned char *p = (unsigned char *)*buf; + int r; + + if (p >= (unsigned char *)end) + return -1; + + if (i < 240) { + *p++ = i; + *buf = (char *)p; + return 1; + } + + *p++ = (unsigned char)i | 240; + i = (i - 240) >> 4; + while (i >= 128) { + if (p >= (unsigned char *)end) + return -1; + *p++ = (unsigned char)i | 128; + i = (i - 128) >> 7; + } + + if (p >= (unsigned char *)end) + return -1; + *p++ = (unsigned char)i; + + r = ((char *)p - *buf); + *buf = (char *)p; + return r; +} + +/* Decode a varint from <*buf> and save the decoded value in <*i>. See + * 'spoe_encode_varint' for details about varint. + * On success, it returns the number of read bytes and <*buf> is moved after the + * varint. Otherwise, it returns -1. */ +static inline int decode_varint(char **buf, char *end, uint64_t *i) +{ + unsigned char *p = (unsigned char *)*buf; + int r; + + if (p >= (unsigned char *)end) + return -1; + + *i = *p++; + if (*i < 240) { + *buf = (char *)p; + return 1; + } + + r = 4; + do { + if (p >= (unsigned char *)end) + return -1; + *i += (uint64_t)*p << r; + r += 7; + } while (*p++ >= 128); + + r = ((char *)p - *buf); + *buf = (char *)p; + return r; +} + +#endif /* _HAPROXY_INTOPS_H */ + +/* + * Local variables: + * c-indent-level: 8 + * c-basic-offset: 8 + * End: + */ |