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Diffstat (limited to 'src/include/qemu/host-utils.h')
-rw-r--r-- | src/include/qemu/host-utils.h | 521 |
1 files changed, 521 insertions, 0 deletions
diff --git a/src/include/qemu/host-utils.h b/src/include/qemu/host-utils.h new file mode 100644 index 0000000..3ef97d5 --- /dev/null +++ b/src/include/qemu/host-utils.h @@ -0,0 +1,521 @@ +/* + * Utility compute operations used by translated code. + * + * Copyright (c) 2007 Thiemo Seufer + * Copyright (c) 2007 Jocelyn Mayer + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +#ifndef HOST_UTILS_H +#define HOST_UTILS_H 1 + +#include "qemu/compiler.h" /* QEMU_GNUC_PREREQ */ +#include "qemu/bswap.h" +#include <limits.h> +#include <stdbool.h> + +#ifdef CONFIG_INT128 +static inline void mulu64(uint64_t *plow, uint64_t *phigh, + uint64_t a, uint64_t b) +{ + __uint128_t r = (__uint128_t)a * b; + *plow = r; + *phigh = r >> 64; +} + +static inline void muls64(uint64_t *plow, uint64_t *phigh, + int64_t a, int64_t b) +{ + __int128_t r = (__int128_t)a * b; + *plow = r; + *phigh = r >> 64; +} + +/* compute with 96 bit intermediate result: (a*b)/c */ +static inline uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c) +{ + return (__int128_t)a * b / c; +} + +static inline int divu128(uint64_t *plow, uint64_t *phigh, uint64_t divisor) +{ + if (divisor == 0) { + return 1; + } else { + __uint128_t dividend = ((__uint128_t)*phigh << 64) | *plow; + __uint128_t result = dividend / divisor; + *plow = result; + *phigh = dividend % divisor; + return result > UINT64_MAX; + } +} + +static inline int divs128(int64_t *plow, int64_t *phigh, int64_t divisor) +{ + if (divisor == 0) { + return 1; + } else { + __int128_t dividend = ((__int128_t)*phigh << 64) | *plow; + __int128_t result = dividend / divisor; + *plow = result; + *phigh = dividend % divisor; + return result != *plow; + } +} +#else +void muls64(uint64_t *phigh, uint64_t *plow, int64_t a, int64_t b); +void mulu64(uint64_t *phigh, uint64_t *plow, uint64_t a, uint64_t b); +int divu128(uint64_t *plow, uint64_t *phigh, uint64_t divisor); +int divs128(int64_t *plow, int64_t *phigh, int64_t divisor); + +static inline uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c) +{ + union { + uint64_t ll; + struct { +#ifdef HOST_WORDS_BIGENDIAN + uint32_t high, low; +#else + uint32_t low, high; +#endif + } l; + } u, res; + uint64_t rl, rh; + + u.ll = a; + rl = (uint64_t)u.l.low * (uint64_t)b; + rh = (uint64_t)u.l.high * (uint64_t)b; + rh += (rl >> 32); + res.l.high = rh / c; + res.l.low = (((rh % c) << 32) + (rl & 0xffffffff)) / c; + return res.ll; +} +#endif + +/** + * clz32 - count leading zeros in a 32-bit value. + * @val: The value to search + * + * Returns 32 if the value is zero. Note that the GCC builtin is + * undefined if the value is zero. + */ +static inline int clz32(uint32_t val) +{ +#if QEMU_GNUC_PREREQ(3, 4) + return val ? __builtin_clz(val) : 32; +#else + /* Binary search for the leading one bit. */ + int cnt = 0; + + if (!(val & 0xFFFF0000U)) { + cnt += 16; + val <<= 16; + } + if (!(val & 0xFF000000U)) { + cnt += 8; + val <<= 8; + } + if (!(val & 0xF0000000U)) { + cnt += 4; + val <<= 4; + } + if (!(val & 0xC0000000U)) { + cnt += 2; + val <<= 2; + } + if (!(val & 0x80000000U)) { + cnt++; + val <<= 1; + } + if (!(val & 0x80000000U)) { + cnt++; + } + return cnt; +#endif +} + +/** + * clo32 - count leading ones in a 32-bit value. + * @val: The value to search + * + * Returns 32 if the value is -1. + */ +static inline int clo32(uint32_t val) +{ + return clz32(~val); +} + +/** + * clz64 - count leading zeros in a 64-bit value. + * @val: The value to search + * + * Returns 64 if the value is zero. Note that the GCC builtin is + * undefined if the value is zero. + */ +static inline int clz64(uint64_t val) +{ +#if QEMU_GNUC_PREREQ(3, 4) + return val ? __builtin_clzll(val) : 64; +#else + int cnt = 0; + + if (!(val >> 32)) { + cnt += 32; + } else { + val >>= 32; + } + + return cnt + clz32(val); +#endif +} + +/** + * clo64 - count leading ones in a 64-bit value. + * @val: The value to search + * + * Returns 64 if the value is -1. + */ +static inline int clo64(uint64_t val) +{ + return clz64(~val); +} + +/** + * ctz32 - count trailing zeros in a 32-bit value. + * @val: The value to search + * + * Returns 32 if the value is zero. Note that the GCC builtin is + * undefined if the value is zero. + */ +static inline int ctz32(uint32_t val) +{ +#if QEMU_GNUC_PREREQ(3, 4) + return val ? __builtin_ctz(val) : 32; +#else + /* Binary search for the trailing one bit. */ + int cnt; + + cnt = 0; + if (!(val & 0x0000FFFFUL)) { + cnt += 16; + val >>= 16; + } + if (!(val & 0x000000FFUL)) { + cnt += 8; + val >>= 8; + } + if (!(val & 0x0000000FUL)) { + cnt += 4; + val >>= 4; + } + if (!(val & 0x00000003UL)) { + cnt += 2; + val >>= 2; + } + if (!(val & 0x00000001UL)) { + cnt++; + val >>= 1; + } + if (!(val & 0x00000001UL)) { + cnt++; + } + + return cnt; +#endif +} + +/** + * cto32 - count trailing ones in a 32-bit value. + * @val: The value to search + * + * Returns 32 if the value is -1. + */ +static inline int cto32(uint32_t val) +{ + return ctz32(~val); +} + +/** + * ctz64 - count trailing zeros in a 64-bit value. + * @val: The value to search + * + * Returns 64 if the value is zero. Note that the GCC builtin is + * undefined if the value is zero. + */ +static inline int ctz64(uint64_t val) +{ +#if QEMU_GNUC_PREREQ(3, 4) + return val ? __builtin_ctzll(val) : 64; +#else + int cnt; + + cnt = 0; + if (!((uint32_t)val)) { + cnt += 32; + val >>= 32; + } + + return cnt + ctz32(val); +#endif +} + +/** + * cto64 - count trailing ones in a 64-bit value. + * @val: The value to search + * + * Returns 64 if the value is -1. + */ +static inline int cto64(uint64_t val) +{ + return ctz64(~val); +} + +/** + * clrsb32 - count leading redundant sign bits in a 32-bit value. + * @val: The value to search + * + * Returns the number of bits following the sign bit that are equal to it. + * No special cases; output range is [0-31]. + */ +static inline int clrsb32(uint32_t val) +{ +#if QEMU_GNUC_PREREQ(4, 7) + return __builtin_clrsb(val); +#else + return clz32(val ^ ((int32_t)val >> 1)) - 1; +#endif +} + +/** + * clrsb64 - count leading redundant sign bits in a 64-bit value. + * @val: The value to search + * + * Returns the number of bits following the sign bit that are equal to it. + * No special cases; output range is [0-63]. + */ +static inline int clrsb64(uint64_t val) +{ +#if QEMU_GNUC_PREREQ(4, 7) + return __builtin_clrsbll(val); +#else + return clz64(val ^ ((int64_t)val >> 1)) - 1; +#endif +} + +/** + * ctpop8 - count the population of one bits in an 8-bit value. + * @val: The value to search + */ +static inline int ctpop8(uint8_t val) +{ +#if QEMU_GNUC_PREREQ(3, 4) + return __builtin_popcount(val); +#else + val = (val & 0x55) + ((val >> 1) & 0x55); + val = (val & 0x33) + ((val >> 2) & 0x33); + val = (val & 0x0f) + ((val >> 4) & 0x0f); + + return val; +#endif +} + +/** + * ctpop16 - count the population of one bits in a 16-bit value. + * @val: The value to search + */ +static inline int ctpop16(uint16_t val) +{ +#if QEMU_GNUC_PREREQ(3, 4) + return __builtin_popcount(val); +#else + val = (val & 0x5555) + ((val >> 1) & 0x5555); + val = (val & 0x3333) + ((val >> 2) & 0x3333); + val = (val & 0x0f0f) + ((val >> 4) & 0x0f0f); + val = (val & 0x00ff) + ((val >> 8) & 0x00ff); + + return val; +#endif +} + +/** + * ctpop32 - count the population of one bits in a 32-bit value. + * @val: The value to search + */ +static inline int ctpop32(uint32_t val) +{ +#if QEMU_GNUC_PREREQ(3, 4) + return __builtin_popcount(val); +#else + val = (val & 0x55555555) + ((val >> 1) & 0x55555555); + val = (val & 0x33333333) + ((val >> 2) & 0x33333333); + val = (val & 0x0f0f0f0f) + ((val >> 4) & 0x0f0f0f0f); + val = (val & 0x00ff00ff) + ((val >> 8) & 0x00ff00ff); + val = (val & 0x0000ffff) + ((val >> 16) & 0x0000ffff); + + return val; +#endif +} + +/** + * ctpop64 - count the population of one bits in a 64-bit value. + * @val: The value to search + */ +static inline int ctpop64(uint64_t val) +{ +#if QEMU_GNUC_PREREQ(3, 4) + return __builtin_popcountll(val); +#else + val = (val & 0x5555555555555555ULL) + ((val >> 1) & 0x5555555555555555ULL); + val = (val & 0x3333333333333333ULL) + ((val >> 2) & 0x3333333333333333ULL); + val = (val & 0x0f0f0f0f0f0f0f0fULL) + ((val >> 4) & 0x0f0f0f0f0f0f0f0fULL); + val = (val & 0x00ff00ff00ff00ffULL) + ((val >> 8) & 0x00ff00ff00ff00ffULL); + val = (val & 0x0000ffff0000ffffULL) + ((val >> 16) & 0x0000ffff0000ffffULL); + val = (val & 0x00000000ffffffffULL) + ((val >> 32) & 0x00000000ffffffffULL); + + return val; +#endif +} + +/** + * revbit8 - reverse the bits in an 8-bit value. + * @x: The value to modify. + */ +static inline uint8_t revbit8(uint8_t x) +{ + /* Assign the correct nibble position. */ + x = ((x & 0xf0) >> 4) + | ((x & 0x0f) << 4); + /* Assign the correct bit position. */ + x = ((x & 0x88) >> 3) + | ((x & 0x44) >> 1) + | ((x & 0x22) << 1) + | ((x & 0x11) << 3); + return x; +} + +/** + * revbit16 - reverse the bits in a 16-bit value. + * @x: The value to modify. + */ +static inline uint16_t revbit16(uint16_t x) +{ + /* Assign the correct byte position. */ + x = bswap16(x); + /* Assign the correct nibble position. */ + x = ((x & 0xf0f0) >> 4) + | ((x & 0x0f0f) << 4); + /* Assign the correct bit position. */ + x = ((x & 0x8888) >> 3) + | ((x & 0x4444) >> 1) + | ((x & 0x2222) << 1) + | ((x & 0x1111) << 3); + return x; +} + +/** + * revbit32 - reverse the bits in a 32-bit value. + * @x: The value to modify. + */ +static inline uint32_t revbit32(uint32_t x) +{ + /* Assign the correct byte position. */ + x = bswap32(x); + /* Assign the correct nibble position. */ + x = ((x & 0xf0f0f0f0u) >> 4) + | ((x & 0x0f0f0f0fu) << 4); + /* Assign the correct bit position. */ + x = ((x & 0x88888888u) >> 3) + | ((x & 0x44444444u) >> 1) + | ((x & 0x22222222u) << 1) + | ((x & 0x11111111u) << 3); + return x; +} + +/** + * revbit64 - reverse the bits in a 64-bit value. + * @x: The value to modify. + */ +static inline uint64_t revbit64(uint64_t x) +{ + /* Assign the correct byte position. */ + x = bswap64(x); + /* Assign the correct nibble position. */ + x = ((x & 0xf0f0f0f0f0f0f0f0ull) >> 4) + | ((x & 0x0f0f0f0f0f0f0f0full) << 4); + /* Assign the correct bit position. */ + x = ((x & 0x8888888888888888ull) >> 3) + | ((x & 0x4444444444444444ull) >> 1) + | ((x & 0x2222222222222222ull) << 1) + | ((x & 0x1111111111111111ull) << 3); + return x; +} + +/* Host type specific sizes of these routines. */ + +#if ULONG_MAX == UINT32_MAX +# define clzl clz32 +# define ctzl ctz32 +# define clol clo32 +# define ctol cto32 +# define ctpopl ctpop32 +# define revbitl revbit32 +#elif ULONG_MAX == UINT64_MAX +# define clzl clz64 +# define ctzl ctz64 +# define clol clo64 +# define ctol cto64 +# define ctpopl ctpop64 +# define revbitl revbit64 +#else +# error Unknown sizeof long +#endif + +static inline bool is_power_of_2(uint64_t value) +{ + if (!value) { + return 0; + } + + return !(value & (value - 1)); +} + +/* round down to the nearest power of 2*/ +static inline int64_t pow2floor(int64_t value) +{ + if (!is_power_of_2(value)) { + value = 0x8000000000000000ULL >> clz64(value); + } + return value; +} + +/* round up to the nearest power of 2 (0 if overflow) */ +static inline uint64_t pow2ceil(uint64_t value) +{ + uint8_t nlz = clz64(value); + + if (is_power_of_2(value)) { + return value; + } + if (!nlz) { + return 0; + } + return 1ULL << (64 - nlz); +} + +#endif |