mirror of
https://github.com/xemu-project/xemu.git
synced 2024-12-03 00:57:25 +00:00
652a4b7e73
Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Richard Henderson <rth@twiddle.net>
522 lines
12 KiB
C
522 lines
12 KiB
C
/*
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* Utility compute operations used by translated code.
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*
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* Copyright (c) 2007 Thiemo Seufer
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* Copyright (c) 2007 Jocelyn Mayer
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#ifndef HOST_UTILS_H
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#define HOST_UTILS_H 1
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#include "qemu/compiler.h" /* QEMU_GNUC_PREREQ */
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#include "qemu/bswap.h"
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#include <limits.h>
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#include <stdbool.h>
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#ifdef CONFIG_INT128
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static inline void mulu64(uint64_t *plow, uint64_t *phigh,
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uint64_t a, uint64_t b)
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{
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__uint128_t r = (__uint128_t)a * b;
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*plow = r;
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*phigh = r >> 64;
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}
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static inline void muls64(uint64_t *plow, uint64_t *phigh,
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int64_t a, int64_t b)
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{
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__int128_t r = (__int128_t)a * b;
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*plow = r;
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*phigh = r >> 64;
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}
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/* compute with 96 bit intermediate result: (a*b)/c */
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static inline uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c)
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{
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return (__int128_t)a * b / c;
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}
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static inline int divu128(uint64_t *plow, uint64_t *phigh, uint64_t divisor)
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{
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if (divisor == 0) {
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return 1;
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} else {
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__uint128_t dividend = ((__uint128_t)*phigh << 64) | *plow;
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__uint128_t result = dividend / divisor;
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*plow = result;
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*phigh = dividend % divisor;
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return result > UINT64_MAX;
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}
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}
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static inline int divs128(int64_t *plow, int64_t *phigh, int64_t divisor)
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{
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if (divisor == 0) {
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return 1;
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} else {
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__int128_t dividend = ((__int128_t)*phigh << 64) | *plow;
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__int128_t result = dividend / divisor;
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*plow = result;
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*phigh = dividend % divisor;
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return result != *plow;
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}
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}
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#else
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void muls64(uint64_t *phigh, uint64_t *plow, int64_t a, int64_t b);
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void mulu64(uint64_t *phigh, uint64_t *plow, uint64_t a, uint64_t b);
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int divu128(uint64_t *plow, uint64_t *phigh, uint64_t divisor);
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int divs128(int64_t *plow, int64_t *phigh, int64_t divisor);
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static inline uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c)
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{
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union {
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uint64_t ll;
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struct {
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#ifdef HOST_WORDS_BIGENDIAN
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uint32_t high, low;
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#else
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uint32_t low, high;
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#endif
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} l;
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} u, res;
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uint64_t rl, rh;
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u.ll = a;
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rl = (uint64_t)u.l.low * (uint64_t)b;
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rh = (uint64_t)u.l.high * (uint64_t)b;
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rh += (rl >> 32);
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res.l.high = rh / c;
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res.l.low = (((rh % c) << 32) + (rl & 0xffffffff)) / c;
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return res.ll;
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}
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#endif
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/**
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* clz32 - count leading zeros in a 32-bit value.
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* @val: The value to search
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*
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* Returns 32 if the value is zero. Note that the GCC builtin is
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* undefined if the value is zero.
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*/
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static inline int clz32(uint32_t val)
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{
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#if QEMU_GNUC_PREREQ(3, 4)
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return val ? __builtin_clz(val) : 32;
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#else
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/* Binary search for the leading one bit. */
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int cnt = 0;
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if (!(val & 0xFFFF0000U)) {
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cnt += 16;
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val <<= 16;
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}
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if (!(val & 0xFF000000U)) {
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cnt += 8;
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val <<= 8;
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}
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if (!(val & 0xF0000000U)) {
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cnt += 4;
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val <<= 4;
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}
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if (!(val & 0xC0000000U)) {
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cnt += 2;
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val <<= 2;
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}
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if (!(val & 0x80000000U)) {
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cnt++;
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val <<= 1;
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}
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if (!(val & 0x80000000U)) {
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cnt++;
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}
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return cnt;
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#endif
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}
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/**
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* clo32 - count leading ones in a 32-bit value.
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* @val: The value to search
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*
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* Returns 32 if the value is -1.
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*/
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static inline int clo32(uint32_t val)
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{
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return clz32(~val);
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}
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/**
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* clz64 - count leading zeros in a 64-bit value.
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* @val: The value to search
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*
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* Returns 64 if the value is zero. Note that the GCC builtin is
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* undefined if the value is zero.
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*/
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static inline int clz64(uint64_t val)
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{
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#if QEMU_GNUC_PREREQ(3, 4)
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return val ? __builtin_clzll(val) : 64;
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#else
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int cnt = 0;
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if (!(val >> 32)) {
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cnt += 32;
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} else {
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val >>= 32;
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}
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return cnt + clz32(val);
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#endif
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}
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/**
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* clo64 - count leading ones in a 64-bit value.
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* @val: The value to search
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*
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* Returns 64 if the value is -1.
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*/
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static inline int clo64(uint64_t val)
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{
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return clz64(~val);
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}
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/**
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* ctz32 - count trailing zeros in a 32-bit value.
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* @val: The value to search
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*
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* Returns 32 if the value is zero. Note that the GCC builtin is
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* undefined if the value is zero.
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*/
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static inline int ctz32(uint32_t val)
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{
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#if QEMU_GNUC_PREREQ(3, 4)
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return val ? __builtin_ctz(val) : 32;
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#else
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/* Binary search for the trailing one bit. */
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int cnt;
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cnt = 0;
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if (!(val & 0x0000FFFFUL)) {
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cnt += 16;
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val >>= 16;
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}
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if (!(val & 0x000000FFUL)) {
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cnt += 8;
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val >>= 8;
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}
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if (!(val & 0x0000000FUL)) {
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cnt += 4;
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val >>= 4;
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}
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if (!(val & 0x00000003UL)) {
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cnt += 2;
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val >>= 2;
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}
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if (!(val & 0x00000001UL)) {
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cnt++;
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val >>= 1;
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}
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if (!(val & 0x00000001UL)) {
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cnt++;
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}
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return cnt;
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#endif
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}
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/**
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* cto32 - count trailing ones in a 32-bit value.
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* @val: The value to search
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*
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* Returns 32 if the value is -1.
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*/
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static inline int cto32(uint32_t val)
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{
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return ctz32(~val);
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}
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/**
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* ctz64 - count trailing zeros in a 64-bit value.
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* @val: The value to search
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*
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* Returns 64 if the value is zero. Note that the GCC builtin is
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* undefined if the value is zero.
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*/
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static inline int ctz64(uint64_t val)
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{
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#if QEMU_GNUC_PREREQ(3, 4)
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return val ? __builtin_ctzll(val) : 64;
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#else
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int cnt;
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cnt = 0;
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if (!((uint32_t)val)) {
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cnt += 32;
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val >>= 32;
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}
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return cnt + ctz32(val);
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#endif
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}
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/**
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* cto64 - count trailing ones in a 64-bit value.
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* @val: The value to search
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*
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* Returns 64 if the value is -1.
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*/
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static inline int cto64(uint64_t val)
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{
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return ctz64(~val);
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}
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/**
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* clrsb32 - count leading redundant sign bits in a 32-bit value.
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* @val: The value to search
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*
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* Returns the number of bits following the sign bit that are equal to it.
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* No special cases; output range is [0-31].
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*/
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static inline int clrsb32(uint32_t val)
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{
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#if QEMU_GNUC_PREREQ(4, 7)
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return __builtin_clrsb(val);
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#else
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return clz32(val ^ ((int32_t)val >> 1)) - 1;
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#endif
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}
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/**
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* clrsb64 - count leading redundant sign bits in a 64-bit value.
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* @val: The value to search
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*
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* Returns the number of bits following the sign bit that are equal to it.
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* No special cases; output range is [0-63].
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*/
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static inline int clrsb64(uint64_t val)
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{
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#if QEMU_GNUC_PREREQ(4, 7)
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return __builtin_clrsbll(val);
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#else
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return clz64(val ^ ((int64_t)val >> 1)) - 1;
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#endif
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}
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/**
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* ctpop8 - count the population of one bits in an 8-bit value.
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* @val: The value to search
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*/
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static inline int ctpop8(uint8_t val)
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{
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#if QEMU_GNUC_PREREQ(3, 4)
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return __builtin_popcount(val);
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#else
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val = (val & 0x55) + ((val >> 1) & 0x55);
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val = (val & 0x33) + ((val >> 2) & 0x33);
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val = (val & 0x0f) + ((val >> 4) & 0x0f);
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return val;
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#endif
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}
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/**
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* ctpop16 - count the population of one bits in a 16-bit value.
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* @val: The value to search
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*/
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static inline int ctpop16(uint16_t val)
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{
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#if QEMU_GNUC_PREREQ(3, 4)
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return __builtin_popcount(val);
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#else
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val = (val & 0x5555) + ((val >> 1) & 0x5555);
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val = (val & 0x3333) + ((val >> 2) & 0x3333);
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val = (val & 0x0f0f) + ((val >> 4) & 0x0f0f);
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val = (val & 0x00ff) + ((val >> 8) & 0x00ff);
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return val;
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#endif
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}
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/**
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* ctpop32 - count the population of one bits in a 32-bit value.
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* @val: The value to search
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*/
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static inline int ctpop32(uint32_t val)
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{
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#if QEMU_GNUC_PREREQ(3, 4)
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return __builtin_popcount(val);
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#else
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val = (val & 0x55555555) + ((val >> 1) & 0x55555555);
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val = (val & 0x33333333) + ((val >> 2) & 0x33333333);
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val = (val & 0x0f0f0f0f) + ((val >> 4) & 0x0f0f0f0f);
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val = (val & 0x00ff00ff) + ((val >> 8) & 0x00ff00ff);
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val = (val & 0x0000ffff) + ((val >> 16) & 0x0000ffff);
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return val;
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#endif
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}
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/**
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* ctpop64 - count the population of one bits in a 64-bit value.
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* @val: The value to search
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*/
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static inline int ctpop64(uint64_t val)
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{
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#if QEMU_GNUC_PREREQ(3, 4)
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return __builtin_popcountll(val);
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#else
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val = (val & 0x5555555555555555ULL) + ((val >> 1) & 0x5555555555555555ULL);
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val = (val & 0x3333333333333333ULL) + ((val >> 2) & 0x3333333333333333ULL);
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val = (val & 0x0f0f0f0f0f0f0f0fULL) + ((val >> 4) & 0x0f0f0f0f0f0f0f0fULL);
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val = (val & 0x00ff00ff00ff00ffULL) + ((val >> 8) & 0x00ff00ff00ff00ffULL);
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val = (val & 0x0000ffff0000ffffULL) + ((val >> 16) & 0x0000ffff0000ffffULL);
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val = (val & 0x00000000ffffffffULL) + ((val >> 32) & 0x00000000ffffffffULL);
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return val;
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#endif
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}
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/**
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* revbit8 - reverse the bits in an 8-bit value.
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* @x: The value to modify.
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*/
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static inline uint8_t revbit8(uint8_t x)
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{
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/* Assign the correct nibble position. */
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x = ((x & 0xf0) >> 4)
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| ((x & 0x0f) << 4);
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/* Assign the correct bit position. */
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x = ((x & 0x88) >> 3)
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| ((x & 0x44) >> 1)
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| ((x & 0x22) << 1)
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| ((x & 0x11) << 3);
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return x;
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}
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/**
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* revbit16 - reverse the bits in a 16-bit value.
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* @x: The value to modify.
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*/
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static inline uint16_t revbit16(uint16_t x)
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{
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/* Assign the correct byte position. */
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x = bswap16(x);
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/* Assign the correct nibble position. */
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x = ((x & 0xf0f0) >> 4)
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| ((x & 0x0f0f) << 4);
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/* Assign the correct bit position. */
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x = ((x & 0x8888) >> 3)
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| ((x & 0x4444) >> 1)
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| ((x & 0x2222) << 1)
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| ((x & 0x1111) << 3);
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return x;
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}
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/**
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* revbit32 - reverse the bits in a 32-bit value.
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* @x: The value to modify.
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*/
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static inline uint32_t revbit32(uint32_t x)
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{
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/* Assign the correct byte position. */
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x = bswap32(x);
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/* Assign the correct nibble position. */
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x = ((x & 0xf0f0f0f0u) >> 4)
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| ((x & 0x0f0f0f0fu) << 4);
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/* Assign the correct bit position. */
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x = ((x & 0x88888888u) >> 3)
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| ((x & 0x44444444u) >> 1)
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| ((x & 0x22222222u) << 1)
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| ((x & 0x11111111u) << 3);
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return x;
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}
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/**
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* revbit64 - reverse the bits in a 64-bit value.
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* @x: The value to modify.
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*/
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static inline uint64_t revbit64(uint64_t x)
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{
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/* Assign the correct byte position. */
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x = bswap64(x);
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/* Assign the correct nibble position. */
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x = ((x & 0xf0f0f0f0f0f0f0f0ull) >> 4)
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| ((x & 0x0f0f0f0f0f0f0f0full) << 4);
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/* Assign the correct bit position. */
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x = ((x & 0x8888888888888888ull) >> 3)
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| ((x & 0x4444444444444444ull) >> 1)
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| ((x & 0x2222222222222222ull) << 1)
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| ((x & 0x1111111111111111ull) << 3);
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return x;
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}
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/* Host type specific sizes of these routines. */
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#if ULONG_MAX == UINT32_MAX
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# define clzl clz32
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# define ctzl ctz32
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# define clol clo32
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# define ctol cto32
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# define ctpopl ctpop32
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# define revbitl revbit32
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#elif ULONG_MAX == UINT64_MAX
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# define clzl clz64
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# define ctzl ctz64
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# define clol clo64
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# define ctol cto64
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# define ctpopl ctpop64
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# define revbitl revbit64
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#else
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# error Unknown sizeof long
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#endif
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static inline bool is_power_of_2(uint64_t value)
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{
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if (!value) {
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return 0;
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}
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return !(value & (value - 1));
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}
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/* round down to the nearest power of 2*/
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static inline int64_t pow2floor(int64_t value)
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{
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if (!is_power_of_2(value)) {
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value = 0x8000000000000000ULL >> clz64(value);
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}
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return value;
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}
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/* round up to the nearest power of 2 (0 if overflow) */
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static inline uint64_t pow2ceil(uint64_t value)
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{
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uint8_t nlz = clz64(value);
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if (is_power_of_2(value)) {
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return value;
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}
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if (!nlz) {
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return 0;
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}
|
|
return 1ULL << (64 - nlz);
|
|
}
|
|
|
|
#endif
|