qemu-e2k/include/qemu/host-utils.h
Richard Henderson 7bdcecb7b2 qemu/host-utils.h: Reduce the operation count in the fallback ctpop
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-01-10 08:49:59 -08:00

517 lines
12 KiB
C

/*
* 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
#include "qemu/bswap.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 + (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 + (val >> 4)) & 0x0f0f;
val = (val + (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 + (val >> 4)) & 0x0f0f0f0f;
val = (val * 0x01010101) >> 24;
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 + (val >> 4)) & 0x0f0f0f0f0f0f0f0fULL;
val = (val * 0x0101010101010101ULL) >> 56;
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 false;
}
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