utils.h

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/*
 * Copyright (c) 2013 The University of Manchester
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
 
#ifndef __UTILS_H__
#define __UTILS_H__
 
#include <stdint.h>
 
static inline uint32_t __hi(uint64_t x) {
    return (uint32_t) (x >> 32);
}
 
static inline uint32_t __lo(uint64_t x) {
    return __hi(x << 32);
}
 
static inline uint64_t round64(uint64_t x) {
    uint64_t r = (uint64_t) __hi(x);
 
    if (__lo(x) >= INT32_MAX) {
    r++;
    }
    return r;
}
 
static inline uint64_t scale64(
    uint64_t x,
    uint32_t y)
{
    uint64_t r = round64((uint64_t) __lo(x) * (uint64_t) y);
 
    r += (uint64_t) __hi(x) * (uint64_t) y;
    return r;
}
 
static inline uint32_t scale32(
    uint32_t x,
    uint32_t y)
{
    return (uint32_t) round64((uint64_t) x * (uint64_t) y);
}
 
static inline uint32_t log_next_power_of_2(uint32_t v) {
    return 32 - __builtin_clz(v);
}
 
static inline uint32_t ilog_2(uint32_t v) {
    return 31 - __builtin_clz(v);
}
 
static inline uint32_t next_power_of_2(uint32_t v) {
    return 1 << log_next_power_of_2(v);
}
 
static inline bool is_power_of_2(uint32_t v) {
    return (v & (v - 1)) == 0;
}
 
#endif /*__UTILS_H__*/