quickerNES/extern/metrohash128/platform.h

51 lines
1.5 KiB
C

// platform.h
//
// Copyright 2015-2018 J. Andrew Rogers
//
// 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
//
// http://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 METROHASH_PLATFORM_H
#define METROHASH_PLATFORM_H
#include <stdint.h>
// rotate right idiom recognized by most compilers
inline static uint64_t rotate_right(uint64_t v, unsigned k)
{
return (v >> k) | (v << (64 - k));
}
// unaligned reads, fast and safe on Nehalem and later microarchitectures
inline static uint64_t read_u64(const void * const ptr)
{
return static_cast<uint64_t>(*reinterpret_cast<const uint64_t*>(ptr));
}
inline static uint64_t read_u32(const void * const ptr)
{
return static_cast<uint64_t>(*reinterpret_cast<const uint32_t*>(ptr));
}
inline static uint64_t read_u16(const void * const ptr)
{
return static_cast<uint64_t>(*reinterpret_cast<const uint16_t*>(ptr));
}
inline static uint64_t read_u8 (const void * const ptr)
{
return static_cast<uint64_t>(*reinterpret_cast<const uint8_t *>(ptr));
}
#endif // #ifndef METROHASH_PLATFORM_H