// Copyright 2021 ByteDance Inc.
//
// 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.

//go:build ppc64 || s390x || mips || mips64
// +build ppc64 s390x mips mips64

//
// from golang-go/src/os/endian_big.go

package runtimex

import (
	"unsafe"
)

func ReadUnaligned64(p unsafe.Pointer) uint64 {
	// Equal to runtime.readUnaligned64, but this function can be inlined
	// compared to  use runtime.readUnaligned64 via go:linkname.
	q := (*[8]byte)(p)
	return uint64(q[7]) | uint64(q[6])<<8 | uint64(q[5])<<16 | uint64(q[4])<<24 |
		uint64(q[3])<<32 | uint64(q[2])<<40 | uint64(q[1])<<48 | uint64(q[0])<<56
}

func ReadUnaligned32(p unsafe.Pointer) uint64 {
	q := (*[4]byte)(p)
	return uint64(uint32(q[3]) | uint32(q[2])<<8 | uint32(q[1])<<16 | uint32(q[0])<<24)
}

func ReadUnaligned16(p unsafe.Pointer) uint64 {
	q := (*[2]byte)(p)
	return uint64(uint32(q[1]) | uint32(q[0])<<8)
}