// license that can be found in the LICENSE file.

//go:build mips || mipsle

// Export some functions via linkname to assembly in sync/atomic.
//
//go:linkname Xadd64
//go:linkname Xchg64
//go:linkname Cas64
//go:linkname Load64
//go:linkname Store64
//go:linkname Or64
//go:linkname And64

package atomic

import (
	"internal/cpu"
	"unsafe"
)

// TODO implement lock striping

	MOVW	new+8(FP), R5

	SYNC
	MOVV	R5, R3
	LL	(R2), R1
	SC	R3, (R2)
	BEQ	R3, -3(PC)
	MOVW	R1, ret+16(FP)
	SYNC
	RET

// uint64 Xchg64(ptr *uint64, new uint64)
// Atomically:
//	old := *ptr;
//	*ptr = new;
//	return old;
TEXT ·Xchg64(SB), NOSPLIT, $0-24
	MOVV	ptr+0(FP), R2
	MOVV	new+8(FP), R5

	SYNC
	MOVV	R5, R3
	LLV	(R2), R1
	SCV	R3, (R2)
	BEQ	R3, -3(PC)

//go:linkname Loaduintptr
//go:linkname LoadAcquintptr
//go:linkname Xadd
//go:linkname Xaddint32
//go:linkname Xaddint64
//go:linkname Xadd64
//go:linkname Xadduintptr
//go:linkname Xchg
//go:linkname Xchg64
//go:linkname Xchgint32
//go:linkname Xchgint64
//go:linkname Xchguintptr
//go:linkname Cas
//go:linkname Cas64
//go:linkname Casint32
//go:linkname Casint64
//go:linkname Casuintptr
//go:linkname Store

//go:noescape
func Xadd64(ptr *uint64, delta int64) uint64

//go:noescape
func Xadduintptr(ptr *uintptr, delta uintptr) uintptr

//go:noescape
func Xchg(ptr *uint32, new uint32) uint32

//go:noescape
func Xchg64(ptr *uint64, new uint64) uint64

//go:noescape
func Xchguintptr(ptr *uintptr, new uintptr) uintptr

//go:noescape
func Load(ptr *uint32) uint32

//go:noescape
func Load8(ptr *uint8) uint8

//go:noescape
func Xadd64(ptr *uint64, delta int64) uint64

//go:noescape
func Xadduintptr(ptr *uintptr, delta uintptr) uintptr

//go:noescape
func Xadd(ptr *uint32, delta int32) uint32

//go:noescape
func Xchg64(ptr *uint64, new uint64) uint64

//go:noescape
func Xchg(ptr *uint32, new uint32) uint32

//go:noescape
func Xchguintptr(ptr *uintptr, new uintptr) uintptr

//go:noescape
func Load64(ptr *uint64) uint64

		throw("xadd64 failed")
	}
	if atomic.Load64(&test_z64) != (2<<40)+2 {
		throw("xadd64 failed")
	}
	if atomic.Xchg64(&test_z64, (3<<40)+3) != (2<<40)+2 {
		throw("xchg64 failed")
	}
	if atomic.Load64(&test_z64) != (3<<40)+3 {
		throw("xchg64 failed")
	}
}

func check() {
	var (
		a     int8
		b     uint8
		c     int16
		d     uint16
		e     int32

//go:noescape
func Cas64(addr *uint64, old, new uint64) bool

//go:noescape
func CasRel(addr *uint32, old, new uint32) bool

//go:noescape
func Xadd64(addr *uint64, delta int64) uint64

//go:noescape
func Xchg64(addr *uint64, v uint64) uint64

//go:noescape
func Load64(addr *uint64) uint64

//go:noescape
func Store8(addr *uint8, v uint8)

//go:noescape

TEXT ·Xaddint64(SB),NOSPLIT,$0-20
	JMP	·Xadd64(SB)

TEXT ·Casp1(SB),NOSPLIT,$0-13
	JMP	·Cas(SB)

TEXT ·Xchgint32(SB),NOSPLIT,$0-12
	JMP	·Xchg(SB)

TEXT ·Xchgint64(SB),NOSPLIT,$0-20
	JMP	·Xchg64(SB)

TEXT ·Xchguintptr(SB),NOSPLIT,$0-12
	JMP	·Xchg(SB)

TEXT ·StorepNoWB(SB),NOSPLIT,$0-8
	JMP	·Store(SB)

TEXT ·StoreRel(SB),NOSPLIT,$0-8
	JMP	·Store(SB)

	alias("sync/atomic", "SwapInt64", "internal/runtime/atomic", "Xchg64", all...)
	alias("sync/atomic", "SwapUint32", "internal/runtime/atomic", "Xchg", all...)
	alias("sync/atomic", "SwapUint64", "internal/runtime/atomic", "Xchg64", all...)
	alias("sync/atomic", "SwapUintptr", "internal/runtime/atomic", "Xchg", p4...)
	alias("sync/atomic", "SwapUintptr", "internal/runtime/atomic", "Xchg64", p8...)

// license that can be found in the LICENSE file.

package rand

import (
	"errors"
	"internal/byteorder"
	"math/bits"
)

// https://numpy.org/devdocs/reference/random/upgrading-pcg64.html
// https://github.com/imneme/pcg-cpp/commit/871d0494ee9c9a7b7c43f753e3d8ca47c26f8005

// A PCG is a PCG generator with 128 bits of internal state.
// A zero PCG is equivalent to NewPCG(0, 0).
type PCG struct {