// Copyright 2014 The Go Authors. All rights reserved.
|
// Use of this source code is governed by a BSD-style
|
// license that can be found in the LICENSE file.
|
|
package runtime
|
|
import (
|
"internal/cpu"
|
"runtime/internal/sys"
|
"unsafe"
|
)
|
|
const (
|
c0 = uintptr((8-sys.PtrSize)/4*2860486313 + (sys.PtrSize-4)/4*33054211828000289)
|
c1 = uintptr((8-sys.PtrSize)/4*3267000013 + (sys.PtrSize-4)/4*23344194077549503)
|
)
|
|
// type algorithms - known to compiler
|
const (
|
alg_NOEQ = iota
|
alg_MEM0
|
alg_MEM8
|
alg_MEM16
|
alg_MEM32
|
alg_MEM64
|
alg_MEM128
|
alg_STRING
|
alg_INTER
|
alg_NILINTER
|
alg_FLOAT32
|
alg_FLOAT64
|
alg_CPLX64
|
alg_CPLX128
|
alg_max
|
)
|
|
// typeAlg is also copied/used in reflect/type.go.
|
// keep them in sync.
|
type typeAlg struct {
|
// function for hashing objects of this type
|
// (ptr to object, seed) -> hash
|
hash func(unsafe.Pointer, uintptr) uintptr
|
// function for comparing objects of this type
|
// (ptr to object A, ptr to object B) -> ==?
|
equal func(unsafe.Pointer, unsafe.Pointer) bool
|
}
|
|
func memhash0(p unsafe.Pointer, h uintptr) uintptr {
|
return h
|
}
|
|
func memhash8(p unsafe.Pointer, h uintptr) uintptr {
|
return memhash(p, h, 1)
|
}
|
|
func memhash16(p unsafe.Pointer, h uintptr) uintptr {
|
return memhash(p, h, 2)
|
}
|
|
func memhash128(p unsafe.Pointer, h uintptr) uintptr {
|
return memhash(p, h, 16)
|
}
|
|
//go:nosplit
|
func memhash_varlen(p unsafe.Pointer, h uintptr) uintptr {
|
ptr := getclosureptr()
|
size := *(*uintptr)(unsafe.Pointer(ptr + unsafe.Sizeof(h)))
|
return memhash(p, h, size)
|
}
|
|
var algarray = [alg_max]typeAlg{
|
alg_NOEQ: {nil, nil},
|
alg_MEM0: {memhash0, memequal0},
|
alg_MEM8: {memhash8, memequal8},
|
alg_MEM16: {memhash16, memequal16},
|
alg_MEM32: {memhash32, memequal32},
|
alg_MEM64: {memhash64, memequal64},
|
alg_MEM128: {memhash128, memequal128},
|
alg_STRING: {strhash, strequal},
|
alg_INTER: {interhash, interequal},
|
alg_NILINTER: {nilinterhash, nilinterequal},
|
alg_FLOAT32: {f32hash, f32equal},
|
alg_FLOAT64: {f64hash, f64equal},
|
alg_CPLX64: {c64hash, c64equal},
|
alg_CPLX128: {c128hash, c128equal},
|
}
|
|
var useAeshash bool
|
|
// in asm_*.s
|
func aeshash(p unsafe.Pointer, h, s uintptr) uintptr
|
func aeshash32(p unsafe.Pointer, h uintptr) uintptr
|
func aeshash64(p unsafe.Pointer, h uintptr) uintptr
|
func aeshashstr(p unsafe.Pointer, h uintptr) uintptr
|
|
func strhash(a unsafe.Pointer, h uintptr) uintptr {
|
x := (*stringStruct)(a)
|
return memhash(x.str, h, uintptr(x.len))
|
}
|
|
// NOTE: Because NaN != NaN, a map can contain any
|
// number of (mostly useless) entries keyed with NaNs.
|
// To avoid long hash chains, we assign a random number
|
// as the hash value for a NaN.
|
|
func f32hash(p unsafe.Pointer, h uintptr) uintptr {
|
f := *(*float32)(p)
|
switch {
|
case f == 0:
|
return c1 * (c0 ^ h) // +0, -0
|
case f != f:
|
return c1 * (c0 ^ h ^ uintptr(fastrand())) // any kind of NaN
|
default:
|
return memhash(p, h, 4)
|
}
|
}
|
|
func f64hash(p unsafe.Pointer, h uintptr) uintptr {
|
f := *(*float64)(p)
|
switch {
|
case f == 0:
|
return c1 * (c0 ^ h) // +0, -0
|
case f != f:
|
return c1 * (c0 ^ h ^ uintptr(fastrand())) // any kind of NaN
|
default:
|
return memhash(p, h, 8)
|
}
|
}
|
|
func c64hash(p unsafe.Pointer, h uintptr) uintptr {
|
x := (*[2]float32)(p)
|
return f32hash(unsafe.Pointer(&x[1]), f32hash(unsafe.Pointer(&x[0]), h))
|
}
|
|
func c128hash(p unsafe.Pointer, h uintptr) uintptr {
|
x := (*[2]float64)(p)
|
return f64hash(unsafe.Pointer(&x[1]), f64hash(unsafe.Pointer(&x[0]), h))
|
}
|
|
func interhash(p unsafe.Pointer, h uintptr) uintptr {
|
a := (*iface)(p)
|
tab := a.tab
|
if tab == nil {
|
return h
|
}
|
t := tab._type
|
fn := t.alg.hash
|
if fn == nil {
|
panic(errorString("hash of unhashable type " + t.string()))
|
}
|
if isDirectIface(t) {
|
return c1 * fn(unsafe.Pointer(&a.data), h^c0)
|
} else {
|
return c1 * fn(a.data, h^c0)
|
}
|
}
|
|
func nilinterhash(p unsafe.Pointer, h uintptr) uintptr {
|
a := (*eface)(p)
|
t := a._type
|
if t == nil {
|
return h
|
}
|
fn := t.alg.hash
|
if fn == nil {
|
panic(errorString("hash of unhashable type " + t.string()))
|
}
|
if isDirectIface(t) {
|
return c1 * fn(unsafe.Pointer(&a.data), h^c0)
|
} else {
|
return c1 * fn(a.data, h^c0)
|
}
|
}
|
|
func memequal0(p, q unsafe.Pointer) bool {
|
return true
|
}
|
func memequal8(p, q unsafe.Pointer) bool {
|
return *(*int8)(p) == *(*int8)(q)
|
}
|
func memequal16(p, q unsafe.Pointer) bool {
|
return *(*int16)(p) == *(*int16)(q)
|
}
|
func memequal32(p, q unsafe.Pointer) bool {
|
return *(*int32)(p) == *(*int32)(q)
|
}
|
func memequal64(p, q unsafe.Pointer) bool {
|
return *(*int64)(p) == *(*int64)(q)
|
}
|
func memequal128(p, q unsafe.Pointer) bool {
|
return *(*[2]int64)(p) == *(*[2]int64)(q)
|
}
|
func f32equal(p, q unsafe.Pointer) bool {
|
return *(*float32)(p) == *(*float32)(q)
|
}
|
func f64equal(p, q unsafe.Pointer) bool {
|
return *(*float64)(p) == *(*float64)(q)
|
}
|
func c64equal(p, q unsafe.Pointer) bool {
|
return *(*complex64)(p) == *(*complex64)(q)
|
}
|
func c128equal(p, q unsafe.Pointer) bool {
|
return *(*complex128)(p) == *(*complex128)(q)
|
}
|
func strequal(p, q unsafe.Pointer) bool {
|
return *(*string)(p) == *(*string)(q)
|
}
|
func interequal(p, q unsafe.Pointer) bool {
|
x := *(*iface)(p)
|
y := *(*iface)(q)
|
return x.tab == y.tab && ifaceeq(x.tab, x.data, y.data)
|
}
|
func nilinterequal(p, q unsafe.Pointer) bool {
|
x := *(*eface)(p)
|
y := *(*eface)(q)
|
return x._type == y._type && efaceeq(x._type, x.data, y.data)
|
}
|
func efaceeq(t *_type, x, y unsafe.Pointer) bool {
|
if t == nil {
|
return true
|
}
|
eq := t.alg.equal
|
if eq == nil {
|
panic(errorString("comparing uncomparable type " + t.string()))
|
}
|
if isDirectIface(t) {
|
return eq(noescape(unsafe.Pointer(&x)), noescape(unsafe.Pointer(&y)))
|
}
|
return eq(x, y)
|
}
|
func ifaceeq(tab *itab, x, y unsafe.Pointer) bool {
|
if tab == nil {
|
return true
|
}
|
t := tab._type
|
eq := t.alg.equal
|
if eq == nil {
|
panic(errorString("comparing uncomparable type " + t.string()))
|
}
|
if isDirectIface(t) {
|
return eq(noescape(unsafe.Pointer(&x)), noescape(unsafe.Pointer(&y)))
|
}
|
return eq(x, y)
|
}
|
|
// Testing adapters for hash quality tests (see hash_test.go)
|
func stringHash(s string, seed uintptr) uintptr {
|
return algarray[alg_STRING].hash(noescape(unsafe.Pointer(&s)), seed)
|
}
|
|
func bytesHash(b []byte, seed uintptr) uintptr {
|
s := (*slice)(unsafe.Pointer(&b))
|
return memhash(s.array, seed, uintptr(s.len))
|
}
|
|
func int32Hash(i uint32, seed uintptr) uintptr {
|
return algarray[alg_MEM32].hash(noescape(unsafe.Pointer(&i)), seed)
|
}
|
|
func int64Hash(i uint64, seed uintptr) uintptr {
|
return algarray[alg_MEM64].hash(noescape(unsafe.Pointer(&i)), seed)
|
}
|
|
func efaceHash(i interface{}, seed uintptr) uintptr {
|
return algarray[alg_NILINTER].hash(noescape(unsafe.Pointer(&i)), seed)
|
}
|
|
func ifaceHash(i interface {
|
F()
|
}, seed uintptr) uintptr {
|
return algarray[alg_INTER].hash(noescape(unsafe.Pointer(&i)), seed)
|
}
|
|
const hashRandomBytes = sys.PtrSize / 4 * 64
|
|
// used in asm_{386,amd64,arm64}.s to seed the hash function
|
var aeskeysched [hashRandomBytes]byte
|
|
// used in hash{32,64}.go to seed the hash function
|
var hashkey [4]uintptr
|
|
func alginit() {
|
// Install AES hash algorithms if the instructions needed are present.
|
if (GOARCH == "386" || GOARCH == "amd64") &&
|
GOOS != "nacl" &&
|
cpu.X86.HasAES && // AESENC
|
cpu.X86.HasSSSE3 && // PSHUFB
|
cpu.X86.HasSSE41 { // PINSR{D,Q}
|
initAlgAES()
|
return
|
}
|
if GOARCH == "arm64" && cpu.ARM64.HasAES {
|
initAlgAES()
|
return
|
}
|
getRandomData((*[len(hashkey) * sys.PtrSize]byte)(unsafe.Pointer(&hashkey))[:])
|
hashkey[0] |= 1 // make sure these numbers are odd
|
hashkey[1] |= 1
|
hashkey[2] |= 1
|
hashkey[3] |= 1
|
}
|
|
func initAlgAES() {
|
if GOOS == "aix" {
|
// runtime.algarray is immutable on AIX: see cmd/link/internal/ld/xcoff.go
|
return
|
}
|
useAeshash = true
|
algarray[alg_MEM32].hash = aeshash32
|
algarray[alg_MEM64].hash = aeshash64
|
algarray[alg_STRING].hash = aeshashstr
|
// Initialize with random data so hash collisions will be hard to engineer.
|
getRandomData(aeskeysched[:])
|
}
|
