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// 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 (
"runtime/internal/sys"
"unsafe"
)
// For gccgo, use go:linkname to rename compiler-called functions to
// themselves, so that the compiler will export them.
//
//go:linkname interhash runtime.interhash
//go:linkname nilinterhash runtime.nilinterhash
//go:linkname interequal runtime.interequal
//go:linkname nilinterequal runtime.nilinterequal
//go:linkname efaceeq runtime.efaceeq
//go:linkname ifaceeq runtime.ifaceeq
//go:linkname ifacevaleq runtime.ifacevaleq
//go:linkname ifaceefaceeq runtime.ifaceefaceeq
//go:linkname efacevaleq runtime.efacevaleq
//go:linkname eqstring runtime.eqstring
//go:linkname cmpstring runtime.cmpstring
//
// Temporary to be called from C code.
//go:linkname alginit runtime.alginit
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)
)
var useAeshash bool
// in C code
func aeshashbody(p unsafe.Pointer, h, s uintptr, sched []byte) uintptr
func aeshash(p unsafe.Pointer, h, s uintptr) uintptr {
return aeshashbody(p, h, s, aeskeysched[:])
}
func aeshashstr(p unsafe.Pointer, h uintptr) uintptr {
ps := (*stringStruct)(p)
return aeshashbody(unsafe.Pointer(ps.str), h, uintptr(ps.len), aeskeysched[:])
}
func interhash(p unsafe.Pointer, h uintptr, size uintptr) uintptr {
a := (*iface)(p)
tab := a.tab
if tab == nil {
return h
}
t := *(**_type)(tab)
fn := t.hashfn
if fn == nil {
panic(errorString("hash of unhashable type " + *t.string))
}
if isDirectIface(t) {
return c1 * fn(unsafe.Pointer(&a.data), h^c0, t.size)
} else {
return c1 * fn(a.data, h^c0, t.size)
}
}
func nilinterhash(p unsafe.Pointer, h uintptr, size uintptr) uintptr {
a := (*eface)(p)
t := a._type
if t == nil {
return h
}
fn := t.hashfn
if fn == nil {
panic(errorString("hash of unhashable type " + *t.string))
}
if isDirectIface(t) {
return c1 * fn(unsafe.Pointer(&a.data), h^c0, t.size)
} else {
return c1 * fn(a.data, h^c0, t.size)
}
}
func interequal(p, q unsafe.Pointer, size uintptr) bool {
return ifaceeq(*(*iface)(p), *(*iface)(q))
}
func nilinterequal(p, q unsafe.Pointer, size uintptr) bool {
return efaceeq(*(*eface)(p), *(*eface)(q))
}
func efaceeq(x, y eface) bool {
t := x._type
if !eqtype(t, y._type) {
return false
}
if t == nil {
return true
}
eq := t.equalfn
if eq == nil {
panic(errorString("comparing uncomparable type " + *t.string))
}
if isDirectIface(t) {
return x.data == y.data
}
return eq(x.data, y.data, t.size)
}
func ifaceeq(x, y iface) bool {
xtab := x.tab
if xtab == nil && y.tab == nil {
return true
}
if xtab == nil || y.tab == nil {
return false
}
t := *(**_type)(xtab)
if !eqtype(t, *(**_type)(y.tab)) {
return false
}
eq := t.equalfn
if eq == nil {
panic(errorString("comparing uncomparable type " + *t.string))
}
if isDirectIface(t) {
return x.data == y.data
}
return eq(x.data, y.data, t.size)
}
func ifacevaleq(x iface, t *_type, p unsafe.Pointer) bool {
if x.tab == nil {
return false
}
xt := *(**_type)(x.tab)
if !eqtype(xt, t) {
return false
}
eq := t.equalfn
if eq == nil {
panic(errorString("comparing uncomparable type " + *t.string))
}
if isDirectIface(t) {
return x.data == p
}
return eq(x.data, p, t.size)
}
func ifaceefaceeq(x iface, y eface) bool {
if x.tab == nil && y._type == nil {
return true
}
if x.tab == nil || y._type == nil {
return false
}
xt := *(**_type)(x.tab)
if !eqtype(xt, y._type) {
return false
}
eq := xt.equalfn
if eq == nil {
panic(errorString("comparing uncomparable type " + *xt.string))
}
if isDirectIface(xt) {
return x.data == y.data
}
return eq(x.data, y.data, xt.size)
}
func efacevaleq(x eface, t *_type, p unsafe.Pointer) bool {
if x._type == nil {
return false
}
if !eqtype(x._type, t) {
return false
}
eq := t.equalfn
if eq == nil {
panic(errorString("comparing uncomparable type " + *t.string))
}
if isDirectIface(t) {
return x.data == p
}
return eq(x.data, p, t.size)
}
func eqstring(x, y string) bool {
a := stringStructOf(&x)
b := stringStructOf(&y)
if a.len != b.len {
return false
}
return memcmp(unsafe.Pointer(a.str), unsafe.Pointer(b.str), uintptr(a.len)) == 0
}
func cmpstring(x, y string) int {
a := stringStructOf(&x)
b := stringStructOf(&y)
l := a.len
if l > b.len {
l = b.len
}
i := memcmp(unsafe.Pointer(a.str), unsafe.Pointer(b.str), uintptr(l))
if i != 0 {
return int(i)
}
if a.len < b.len {
return -1
} else if a.len > b.len {
return 1
}
return 0
}
// Force the creation of function descriptors for equality and hash
// functions. These will be referenced directly by the compiler.
var _ = memhash
var _ = interhash
var _ = interequal
var _ = nilinterhash
var _ = nilinterequal
const hashRandomBytes = sys.PtrSize / 4 * 64
// used in asm_{386,amd64}.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 algorithm if we have the instructions we need
if (GOARCH == "386" || GOARCH == "amd64") &&
GOOS != "nacl" &&
cpuid_ecx&(1<<25) != 0 && // aes (aesenc)
cpuid_ecx&(1<<9) != 0 && // sse3 (pshufb)
cpuid_ecx&(1<<19) != 0 { // sse4.1 (pinsr{d,q})
useAeshash = true
// Initialize with random data so hash collisions will be hard to engineer.
getRandomData(aeskeysched[:])
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
}
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