gotosocial/vendor/github.com/bytedance/sonic/internal/jit/assembler_amd64.go

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2023-02-25 13:12:40 +01:00
/*
* 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.
*/
package jit
import (
`encoding/binary`
`strconv`
`strings`
`sync`
`github.com/bytedance/sonic/loader`
`github.com/bytedance/sonic/internal/rt`
`github.com/twitchyliquid64/golang-asm/obj`
`github.com/twitchyliquid64/golang-asm/obj/x86`
)
const (
_LB_jump_pc = "_jump_pc_"
)
type BaseAssembler struct {
i int
f func()
c []byte
o sync.Once
pb *Backend
xrefs map[string][]*obj.Prog
labels map[string]*obj.Prog
pendings map[string][]*obj.Prog
}
/** Instruction Encoders **/
var _NOPS = [][16]byte {
{0x90}, // NOP
{0x66, 0x90}, // 66 NOP
{0x0f, 0x1f, 0x00}, // NOP DWORD ptr [EAX]
{0x0f, 0x1f, 0x40, 0x00}, // NOP DWORD ptr [EAX + 00H]
{0x0f, 0x1f, 0x44, 0x00, 0x00}, // NOP DWORD ptr [EAX + EAX*1 + 00H]
{0x66, 0x0f, 0x1f, 0x44, 0x00, 0x00}, // 66 NOP DWORD ptr [EAX + EAX*1 + 00H]
{0x0f, 0x1f, 0x80, 0x00, 0x00, 0x00, 0x00}, // NOP DWORD ptr [EAX + 00000000H]
{0x0f, 0x1f, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00}, // NOP DWORD ptr [EAX + EAX*1 + 00000000H]
{0x66, 0x0f, 0x1f, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00}, // 66 NOP DWORD ptr [EAX + EAX*1 + 00000000H]
}
func (self *BaseAssembler) NOP() *obj.Prog {
p := self.pb.New()
p.As = obj.ANOP
self.pb.Append(p)
return p
}
func (self *BaseAssembler) NOPn(n int) {
for i := len(_NOPS); i > 0 && n > 0; i-- {
for ; n >= i; n -= i {
self.Byte(_NOPS[i - 1][:i]...)
}
}
}
func (self *BaseAssembler) Byte(v ...byte) {
for ; len(v) >= 8; v = v[8:] { self.From("QUAD", Imm(rt.Get64(v))) }
for ; len(v) >= 4; v = v[4:] { self.From("LONG", Imm(int64(rt.Get32(v)))) }
for ; len(v) >= 2; v = v[2:] { self.From("WORD", Imm(int64(rt.Get16(v)))) }
for ; len(v) >= 1; v = v[1:] { self.From("BYTE", Imm(int64(v[0]))) }
}
func (self *BaseAssembler) Mark(pc int) {
self.i++
self.Link(_LB_jump_pc + strconv.Itoa(pc))
}
func (self *BaseAssembler) Link(to string) {
var p *obj.Prog
var v []*obj.Prog
/* placeholder substitution */
if strings.Contains(to, "{n}") {
to = strings.ReplaceAll(to, "{n}", strconv.Itoa(self.i))
}
/* check for duplications */
if _, ok := self.labels[to]; ok {
panic("label " + to + " has already been linked")
}
/* get the pending links */
p = self.NOP()
v = self.pendings[to]
/* patch all the pending jumps */
for _, q := range v {
q.To.Val = p
}
/* mark the label as resolved */
self.labels[to] = p
delete(self.pendings, to)
}
func (self *BaseAssembler) Xref(pc int, d int64) {
self.Sref(_LB_jump_pc + strconv.Itoa(pc), d)
}
func (self *BaseAssembler) Sref(to string, d int64) {
p := self.pb.New()
p.As = x86.ALONG
p.From = Imm(-d)
/* placeholder substitution */
if strings.Contains(to, "{n}") {
to = strings.ReplaceAll(to, "{n}", strconv.Itoa(self.i))
}
/* record the patch point */
self.pb.Append(p)
self.xrefs[to] = append(self.xrefs[to], p)
}
func (self *BaseAssembler) Xjmp(op string, to int) {
self.Sjmp(op, _LB_jump_pc + strconv.Itoa(to))
}
func (self *BaseAssembler) Sjmp(op string, to string) {
p := self.pb.New()
p.As = As(op)
/* placeholder substitution */
if strings.Contains(to, "{n}") {
to = strings.ReplaceAll(to, "{n}", strconv.Itoa(self.i))
}
/* check for backward jumps */
if v, ok := self.labels[to]; ok {
p.To.Val = v
} else {
self.pendings[to] = append(self.pendings[to], p)
}
/* mark as a branch, and add to instruction buffer */
p.To.Type = obj.TYPE_BRANCH
self.pb.Append(p)
}
func (self *BaseAssembler) Rjmp(op string, to obj.Addr) {
p := self.pb.New()
p.To = to
p.As = As(op)
self.pb.Append(p)
}
func (self *BaseAssembler) From(op string, val obj.Addr) {
p := self.pb.New()
p.As = As(op)
p.From = val
self.pb.Append(p)
}
func (self *BaseAssembler) Emit(op string, args ...obj.Addr) {
p := self.pb.New()
p.As = As(op)
self.assignOperands(p, args)
self.pb.Append(p)
}
func (self *BaseAssembler) assignOperands(p *obj.Prog, args []obj.Addr) {
switch len(args) {
case 0 :
case 1 : p.To = args[0]
case 2 : p.To, p.From = args[1], args[0]
case 3 : p.To, p.From, p.RestArgs = args[2], args[0], args[1:2]
case 4 : p.To, p.From, p.RestArgs = args[2], args[3], args[:2]
default : panic("invalid operands")
}
}
/** Assembler Helpers **/
func (self *BaseAssembler) Size() int {
self.build()
return len(self.c)
}
func (self *BaseAssembler) Init(f func()) {
self.i = 0
self.f = f
self.c = nil
self.o = sync.Once{}
}
var jitLoader = loader.Loader{
Name: "sonic.jit.",
File: "github.com/bytedance/sonic/jit.go",
Options: loader.Options{
NoPreempt: true,
},
}
func (self *BaseAssembler) Load(name string, frameSize int, argSize int, argStackmap []bool, localStackmap []bool) loader.Function {
self.build()
return jitLoader.LoadOne(self.c, name, frameSize, argSize, argStackmap, localStackmap)
}
/** Assembler Stages **/
func (self *BaseAssembler) init() {
self.pb = newBackend("amd64")
self.xrefs = map[string][]*obj.Prog{}
self.labels = map[string]*obj.Prog{}
self.pendings = map[string][]*obj.Prog{}
}
func (self *BaseAssembler) build() {
self.o.Do(func() {
self.init()
self.f()
self.validate()
self.assemble()
self.resolve()
self.release()
})
}
func (self *BaseAssembler) release() {
self.pb.Release()
self.pb = nil
self.xrefs = nil
self.labels = nil
self.pendings = nil
}
func (self *BaseAssembler) resolve() {
for s, v := range self.xrefs {
for _, prog := range v {
if prog.As != x86.ALONG {
panic("invalid RIP relative reference")
} else if p, ok := self.labels[s]; !ok {
panic("links are not fully resolved: " + s)
} else {
off := prog.From.Offset + p.Pc - prog.Pc
binary.LittleEndian.PutUint32(self.c[prog.Pc:], uint32(off))
}
}
}
}
func (self *BaseAssembler) validate() {
for key := range self.pendings {
panic("links are not fully resolved: " + key)
}
}
func (self *BaseAssembler) assemble() {
self.c = self.pb.Assemble()
}