backend.go raw

   1  /*
   2   * Copyright 2021 ByteDance Inc.
   3   *
   4   * Licensed under the Apache License, Version 2.0 (the "License");
   5   * you may not use this file except in compliance with the License.
   6   * You may obtain a copy of the License at
   7   *
   8   *     http://www.apache.org/licenses/LICENSE-2.0
   9   *
  10   * Unless required by applicable law or agreed to in writing, software
  11   * distributed under the License is distributed on an "AS IS" BASIS,
  12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13   * See the License for the specific language governing permissions and
  14   * limitations under the License.
  15   */
  16  
  17  package jit
  18  
  19  import (
  20      `fmt`
  21      `sync`
  22      _ `unsafe`
  23  
  24      `github.com/bytedance/sonic/internal/rt`
  25      `github.com/twitchyliquid64/golang-asm/asm/arch`
  26      `github.com/twitchyliquid64/golang-asm/obj`
  27      `github.com/twitchyliquid64/golang-asm/objabi`
  28  )
  29  
  30  type Backend struct {
  31      Ctxt *obj.Link
  32      Arch *arch.Arch
  33      Head *obj.Prog
  34      Tail *obj.Prog
  35      Prog []*obj.Prog
  36  }
  37  
  38  var (
  39      _progPool sync.Pool
  40  )
  41  
  42  func newProg() *obj.Prog {
  43      if val := _progPool.Get(); val == nil {
  44          return new(obj.Prog)
  45      } else {
  46          return remProg(val.(*obj.Prog))
  47      }
  48  }
  49  
  50  func remProg(p *obj.Prog) *obj.Prog {
  51      *p = obj.Prog{}
  52      return p
  53  }
  54  
  55  func newBackend(name string) (ret *Backend) {
  56      ret      = new(Backend)
  57      ret.Arch = arch.Set(name)
  58      ret.Ctxt = newLinkContext(ret.Arch.LinkArch)
  59      ret.Arch.Init(ret.Ctxt)
  60      return
  61  }
  62  
  63  func newLinkContext(arch *obj.LinkArch) (ret *obj.Link) {
  64      ret          = obj.Linknew(arch)
  65      ret.Headtype = objabi.Hlinux
  66      ret.DiagFunc = diagLinkContext
  67      return
  68  }
  69  
  70  func diagLinkContext(str string, args ...interface{}) {
  71      rt.Throw(fmt.Sprintf(str, args...))
  72  }
  73  
  74  func (self *Backend) New() (ret *obj.Prog) {
  75      ret = newProg()
  76      ret.Ctxt = self.Ctxt
  77      self.Prog = append(self.Prog, ret)
  78      return
  79  }
  80  
  81  func (self *Backend) Append(p *obj.Prog) {
  82      if self.Head == nil {
  83          self.Head = p
  84          self.Tail = p
  85      } else {
  86          self.Tail.Link = p
  87          self.Tail = p
  88      }
  89  }
  90  
  91  func (self *Backend) Release() {
  92      self.Arch = nil
  93      self.Ctxt = nil
  94  
  95      /* return all the progs into pool */
  96      for _, p := range self.Prog {
  97          _progPool.Put(p)
  98      }
  99  
 100      /* clear all the references */
 101      self.Head = nil
 102      self.Tail = nil
 103      self.Prog = nil
 104  }
 105  
 106  func (self *Backend) Assemble() []byte {
 107      var sym obj.LSym
 108      var fnv obj.FuncInfo
 109  
 110      /* construct the function */
 111      sym.Func = &fnv
 112      fnv.Text = self.Head
 113  
 114      /* call the assembler */
 115      self.Arch.Assemble(self.Ctxt, &sym, self.New)
 116      return sym.P
 117  }
 118