1 // Copyright 2017 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 package ssa 6 7 import "sort" 8 9 // A Cache holds reusable compiler state. 10 // It is intended to be re-used for multiple Func compilations. 11 type Cache struct { 12 // Storage for low-numbered values and blocks. 13 values [2000]Value 14 blocks [200]Block 15 locs [2000]Location 16 17 // Storage for DWARF variable locations. Lazily allocated 18 // since location lists are off by default. 19 varLocs []VarLoc 20 curVarLoc int 21 22 // Reusable stackAllocState. 23 // See stackalloc.go's {new,put}StackAllocState. 24 stackAllocState *stackAllocState 25 26 domblockstore []ID // scratch space for computing dominators 27 scrSparse []*sparseSet // scratch sparse sets to be re-used. 28 } 29 30 func (c *Cache) Reset() { 31 nv := sort.Search(len(c.values), func(i int) bool { return c.values[i].ID == 0 }) 32 xv := c.values[:nv] 33 for i := range xv { 34 xv[i] = Value{} 35 } 36 nb := sort.Search(len(c.blocks), func(i int) bool { return c.blocks[i].ID == 0 }) 37 xb := c.blocks[:nb] 38 for i := range xb { 39 xb[i] = Block{} 40 } 41 nl := sort.Search(len(c.locs), func(i int) bool { return c.locs[i] == nil }) 42 xl := c.locs[:nl] 43 for i := range xl { 44 xl[i] = nil 45 } 46 xvl := c.varLocs[:c.curVarLoc] 47 for i := range xvl { 48 xvl[i] = VarLoc{} 49 } 50 c.curVarLoc = 0 51 } 52 53 func (c *Cache) NewVarLoc() *VarLoc { 54 if c.varLocs == nil { 55 c.varLocs = make([]VarLoc, 4000) 56 } 57 if c.curVarLoc == len(c.varLocs) { 58 return &VarLoc{} 59 } 60 vl := &c.varLocs[c.curVarLoc] 61 c.curVarLoc++ 62 return vl 63 } 64
