github.com/gocuntian/go@v0.0.0-20160610041250-fee02d270bf8/src/cmd/compile/internal/ssa/location.go (about)

     1  // Copyright 2015 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 "fmt"
     8  
     9  // A place that an ssa variable can reside.
    10  type Location interface {
    11  	Name() string // name to use in assembly templates: %rax, 16(%rsp), ...
    12  }
    13  
    14  // A Register is a machine register, like %rax.
    15  // They are numbered densely from 0 (for each architecture).
    16  type Register struct {
    17  	Num  int32
    18  	name string
    19  }
    20  
    21  func (r *Register) Name() string {
    22  	return r.name
    23  }
    24  
    25  // A LocalSlot is a location in the stack frame.
    26  // It is (possibly a subpiece of) a PPARAM, PPARAMOUT, or PAUTO ONAME node.
    27  type LocalSlot struct {
    28  	N    GCNode // an ONAME *gc.Node representing a variable on the stack
    29  	Type Type   // type of slot
    30  	Off  int64  // offset of slot in N
    31  }
    32  
    33  func (s LocalSlot) Name() string {
    34  	if s.Off == 0 {
    35  		return fmt.Sprintf("%s[%s]", s.N, s.Type)
    36  	}
    37  	return fmt.Sprintf("%s+%d[%s]", s.N, s.Off, s.Type)
    38  }