1 files changed, 355 insertions, 0 deletions
diff --git a/vendor/github.com/mmcloughlin/avo/ir/ir.go b/vendor/github.com/mmcloughlin/avo/ir/ir.go
new file mode 100644
index 0000000..6fb9216
--- /dev/null
+++ b/vendor/github.com/mmcloughlin/avo/ir/ir.go
@@ -0,0 +1,355 @@
+package ir
+
+import (
+	"errors"
+
+	"github.com/mmcloughlin/avo/attr"
+	"github.com/mmcloughlin/avo/buildtags"
+	"github.com/mmcloughlin/avo/gotypes"
+	"github.com/mmcloughlin/avo/operand"
+	"github.com/mmcloughlin/avo/reg"
+)
+
+// Node is a part of a Function.
+type Node interface {
+	node()
+}
+
+// Label within a function.
+type Label string
+
+func (l Label) node() {}
+
+// Comment represents a multi-line comment.
+type Comment struct {
+	Lines []string
+}
+
+func (c *Comment) node() {}
+
+// NewComment builds a Comment consisting of the provided lines.
+func NewComment(lines ...string) *Comment {
+	return &Comment{
+		Lines: lines,
+	}
+}
+
+// Instruction is a single instruction in a function.
+type Instruction struct {
+	Opcode   string
+	Operands []operand.Op
+
+	Inputs  []operand.Op
+	Outputs []operand.Op
+
+	IsTerminal       bool
+	IsBranch         bool
+	IsConditional    bool
+	CancellingInputs bool
+
+	// ISA is the list of required instruction set extensions.
+	ISA []string
+
+	// CFG.
+	Pred []*Instruction
+	Succ []*Instruction
+
+	// LiveIn/LiveOut are sets of live register IDs pre/post execution.
+	LiveIn  reg.MaskSet
+	LiveOut reg.MaskSet
+}
+
+func (i *Instruction) node() {}
+
+// IsUnconditionalBranch reports whether i is an unconditional branch.
+func (i Instruction) IsUnconditionalBranch() bool {
+	return i.IsBranch && !i.IsConditional
+}
+
+// TargetLabel returns the label referenced by this instruction. Returns nil if
+// no label is referenced.
+func (i Instruction) TargetLabel() *Label {
+	if !i.IsBranch {
+		return nil
+	}
+	if len(i.Operands) == 0 {
+		return nil
+	}
+	if ref, ok := i.Operands[0].(operand.LabelRef); ok {
+		lbl := Label(ref)
+		return &lbl
+	}
+	return nil
+}
+
+// Registers returns all registers involved in the instruction.
+func (i Instruction) Registers() []reg.Register {
+	var rs []reg.Register
+	for _, op := range i.Operands {
+		rs = append(rs, operand.Registers(op)...)
+	}
+	return rs
+}
+
+// InputRegisters returns all registers read by this instruction.
+func (i Instruction) InputRegisters() []reg.Register {
+	var rs []reg.Register
+	for _, op := range i.Inputs {
+		rs = append(rs, operand.Registers(op)...)
+	}
+	if i.CancellingInputs && rs[0] == rs[1] {
+		rs = []reg.Register{}
+	}
+	for _, op := range i.Outputs {
+		if operand.IsMem(op) {
+			rs = append(rs, operand.Registers(op)...)
+		}
+	}
+	return rs
+}
+
+// OutputRegisters returns all registers written by this instruction.
+func (i Instruction) OutputRegisters() []reg.Register {
+	var rs []reg.Register
+	for _, op := range i.Outputs {
+		if r, ok := op.(reg.Register); ok {
+			rs = append(rs, r)
+		}
+	}
+	return rs
+}
+
+// Section is a part of a file.
+type Section interface {
+	section()
+}
+
+// File represents an assembly file.
+type File struct {
+	Constraints buildtags.Constraints
+	Includes    []string
+	Sections    []Section
+}
+
+// NewFile initializes an empty file.
+func NewFile() *File {
+	return &File{}
+}
+
+// AddSection appends a Section to the file.
+func (f *File) AddSection(s Section) {
+	f.Sections = append(f.Sections, s)
+}
+
+// Functions returns all functions in the file.
+func (f *File) Functions() []*Function {
+	var fns []*Function
+	for _, s := range f.Sections {
+		if fn, ok := s.(*Function); ok {
+			fns = append(fns, fn)
+		}
+	}
+	return fns
+}
+
+// Pragma represents a function compiler directive.
+type Pragma struct {
+	Directive string
+	Arguments []string
+}
+
+// Function represents an assembly function.
+type Function struct {
+	Name       string
+	Attributes attr.Attribute
+	Pragmas    []Pragma
+	Doc        []string
+	Signature  *gotypes.Signature
+	LocalSize  int
+
+	Nodes []Node
+
+	// LabelTarget maps from label name to the following instruction.
+	LabelTarget map[Label]*Instruction
+
+	// Register allocation.
+	Allocation reg.Allocation
+
+	// ISA is the list of required instruction set extensions.
+	ISA []string
+}
+
+func (f *Function) section() {}
+
+// NewFunction builds an empty function of the given name.
+func NewFunction(name string) *Function {
+	return &Function{
+		Name:      name,
+		Signature: gotypes.NewSignatureVoid(),
+	}
+}
+
+// AddPragma adds a pragma to this function.
+func (f *Function) AddPragma(directive string, args ...string) {
+	f.Pragmas = append(f.Pragmas, Pragma{
+		Directive: directive,
+		Arguments: args,
+	})
+}
+
+// SetSignature sets the function signature.
+func (f *Function) SetSignature(s *gotypes.Signature) {
+	f.Signature = s
+}
+
+// AllocLocal allocates size bytes in this function's stack.
+// Returns a reference to the base pointer for the newly allocated region.
+func (f *Function) AllocLocal(size int) operand.Mem {
+	ptr := operand.NewStackAddr(f.LocalSize)
+	f.LocalSize += size
+	return ptr
+}
+
+// AddInstruction appends an instruction to f.
+func (f *Function) AddInstruction(i *Instruction) {
+	f.AddNode(i)
+}
+
+// AddLabel appends a label to f.
+func (f *Function) AddLabel(l Label) {
+	f.AddNode(l)
+}
+
+// AddComment adds comment lines to f.
+func (f *Function) AddComment(lines ...string) {
+	f.AddNode(NewComment(lines...))
+}
+
+// AddNode appends a Node to f.
+func (f *Function) AddNode(n Node) {
+	f.Nodes = append(f.Nodes, n)
+}
+
+// Instructions returns just the list of instruction nodes.
+func (f *Function) Instructions() []*Instruction {
+	var is []*Instruction
+	for _, n := range f.Nodes {
+		i, ok := n.(*Instruction)
+		if ok {
+			is = append(is, i)
+		}
+	}
+	return is
+}
+
+// Labels returns just the list of label nodes.
+func (f *Function) Labels() []Label {
+	var lbls []Label
+	for _, n := range f.Nodes {
+		lbl, ok := n.(Label)
+		if ok {
+			lbls = append(lbls, lbl)
+		}
+	}
+	return lbls
+}
+
+// Stub returns the Go function declaration.
+func (f *Function) Stub() string {
+	return "func " + f.Name + f.Signature.String()
+}
+
+// FrameBytes returns the size of the stack frame in bytes.
+func (f *Function) FrameBytes() int {
+	return f.LocalSize
+}
+
+// ArgumentBytes returns the size of the arguments in bytes.
+func (f *Function) ArgumentBytes() int {
+	return f.Signature.Bytes()
+}
+
+// Datum represents a data element at a particular offset of a data section.
+type Datum struct {
+	Offset int
+	Value  operand.Constant
+}
+
+// NewDatum builds a Datum from the given constant.
+func NewDatum(offset int, v operand.Constant) Datum {
+	return Datum{
+		Offset: offset,
+		Value:  v,
+	}
+}
+
+// Interval returns the range of bytes this datum will occupy within its section.
+func (d Datum) Interval() (int, int) {
+	return d.Offset, d.Offset + d.Value.Bytes()
+}
+
+// Overlaps returns true
+func (d Datum) Overlaps(other Datum) bool {
+	s, e := d.Interval()
+	so, eo := other.Interval()
+	return !(eo <= s || e <= so)
+}
+
+// Global represents a DATA section.
+type Global struct {
+	Symbol     operand.Symbol
+	Attributes attr.Attribute
+	Data       []Datum
+	Size       int
+}
+
+// NewGlobal constructs an empty DATA section.
+func NewGlobal(sym operand.Symbol) *Global {
+	return &Global{
+		Symbol: sym,
+	}
+}
+
+// NewStaticGlobal is a convenience for building a static DATA section.
+func NewStaticGlobal(name string) *Global {
+	return NewGlobal(operand.NewStaticSymbol(name))
+}
+
+func (g *Global) section() {}
+
+// Base returns a pointer to the start of the data section.
+func (g *Global) Base() operand.Mem {
+	return operand.NewDataAddr(g.Symbol, 0)
+}
+
+// Grow ensures that the data section has at least the given size.
+func (g *Global) Grow(size int) {
+	if g.Size < size {
+		g.Size = size
+	}
+}
+
+// AddDatum adds d to this data section, growing it if necessary. Errors if the datum overlaps with existing data.
+func (g *Global) AddDatum(d Datum) error {
+	for _, other := range g.Data {
+		if d.Overlaps(other) {
+			return errors.New("overlaps existing datum")
+		}
+	}
+	g.add(d)
+	return nil
+}
+
+// Append the constant to the end of the data section.
+func (g *Global) Append(v operand.Constant) {
+	g.add(Datum{
+		Offset: g.Size,
+		Value:  v,
+	})
+}
+
+func (g *Global) add(d Datum) {
+	_, end := d.Interval()
+	g.Grow(end)
+	g.Data = append(g.Data, d)
+}