Golang obj.Rconv函數代碼示例

func gclean() {
	for _, r := range Thearch.ReservedRegs {
		reg[r-Thearch.REGMIN]--
	}

	for r := Thearch.REGMIN; r <= Thearch.REGMAX; r++ {
		n := reg[r-Thearch.REGMIN]
		if n != 0 {
			if Debug['v'] != 0 {
				Regdump()
			}
			Yyerror("reg %v left allocated", obj.Rconv(r))
		}
	}

	for r := Thearch.FREGMIN; r <= Thearch.FREGMAX; r++ {
		n := reg[r-Thearch.REGMIN]
		if n != 0 {
			if Debug['v'] != 0 {
				Regdump()
			}
			Yyerror("reg %v left allocated", obj.Rconv(r))
		}
	}
}

func archPPC64() *Arch {
	register := make(map[string]int16)
	// Create maps for easy lookup of instruction names etc.
	// Note that there is no list of names as there is for x86.
	for i := ppc64.REG_R0; i <= ppc64.REG_R31; i++ {
		register[obj.Rconv(i)] = int16(i)
	}
	for i := ppc64.REG_F0; i <= ppc64.REG_F31; i++ {
		register[obj.Rconv(i)] = int16(i)
	}
	for i := ppc64.REG_CR0; i <= ppc64.REG_CR7; i++ {
		register[obj.Rconv(i)] = int16(i)
	}
	for i := ppc64.REG_MSR; i <= ppc64.REG_CR; i++ {
		register[obj.Rconv(i)] = int16(i)
	}
	register["CR"] = ppc64.REG_CR
	register["XER"] = ppc64.REG_XER
	register["LR"] = ppc64.REG_LR
	register["CTR"] = ppc64.REG_CTR
	register["FPSCR"] = ppc64.REG_FPSCR
	register["MSR"] = ppc64.REG_MSR
	// Pseudo-registers.
	register["SB"] = RSB
	register["FP"] = RFP
	register["PC"] = RPC
	// Avoid unintentionally clobbering g using R30.
	delete(register, "R30")
	register["g"] = ppc64.REG_R30
	registerPrefix := map[string]bool{
		"CR":  true,
		"F":   true,
		"R":   true,
		"SPR": true,
	}

	instructions := make(map[string]int)
	for i, s := range obj.Anames {
		instructions[s] = i
	}
	for i, s := range ppc64.Anames {
		if i >= obj.A_ARCHSPECIFIC {
			instructions[s] = i + obj.ABasePPC64
		}
	}
	// Annoying aliases.
	instructions["BR"] = ppc64.ABR
	instructions["BL"] = ppc64.ABL
	instructions["RETURN"] = ppc64.ARETURN

	return &Arch{
		LinkArch:       &ppc64.Linkppc64,
		Instructions:   instructions,
		Register:       register,
		RegisterPrefix: registerPrefix,
		RegisterNumber: ppc64RegisterNumber,
		IsJump:         jumpPPC64,
	}
}

func archMips64() *Arch {
	register := make(map[string]int16)
	// Create maps for easy lookup of instruction names etc.
	// Note that there is no list of names as there is for x86.
	for i := mips.REG_R0; i <= mips.REG_R31; i++ {
		register[obj.Rconv(i)] = int16(i)
	}
	for i := mips.REG_F0; i <= mips.REG_F31; i++ {
		register[obj.Rconv(i)] = int16(i)
	}
	for i := mips.REG_M0; i <= mips.REG_M31; i++ {
		register[obj.Rconv(i)] = int16(i)
	}
	for i := mips.REG_FCR0; i <= mips.REG_FCR31; i++ {
		register[obj.Rconv(i)] = int16(i)
	}
	register["HI"] = mips.REG_HI
	register["LO"] = mips.REG_LO
	// Pseudo-registers.
	register["SB"] = RSB
	register["FP"] = RFP
	register["PC"] = RPC
	// Avoid unintentionally clobbering g using R30.
	delete(register, "R30")
	register["g"] = mips.REG_R30
	// Avoid unintentionally clobbering RSB using R28.
	delete(register, "R28")
	register["RSB"] = mips.REG_R28
	registerPrefix := map[string]bool{
		"F":   true,
		"FCR": true,
		"M":   true,
		"R":   true,
	}

	instructions := make(map[string]obj.As)
	for i, s := range obj.Anames {
		instructions[s] = obj.As(i)
	}
	for i, s := range mips.Anames {
		if obj.As(i) >= obj.A_ARCHSPECIFIC {
			instructions[s] = obj.As(i) + obj.ABaseMIPS64
		}
	}
	// Annoying alias.
	instructions["JAL"] = mips.AJAL

	return &Arch{
		LinkArch:       &mips.Linkmips64,
		Instructions:   instructions,
		Register:       register,
		RegisterPrefix: registerPrefix,
		RegisterNumber: mipsRegisterNumber,
		IsJump:         jumpMIPS64,
	}
}

func archS390x() *Arch {
	register := make(map[string]int16)
	// Create maps for easy lookup of instruction names etc.
	// Note that there is no list of names as there is for x86.
	for i := s390x.REG_R0; i <= s390x.REG_R15; i++ {
		register[obj.Rconv(i)] = int16(i)
	}
	for i := s390x.REG_F0; i <= s390x.REG_F15; i++ {
		register[obj.Rconv(i)] = int16(i)
	}
	for i := s390x.REG_V0; i <= s390x.REG_V31; i++ {
		register[obj.Rconv(i)] = int16(i)
	}
	for i := s390x.REG_AR0; i <= s390x.REG_AR15; i++ {
		register[obj.Rconv(i)] = int16(i)
	}
	register["LR"] = s390x.REG_LR
	// Pseudo-registers.
	register["SB"] = RSB
	register["FP"] = RFP
	register["PC"] = RPC
	// Avoid unintentionally clobbering g using R13.
	delete(register, "R13")
	register["g"] = s390x.REG_R13
	registerPrefix := map[string]bool{
		"AR": true,
		"F":  true,
		"R":  true,
	}

	instructions := make(map[string]obj.As)
	for i, s := range obj.Anames {
		instructions[s] = obj.As(i)
	}
	for i, s := range s390x.Anames {
		if obj.As(i) >= obj.A_ARCHSPECIFIC {
			instructions[s] = obj.As(i) + obj.ABaseS390X
		}
	}
	// Annoying aliases.
	instructions["BR"] = s390x.ABR
	instructions["BL"] = s390x.ABL

	return &Arch{
		LinkArch:       &s390x.Links390x,
		Instructions:   instructions,
		Register:       register,
		RegisterPrefix: registerPrefix,
		RegisterNumber: s390xRegisterNumber,
		IsJump:         jumpS390x,
	}
}

func gclean() {
	for i := 0; i < len(resvd); i++ {
		reg[resvd[i]]--
	}

	for i := x86.REG_AX; i <= x86.REG_DI; i++ {
		if reg[i] != 0 {
			gc.Yyerror("reg %v left allocated at %x", obj.Rconv(i), regpc[i])
		}
	}
	for i := x86.REG_X0; i <= x86.REG_X7; i++ {
		if reg[i] != 0 {
			gc.Yyerror("reg %v left allocated\n", obj.Rconv(i))
		}
	}
}

func Regdump() {
	if Debug['v'] == 0 {
		fmt.Printf("run compiler with -v for register allocation sites\n")
		return
	}

	dump := func(r int) {
		stk := regstk[r-Thearch.REGMIN]
		if len(stk) == 0 {
			return
		}
		fmt.Printf("reg %v allocated at:\n", obj.Rconv(r))
		fmt.Printf("\t%s\n", strings.Replace(strings.TrimSpace(string(stk)), "\n", "\n\t", -1))
	}

	for r := Thearch.REGMIN; r <= Thearch.REGMAX; r++ {
		if reg[r-Thearch.REGMIN] != 0 {
			dump(r)
		}
	}
	for r := Thearch.FREGMIN; r <= Thearch.FREGMAX; r++ {
		if reg[r-Thearch.REGMIN] == 0 {
			dump(r)
		}
	}
}

func archArm() *Arch {
	register := make(map[string]int16)
	// Create maps for easy lookup of instruction names etc.
	// Note that there is no list of names as there is for x86.
	for i := arm.REG_R0; i < arm.REG_SPSR; i++ {
		register[obj.Rconv(i)] = int16(i)
	}
	// Avoid unintentionally clobbering g using R10.
	delete(register, "R10")
	register["g"] = arm.REG_R10
	for i := 0; i < 16; i++ {
		register[fmt.Sprintf("C%d", i)] = int16(i)
	}

	// Pseudo-registers.
	register["SB"] = RSB
	register["FP"] = RFP
	register["PC"] = RPC
	register["SP"] = RSP
	registerPrefix := map[string]bool{
		"F": true,
		"R": true,
	}

	instructions := make(map[string]int)
	for i, s := range obj.Anames {
		instructions[s] = i
	}
	for i, s := range arm.Anames {
		if i >= obj.A_ARCHSPECIFIC {
			instructions[s] = i + obj.ABaseARM
		}
	}
	// Annoying aliases.
	instructions["B"] = obj.AJMP
	instructions["BL"] = obj.ACALL
	// MCR differs from MRC by the way fields of the word are encoded.
	// (Details in arm.go). Here we add the instruction so parse will find
	// it, but give it an opcode number known only to us.
	instructions["MCR"] = aMCR

	return &Arch{
		LinkArch:       &arm.Linkarm,
		Instructions:   instructions,
		Register:       register,
		RegisterPrefix: registerPrefix,
		RegisterNumber: armRegisterNumber,
		IsJump:         jumpArm,
	}
}

// If s==nil, copyu returns the set/use of v in p; otherwise, it
// modifies p to replace reads of v with reads of s and returns 0 for
// success or non-zero for failure.
//
// If s==nil, copy returns one of the following values:
//	1 if v only used
//	2 if v is set and used in one address (read-alter-rewrite;
//	  can't substitute)
//	3 if v is only set
//	4 if v is set in one address and used in another (so addresses
//	  can be rewritten independently)
//	0 otherwise (not touched)
func copyu(p *obj.Prog, v *obj.Addr, s *obj.Addr) int {
	if p.From3Type() != obj.TYPE_NONE {
		// 7g never generates a from3
		fmt.Printf("copyu: from3 (%v) not implemented\n", gc.Ctxt.Dconv(p.From3))
	}
	if p.RegTo2 != obj.REG_NONE {
		// 7g never generates a to2
		fmt.Printf("copyu: RegTo2 (%v) not implemented\n", obj.Rconv(int(p.RegTo2)))
	}

	switch p.As {
	default:
		fmt.Printf("copyu: can't find %v\n", obj.Aconv(p.As))
		return 2

	case obj.ANOP, /* read p->from, write p->to */
		arm64.ANEG,
		arm64.AFNEGD,
		arm64.AFNEGS,
		arm64.AFSQRTD,
		arm64.AFCVTZSD,
		arm64.AFCVTZSS,
		arm64.AFCVTZSDW,
		arm64.AFCVTZSSW,
		arm64.AFCVTZUD,
		arm64.AFCVTZUS,
		arm64.AFCVTZUDW,
		arm64.AFCVTZUSW,
		arm64.AFCVTSD,
		arm64.AFCVTDS,
		arm64.ASCVTFD,
		arm64.ASCVTFS,
		arm64.ASCVTFWD,
		arm64.ASCVTFWS,
		arm64.AUCVTFD,
		arm64.AUCVTFS,
		arm64.AUCVTFWD,
		arm64.AUCVTFWS,
		arm64.AMOVB,
		arm64.AMOVBU,
		arm64.AMOVH,
		arm64.AMOVHU,
		arm64.AMOVW,
		arm64.AMOVWU,
		arm64.AMOVD,
		arm64.AFMOVS,
		arm64.AFMOVD:
		if p.Scond == 0 {
			if s != nil {
				if copysub(&p.From, v, s, true) {
					return 1
				}

				// Update only indirect uses of v in p->to
				if !copyas(&p.To, v) {
					if copysub(&p.To, v, s, true) {
						return 1
					}
				}
				return 0
			}

			if copyas(&p.To, v) {
				// Fix up implicit from
				if p.From.Type == obj.TYPE_NONE {
					p.From = p.To
				}
				if copyau(&p.From, v) {
					return 4
				}
				return 3
			}

			if copyau(&p.From, v) {
				return 1
			}
			if copyau(&p.To, v) {
				// p->to only indirectly uses v
				return 1
			}

			return 0
		}

		/* rar p->from, write p->to or read p->from, rar p->to */
		if p.From.Type == obj.TYPE_MEM {
			if copyas(&p.From, v) {
				// No s!=nil check; need to fail
//.........這裏部分代碼省略.........

//.........這裏部分代碼省略.........
}

func regfree(n *gc.Node) {
	if false && gc.Debug['r'] != 0 {
		fixfree := 0
		for i := REGALLOC_R0; i <= REGALLOC_RMAX; i++ {
			if reg[i] == 0 {
				fixfree++
			}
		}
		floatfree := 0
		for i := REGALLOC_F0; i <= REGALLOC_FMAX; i++ {
			if reg[i] == 0 {
				floatfree++
			}
		}
		fmt.Printf("regalloc fix %d float %d\n", fixfree, floatfree)
	}

	if n.Op == gc.ONAME {
		return
	}
	if n.Op != gc.OREGISTER && n.Op != gc.OINDREG {
		gc.Fatal("regfree: not a register")
	}
	i := int(n.Val.U.Reg)
	if i == arm.REGSP {
		return
	}
	if i < 0 || i >= len(reg) || i >= len(regpc) {
		gc.Fatal("regfree: reg out of range")
	}
	if reg[i] <= 0 {
		gc.Fatal("regfree: reg %v not allocated", obj.Rconv(i))
	}
	reg[i]--
	if reg[i] == 0 {
		regpc[i] = 0
	}
}

/*
 * return constant i node.
 * overwritten by next call, but useful in calls to gins.
 */

var ncon_n gc.Node

func ncon(i uint32) *gc.Node {
	if ncon_n.Type == nil {
		gc.Nodconst(&ncon_n, gc.Types[gc.TUINT32], 0)
	}
	gc.Mpmovecfix(ncon_n.Val.U.Xval, int64(i))
	return &ncon_n
}

var sclean [10]gc.Node

var nsclean int

/*
 * n is a 64-bit value.  fill in lo and hi to refer to its 32-bit halves.
 */
func split64(n *gc.Node, lo *gc.Node, hi *gc.Node) {
	if !gc.Is64(n.Type) {
		gc.Fatal("split64 %v", gc.Tconv(n.Type, 0))

func clearfat(nl *gc.Node) {
	/* clear a fat object */
	if gc.Debug['g'] != 0 {
		fmt.Printf("clearfat %v (%v, size: %d)\n", nl, nl.Type, nl.Type.Width)
	}

	w := uint64(uint64(nl.Type.Width))

	// Avoid taking the address for simple enough types.
	if gc.Componentgen(nil, nl) {
		return
	}

	c := uint64(w % 8) // bytes
	q := uint64(w / 8) // dwords

	if gc.Reginuse(ppc64.REGRT1) {
		gc.Fatal("%v in use during clearfat", obj.Rconv(ppc64.REGRT1))
	}

	var r0 gc.Node
	gc.Nodreg(&r0, gc.Types[gc.TUINT64], ppc64.REGZERO)
	var dst gc.Node
	gc.Nodreg(&dst, gc.Types[gc.Tptr], ppc64.REGRT1)
	gc.Regrealloc(&dst)
	gc.Agen(nl, &dst)

	var boff uint64
	if q > 128 {
		p := gins(ppc64.ASUB, nil, &dst)
		p.From.Type = obj.TYPE_CONST
		p.From.Offset = 8

		var end gc.Node
		gc.Regalloc(&end, gc.Types[gc.Tptr], nil)
		p = gins(ppc64.AMOVD, &dst, &end)
		p.From.Type = obj.TYPE_ADDR
		p.From.Offset = int64(q * 8)

		p = gins(ppc64.AMOVDU, &r0, &dst)
		p.To.Type = obj.TYPE_MEM
		p.To.Offset = 8
		pl := (*obj.Prog)(p)

		p = gins(ppc64.ACMP, &dst, &end)
		gc.Patch(gc.Gbranch(ppc64.ABNE, nil, 0), pl)

		gc.Regfree(&end)

		// The loop leaves R3 on the last zeroed dword
		boff = 8
	} else if q >= 4 {
		p := gins(ppc64.ASUB, nil, &dst)
		p.From.Type = obj.TYPE_CONST
		p.From.Offset = 8
		f := (*gc.Node)(gc.Sysfunc("duffzero"))
		p = gins(obj.ADUFFZERO, nil, f)
		gc.Afunclit(&p.To, f)

		// 4 and 128 = magic constants: see ../../runtime/asm_ppc64x.s
		p.To.Offset = int64(4 * (128 - q))

		// duffzero leaves R3 on the last zeroed dword
		boff = 8
	} else {
		var p *obj.Prog
		for t := uint64(0); t < q; t++ {
			p = gins(ppc64.AMOVD, &r0, &dst)
			p.To.Type = obj.TYPE_MEM
			p.To.Offset = int64(8 * t)
		}

		boff = 8 * q
	}

	var p *obj.Prog
	for t := uint64(0); t < c; t++ {
		p = gins(ppc64.AMOVB, &r0, &dst)
		p.To.Type = obj.TYPE_MEM
		p.To.Offset = int64(t + boff)
	}

	gc.Regfree(&dst)
}

func nodedump(n *Node, flag int) string {
	if n == nil {
		return ""
	}

	recur := flag&obj.FmtShort == 0 /*untyped*/

	var buf bytes.Buffer
	if recur {
		indent(&buf)
		if dumpdepth > 10 {
			buf.WriteString("...")
			return buf.String()
		}

		if n.Ninit != nil {
			fmt.Fprintf(&buf, "%v-init%v", Oconv(int(n.Op), 0), Hconv(n.Ninit, 0))
			indent(&buf)
		}
	}

	switch n.Op {
	default:
		fmt.Fprintf(&buf, "%v%v", Oconv(int(n.Op), 0), Jconv(n, 0))

	case OREGISTER,
		OINDREG:
		fmt.Fprintf(&buf, "%v-%v%v", Oconv(int(n.Op), 0), obj.Rconv(int(n.Val.U.Reg)), Jconv(n, 0))

	case OLITERAL:
		fmt.Fprintf(&buf, "%v-%v%v", Oconv(int(n.Op), 0), Vconv(&n.Val, 0), Jconv(n, 0))

	case ONAME,
		ONONAME:
		if n.Sym != nil {
			fmt.Fprintf(&buf, "%v-%v%v", Oconv(int(n.Op), 0), Sconv(n.Sym, 0), Jconv(n, 0))
		} else {
			fmt.Fprintf(&buf, "%v%v", Oconv(int(n.Op), 0), Jconv(n, 0))
		}
		if recur && n.Type == nil && n.Ntype != nil {
			indent(&buf)
			fmt.Fprintf(&buf, "%v-ntype%v", Oconv(int(n.Op), 0), Nconv(n.Ntype, 0))
		}

	case OASOP:
		fmt.Fprintf(&buf, "%v-%v%v", Oconv(int(n.Op), 0), Oconv(int(n.Etype), 0), Jconv(n, 0))

	case OTYPE:
		fmt.Fprintf(&buf, "%v %v%v type=%v", Oconv(int(n.Op), 0), Sconv(n.Sym, 0), Jconv(n, 0), Tconv(n.Type, 0))
		if recur && n.Type == nil && n.Ntype != nil {
			indent(&buf)
			fmt.Fprintf(&buf, "%v-ntype%v", Oconv(int(n.Op), 0), Nconv(n.Ntype, 0))
		}
	}

	if n.Sym != nil && n.Op != ONAME {
		fmt.Fprintf(&buf, " %v G%d", Sconv(n.Sym, 0), n.Vargen)
	}

	if n.Type != nil {
		fmt.Fprintf(&buf, " %v", Tconv(n.Type, 0))
	}

	if recur {
		if n.Left != nil {
			buf.WriteString(Nconv(n.Left, 0))
		}
		if n.Right != nil {
			buf.WriteString(Nconv(n.Right, 0))
		}
		if n.List != nil {
			indent(&buf)
			fmt.Fprintf(&buf, "%v-list%v", Oconv(int(n.Op), 0), Hconv(n.List, 0))
		}

		if n.Rlist != nil {
			indent(&buf)
			fmt.Fprintf(&buf, "%v-rlist%v", Oconv(int(n.Op), 0), Hconv(n.Rlist, 0))
		}

		if n.Ntest != nil {
			indent(&buf)
			fmt.Fprintf(&buf, "%v-test%v", Oconv(int(n.Op), 0), Nconv(n.Ntest, 0))
		}

		if n.Nbody != nil {
			indent(&buf)
			fmt.Fprintf(&buf, "%v-body%v", Oconv(int(n.Op), 0), Hconv(n.Nbody, 0))
		}

		if n.Nelse != nil {
			indent(&buf)
			fmt.Fprintf(&buf, "%v-else%v", Oconv(int(n.Op), 0), Hconv(n.Nelse, 0))
		}

		if n.Nincr != nil {
			indent(&buf)
			fmt.Fprintf(&buf, "%v-incr%v", Oconv(int(n.Op), 0), Nconv(n.Nincr, 0))
		}
	}
//.........這裏部分代碼省略.........

func exprfmt(n *Node, prec int) string {
	for n != nil && n.Implicit && (n.Op == OIND || n.Op == OADDR) {
		n = n.Left
	}

	if n == nil {
		return "<N>"
	}

	nprec := opprec[n.Op]
	if n.Op == OTYPE && n.Sym != nil {
		nprec = 8
	}

	if prec > nprec {
		return fmt.Sprintf("(%v)", Nconv(n, 0))
	}

	switch n.Op {
	case OPAREN:
		return fmt.Sprintf("(%v)", Nconv(n.Left, 0))

	case ODDDARG:
		return "... argument"

	case OREGISTER:
		return obj.Rconv(int(n.Val.U.Reg))

	case OLITERAL: // this is a bit of a mess
		if fmtmode == FErr {
			if n.Orig != nil && n.Orig != n {
				return exprfmt(n.Orig, prec)
			}
			if n.Sym != nil {
				return Sconv(n.Sym, 0)
			}
		}
		if n.Val.Ctype == CTNIL && n.Orig != nil && n.Orig != n {
			return exprfmt(n.Orig, prec)
		}
		if n.Type != nil && n.Type != Types[n.Type.Etype] && n.Type != idealbool && n.Type != idealstring {
			// Need parens when type begins with what might
			// be misinterpreted as a unary operator: * or <-.
			if Isptr[n.Type.Etype] || (n.Type.Etype == TCHAN && n.Type.Chan == Crecv) {
				return fmt.Sprintf("(%v)(%v)", Tconv(n.Type, 0), Vconv(&n.Val, 0))
			} else {
				return fmt.Sprintf("%v(%v)", Tconv(n.Type, 0), Vconv(&n.Val, 0))
			}
		}

		return Vconv(&n.Val, 0)

		// Special case: name used as local variable in export.
	// _ becomes ~b%d internally; print as _ for export
	case ONAME:
		if fmtmode == FExp && n.Sym != nil && n.Sym.Name[0] == '~' && n.Sym.Name[1] == 'b' {
			return "_"
		}
		if fmtmode == FExp && n.Sym != nil && !isblank(n) && n.Vargen > 0 {
			return fmt.Sprintf("%v·%d", Sconv(n.Sym, 0), n.Vargen)
		}

		// Special case: explicit name of func (*T) method(...) is turned into pkg.(*T).method,
		// but for export, this should be rendered as (*pkg.T).meth.
		// These nodes have the special property that they are names with a left OTYPE and a right ONAME.
		if fmtmode == FExp && n.Left != nil && n.Left.Op == OTYPE && n.Right != nil && n.Right.Op == ONAME {
			if Isptr[n.Left.Type.Etype] {
				return fmt.Sprintf("(%v).%v", Tconv(n.Left.Type, 0), Sconv(n.Right.Sym, obj.FmtShort|obj.FmtByte))
			} else {
				return fmt.Sprintf("%v.%v", Tconv(n.Left.Type, 0), Sconv(n.Right.Sym, obj.FmtShort|obj.FmtByte))
			}
		}
		fallthrough

		//fallthrough
	case OPACK,
		ONONAME:
		return Sconv(n.Sym, 0)

	case OTYPE:
		if n.Type == nil && n.Sym != nil {
			return Sconv(n.Sym, 0)
		}
		return Tconv(n.Type, 0)

	case OTARRAY:
		if n.Left != nil {
			return fmt.Sprintf("[]%v", Nconv(n.Left, 0))
		}
		var f string
		f += fmt.Sprintf("[]%v", Nconv(n.Right, 0))
		return f // happens before typecheck

	case OTMAP:
		return fmt.Sprintf("map[%v]%v", Nconv(n.Left, 0), Nconv(n.Right, 0))

	case OTCHAN:
		switch n.Etype {
		case Crecv:
			return fmt.Sprintf("<-chan %v", Nconv(n.Left, 0))
//.........這裏部分代碼省略.........

//.........這裏部分代碼省略.........
	}
	if nregion >= MaxRgn {
		if Debug['v'] != 0 {
			Warn("too many regions: %d\n", nregion)
		}
		nregion = MaxRgn
	}

	sort.Sort(rcmp(region[:nregion]))

	if Debug['R'] != 0 && Debug['v'] != 0 {
		Dumpit("pass5", firstf, 1)
	}

	// pass 6
	// determine used registers (paint2)
	// replace code (paint3)
	if Debug['R'] != 0 && Debug['v'] != 0 {
		fmt.Printf("\nregisterizing\n")
	}
	var usedreg uint64
	var vreg uint64
	for i := 0; i < nregion; i++ {
		rgp = &region[i]
		if Debug['R'] != 0 && Debug['v'] != 0 {
			fmt.Printf("region %d: cost %d varno %d enter %d\n", i, rgp.cost, rgp.varno, rgp.enter.Prog.Pc)
		}
		bit = blsh(uint(rgp.varno))
		usedreg = paint2(rgp.enter, int(rgp.varno), 0)
		vreg = allreg(usedreg, rgp)
		if rgp.regno != 0 {
			if Debug['R'] != 0 && Debug['v'] != 0 {
				v := &vars[rgp.varno]
				fmt.Printf("registerize %v+%d (bit=%2d et=%v) in %v usedreg=%#x vreg=%#x\n", v.node, v.offset, rgp.varno, Econv(v.etype), obj.Rconv(int(rgp.regno)), usedreg, vreg)
			}

			paint3(rgp.enter, int(rgp.varno), vreg, int(rgp.regno))
		}
	}

	// free aux structures. peep allocates new ones.
	for i := 0; i < nvar; i++ {
		vars[i].node.SetOpt(nil)
	}
	Flowend(g)
	firstf = nil

	if Debug['R'] != 0 && Debug['v'] != 0 {
		// Rebuild flow graph, since we inserted instructions
		g := Flowstart(firstp, nil)
		firstf = g.Start
		Dumpit("pass6", firstf, 0)
		Flowend(g)
		firstf = nil
	}

	// pass 7
	// peep-hole on basic block
	if Debug['R'] == 0 || Debug['P'] != 0 {
		Thearch.Peep(firstp)
	}

	// eliminate nops
	for p := firstp; p != nil; p = p.Link {
		for p.Link != nil && p.Link.As == obj.ANOP {
			p.Link = p.Link.Link

func clearfat(nl *gc.Node) {
	/* clear a fat object */
	if gc.Debug['g'] != 0 {
		fmt.Printf("clearfat %v (%v, size: %d)\n", nl, nl.Type, nl.Type.Width)
	}

	w := uint64(nl.Type.Width)

	// Avoid taking the address for simple enough types.
	if gc.Componentgen(nil, nl) {
		return
	}

	c := w % 8 // bytes
	q := w / 8 // dwords

	if gc.Reginuse(mips.REGRT1) {
		gc.Fatalf("%v in use during clearfat", obj.Rconv(mips.REGRT1))
	}

	var r0 gc.Node
	gc.Nodreg(&r0, gc.Types[gc.TUINT64], mips.REGZERO)
	var dst gc.Node
	gc.Nodreg(&dst, gc.Types[gc.Tptr], mips.REGRT1)
	gc.Regrealloc(&dst)
	gc.Agen(nl, &dst)

	var boff uint64
	if q > 128 {
		p := gins(mips.ASUBV, nil, &dst)
		p.From.Type = obj.TYPE_CONST
		p.From.Offset = 8

		var end gc.Node
		gc.Regalloc(&end, gc.Types[gc.Tptr], nil)
		p = gins(mips.AMOVV, &dst, &end)
		p.From.Type = obj.TYPE_ADDR
		p.From.Offset = int64(q * 8)

		p = gins(mips.AMOVV, &r0, &dst)
		p.To.Type = obj.TYPE_MEM
		p.To.Offset = 8
		pl := p

		p = gins(mips.AADDV, nil, &dst)
		p.From.Type = obj.TYPE_CONST
		p.From.Offset = 8

		gc.Patch(ginsbranch(mips.ABNE, nil, &dst, &end, 0), pl)

		gc.Regfree(&end)

		// The loop leaves R1 on the last zeroed dword
		boff = 8
		// TODO(dfc): https://golang.org/issue/12108
		// If DUFFZERO is used inside a tail call (see genwrapper) it will
		// overwrite the link register.
	} else if false && q >= 4 {
		p := gins(mips.ASUBV, nil, &dst)
		p.From.Type = obj.TYPE_CONST
		p.From.Offset = 8
		f := gc.Sysfunc("duffzero")
		p = gins(obj.ADUFFZERO, nil, f)
		gc.Afunclit(&p.To, f)

		// 8 and 128 = magic constants: see ../../runtime/asm_mips64x.s
		p.To.Offset = int64(8 * (128 - q))

		// duffzero leaves R1 on the last zeroed dword
		boff = 8
	} else {
		var p *obj.Prog
		for t := uint64(0); t < q; t++ {
			p = gins(mips.AMOVV, &r0, &dst)
			p.To.Type = obj.TYPE_MEM
			p.To.Offset = int64(8 * t)
		}

		boff = 8 * q
	}

	var p *obj.Prog
	for t := uint64(0); t < c; t++ {
		p = gins(mips.AMOVB, &r0, &dst)
		p.To.Type = obj.TYPE_MEM
		p.To.Offset = int64(t + boff)
	}

	gc.Regfree(&dst)
}

func (n *Node) exprfmt(s fmt.State, prec int) {
	for n != nil && n.Implicit && (n.Op == OIND || n.Op == OADDR) {
		n = n.Left
	}

	if n == nil {
		fmt.Fprint(s, "<N>")
		return
	}

	nprec := opprec[n.Op]
	if n.Op == OTYPE && n.Sym != nil {
		nprec = 8
	}

	if prec > nprec {
		fmt.Fprintf(s, "(%v)", n)
		return
	}

	switch n.Op {
	case OPAREN:
		fmt.Fprintf(s, "(%v)", n.Left)

	case ODDDARG:
		fmt.Fprint(s, "... argument")

	case OREGISTER:
		fmt.Fprint(s, obj.Rconv(int(n.Reg)))

	case OLITERAL: // this is a bit of a mess
		if fmtmode == FErr {
			if n.Orig != nil && n.Orig != n {
				n.Orig.exprfmt(s, prec)
				return
			}
			if n.Sym != nil {
				fmt.Fprint(s, n.Sym.String())
				return
			}
		}
		if n.Val().Ctype() == CTNIL && n.Orig != nil && n.Orig != n {
			n.Orig.exprfmt(s, prec)
			return
		}
		if n.Type != nil && n.Type.Etype != TIDEAL && n.Type.Etype != TNIL && n.Type != idealbool && n.Type != idealstring {
			// Need parens when type begins with what might
			// be misinterpreted as a unary operator: * or <-.
			if n.Type.IsPtr() || (n.Type.IsChan() && n.Type.ChanDir() == Crecv) {
				fmt.Fprintf(s, "(%v)(%v)", n.Type, n.Val())
				return
			} else {
				fmt.Fprintf(s, "%v(%v)", n.Type, n.Val())
				return
			}
		}

		fmt.Fprintf(s, "%v", n.Val())

	// Special case: name used as local variable in export.
	// _ becomes ~b%d internally; print as _ for export
	case ONAME:
		if fmtmode == FErr && n.Sym != nil && n.Sym.Name[0] == '~' && n.Sym.Name[1] == 'b' {
			fmt.Fprint(s, "_")
			return
		}
		fallthrough
	case OPACK, ONONAME:
		fmt.Fprint(s, n.Sym.String())

	case OTYPE:
		if n.Type == nil && n.Sym != nil {
			fmt.Fprint(s, n.Sym.String())
			return
		}
		fmt.Fprintf(s, "%v", n.Type)

	case OTARRAY:
		if n.Left != nil {
			fmt.Fprintf(s, "[]%v", n.Left)
			return
		}
		fmt.Fprintf(s, "[]%v", n.Right) // happens before typecheck

	case OTMAP:
		fmt.Fprintf(s, "map[%v]%v", n.Left, n.Right)

	case OTCHAN:
		switch ChanDir(n.Etype) {
		case Crecv:
			fmt.Fprintf(s, "<-chan %v", n.Left)

		case Csend:
			fmt.Fprintf(s, "chan<- %v", n.Left)

		default:
			if n.Left != nil && n.Left.Op == OTCHAN && n.Left.Sym == nil && ChanDir(n.Left.Etype) == Crecv {
				fmt.Fprintf(s, "chan (%v)", n.Left)
			} else {
				fmt.Fprintf(s, "chan %v", n.Left)
//.........這裏部分代碼省略.........