Golang cmd-internal-obj.Addr类(方法)实例源码

/*
 * substitute s for v in a
 * return failure to substitute
 */
func copysub(a *obj.Addr, v *obj.Addr, s *obj.Addr, f int) int {
	if f != 0 {
		if copyau(a, v) {
			if a.Type == obj.TYPE_SHIFT {
				if a.Offset&0xf == int64(v.Reg-arm.REG_R0) {
					a.Offset = a.Offset&^0xf | int64(s.Reg)&0xf
				}
				if (a.Offset&(1<<4) != 0) && (a.Offset>>8)&0xf == int64(v.Reg-arm.REG_R0) {
					a.Offset = a.Offset&^(0xf<<8) | (int64(s.Reg)&0xf)<<8
				}
			} else if a.Type == obj.TYPE_REGREG || a.Type == obj.TYPE_REGREG2 {
				if a.Offset == int64(v.Reg) {
					a.Offset = int64(s.Reg)
				}
				if a.Reg == v.Reg {
					a.Reg = s.Reg
				}
			} else {
				a.Reg = s.Reg
			}
		}
	}

	return 0
}

// scratchFpMem initializes an Addr (field of a Prog)
// to reference the scratchpad memory for movement between
// F and G registers for FP conversions.
func scratchFpMem(s *gc.SSAGenState, a *obj.Addr) {
	a.Type = obj.TYPE_MEM
	a.Name = obj.NAME_AUTO
	a.Node = s.ScratchFpMem
	a.Sym = gc.Linksym(s.ScratchFpMem.Sym)
	a.Reg = ppc64.REGSP
}

func nacladdr(ctxt *obj.Link, p *obj.Prog, a *obj.Addr) {
	if p.As == ALEAL || p.As == ALEAQ {
		return
	}

	if a.Reg == REG_BP {
		ctxt.Diag("invalid address: %v", p)
		return
	}

	if a.Reg == REG_TLS {
		a.Reg = REG_BP
	}
	if a.Type == obj.TYPE_MEM && a.Name == obj.NAME_NONE {
		switch a.Reg {
		// all ok
		case REG_BP, REG_SP, REG_R15:
			break

		default:
			if a.Index != REG_NONE {
				ctxt.Diag("invalid address %v", p)
			}
			a.Index = a.Reg
			if a.Index != REG_NONE {
				a.Scale = 1
			}
			a.Reg = REG_R15
		}
	}
}

func datagostring(sval string, a *obj.Addr) {
	symhdr, _ := stringsym(sval)
	a.Type = obj.TYPE_MEM
	a.Name = obj.NAME_EXTERN
	a.Sym = symhdr
	a.Offset = 0
}

// copysub substitute s for v in a.
// copysub returns true on failure to substitute. TODO(dfc) reverse this logic, copysub should return false on failure
func copysub(a *obj.Addr, v *obj.Addr, s *obj.Addr, f bool) bool {
	if copyas(a, v) {
		if s.Reg >= x86.REG_AX && s.Reg <= x86.REG_R15 || s.Reg >= x86.REG_X0 && s.Reg <= x86.REG_X0+15 {
			if f {
				a.Reg = s.Reg
			}
		}
		return false
	}

	if regtyp(v) {
		if a.Type == obj.TYPE_MEM && a.Reg == v.Reg {
			if (s.Reg == x86.REG_BP || s.Reg == x86.REG_R13) && a.Index != x86.REG_NONE {
				return true /* can't use BP-base with index */
			}
			if f {
				a.Reg = s.Reg
			}
		}
		if a.Index == v.Reg {
			if f {
				a.Index = s.Reg
			}
		}
	}
	return false
}

// registerList parses an ARM register list expression, a list of registers in [].
// There may be comma-separated ranges or individual registers, as in
// [R1,R3-R5]. Only R0 through R15 may appear.
// The opening bracket has been consumed.
func (p *Parser) registerList(a *obj.Addr) {
	// One range per loop.
	var bits uint16
	for {
		tok := p.next()
		if tok.ScanToken == ']' {
			break
		}
		lo := p.registerNumber(tok.String())
		hi := lo
		if p.peek() == '-' {
			p.next()
			hi = p.registerNumber(p.next().String())
		}
		if hi < lo {
			lo, hi = hi, lo
		}
		for lo <= hi {
			if bits&(1<<lo) != 0 {
				p.errorf("register R%d already in list", lo)
			}
			bits |= 1 << lo
			lo++
		}
		if p.peek() != ']' {
			p.get(',')
		}
	}
	a.Type = obj.TYPE_REGLIST
	a.Offset = int64(bits)
}

func Datastring(s string, a *obj.Addr) {
	_, symdata := stringsym(s)
	a.Type = obj.TYPE_MEM
	a.Name = obj.NAME_EXTERN
	a.Sym = symdata
	a.Offset = 0
	a.Etype = uint8(Simtype[TINT])
}

// copysub replaces v with s in a if f!=0 or indicates it if could if f==0.
// Returns 1 on failure to substitute (it always succeeds on mips).
func copysub(a *obj.Addr, v *obj.Addr, s *obj.Addr, f int) int {
	if f != 0 {
		if copyau(a, v) {
			a.Reg = s.Reg
		}
	}
	return 0
}

// registerList parses an ARM register list expression, a list of registers in [].
// There may be comma-separated ranges or individual registers, as in
// [R1,R3-R5]. Only R0 through R15 may appear.
// The opening bracket has been consumed.
func (p *Parser) registerList(a *obj.Addr) {
	// One range per loop.
	const maxReg = 16
	var bits uint16
ListLoop:
	for {
		tok := p.next()
		switch tok.ScanToken {
		case ']':
			break ListLoop
		case scanner.EOF:
			p.errorf("missing ']' in register list")
			return
		}
		// Parse the upper and lower bounds.
		lo := p.registerNumber(tok.String())
		hi := lo
		if p.peek() == '-' {
			p.next()
			hi = p.registerNumber(p.next().String())
		}
		if hi < lo {
			lo, hi = hi, lo
		}
		// Check there are no duplicates in the register list.
		for i := 0; lo <= hi && i < maxReg; i++ {
			if bits&(1<<lo) != 0 {
				p.errorf("register R%d already in list", lo)
			}
			bits |= 1 << lo
			lo++
		}
		if p.peek() != ']' {
			p.get(',')
		}
	}
	a.Type = obj.TYPE_REGLIST
	a.Offset = int64(bits)
}

func Datastring(s string, a *obj.Addr) {
	_, symdata := stringsym(s)
	a.Type = obj.TYPE_MEM
	a.Name = obj.NAME_EXTERN
	a.Sym = Linksym(symdata)
	a.Node = symdata.Def
	a.Offset = 0
	a.Etype = Simtype[TINT]
}

func datagostring(sval string, a *obj.Addr) {
	symhdr, _ := stringsym(sval)
	a.Type = obj.TYPE_MEM
	a.Name = obj.NAME_EXTERN
	a.Sym = Linksym(symhdr)
	a.Node = symhdr.Def
	a.Offset = 0
	a.Etype = TSTRING
}

func Datastring(s string, a *obj.Addr) {
	sym := stringsym(s)
	a.Type = obj.TYPE_MEM
	a.Name = obj.NAME_EXTERN
	a.Sym = Linksym(sym)
	a.Node = sym.Def
	a.Offset = int64(Widthptr) + int64(Widthint) // skip header
	a.Etype = Simtype[TINT]
}

/*
 * substitute s for v in a
 * return failure to substitute
 */
func copysub(a *obj.Addr, v *obj.Addr, s *obj.Addr, f int) int {
	if copyas(a, v) {
		reg := int(s.Reg)
		if reg >= x86.REG_AX && reg <= x86.REG_DI || reg >= x86.REG_X0 && reg <= x86.REG_X7 {
			if f != 0 {
				a.Reg = int16(reg)
			}
		}

		return 0
	}

	if regtyp(v) {
		reg := int(v.Reg)
		if a.Type == obj.TYPE_MEM && int(a.Reg) == reg {
			if (s.Reg == x86.REG_BP) && a.Index != obj.TYPE_NONE {
				return 1 /* can't use BP-base with index */
			}
			if f != 0 {
				a.Reg = s.Reg
			}
		}

		//			return 0;
		if int(a.Index) == reg {
			if f != 0 {
				a.Index = s.Reg
			}
			return 0
		}

		return 0
	}

	return 0
}

func addreg(a *obj.Addr, rn int) {
	a.Sym = nil
	a.Node = nil
	a.Offset = 0
	a.Type = obj.TYPE_REG
	a.Reg = int16(rn)
	a.Name = 0

	Ostats.Ncvtreg++
}

func indir_cx(ctxt *obj.Link, p *obj.Prog, a *obj.Addr) {
	if ctxt.Headtype == obj.Hnacl && p.Mode == 64 {
		a.Type = obj.TYPE_MEM
		a.Reg = REG_R15
		a.Index = REG_CX
		a.Scale = 1
		return
	}

	a.Type = obj.TYPE_MEM
	a.Reg = REG_CX
}

// Naddr rewrites a to refer to n.
// It assumes that a is zeroed on entry.
func Naddr(a *obj.Addr, n *Node) {
	if n == nil {
		return
	}

	if n.Op != ONAME {
		Debug['h'] = 1
		Dump("naddr", n)
		Fatalf("naddr: bad %v %v", n.Op, Ctxt.Dconv(a))
	}

	a.Offset = n.Xoffset
	s := n.Sym
	a.Node = n.Orig

	if s == nil {
		Fatalf("naddr: nil sym %v", n)
	}
	if n.Name.Method && n.Type != nil && n.Type.Sym != nil && n.Type.Sym.Pkg != nil {
		Fatalf("naddr: weird method %v", n)
	}

	a.Type = obj.TYPE_MEM
	switch n.Class {
	default:
		Fatalf("naddr: ONAME class %v %d\n", n.Sym, n.Class)

	case PEXTERN, PFUNC:
		a.Name = obj.NAME_EXTERN

	case PAUTO:
		a.Name = obj.NAME_AUTO

	case PPARAM, PPARAMOUT:
		a.Name = obj.NAME_PARAM
	}

	a.Sym = Linksym(s)
}

/*
 * ASLL x,y,w
 * .. (not use w, not set x y w)
 * AXXX w,a,b (a != w)
 * .. (not use w)
 * (set w)
 * ----------- changed to
 * ..
 * AXXX (x<<y),a,b
 * ..
 */
func shiftprop(r *gc.Flow) bool {
	p := r.Prog
	if p.To.Type != obj.TYPE_REG {
		if gc.Debug['P'] != 0 {
			fmt.Printf("\tBOTCH: result not reg; FAILURE\n")
		}
		return false
	}

	n := p.To.Reg
	var a obj.Addr
	if p.Reg != 0 && p.Reg != p.To.Reg {
		a.Type = obj.TYPE_REG
		a.Reg = p.Reg
	}

	if gc.Debug['P'] != 0 {
		fmt.Printf("shiftprop\n%v", p)
	}
	r1 := r
	var p1 *obj.Prog
	for {
		/* find first use of shift result; abort if shift operands or result are changed */
		r1 = gc.Uniqs(r1)

		if r1 == nil {
			if gc.Debug['P'] != 0 {
				fmt.Printf("\tbranch; FAILURE\n")
			}
			return false
		}

		if gc.Uniqp(r1) == nil {
			if gc.Debug['P'] != 0 {
				fmt.Printf("\tmerge; FAILURE\n")
			}
			return false
		}

		p1 = r1.Prog
		if gc.Debug['P'] != 0 {
			fmt.Printf("\n%v", p1)
		}
		switch copyu(p1, &p.To, nil) {
		case 0: /* not used or set */
			if (p.From.Type == obj.TYPE_REG && copyu(p1, &p.From, nil) > 1) || (a.Type == obj.TYPE_REG && copyu(p1, &a, nil) > 1) {
				if gc.Debug['P'] != 0 {
					fmt.Printf("\targs modified; FAILURE\n")
				}
				return false
			}

			continue
		case 3: /* set, not used */
			{
				if gc.Debug['P'] != 0 {
					fmt.Printf("\tBOTCH: noref; FAILURE\n")
				}
				return false
			}
		}

		break
	}

	/* check whether substitution can be done */
	switch p1.As {
	default:
		if gc.Debug['P'] != 0 {
			fmt.Printf("\tnon-dpi; FAILURE\n")
		}
		return false

	case arm.AAND,
		arm.AEOR,
		arm.AADD,
		arm.AADC,
		arm.AORR,
		arm.ASUB,
		arm.ASBC,
		arm.ARSB,
		arm.ARSC:
		if p1.Reg == n || (p1.Reg == 0 && p1.To.Type == obj.TYPE_REG && p1.To.Reg == n) {
			if p1.From.Type != obj.TYPE_REG {
				if gc.Debug['P'] != 0 {
					fmt.Printf("\tcan't swap; FAILURE\n")
				}
				return false
			}
//.........这里部分代码省略.........

// copysub replaces v with s in a if f==true or indicates it if could if f==false.
// Returns true on failure to substitute (it always succeeds on ppc64).
// TODO(dfc) remove unused return value and callers where f=false.
func copysub(a *obj.Addr, v *obj.Addr, s *obj.Addr, f bool) bool {
	if f && copyau(a, v) {
		a.Reg = s.Reg
	}
	return false
}

func mkvar(f *Flow, a *obj.Addr) Bits {
	// mark registers used
	if a.Type == obj.TYPE_NONE {
		return zbits
	}

	r := f.Data.(*Reg)
	r.use1.b[0] |= Thearch.Doregbits(int(a.Index)) // TODO: Use RtoB

	var n int
	switch a.Type {
	default:
		regu := Thearch.Doregbits(int(a.Reg)) | Thearch.RtoB(int(a.Reg)) // TODO: Use RtoB
		if regu == 0 {
			return zbits
		}
		bit := zbits
		bit.b[0] = regu
		return bit

		// TODO(rsc): Remove special case here.
	case obj.TYPE_ADDR:
		var bit Bits
		if Thearch.Thechar == '0' || Thearch.Thechar == '5' || Thearch.Thechar == '7' || Thearch.Thechar == '9' {
			goto memcase
		}
		a.Type = obj.TYPE_MEM
		bit = mkvar(f, a)
		setaddrs(bit)
		a.Type = obj.TYPE_ADDR
		Ostats.Naddr++
		return zbits

	memcase:
		fallthrough

	case obj.TYPE_MEM:
		if r != nil {
			r.use1.b[0] |= Thearch.RtoB(int(a.Reg))
		}

		/* NOTE: 5g did
		if(r->f.prog->scond & (C_PBIT|C_WBIT))
			r->set.b[0] |= RtoB(a->reg);
		*/
		switch a.Name {
		default:
			// Note: This case handles NAME_EXTERN and NAME_STATIC.
			// We treat these as requiring eager writes to memory, due to
			// the possibility of a fault handler looking at them, so there is
			// not much point in registerizing the loads.
			// If we later choose the set of candidate variables from a
			// larger list, these cases could be deprioritized instead of
			// removed entirely.
			return zbits

		case obj.NAME_PARAM,
			obj.NAME_AUTO:
			n = int(a.Name)
		}
	}

	node, _ := a.Node.(*Node)
	if node == nil || node.Op != ONAME || node.Orig == nil {
		return zbits
	}
	node = node.Orig
	if node.Orig != node {
		Fatalf("%v: bad node", Ctxt.Dconv(a))
	}
	if node.Sym == nil || node.Sym.Name[0] == '.' {
		return zbits
	}
	et := EType(a.Etype)
	o := a.Offset
	w := a.Width
	if w < 0 {
		Fatalf("bad width %d for %v", w, Ctxt.Dconv(a))
	}

	flag := 0
	var v *Var
	for i := 0; i < nvar; i++ {
		v = &vars[i]
		if v.node == node && int(v.name) == n {
			if v.offset == o {
				if v.etype == et {
					if int64(v.width) == w {
						// TODO(rsc): Remove special case for arm here.
						if flag == 0 || Thearch.Thechar != '5' {
							return blsh(uint(i))
						}
					}
				}
			}

			// if they overlap, disable both
			if overlap_reg(v.offset, v.width, o, int(w)) {
				//				print("disable overlap %s %d %d %d %d, %E != %E\n", s->name, v->offset, v->width, o, w, v->etype, et);
				v.addr = 1
//.........这里部分代码省略.........

func Addrconst(a *obj.Addr, v int64) {
	a.Sym = nil
	a.Type = obj.TYPE_CONST
	a.Offset = v
}