Golang obj.Addr类代码示例

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) {
	sym := stringsym(sval)
	a.Type = obj.TYPE_MEM
	a.Name = obj.NAME_EXTERN
	a.Sym = Linksym(sym)
	a.Node = sym.Def
	a.Offset = 0 // header
	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(int(s.Reg))
		if reg >= x86.REG_AX && reg <= x86.REG_R15 || reg >= x86.REG_X0 && reg <= x86.REG_X0+15 {
			if f != 0 {
				a.Reg = int16(reg)
			}
		}

		return 0
	}

	if regtyp(v) {
		reg := int(int(v.Reg))
		if a.Type == obj.TYPE_MEM && int(a.Reg) == reg {
			if (s.Reg == x86.REG_BP || s.Reg == x86.REG_R13) && a.Index != x86.REG_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 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 == '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 {
		Fatal("%v: bad node", Ctxt.Dconv(a))
	}
	if node.Sym == nil || node.Sym.Name[0] == '.' {
		return zbits
	}
	et := int(a.Etype)
	o := a.Offset
	w := a.Width
	if w < 0 {
		Fatal("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 int(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)) {
//.........这里部分代码省略.........

// 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.Type != nil && n.Type.Etype != TIDEAL {
		// TODO(rsc): This is undone by the selective clearing of width below,
		// to match architectures that were not as aggressive in setting width
		// during naddr. Those widths must be cleared to avoid triggering
		// failures in gins when it detects real but heretofore latent (and one
		// hopes innocuous) type mismatches.
		// The type mismatches should be fixed and the clearing below removed.
		dowidth(n.Type)

		a.Width = n.Type.Width
	}

	switch n.Op {
	default:
		a := a // copy to let escape into Ctxt.Dconv
		Debug['h'] = 1
		Dump("naddr", n)
		Fatal("naddr: bad %v %v", Oconv(int(n.Op), 0), Ctxt.Dconv(a))

	case OREGISTER:
		a.Type = obj.TYPE_REG
		a.Reg = n.Reg
		a.Sym = nil
		if Thearch.Thechar == '8' { // TODO(rsc): Never clear a->width.
			a.Width = 0
		}

	case OINDREG:
		a.Type = obj.TYPE_MEM
		a.Reg = n.Reg
		a.Sym = Linksym(n.Sym)
		a.Offset = n.Xoffset
		if a.Offset != int64(int32(a.Offset)) {
			Yyerror("offset %d too large for OINDREG", a.Offset)
		}
		if Thearch.Thechar == '8' { // TODO(rsc): Never clear a->width.
			a.Width = 0
		}

		// n->left is PHEAP ONAME for stack parameter.
	// compute address of actual parameter on stack.
	case OPARAM:
		a.Etype = Simtype[n.Left.Type.Etype]

		a.Width = n.Left.Type.Width
		a.Offset = n.Xoffset
		a.Sym = Linksym(n.Left.Sym)
		a.Type = obj.TYPE_MEM
		a.Name = obj.NAME_PARAM
		a.Node = n.Left.Orig

	case OCLOSUREVAR:
		if !Curfn.Func.Needctxt {
			Fatal("closurevar without needctxt")
		}
		a.Type = obj.TYPE_MEM
		a.Reg = int16(Thearch.REGCTXT)
		a.Sym = nil
		a.Offset = n.Xoffset

	case OCFUNC:
		Naddr(a, n.Left)
		a.Sym = Linksym(n.Left.Sym)

	case ONAME:
		a.Etype = 0
		if n.Type != nil {
			a.Etype = Simtype[n.Type.Etype]
		}
		a.Offset = n.Xoffset
		s := n.Sym
		a.Node = n.Orig

		//if(a->node >= (Node*)&n)
		//	fatal("stack node");
		if s == nil {
			s = Lookup(".noname")
		}
		if n.Method {
			if n.Type != nil {
				if n.Type.Sym != nil {
					if n.Type.Sym.Pkg != nil {
						s = Pkglookup(s.Name, n.Type.Sym.Pkg)
					}
				}
			}
		}

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

//.........这里部分代码省略.........

func Afunclit(a *obj.Addr, n *Node) {
	if a.Type == obj.TYPE_ADDR && a.Name == obj.NAME_EXTERN {
		a.Type = obj.TYPE_MEM
		a.Sym = Linksym(n.Sym)
	}
}

/*
 * generate code to compute address of n,
 * a reference to a (perhaps nested) field inside
 * an array or struct.
 * return 0 on failure, 1 on success.
 * on success, leaves usable address in a.
 *
 * caller is responsible for calling sudoclean
 * after successful sudoaddable,
 * to release the register used for a.
 */
func sudoaddable(as int, n *gc.Node, a *obj.Addr) bool {
	if n.Type == nil {
		return false
	}

	*a = obj.Addr{}

	switch n.Op {
	case gc.OLITERAL:
		if !gc.Isconst(n, gc.CTINT) {
			break
		}
		v := gc.Mpgetfix(n.Val.U.Xval)
		if v >= 32000 || v <= -32000 {
			break
		}
		switch as {
		default:
			return false

		case x86.AADDB,
			x86.AADDW,
			x86.AADDL,
			x86.AADDQ,
			x86.ASUBB,
			x86.ASUBW,
			x86.ASUBL,
			x86.ASUBQ,
			x86.AANDB,
			x86.AANDW,
			x86.AANDL,
			x86.AANDQ,
			x86.AORB,
			x86.AORW,
			x86.AORL,
			x86.AORQ,
			x86.AXORB,
			x86.AXORW,
			x86.AXORL,
			x86.AXORQ,
			x86.AINCB,
			x86.AINCW,
			x86.AINCL,
			x86.AINCQ,
			x86.ADECB,
			x86.ADECW,
			x86.ADECL,
			x86.ADECQ,
			x86.AMOVB,
			x86.AMOVW,
			x86.AMOVL,
			x86.AMOVQ:
			break
		}

		cleani += 2
		reg := &clean[cleani-1]
		reg1 := &clean[cleani-2]
		reg.Op = gc.OEMPTY
		reg1.Op = gc.OEMPTY
		gc.Naddr(a, n)
		return true

	case gc.ODOT,
		gc.ODOTPTR:
		cleani += 2
		reg := &clean[cleani-1]
		reg1 := &clean[cleani-2]
		reg.Op = gc.OEMPTY
		reg1.Op = gc.OEMPTY
		var nn *gc.Node
		var oary [10]int64
		o := gc.Dotoffset(n, oary[:], &nn)
		if nn == nil {
			sudoclean()
			return false
		}

		if nn.Addable && o == 1 && oary[0] >= 0 {
			// directly addressable set of DOTs
			n1 := *nn

			n1.Type = n.Type
			n1.Xoffset += oary[0]
			gc.Naddr(a, &n1)
			return true
		}

		gc.Regalloc(reg, gc.Types[gc.Tptr], nil)
//.........这里部分代码省略.........