Example #1
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++
}
Example #2
0
/*
 * 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 obj.As, 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 := n.Int64()
		if v >= 32000 || v <= -32000 {
			break
		}
		switch as {
		default:
			return false

		case arm.AADD,
			arm.ASUB,
			arm.AAND,
			arm.AORR,
			arm.AEOR,
			arm.AMOVB,
			arm.AMOVBS,
			arm.AMOVBU,
			arm.AMOVH,
			arm.AMOVHS,
			arm.AMOVHU,
			arm.AMOVW:
			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)
		n1 := *reg
		n1.Op = gc.OINDREG
		if oary[0] >= 0 {
			gc.Agen(nn, reg)
			n1.Xoffset = oary[0]
		} else {
			gc.Cgen(nn, reg)
			gc.Cgen_checknil(reg)
			n1.Xoffset = -(oary[0] + 1)
		}

		for i := 1; i < o; i++ {
			if oary[i] >= 0 {
				gc.Fatalf("can't happen")
			}
			gins(arm.AMOVW, &n1, reg)
			gc.Cgen_checknil(reg)
			n1.Xoffset = -(oary[i] + 1)
		}

		a.Type = obj.TYPE_NONE
		a.Name = obj.NAME_NONE
		n1.Type = n.Type
		gc.Naddr(a, &n1)
		return true

	case gc.OINDEX:
		return false
	}

	return false
}
Example #3
0
// 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)
		Fatalf("naddr: bad %v %v", n.Op, Ctxt.Dconv(a))

	case OREGISTER:
		a.Type = obj.TYPE_REG
		a.Reg = n.Reg
		a.Sym = nil
		if Thearch.LinkArch.Family == sys.I386 { // 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.LinkArch.Family == sys.I386 { // TODO(rsc): Never clear a->width.
			a.Width = 0
		}

	case OCLOSUREVAR:
		if !Curfn.Func.Needctxt {
			Fatalf("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 = uint8(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.Name.Method && n.Type != nil && n.Type.Sym != nil && n.Type.Sym.Pkg != nil {
			s = Pkglookup(s.Name, n.Type.Sym.Pkg)
		}

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

		case PEXTERN:
			a.Name = obj.NAME_EXTERN

		case PAUTO:
			a.Name = obj.NAME_AUTO

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

		case PFUNC:
			a.Name = obj.NAME_EXTERN
			a.Type = obj.TYPE_ADDR
			a.Width = int64(Widthptr)
			s = funcsym(s)
		}

		a.Sym = Linksym(s)

	case ODOT:
		// A special case to make write barriers more efficient.
		// Taking the address of the first field of a named struct
		// is the same as taking the address of the struct.
		if !n.Left.Type.IsStruct() || n.Left.Type.Field(0).Sym != n.Sym {
			Debug['h'] = 1
			Dump("naddr", n)
			Fatalf("naddr: bad %v %v", n.Op, Ctxt.Dconv(a))
		}
		Naddr(a, n.Left)

	case OLITERAL:
		if Thearch.LinkArch.Family == sys.I386 {
			a.Width = 0
		}
		switch u := n.Val().U.(type) {
		default:
			Fatalf("naddr: const %v", Tconv(n.Type, FmtLong))

		case *Mpflt:
			a.Type = obj.TYPE_FCONST
			a.Val = u.Float64()

		case *Mpint:
			a.Sym = nil
			a.Type = obj.TYPE_CONST
			a.Offset = u.Int64()

		case string:
			datagostring(u, a)

		case bool:
			a.Sym = nil
			a.Type = obj.TYPE_CONST
			a.Offset = int64(obj.Bool2int(u))

		case *NilVal:
			a.Sym = nil
			a.Type = obj.TYPE_CONST
			a.Offset = 0
		}

	case OADDR:
		Naddr(a, n.Left)
		a.Etype = uint8(Tptr)
		if !Thearch.LinkArch.InFamily(sys.MIPS64, sys.ARM, sys.ARM64, sys.PPC64, sys.S390X) { // TODO(rsc): Do this even for these architectures.
			a.Width = int64(Widthptr)
		}
		if a.Type != obj.TYPE_MEM {
			a := a // copy to let escape into Ctxt.Dconv
			Fatalf("naddr: OADDR %v (from %v)", Ctxt.Dconv(a), n.Left.Op)
		}
		a.Type = obj.TYPE_ADDR

		// itable of interface value
	case OITAB:
		Naddr(a, n.Left)

		if a.Type == obj.TYPE_CONST && a.Offset == 0 {
			break // itab(nil)
		}
		a.Etype = uint8(Tptr)
		a.Width = int64(Widthptr)

		// pointer in a string or slice
	case OSPTR:
		Naddr(a, n.Left)

		if a.Type == obj.TYPE_CONST && a.Offset == 0 {
			break // ptr(nil)
		}
		a.Etype = uint8(Simtype[Tptr])
		a.Offset += int64(Array_array)
		a.Width = int64(Widthptr)

		// len of string or slice
	case OLEN:
		Naddr(a, n.Left)

		if a.Type == obj.TYPE_CONST && a.Offset == 0 {
			break // len(nil)
		}
		a.Etype = uint8(Simtype[TUINT])
		a.Offset += int64(Array_nel)
		if Thearch.LinkArch.Family != sys.ARM { // TODO(rsc): Do this even on arm.
			a.Width = int64(Widthint)
		}

		// cap of string or slice
	case OCAP:
		Naddr(a, n.Left)

		if a.Type == obj.TYPE_CONST && a.Offset == 0 {
			break // cap(nil)
		}
		a.Etype = uint8(Simtype[TUINT])
		a.Offset += int64(Array_cap)
		if Thearch.LinkArch.Family != sys.ARM { // TODO(rsc): Do this even on arm.
			a.Width = int64(Widthint)
		}
	}
}