func IsStackAddr(v *Value) bool {
	for v.Op == OpOffPtr || v.Op == OpAddPtr || v.Op == OpPtrIndex || v.Op == OpCopy {
		v = v.Args[0]
	}
	switch v.Op {
	case OpSP, OpLocalAddr, OpSelectNAddr, OpGetCallerSP:
		return true
	}
	return false
}

// IsGlobalAddr reports whether v is known to be an address of a global (or nil).
func IsGlobalAddr(v *Value) bool {

		}

		for pcsp.Init(d.linkctxt.loader.Data(fpcsp)); !pcsp.Done; pcsp.Next() {
			nextpc := pcsp.NextPC

			// pciterinit goes up to the end of the function,
			// but DWARF expects us to stop just before the end.
			if int64(nextpc) == int64(len(d.ldr.Data(fn))) {
				nextpc--
				if nextpc < pcsp.PC {
					continue
				}
			}

	elemtype := s.Type().Elem()

	// Decompose slice.
	oldPtr := ir.NewUnaryExpr(base.Pos, ir.OSPTR, s)
	oldLen := ir.NewUnaryExpr(base.Pos, ir.OLEN, s)
	oldCap := ir.NewUnaryExpr(base.Pos, ir.OCAP, s)

	// Number of elements we are adding
	num := ir.NewUnaryExpr(base.Pos, ir.OLEN, l2)

	// newLen := oldLen + num
	newLen := typecheck.TempAt(base.Pos, ir.CurFunc, types.Types[types.TINT])

	// if uint(newLen) <= uint(s.cap)
	nif := ir.NewIfStmt(base.Pos, nil, nil, nil)
	nif.Cond = ir.NewBinaryExpr(base.Pos, ir.OLE, typecheck.Conv(newLen, types.Types[types.TUINT]), typecheck.Conv(ir.NewUnaryExpr(base.Pos, ir.OCAP, s), types.Types[types.TUINT]))
	nif.Likely = true

	// then { s = s[:n] }
	slice := ir.NewSliceExpr(base.Pos, ir.OSLICE, s, nil, newLen, nil)
	slice.SetBounded(true)
	nif.Body = []ir.Node{

		types.NewField(src.NoXPos, &types.Sym{Name: "B"}, c.config.Types.Int),
	})
	name := c.Temp(typ)
	fun := c.Fun("entry",
		Bloc("entry",
			Valu("start", OpInitMem, types.TypeMem, 0, nil),
			Valu("sp", OpSP, c.config.Types.Uintptr, 0, nil),
			Valu("zero", OpConst64, c.config.Types.Int, 0, nil),
			Valu("v6", OpLocalAddr, ptrType, 0, name, "sp", "start"),
			Valu("v3", OpOffPtr, ptrType, 8, nil, "v6"),

	OANDNOT:           "&^",
	OAND:              "&",
	OAPPEND:           "append",
	OAS:               "=",
	OAS2:              "=",
	OBREAK:            "break",
	OCALL:             "function call", // not actual syntax
	OCAP:              "cap",
	OCASE:             "case",
	OCLEAR:            "clear",
	OCLOSE:            "close",
	OCOMPLEX:          "complex",
	OBITNOT:           "^",
	OCONTINUE:         "continue",

					f.Fatalf("bad arg to OpAddr %v", v)
				}
			}

			if v.Op == OpLocalAddr {
				if len(v.Args) != 2 {
					f.Fatalf("wrong # of args for OpLocalAddr %s", v.LongString())
				}
				if v.Args[0].Op != OpSP {
					f.Fatalf("bad arg 0 to OpLocalAddr %v", v)
				}
				if !v.Args[1].Type.IsMemory() {
					f.Fatalf("bad arg 1 to OpLocalAddr %v", v)
				}
			}

			narg := 0
			for _, a := range v.Args {
				// SP and SB are special registers and have no effect on
				// the allocation of general-purpose registers.
				if a.needRegister() && a.Op != OpSB && a.Op != OpSP {
					narg++
				}
			}
			if narg >= 2 && !v.Type.IsFlags() {
				// Don't move values with more than one input, as that may
				// increase register pressure.

		OpIMake, OpStringMake, OpSliceMake, OpStructMake0, OpStructMake1, OpStructMake2, OpStructMake3, OpStructMake4,
		OpConstBool, OpConst8, OpConst16, OpConst32, OpConst64, OpConst32F, OpConst64F, OpSB, OpSP,
		OpArgIntReg, OpArgFloatReg:
		return true
	}
	return false
}

// nextGoodStatementIndex returns an index at i or later that is believed
// to be a good place to start the statement for b.  This decision is

		if p2.Op == OpAddr || p2.Op == OpLocalAddr || p2.Op == OpSP {
			return true
		}
		return (p2.Op == OpArg || p2.Op == OpArgIntReg) && p1.Args[0].Op == OpSP
	case OpArg, OpArgIntReg:
		if p2.Op == OpSP || p2.Op == OpLocalAddr {
			return true
		}
	case OpSP:
		return p2.Op == OpAddr || p2.Op == OpLocalAddr || p2.Op == OpArg || p2.Op == OpArgIntReg || p2.Op == OpSP
	}
	return false
}