func interfaceSwitch(x any) int {
	// amd64:`CALL\truntime.interfaceSwitch`,`MOVL\t16\(AX\)`,`MOVQ\t8\(.*\)(.*\*8)`
	// arm64:`CALL\truntime.interfaceSwitch`,`LDAR`,`MOVWU\t16\(R0\)`,`MOVD\t\(R.*\)\(R.*\)`
	switch x.(type) {
	case I:
		return 1
	case J:
		return 2
	default:
		return 3
	}
}

func interfaceSwitch2(x K) int {

		if len(interfaceCases) > 0 {

			// Build an internal/abi.InterfaceSwitch descriptor to pass to the runtime.
			lsym := types.LocalPkg.Lookup(fmt.Sprintf(".interfaceSwitch.%d", interfaceSwitchGen)).LinksymABI(obj.ABI0)
			interfaceSwitchGen++
			c := rttype.NewCursor(lsym, 0, rttype.InterfaceSwitch)
			c.Field("Cache").WritePtr(typecheck.LookupRuntimeVar("emptyInterfaceSwitchCache"))

// Copyright 2023 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package abi

type InterfaceSwitch struct {
	Cache  *InterfaceSwitchCache
	NCases int

	// Array of NCases elements.
	// Each case must be a non-empty interface type.
	Cases [1]*InterfaceType
}

type InterfaceSwitchCache struct {

	DeferprocStack    *obj.LSym
	Deferreturn       *obj.LSym
	Duffcopy          *obj.LSym
	Duffzero          *obj.LSym
	GCWriteBarrier    [8]*obj.LSym
	Goschedguarded    *obj.LSym
	Growslice         *obj.LSym
	InterfaceSwitch   *obj.LSym
	Memmove           *obj.LSym
	Msanread          *obj.LSym
	Msanwrite         *obj.LSym
	Msanmove          *obj.LSym
	Newobject         *obj.LSym
	Newproc           *obj.LSym

	{"runtime.assertE2I", 1},
	{"runtime.assertE2I2", 1},
	{"runtime.panicdottypeE", 1},
	{"runtime.panicdottypeI", 1},
	{"runtime.panicnildottype", 1},
	{"runtime.typeAssert", 1},
	{"runtime.interfaceSwitch", 1},
	{"runtime.ifaceeq", 1},
	{"runtime.efaceeq", 1},
	{"runtime.panicrangestate", 1},
	{"runtime.deferrangefunc", 1},
	{"runtime.rand32", 1},
	{"runtime.makemap64", 1},
	{"runtime.makemap", 1},

var emptyTypeAssertCache = abi.TypeAssertCache{Mask: 0}

// interfaceSwitch compares t against the list of cases in s.
// If t matches case i, interfaceSwitch returns the case index i and
// an itab for the pair <t, s.Cases[i]>.
// If there is no match, return N,nil, where N is the number
// of cases.
func interfaceSwitch(s *abi.InterfaceSwitch, t *_type) (int, *itab) {
	cases := unsafe.Slice(&s.Cases[0], s.NCases)

func panicdottypeE(have, want, iface *byte)
func panicdottypeI(have, want, iface *byte)
func panicnildottype(want *byte)
func typeAssert(s *byte, typ *byte) *byte

// interface switches
func interfaceSwitch(s *byte, t *byte) (int, *byte)

// interface equality. Type/itab pointers are already known to be equal, so
// we only need to pass one.
func ifaceeq(tab *uintptr, x, y unsafe.Pointer) (ret bool)

	{"assertE2I", funcTag, 67},
	{"assertE2I2", funcTag, 67},
	{"panicdottypeE", funcTag, 68},
	{"panicdottypeI", funcTag, 68},
	{"panicnildottype", funcTag, 69},
	{"typeAssert", funcTag, 67},
	{"interfaceSwitch", funcTag, 70},
	{"ifaceeq", funcTag, 72},
	{"efaceeq", funcTag, 72},
	{"panicrangestate", funcTag, 73},
	{"deferrangefunc", funcTag, 74},
	{"rand32", funcTag, 75},
	{"makemap64", funcTag, 77},

	ir.Syms.Goschedguarded = typecheck.LookupRuntimeFunc("goschedguarded")
	ir.Syms.Growslice = typecheck.LookupRuntimeFunc("growslice")
	ir.Syms.InterfaceSwitch = typecheck.LookupRuntimeFunc("interfaceSwitch")
	ir.Syms.Memmove = typecheck.LookupRuntimeFunc("memmove")
	ir.Syms.Msanread = typecheck.LookupRuntimeFunc("msanread")
	ir.Syms.Msanwrite = typecheck.LookupRuntimeFunc("msanwrite")

	// the value received.
	case ir.ORECV:
		n := n.(*ir.UnaryExpr)
		return walkRecv(n)

	case ir.OBREAK,
		ir.OCONTINUE,
		ir.OFALL,
		ir.OGOTO,
		ir.OLABEL,
		ir.OJUMPTABLE,
		ir.OINTERFACESWITCH,
		ir.ODCL,
		ir.OCHECKNIL:
		return n

	case ir.OBLOCK:
		n := n.(*ir.BlockStmt)
		walkStmtList(n.List)
		return n

	case ir.OCASE:
		base.Errorf("case statement out of place")