The [CopyFS] function copies an [io/fs.FS] into the local filesystem....

(BTLconst [c] (SHLLconst [d] x)) && c>d      => (BTLconst [c-d] x)
(BTLconst [0] s:(SHR(L|XL) x y)) => (BTL y x)

// Rewrite a & 1 != 1 into a & 1 == 0.
// Among other things, this lets us turn (a>>b)&1 != 1 into a bit test.
(SET(NE|EQ) (CMPLconst [1] s:(ANDLconst [1] _))) => (SET(EQ|NE) (CMPLconst [0] s))

	fn.ABI = wrapperABI
	typecheck.DeclFunc(fn)

	fn.SetABIWrapper(true)
	fn.SetDupok(true)

	// ABI0-to-ABIInternal wrappers will be mainly loading params from
	// stack into registers (and/or storing stack locations back to
	// registers after the wrapped call); in most cases they won't
	// need to allocate stack space, so it should be OK to mark them

	if mk.Cap != nil {
		return false
	}

	// y must be either an integer constant or the largest possible positive value
	// of variable y needs to fit into a uint.

	// typecheck made sure that constant arguments to make are not negative and fit into an int.

	// The care of overflow of the len argument to make will be handled by an explicit check of int(len) < 0 during runtime.
	y := mk.Len

// or -1 based on the sign bit of x.
//
// We implement this by performing the max shift (-1) if y > the maximum value.
//
// We OR (uint64(y < 64) - 1) into y before passing it to SRA. This leaves
// us with -1 (0xffff...) if y >= 64.  Similarly, we OR (uint64(y < 32) - 1) into y
// before passing it to SRAW.
//
// We don't need to sign-extend the OR result, as it will be at minimum 8 bits,

			if val.Op() == ir.ONIL {
				// Nil is zero, nothing to do.
				return true
			}
			// Copy val directly into n.
			ir.SetPos(val)
			assign(base.Pos, l, loff+int64(types.PtrSize), val)
		} else {
			// Construct temp to hold val, write pointer to temp into n.
			a := StaticName(val.Type())
			s.Temps[val] = a
			assign(base.Pos, a, 0, val)

	outdir := filepath.Join(s.dir, "simpleMergeOut"+tag)
	if err := os.Mkdir(outdir, 0777); err != nil {
		t.Fatalf("can't create outdir %s: %v", outdir, err)
	}

	// Merge the two dirs into a final result.
	ins := fmt.Sprintf("-i=%s,%s", indir1, indir2)
	out := fmt.Sprintf("-o=%s", outdir)
	margs := []string{ins, out}
	lines := runToolOp(t, s, "merge", margs)
	if len(lines) != 0 {

// Copyright 2015 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 ssa

// combine copyelim and phielim into a single pass.
// copyelim removes all uses of OpCopy values from f.
// A subsequent deadcode pass is needed to actually remove the copies.
func copyelim(f *Func) {
	phielim(f)

			strings.HasPrefix(arg, "--vettool=") {
			vetTool = arg[strings.IndexByte(arg, '=')+1:]
			return
		}
	}
}

// vetFlags processes the command line, splitting it at the first non-flag
// into the list of flags and list of packages.
func vetFlags(args []string) (passToVet, packageNames []string) {
	parseVettoolFlag(args)

	// Query the vet command for its flags.
	var tool string
	if vetTool == "" {

			m = n.Elem
		case *DotsType:
			m = n.Elem
		case *StructType:
			if l := lastField(n.FieldList); l != nil {
				m = l
				continue
			}
			return n.Pos()
			// TODO(gri) need to take TagList into account
		case *Field:
			if n.Type != nil {
				m = n.Type
				continue
			}
			m = n.Name
		case *InterfaceType:
			if l := lastField(n.MethodList); l != nil {
				m = l
				continue
			}