// Since the number of directory records is not validated, it is not
	// safe to preallocate r.File without first checking that the specified
	// number of files is reasonable, since a malformed archive may
	// indicate it contains up to 1 << 128 - 1 files. Since each file has a
	// header which will be _at least_ 30 bytes we can safely preallocate
	// if (data size / 30) >= end.directoryRecords.

			s.end -= s.start
			s.start = 0
		}
		// Finally we can read some input. Make sure we don't get stuck with
		// a misbehaving Reader. Officially we don't need to do this, but let's
		// be extra careful: Scanner is for safe, simple jobs.
		for loop := 0; ; {
			n, err := s.r.Read(s.buf[s.end:len(s.buf)])
			if n < 0 || len(s.buf)-s.end < n {
				s.setErr(ErrBadReadCount)
				break
			}
			s.end += n
			if err != nil {

When using the compiler and assembler's
<code>-dynlink</code> or <code>-shared</code> modes,
any load or store of a fixed memory location such as a global variable
must be assumed to overwrite <code>CX</code>.
Therefore, to be safe for use with these modes,
assembly sources should typically avoid CX except between memory references.
</p>

<h3 id="amd64">64-bit Intel 386 (a.k.a. amd64)</h3>

<p>

// license that can be found in the LICENSE file.

//go:build goexperiment.arenas

/*
The arena package provides the ability to allocate memory for a collection
of Go values and free that space manually all at once, safely. The purpose
of this functionality is to improve efficiency: manually freeing memory
before a garbage collection delays that cycle. Less frequent cycles means
the CPU cost of the garbage collector is incurred less frequently.

provides facilities for low-level programming including operations
that violate the type system. A package using <code>unsafe</code>
must be vetted manually for type safety and may not be portable.
The package provides the following interface:
</p>

<pre class="grammar">
package unsafe

type ArbitraryType int  // shorthand for an arbitrary Go type; it is not a real type

			}
			for _, spec := range d.Specs {
				if s, ok := spec.(*ast.ImportSpec); ok && s.Path.Value == `"C"` {
					// Replace "C" with _ "unsafe", to keep program valid.
					// (Deleting import statement or clause is not safe if it is followed
					// in the source by an explicit semicolon.)
					f.Edit.Replace(f.offset(s.Path.Pos()), f.offset(s.Path.End()), `_ "unsafe"`)
				}
			}
		}
	}

and of course there is nothing stopping the C code from doing anything
it likes. However, programs that break these rules are likely to fail
in unexpected and unpredictable ways.

The runtime/cgo.Handle type can be used to safely pass Go values
between Go and C. See the runtime/cgo package documentation for details.

Note: the current implementation has a bug. While Go code is permitted

	{"(R1, R3)", "(R1, R3)"},
	{"[R0,R1,g,R15", ""}, // Issue 11764 - asm hung parsing ']' missing register lists.
	{"[):[o-FP", ""},     // Issue 12469 - there was no infinite loop for ARM; these are just sanity checks.
	{"[):[R0-FP", ""},
	{"(", ""}, // Issue 12466 - backed up before beginning of line.
}

var ppc64OperandTests = []operandTest{
	{"$((1<<63)-1)", "$9223372036854775807"},
	{"$(-64*1024)", "$-65536"},

	"compress/flate"
	"errors"
	"io"
	"sync"
)

// A Compressor returns a new compressing writer, writing to w.
// The WriteCloser's Close method must be used to flush pending data to w.
// The Compressor itself must be safe to invoke from multiple goroutines
// simultaneously, but each returned writer will be used only by
// one goroutine at a time.
type Compressor func(w io.Writer) (io.WriteCloser, error)

				typedef[sub.Go.(*ast.Ident).Name].C = t.C
			}

			// If we've seen this typedef before, and it
			// was an anonymous struct/union/class before
			// too, use the old definition.
			// TODO: it would be safer to only do this if
			// we verify that the types are the same.
			if oldType != nil && isStructUnionClass(oldType.Go) {
				t.Go = oldType.Go
			}
		}

	case *dwarf.UcharType:
		if t.Size != 1 {