// output are interpreted as UTF-8-encoded code points.
func Map(mapping func(r rune) rune, s []byte) []byte {
	// In the worst case, the slice can grow when mapped, making
	// things unpleasant. But it's so rare we barge in assuming it's
	// fine. It could also shrink but that falls out naturally.
	b := make([]byte, 0, len(s))
	for i := 0; i < len(s); {
		wid := 1
		r := rune(s[i])

what is explained in that document, and
describes the peculiarities that apply when writing assembly code to interact with Go.
</p>

<p>
The most important thing to know about Go's assembler is that it is not a direct representation of the underlying machine.
Some of the details map precisely to the machine, but some do not.
This is because the compiler suite (see

package, such as C.puts. It collects all such identifiers. The next
step is to determine each kind of name. In C.xxx the xxx might refer
to a type, a function, a constant, or a global variable. Cgo must
decide which.

The obvious thing for cgo to do is to process the preamble, expanding
#includes and processing the corresponding C code. That would require
a full C parser and type checker that was also aware of any extensions

type Arch struct {
	*obj.LinkArch
	// Map of instruction names to enumeration.
	Instructions map[string]obj.As
	// Map of register names to enumeration.
	Register map[string]int16
	// Table of register prefix names. These are things like R for R(0) and SPR for SPR(268).
	RegisterPrefix map[string]bool
	// RegisterNumber converts R(10) into arm.REG_R10.
	RegisterNumber func(string, int16) (int16, bool)
	// Instruction is a jump.

	origX := *px
	*px = ast.NewIdent(fmt.Sprintf("_cgoBase%d", i))
	fmt.Fprintf(sb, "_cgo%d := %s; ", i, gofmtPos(arg, arg.Pos()))
	*px = origX

	// Use "0 == 0" to do the right thing in the unlikely event
	// that "true" is shadowed.
	fmt.Fprintf(sbCheck, "_cgoCheckPointer(_cgoBase%d, 0 == 0); ", i)

	return true
}

// checkSlice checks whether arg has the form x[i:j], possibly inside

		}
	}()
	nestedCall(func() { panic("callback panic") })
	panic("nestedCall returned")
}

// Callback with zero arguments used to make the stack misaligned,
// which broke the garbage collector and other things.
func testZeroArgCallback(t *testing.T) {
	defer func() {
		s := recover()
		if s != nil {
			t.Fatal("panic during callback:", s)
		}
	}()
	C.callGoFoo()
}

//export goFoo

		return i
	}
	if b.buf == nil && n <= smallBufferSize {
		b.buf = make([]byte, n, smallBufferSize)
		return 0
	}
	c := cap(b.buf)
	if n <= c/2-m {
		// We can slide things down instead of allocating a new
		// slice. We only need m+n <= c to slide, but
		// we instead let capacity get twice as large so we
		// don't spend all our time copying.
		copy(b.buf, b.buf[b.off:])

	return w.writeDataDescriptor()
}

func (w *fileWriter) writeDataDescriptor() error {
	if !w.hasDataDescriptor() {
		return nil
	}
	// Write data descriptor. This is more complicated than one would
	// think, see e.g. comments in zipfile.c:putextended() and
	// https://bugs.openjdk.org/browse/JDK-7073588.
	// The approach here is to write 8 byte sizes if needed without
	// adding a zip64 extra in the local header (too late anyway).

and <i>w'</i> happens before <i>r</i>.
That is, each read must observe a value written by a preceding or concurrent write.
</p>

<p>
Additionally, observation of acausal and “out of thin air” writes is disallowed.
</p>

<p>
Reads of memory locations larger than a single machine word
are encouraged but not required to meet the same semantics
as word-sized memory locations,