implementation must:
</p>

<ul>
	<li>Represent integer constants with at least 256 bits.</li>

	<li>Represent floating-point constants, including the parts of
	    a complex constant, with a mantissa of at least 256 bits
	    and a signed binary exponent of at least 16 bits.</li>

	<li>Give an error if unable to represent an integer constant
	    precisely.</li>

// If parsing fails or an integer overflow occurs, err will be set.
func (p *parser) parseNumeric(b []byte) int64 {
	// Check for base-256 (binary) format first.
	// If the first bit is set, then all following bits constitute a two's
	// complement encoded number in big-endian byte order.
	if len(b) > 0 && b[0]&0x80 != 0 {
		// Handling negative numbers relies on the following identity:
		//	-a-1 == ^a
		//

	copy(b2, b)
	return b2[:len(b)]
}

// WriteTo writes data to w until the buffer is drained or an error occurs.
// The return value n is the number of bytes written; it always fits into an
// int, but it is int64 to match the io.WriterTo interface. Any error
// encountered during the write is also returned.
func (b *Buffer) WriteTo(w io.Writer) (n int64, err error) {
	b.lastRead = opInvalid

		return path.Base(path.Clean(fi.h.Name))
	}
	return path.Base(fi.h.Name)
}

// Mode returns the permission and mode bits for the headerFileInfo.
func (fi headerFileInfo) Mode() (mode fs.FileMode) {
	// Set file permission bits.
	mode = fs.FileMode(fi.h.Mode).Perm()

	// Set setuid, setgid and sticky bits.
	if fi.h.Mode&c_ISUID != 0 {
		mode |= fs.ModeSetuid
	}
	if fi.h.Mode&c_ISGID != 0 {
		mode |= fs.ModeSetgid

		return true
	}
	return false
}

// Comment from Darwin's CFInternal.h
/*
// Tagged pointer support
// Low-bit set means tagged object, next 3 bits (currently)
// define the tagged object class, next 4 bits are for type
// information for the specific tagged object class.  Thus,
// the low byte is for type info, and the rest of a pointer
// (32 or 64-bit) is for payload, whatever the tagged class.

The [`asynctimerchan` setting](/pkg/time/#NewTimer) disables this change.
There are no runtime metrics for this change,
This setting may be removed in a future release, Go 1.27 at the earliest.

Go 1.23 changed the mode bits reported by [`os.Lstat`](/pkg/os#Lstat) and [`os.Stat`](/pkg/os#Stat)
for reparse points, which can be controlled with the `winsymlink` setting.

<li>
<code>R0.UXTB</code>
<br>
<code>R0.UXTB&lt;&lt;imm</code>:
<code>UXTB</code>: extract an 8-bit value from the low-order bits of <code>R0</code> and zero-extend it to the size of <code>R0</code>.
<code>R0.UXTB&lt;&lt;imm</code>: left shift the result of <code>R0.UXTB</code> by <code>imm</code> bits.
The <code>imm</code> value can be 0, 1, 2, 3, or 4.

	MOVW	$0, (R1)  // 3f0000b9
	MOVWU	$0, (R1)  // 3f0000b9
	MOVH	$0, (R1)  // 3f000079
	MOVHU	$0, (R1)  // 3f000079
	MOVB	$0, (R1)  // 3f000039
	MOVBU	$0, (R1)  // 3f000039

// small offset fits into instructions
	MOVB	R1, 1(R2) // 41040039
	MOVH	R1, 1(R2) // 41100078
	MOVH	R1, 2(R2) // 41040079
	MOVW	R1, 1(R2) // 411000b8
	MOVW	R1, 4(R2) // 410400b9
	MOVD	R1, 1(R2) // 411000f8

	// If either the uncompressed or compressed size of the file
	// does not fit in 32 bits, CompressedSize is set to ^uint32(0).
	//
	// Deprecated: Use CompressedSize64 instead.
	CompressedSize uint32

	// UncompressedSize is the compressed size of the file in bytes.
	// If either the uncompressed or compressed size of the file
	// does not fit in 32 bits, CompressedSize is set to ^uint32(0).
	//

	if _, err := io.ReadFull(r, buf[off:12]); err != nil {
		return err
	}
	b := readBuf(buf[:12])
	if b.uint32() != f.CRC32 {
		return ErrChecksum
	}

	// The two sizes that follow here can be either 32 bits or 64 bits
	// but the spec is not very clear on this and different
	// interpretations has been made causing incompatibilities. We
	// already have the sizes from the central directory so we can
	// just ignore these.