// structs are in system headers that cannot be corrected.
			continue
		}

		// Round off up to talign, assumed to be a power of 2.
		off = (off + talign - 1) &^ (talign - 1)

		if f.ByteOffset > off {
			fld, sizes = c.pad(fld, sizes, f.ByteOffset-off)
			off = f.ByteOffset
		}
		if f.ByteOffset < off {
			// Drop a packed field that we can't represent.
			continue
		}

		n := len(fld)

	if len(bmbuf) < maxSize {
		bmbuf = make([]byte, maxSize)
	}

	for _, n := range sizes {
		for _, off := range []int{0, 1, 4, 7} {
			buf1 := bmbuf[off : off+n]
			buf2Start := (len(bmbuf) / 2) + off
			buf2 := bmbuf[buf2Start : buf2Start+n]
			buf1[n-1] = 'x'
			buf2[n-1] = 'x'
			b.Run(fmt.Sprint(n, off), func(b *testing.B) {
				b.SetBytes(int64(n))
				for i := 0; i < b.N; i++ {
					eq := Equal(buf1, buf2)