(that is, if <i>W</i>(<i>r</i>) = <i>w</i>),
then <i>w</i> is synchronized before <i>r</i>.
Informally, the synchronized before relation is a subset of the implied total order
mentioned in the previous paragraph,
limited to the information that <i>W</i> directly observes.
</p>

<p>
The <i>happens before</i> relation is defined as the transitive closure of the

  class.
</p>
<p>
  A consequence of this change is that some objects' addresses that were previously
  always aligned to a 16 byte (or higher) boundary will now only be aligned to an 8
  byte boundary.
  Some programs that use assembly instructions that require memory addresses to be
  more than 8-byte aligned and rely on the memory allocator's previous alignment behavior
  may break, but we expect such programs to be rare.

first preceding non-empty expression list and its type if any.
Omitting the list of expressions is therefore equivalent to
repeating the previous list.  The number of identifiers must be equal
to the number of expressions in the previous list.
Together with the <a href="#Iota"><code>iota</code> constant generator</a>
this mechanism permits light-weight declaration of sequential values:
</p>

<pre>

The assembler also supports some (not necessarily all) addressing modes
specific to each architecture.
The sections below list these.
</p>

<p>
One detail evident in the examples from the previous sections is that data in the instructions flows from left to right:
<code>MOVQ</code> <code>$0,</code> <code>CX</code> clears <code>CX</code>.

first preceding non-empty expression list and its type if any.
Omitting the list of expressions is therefore equivalent to
repeating the previous list.  The number of identifiers must be equal
to the number of expressions in the previous list.
Together with the <a href="#Iota"><code>iota</code> constant generator</a>
this mechanism permits light-weight declaration of sequential values:
</p>

<pre>