high bit is set is rejected.
</p>

<h3 id="symbols">Symbols</h3>

<p>
Some symbols, such as <code>R1</code> or <code>LR</code>,
are predefined and refer to registers.
The exact set depends on the architecture.
</p>

<p>
There are four predeclared symbols that refer to pseudo-registers.
These are not real registers, but rather virtual registers maintained by
the toolchain, such as a frame pointer.

          <execution>
            <id>archetype-common</id>
            <goals>
              <goal>java</goal>
              <goal>xsd</goal>
              <goal>xpp3-reader</goal>
              <goal>xpp3-writer</goal>
            </goals>
            <configuration>
              <version>1.0.0</version>
              <model>src/main/mdo/archetype-common.mdo</model>
            </configuration>
          </execution>

            </execution>
            <execution>
              <id>standard</id>
              <goals>
                <goal>java</goal>
                <goal>xpp3-reader</goal>
                <goal>xpp3-writer</goal>
              </goals>
            </execution>
          </executions>
        </plugin>
        <plugin>
          <groupId>org.apache.felix</groupId>

it must not allow a single read to observe multiple values,
and it must not allow a single write to write multiple values.
</p>

<p>
All the following examples assume that `*p` and `*q` refer to
memory locations accessible to multiple goroutines.
</p>

<p>
Not introducing data races into race-free programs means not moving
writes out of conditional statements in which they appear.

            </execution>
            <execution>
              <id>standard</id>
              <goals>
                <goal>java</goal>
                <goal>xpp3-reader</goal>
                <goal>xpp3-writer</goal>
              </goals>
            </execution>
          </executions>
        </plugin>
        <plugin>
          <groupId>org.apache.felix</groupId>

            </execution>
            <execution>
              <id>standard</id>
              <goals>
                <goal>java</goal>
                <goal>xpp3-reader</goal>
                <goal>xpp3-writer</goal>
              </goals>
            </execution>
          </executions>
        </plugin>
        <plugin>
          <groupId>org.apache.felix</groupId>