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| <h5 class="subsubsection">9.3.2.1 Special Characters</h5> |
| |
| <dl> |
| <dt><code>%</code><dd><a name="index-register-name-prefix-character_002c-ARC-636"></a><a name="index-ARC-register-name-prefix-character-637"></a>A register name can optionally be prefixed by a ‘<samp><span class="samp">%</span></samp>’ character. So |
| register <code>%r0</code> is equivalent to <code>r0</code> in the assembly code. |
| |
| <br><dt><code>#</code><dd><a name="index-line-comment-character_002c-ARC-638"></a><a name="index-ARC-line-comment-character-639"></a>The presence of a ‘<samp><span class="samp">#</span></samp>’ character within a line (but not at the |
| start of a line) indicates the start of a comment that extends to the |
| end of the current line. |
| |
| <p><em>Note:</em> if a line starts with a ‘<samp><span class="samp">#</span></samp>’ character then it can |
| also be a logical line number directive (see <a href="Comments.html#Comments">Comments</a>) or a |
| preprocessor control command (see <a href="Preprocessing.html#Preprocessing">Preprocessing</a>). |
| |
| <br><dt><code>@</code><dd><a name="index-symbol-prefix-character_002c-ARC-640"></a><a name="index-ARC-symbol-prefix-character-641"></a>Prefixing an operand with an ‘<samp><span class="samp">@</span></samp>’ specifies that the operand is a |
| symbol and not a register. This is how the assembler disambiguates |
| the use of an ARC register name as a symbol. So the instruction |
| <pre class="example"> mov r0, @r0 |
| </pre> |
| <p>moves the address of symbol <code>r0</code> into register <code>r0</code>. |
| |
| <br><dt><code>`</code><dd><a name="index-line-separator_002c-ARC-642"></a><a name="index-statement-separator_002c-ARC-643"></a><a name="index-ARC-line-separator-644"></a>The ‘<samp><span class="samp">`</span></samp>’ (backtick) character is used to separate statements on a |
| single line. |
| |
| <p><a name="index-line-645"></a><br><dt><code>-</code><dd><a name="index-C-preprocessor-macro-separator_002c-ARC-646"></a><a name="index-ARC-C-preprocessor-macro-separator-647"></a>Used as a separator to obtain a sequence of commands from a C |
| preprocessor macro. |
| |
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