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| <h4 class="subsection">9.15.3 i960 Machine Directives</h4> |
| |
| <p><a name="index-machine-directives_002c-i960-1021"></a><a name="index-i960-machine-directives-1022"></a> |
| |
| <a name="index-g_t_0040code_007bbss_007d-directive_002c-i960-1023"></a> |
| <dl><dt><code>.bss </code><var>symbol</var><code>, </code><var>length</var><code>, </code><var>align</var><dd>Reserve <var>length</var> bytes in the bss section for a local <var>symbol</var>, |
| aligned to the power of two specified by <var>align</var>. <var>length</var> and |
| <var>align</var> must be positive absolute expressions. This directive |
| differs from ‘<samp><span class="samp">.lcomm</span></samp>’ only in that it permits you to specify |
| an alignment. See <a href="Lcomm.html#Lcomm"><code>.lcomm</code></a>. |
| </dl> |
| |
| |
| <a name="index-g_t_0040code_007bextended_007d-directive_002c-i960-1024"></a> |
| <dl><dt><code>.extended </code><var>flonums</var><dd><code>.extended</code> expects zero or more flonums, separated by commas; for |
| each flonum, ‘<samp><span class="samp">.extended</span></samp>’ emits an <span class="sc">ieee</span> extended-format (80-bit) |
| floating-point number. |
| |
| <p><a name="index-g_t_0040code_007bleafproc_007d-directive_002c-i960-1025"></a><br><dt><code>.leafproc </code><var>call-lab</var><code>, </code><var>bal-lab</var><dd>You can use the ‘<samp><span class="samp">.leafproc</span></samp>’ directive in conjunction with the |
| optimized <code>callj</code> instruction to enable faster calls of leaf |
| procedures. If a procedure is known to call no other procedures, you |
| may define an entry point that skips procedure prolog code (and that does |
| not depend on system-supplied saved context), and declare it as the |
| <var>bal-lab</var> using ‘<samp><span class="samp">.leafproc</span></samp>’. If the procedure also has an |
| entry point that goes through the normal prolog, you can specify that |
| entry point as <var>call-lab</var>. |
| |
| <p>A ‘<samp><span class="samp">.leafproc</span></samp>’ declaration is meant for use in conjunction with the |
| optimized call instruction ‘<samp><span class="samp">callj</span></samp>’; the directive records the data |
| needed later to choose between converting the ‘<samp><span class="samp">callj</span></samp>’ into a |
| <code>bal</code> or a <code>call</code>. |
| |
| <p><var>call-lab</var> is optional; if only one argument is present, or if the |
| two arguments are identical, the single argument is assumed to be the |
| <code>bal</code> entry point. |
| |
| <p><a name="index-g_t_0040code_007bsysproc_007d-directive_002c-i960-1026"></a><br><dt><code>.sysproc </code><var>name</var><code>, </code><var>index</var><dd>The ‘<samp><span class="samp">.sysproc</span></samp>’ directive defines a name for a system procedure. |
| After you define it using ‘<samp><span class="samp">.sysproc</span></samp>’, you can use <var>name</var> to |
| refer to the system procedure identified by <var>index</var> when calling |
| procedures with the optimized call instruction ‘<samp><span class="samp">callj</span></samp>’. |
| |
| <p>Both arguments are required; <var>index</var> must be between 0 and 31 |
| (inclusive). |
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