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| <a name="Generating-Code-for-Profiling"></a> |
| <h4 class="subsection">17.10.12 Generating Code for Profiling</h4> |
| <a name="index-profiling_002c-code-generation"></a> |
| |
| <p>These macros will help you generate code for profiling. |
| </p> |
| <dl> |
| <dt><a name="index-FUNCTION_005fPROFILER"></a>Macro: <strong>FUNCTION_PROFILER</strong> <em>(<var>file</var>, <var>labelno</var>)</em></dt> |
| <dd><p>A C statement or compound statement to output to <var>file</var> some |
| assembler code to call the profiling subroutine <code>mcount</code>. |
| </p> |
| <a name="index-mcount"></a> |
| <p>The details of how <code>mcount</code> expects to be called are determined by |
| your operating system environment, not by GCC. To figure them out, |
| compile a small program for profiling using the system’s installed C |
| compiler and look at the assembler code that results. |
| </p> |
| <p>Older implementations of <code>mcount</code> expect the address of a counter |
| variable to be loaded into some register. The name of this variable is |
| ‘<samp>LP</samp>’ followed by the number <var>labelno</var>, so you would generate |
| the name using ‘<samp>LP%d</samp>’ in a <code>fprintf</code>. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-PROFILE_005fHOOK"></a>Macro: <strong>PROFILE_HOOK</strong></dt> |
| <dd><p>A C statement or compound statement to output to <var>file</var> some assembly |
| code to call the profiling subroutine <code>mcount</code> even the target does |
| not support profiling. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-NO_005fPROFILE_005fCOUNTERS"></a>Macro: <strong>NO_PROFILE_COUNTERS</strong></dt> |
| <dd><p>Define this macro to be an expression with a nonzero value if the |
| <code>mcount</code> subroutine on your system does not need a counter variable |
| allocated for each function. This is true for almost all modern |
| implementations. If you define this macro, you must not use the |
| <var>labelno</var> argument to <code>FUNCTION_PROFILER</code>. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-PROFILE_005fBEFORE_005fPROLOGUE"></a>Macro: <strong>PROFILE_BEFORE_PROLOGUE</strong></dt> |
| <dd><p>Define this macro if the code for function profiling should come before |
| the function prologue. Normally, the profiling code comes after. |
| </p></dd></dl> |
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