<html lang="en">
<head>
<title>MSP430 Profiling Capability - Using as</title>
<meta http-equiv="Content-Type" content="text/html">
<meta name="description" content="Using as">
<meta name="generator" content="makeinfo 4.13">
<link title="Top" rel="start" href="index.html#Top">
<link rel="up" href="MSP430_002dDependent.html#MSP430_002dDependent" title="MSP430-Dependent">
<link rel="prev" href="MSP430-Opcodes.html#MSP430-Opcodes" title="MSP430 Opcodes">
<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage">
<!--
This file documents the GNU Assembler "as".
Copyright (C) 1991-2015 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3
or any later version published by the Free Software Foundation;
with no Invariant Sections, with no Front-Cover Texts, and with no
Back-Cover Texts. A copy of the license is included in the
section entitled ``GNU Free Documentation License''.
-->
<meta http-equiv="Content-Style-Type" content="text/css">
<style type="text/css"><!--
pre.display { font-family:inherit }
pre.format { font-family:inherit }
pre.smalldisplay { font-family:inherit; font-size:smaller }
pre.smallformat { font-family:inherit; font-size:smaller }
pre.smallexample { font-size:smaller }
pre.smalllisp { font-size:smaller }
span.sc { font-variant:small-caps }
span.roman { font-family:serif; font-weight:normal; }
span.sansserif { font-family:sans-serif; font-weight:normal; }
--></style>
</head>
<body>
<div class="node">
<a name="MSP430-Profiling-Capability"></a>
<p>
Previous: <a rel="previous" accesskey="p" href="MSP430-Opcodes.html#MSP430-Opcodes">MSP430 Opcodes</a>,
Up: <a rel="up" accesskey="u" href="MSP430_002dDependent.html#MSP430_002dDependent">MSP430-Dependent</a>
<hr>
</div>
<h4 class="subsection">9.29.6 Profiling Capability</h4>
<p><a name="index-MSP-430-profiling-capability-1656"></a><a name="index-profiling-capability-for-MSP-430-1657"></a>It is a performance hit to use gcc's profiling approach for this tiny target.
Even more – jtag hardware facility does not perform any profiling functions.
However we've got gdb's built-in simulator where we can do anything.
<p>We define new section ‘<samp><span class="samp">.profiler</span></samp>’ which holds all profiling information.
We define new pseudo operation ‘<samp><span class="samp">.profiler</span></samp>’ which will instruct assembler to
add new profile entry to the object file. Profile should take place at the
present address.
<p>Pseudo operation format:
<p>‘<samp><span class="samp">.profiler flags,function_to_profile [, cycle_corrector, extra]</span></samp>’
<p>where:
<dl>
<dl>
‘<samp><span class="samp">flags</span></samp>’ is a combination of the following characters:
<dt><code>s</code><dd>function entry
<br><dt><code>x</code><dd>function exit
<br><dt><code>i</code><dd>function is in init section
<br><dt><code>f</code><dd>function is in fini section
<br><dt><code>l</code><dd>library call
<br><dt><code>c</code><dd>libc standard call
<br><dt><code>d</code><dd>stack value demand
<br><dt><code>I</code><dd>interrupt service routine
<br><dt><code>P</code><dd>prologue start
<br><dt><code>p</code><dd>prologue end
<br><dt><code>E</code><dd>epilogue start
<br><dt><code>e</code><dd>epilogue end
<br><dt><code>j</code><dd>long jump / sjlj unwind
<br><dt><code>a</code><dd>an arbitrary code fragment
<br><dt><code>t</code><dd>extra parameter saved (a constant value like frame size)
</dl>
<br><dt><code>function_to_profile</code><dd>a function address
<br><dt><code>cycle_corrector</code><dd>a value which should be added to the cycle counter, zero if omitted.
<br><dt><code>extra</code><dd>any extra parameter, zero if omitted.
</dl>
<p>For example:
<pre class="smallexample"> .global fxx
.type fxx,@function
fxx:
.LFrameOffset_fxx=0x08
.profiler "scdP", fxx ; function entry.
; we also demand stack value to be saved
push r11
push r10
push r9
push r8
.profiler "cdpt",fxx,0, .LFrameOffset_fxx ; check stack value at this point
; (this is a prologue end)
; note, that spare var filled with
; the farme size
mov r15,r8
...
.profiler cdE,fxx ; check stack
pop r8
pop r9
pop r10
pop r11
.profiler xcde,fxx,3 ; exit adds 3 to the cycle counter
ret ; cause 'ret' insn takes 3 cycles
</pre>
<!-- Copyright (C) 2013-2015 Free Software Foundation, Inc. -->
<!-- This is part of the GAS manual. -->
<!-- For copying conditions, see the file as.texinfo. -->
<!-- man end -->
</body></html>