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<a name="Nios-II"></a>
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Next: <a href="PowerPC-ELF32.html#PowerPC-ELF32" accesskey="n" rel="next">PowerPC ELF32</a>, Previous: <a href="NDS32.html#NDS32" accesskey="p" rel="prev">NDS32</a>, Up: <a href="Machine-Dependent.html#Machine-Dependent" accesskey="u" rel="up">Machine Dependent</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="LD-Index.html#LD-Index" title="Index" rel="index">Index</a>]</p>
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<a name="ld-and-the-Altera-Nios-II"></a>
<h3 class="section">4.10 <code>ld</code> and the Altera Nios II</h3>
<a name="index-Nios-II-call-relaxation"></a>
<a name="index-_002d_002drelax-on-Nios-II"></a>

<p>Call and immediate jump instructions on Nios II processors are limited to
transferring control to addresses in the same 256MB memory segment,
which may result in <code>ld</code> giving
&lsquo;<samp>relocation truncated to fit</samp>&rsquo; errors with very large programs.
The command-line option <samp>--relax</samp> enables the generation of
trampolines that can access the entire 32-bit address space for calls
outside the normal <code>call</code> and <code>jmpi</code> address range.  These
trampolines are inserted at section boundaries, so may not themselves
be reachable if an input section and its associated call trampolines are
larger than 256MB.
</p>
<p>The <samp>--relax</samp> option is enabled by default unless <samp>-r</samp>
is also specified.  You can disable trampoline generation by using the
<samp>--no-relax</samp> linker option.  You can also disable this optimization
locally by using the &lsquo;<samp>set .noat</samp>&rsquo; directive in assembly-language
source files, as the linker-inserted trampolines use the <code>at</code>
register as a temporary.
</p>
<p>Note that the linker <samp>--relax</samp> option is independent of assembler
relaxation options, and that using the GNU assembler&rsquo;s <samp>-relax-all</samp>
option interferes with the linker&rsquo;s more selective call instruction relaxation.
</p>


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