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<h3 class="section">4.11 <samp><span class="command">ld</span></samp> and the Altera Nios II</h3>
<p><a name="index-Nios-II-call-relaxation-661"></a><a name="index-g_t_002d_002drelax-on-Nios-II-662"></a>
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 <samp><span class="command">ld</span></samp> giving
‘<samp><span class="samp">relocation truncated to fit</span></samp>’ errors with very large programs.
The command-line option <samp><span class="option">--relax</span></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>The <samp><span class="option">--relax</span></samp> option is enabled by default unless <samp><span class="option">-r</span></samp>
is also specified. You can disable trampoline generation by using the
<samp><span class="option">--no-relax</span></samp> linker option. You can also disable this optimization
locally by using the ‘<samp><span class="samp">set .noat</span></samp>’ directive in assembly-language
source files, as the linker-inserted trampolines use the <code>at</code>
register as a temporary.
<p>Note that the linker <samp><span class="option">--relax</span></samp> option is independent of assembler
relaxation options, and that using the GNU assembler's <samp><span class="option">-relax-all</span></samp>
option interferes with the linker's more selective call instruction relaxation.
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