<p> </p>
<p class="MsoNormal"><span style="font-size: 12.0pt; line-height: 115%;">Instruction BL in the ARM mode can jump by offset +/- 32 MB only. </span></p>
<p class="MsoNormal"><span style="font-size: 12.0pt; line-height: 115%;">If using absolute offset, we need generate a few additional instructions same as:</span></p>
<p class="MsoNormal"><span style="font-size: 12.0pt; line-height: 115%;">load offset into register and jump to address from register, or save LR, and load into PC offset.</span></p>
<p class="MsoNormal"><span style="font-size: 12.0pt; line-height: 115%;">But in both cases change size of code in the function will lead to possibility invalidate offsets </span></p>
<p class="MsoNormal"><span style="font-size: 12.0pt; line-height: 115%;">computed in the "ARM constant island placement and branch shortening pass" and we still need</span></p>
<p class="MsoNormal"><span style="font-size: 12pt; line-height: 115%;">in the thunk. </span></p>
<p>---</p>
<p>Kurmangaleev Shamil</p>
<p><br /> 13.03.2012 17:47, Joerg Sonnenberger пишет:</p>
<blockquote cite="mid:20120313134706.GB6633@britannica.bec.de">
<pre>On Tue, Mar 13, 2012 at 05:27:58PM +0400, Shamil Kurmangaleev wrote:
</pre>
<blockquote type="cite" style="padding-left:5px; border-left:#1010ff 2px solid; margin-left:5px; width:100%">
<pre>Because the ELF file in memory generated by MC JIT does not have the
.plt section, but we need to have the following code to be emitted in it:
</pre>
</blockquote>
<pre>Why do you need it to emit PIC? You know the offsets of all functions it
is calling.
Joerg
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</pre>
</blockquote>
<p> </p>