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<div class="moz-cite-prefix">On 10/2/2012 9:36 AM, 陳韋任 (Wei-Ren
Chen) wrote:<br>
</div>
<blockquote cite="mid:20121002143657.GA83382@cs.nctu.edu.tw"
type="cite">
<pre wrap="">On Tue, Oct 02, 2012 at 09:23:27AM -0500, Matthew Curtis wrote:
</pre>
<blockquote type="cite">
<pre wrap="">I'm adding support for -ffixed-<reg> for Hexagon and was wondering if I should
do it in such a way that other targets get the support as well by default or if
a given target back-end should have to explicitly opt-in for support.
</pre>
</blockquote>
<pre wrap="">
What "-ffixed-<reg>" does?
Regards,
chenwj
</pre>
</blockquote>
<br>
From the GCC manual (<a
href="http://gcc.gnu.org/onlinedocs/gcc-4.7.2/gcc/Code-Gen-Options.html#index-ffixed-2267">http://gcc.gnu.org/onlinedocs/gcc-4.7.2/gcc/Code-Gen-Options.html#index-ffixed-2267</a>)<br>
<br>
<tt>-ffixed-</tt><tt><i>reg</i></tt><br>
<blockquote>Treat the register named reg as a fixed register;
generated code should never refer to it (except perhaps as a stack
pointer, frame pointer or in some other fixed role).<br>
</blockquote>
<blockquote>reg must be the name of a register. The register names
accepted are machine-specific and are defined in the
REGISTER_NAMES macro in the machine description macro file.<br>
</blockquote>
<br>
Useful when writing kernel code or other low-level code (e.g. a VM)
where you want to reserve a particular register for your own use.<br>
<br>
Matthew C<br>
<pre class="moz-signature" cols="72">--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation</pre>
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