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<div class="moz-cite-prefix">I am fine with it. I hope you are not
planning to remove YAML.<br>
<br>
On 2/6/2015 4:54 PM, Rui Ueyama wrote:<br>
</div>
<blockquote
cite="mid:CAJENXgu8y_Z4r7F3G3T4exGGVcN7bcLD9ZQqyRN3WcrMB+dV+A@mail.gmail.com"
type="cite">
<pre wrap="">Can we remove Native format support? I'd like to get input from anyone who
wants to keep the current Native format in LLD.
On Thu, Feb 5, 2015 at 2:03 PM, Shankar Easwaran <a class="moz-txt-link-rfc2396E" href="mailto:shankare@codeaurora.org"><shankare@codeaurora.org></a>
wrote:
</pre>
<blockquote type="cite">
<pre wrap="">The only way currently is to create a new reference, unless we can think
of adding some target specific metadata information in the Atom model.
This has come up over and over again, we need something in the Atom model
to store information that is target specific.
Shankar Easwaran
On 2/5/2015 2:22 PM, Simon Atanasyan wrote:
</pre>
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<pre wrap="">Hi,
I need an advice on implementation of a very specific kind of relocations
used by MIPS N64 ABI. As usual the main problem is how to pass target
specific
data over Native/YAML conversion barrier.
In this ABI relocation record r_info field in fact consists of five
subfields:
* r_sym - symbol index
* r_ssym - special symbol
* r_type3 - third relocation type
* r_type2 - second relocation type
* r_type - first relocation type
Up to three these relocations applied one by one. The first relocation
uses
an addendum from the relocation record. Each subsequent relocation takes
as
its addend the result of the previous operation. Only the final operation
actually modifies the location relocated. The first relocation uses as
a reference symbol specified by the r_sym field. The third relocation
assumes NULL symbol.
The most interesting case is the second relocation. It uses the special
symbol value given by the r_ssym field. This field can contain four
predefined values:
* RSS_UNDEF - zero value
* RSS_GP - value of gp symbol
* RSS_GP0 - gp0 value taken from the .MIPS.options or .reginfo section
* RSS_LOC - address of location being relocated
So the problem is how to store these four constants in the
lld::Reference object.
The RSS_UNDEF is obviously not a problem. To represent the RSS_GP value I
can
set an AbsoluteAtom created for the "_gp" as the reference's target. But
what
about RSS_GP0 and RSS_LOC? I am considering the following approaches but
cannot
select the best one:
a) Create AbsoluteAtom for each of these cases and set them as the
reference's target.
The problem is that these atoms are fake and should not go to the
symbol table.
One more problem is to select unique names for these atoms.
b) Use two high bits of lld::Reference::_kindValue field to encode
RSS_xxx value.
Then decode these bits in the RelocationHandler to calculate result
of relocation.
In that case the problem is how to represent a relocation kind
value in YAML format.
The simple xxxRelocationStringTable::kindStrings[] array will not
satisfy us.
c) Add one more field to the lld::Reference class. Something like the
DefinedAtom::CodeModel
field.
Any advices, ideas, and/or objections are much appreciated.
</pre>
</blockquote>
<pre wrap="">
--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted
by the Linux Foundation
</pre>
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<pre wrap="">
</pre>
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</pre>
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<br>
<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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