<html><head><meta http-equiv="Content-Type" content="text/html charset=iso-8859-1"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On Feb 17, 2013, at 1:11 PM, Reed Kotler <<a href="mailto:rkotler@mips.com">rkotler@mips.com</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">
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<div class="moz-cite-prefix">On 02/17/2013 01:08 PM, Andrew Trick
wrote:<br>
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<div>On Feb 17, 2013, at 1:01 PM, Reed Kotler <<a moz-do-not-send="true" href="mailto:rkotler@mips.com">rkotler@mips.com</a>>
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<div class="moz-cite-prefix">On 02/17/2013 12:48 PM, Andrew
Trick wrote:<br>
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<pre wrap="">On Feb 16, 2013, at 1:31 PM, Cameron Zwarich <a moz-do-not-send="true" class="moz-txt-link-rfc2396E" href="mailto:zwarich@apple.com"><zwarich@apple.com></a> wrote:
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<pre wrap="">That's exactly the right place.
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<pre wrap="">Really? You don't want the expansion to be optimized? You want to specify a machine model for the pseudo's as if they're real instructions? You don't want to schedule or register allocate the real instructions?
-Andy
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So then maybe my code should be called during instruction
selection?<br>
<br>
The very original MIPs port was for Mips I and Mips I has a
need for lots of psuedos because it's primitive.<br>
That code has mostly been removed now because we don't
support Mips I which is just an historical processor at this
time.<br>
<br>
I approach level one implementations of things from the
point of view of correctness and then make things better as
I understand the problem better. <br>
<br>
So my base scheme for all of this was to create multi line
assembler expansion in pseudos.<br>
<br>
Now that I'm passing mostly all of test-suite, I'm starting
improve things.<br>
<br>
At this time, I'm starting to place expansion in <br>
<pre wrap=""><big>expandPostRAPseudo
Would it be possible to call this same code during instruction selection?
When I emitting the code for certain formats, I would need to call some emitter which basically the same kind of I'm calling from expandPostRAPseudo now.</big></pre>
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expandISelPseudos is the place to cleanup after ISEL hacks, and
can create BBs. But, as Cameron explained well in the other
thread, if you want a macro assembler for some sequences, do it
late in expandPostRAPseudos.</div>
<div>-Andy</div>
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I feel like I should expand things as soon as I have all the
information because then other passes can help make things better.<br>
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So maybe I do this earlier in expandIselPseudos.<br>
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Are there any cons ?<br></div></blockquote><div><br></div>If the instructions must be adjacent for correctness or cannot be spilled within the sequence, then you have a problem. Sorry to be vague, but I'll again refer you to Cameron's detailed response.</div><div>-Andy<br><blockquote type="cite"><div bgcolor="#FFFFFF" text="#000000"><blockquote cite="mid:E6086779-B132-4512-9C36-8CF63E2DA28D@apple.com" type="cite"><div><blockquote type="cite"><div bgcolor="#FFFFFF" text="#000000"><blockquote cite="mid:79A2DD5E-F601-430B-99A7-EB29BCB640AF@apple.com" type="cite"><blockquote type="cite"><pre wrap="">On Feb 16, 2013, at 1:08 PM, Reed Kotler <a moz-do-not-send="true" class="moz-txt-link-rfc2396E" href="mailto:rkotler@mips.com"><rkotler@mips.com></a> wrote:
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<pre wrap="">I have a bunch of pseudos that I want to lower right after instruction selection.
Where is the best place to do that?
I was planning to use expandPostRAPseudo.
Is there a better place?
TIA.
Reed
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