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<p class="MsoNormal">I have a register hierarchy that looks like a binary tree.<o:p></o:p></p>
<p class="MsoNormal">v4 -> {v2, v2} -> {s, s}{s, s}(or, {x, y}, {z, w})<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I have an instruction that can access the 2nd and/or 4th scalar and an<o:p></o:p></p>
<p class="MsoNormal">instruction that can access the 1st and/or 3rd scalar. What I need to do<o:p></o:p></p>
<p class="MsoNormal">is that given the first scalar, I need to be able to select the 2nd scalar,<o:p></o:p></p>
<p class="MsoNormal">or/and given the 3rd, select the 4th. I define a sibling register as a register<o:p></o:p></p>
<p class="MsoNormal">that has the same parent and a cousin as a register that has the same grandparent.<o:p></o:p></p>
<p class="MsoNormal">So 'x' is a cousin of 'w' because of the grandparent class and 'x' is a sibling<o:p></o:p></p>
<p class="MsoNormal">of 'y' because of the parent class.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I know I can move to parent/children registers via super/sub classes,<o:p></o:p></p>
<p class="MsoNormal">but is there any way in LLVM currently to easily select a cousin/sibling registers that<o:p></o:p></p>
<p class="MsoNormal">I am not seeing? <o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Currently what I've found to work is I do register - base_scalar_1 + base_scalar_2,<o:p></o:p></p>
<p class="MsoNormal">but this doesn't seem like the best solution since this has an implicit
<o:p></o:p></p>
<p class="MsoNormal">assumption on the ordering of the enumerated register values.
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Any ideas?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks,<o:p></o:p></p>
<p class="MsoNormal">Micah<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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