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<p class="MsoNormal">FrameIndex values come from objects that are still allocated on the stack at the time of the SDAG construction. In your case it seems that the address and the value to store are both on the stack. You don’t need to do anything in particular
with it. If you have a selection pattern of form “(store RegClassA:$Addr, RegClassB:$Val), (STORE $Addr, $Val)”, then it will force loading both, Addr and Val into registers. I think someone has added a pattern to match frame index in patterns as well (it
didn’t use to be possible and you had to use ComplexPattern), so your pattern can handle that directly too.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">-- </span>
<span style="font-size:9.0pt;font-family:Consolas"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:8.0pt;font-family:Consolas">Krzysztof Parzyszek
<a href="mailto:kparzysz@quicinc.com"><span style="color:#0563C1">kparzysz@quicinc.com</span></a> LLVM compiler development<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><b>From:</b> llvm-dev <llvm-dev-bounces@lists.llvm.org> <b>On Behalf Of
</b>Gleb Popov via llvm-dev<br>
<b>Sent:</b> Monday, June 24, 2019 6:16 AM<br>
<b>To:</b> LLVM Dev <llvm-dev@lists.llvm.org><br>
<b>Subject:</b> [EXT] [llvm-dev] How to handle ISD::STORE when both operands are FrameIndex?<o:p></o:p></p>
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<p class="MsoNormal">Hello.<o:p></o:p></p>
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<p class="MsoNormal">After "Initial selection DAG" stage I get a DAG with node<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">t14: ch = store<(store 4 into %ir.p45, align 8, addrspace 1)> t10, FrameIndex:i32<2>, FrameIndex:i32<3>, undef:i32<o:p></o:p></p>
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<p class="MsoNormal">1. Where does it come from? Can I do anything to make it not appear?<o:p></o:p></p>
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<p class="MsoNormal">2. If not, how do I change it so that the operand being stored would be first loaded into a register, and that register would be used instead? Like<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">ch = StoreStackF<Mem:(store 4 into %ir.p45, align 8, addrspace 1)> Register:%1, TargetFrameIndex:i32<3>, t10<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Thanks in advance.<o:p></o:p></p>
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