[llvm] [CodeGen] Remove dead hack for MIPS (PR #148039)

[via llvm-commits]

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@@ -534,9 +534,7 @@ void LiveVariables::runOnInstr(MachineInstr &MI,
         UseRegs.push_back(MOReg);
     } else {
       assert(MO.isDef());
-      // FIXME: We should not remove any dead flags. However the MIPS RDDSP
-      // instruction needs it at the moment: http://llvm.org/PR27116.
-      if (MOReg.isPhysical() && !MRI->isReserved(MOReg))
+      if (!(MOReg.isPhysical() && MRI->isReserved(MOReg)))
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AZero13 wrote:

> The condition should be demorganed. The comment also states that dead flags should not be removed, and this is still removing a dead flag

Fixed!

https://github.com/llvm/llvm-project/pull/148039