[llvm] [X86][BreakFalseDeps] Using reverse order for undef register selection (PR #137569)

[Evgenii Kudriashov via llvm-commits]

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@@ -285,7 +285,7 @@ bool BreakFalseDeps::runOnMachineFunction(MachineFunction &mf) {
   TRI = MF->getSubtarget().getRegisterInfo();
   RDA = &getAnalysis<ReachingDefAnalysis>();
 
-  RegClassInfo.runOnMachineFunction(mf);
+  RegClassInfo.runOnMachineFunction(mf, /*Rev=*/true);
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e-kud wrote:

Do we want to have an option for this?

https://github.com/llvm/llvm-project/pull/137569