[llvm] Move SI Lower Control Flow Up (PR #159557)

[via llvm-commits]

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@@ -323,6 +332,8 @@ void SILowerControlFlow::emitElse(MachineInstr &MI) {
   if (LV)
     LV->replaceKillInstruction(SrcReg, MI, *OrSaveExec);
 
+  move_ins_before_phis(*OrSaveExec);
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alex-t wrote:

If we lower SI_END_CF and don't split block we are going to have Exec = Exec OR Masked in the beginning or middle.

https://github.com/llvm/llvm-project/pull/159557