[llvm] [VPlan] Add VPIRInstruction, use for exit block live-outs. (PR #100735)

[via llvm-commits]

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@@ -8647,13 +8647,17 @@ static MapVector<PHINode *, VPValue *> collectUsersInExitBlock(
   // from scalar loop only.
   if (MiddleVPBB->getNumSuccessors() != 2)
     return {};
-  MapVector<PHINode *, VPValue *> ExitingValuesToFix;
-  BasicBlock *ExitBB =
-      cast<VPIRBasicBlock>(MiddleVPBB->getSuccessors()[0])->getIRBasicBlock();
+  MapVector<VPIRInstruction *, VPValue *> ExitingValuesToFix;
+  VPBasicBlock *ExitVPBB = cast<VPIRBasicBlock>(MiddleVPBB->getSuccessors()[0]);
   BasicBlock *ExitingBB = OrigLoop->getExitingBlock();
-  for (PHINode &ExitPhi : ExitBB->phis()) {
-    Value *IncomingValue =
-        ExitPhi.getIncomingValueForBlock(ExitingBB);
+  for (VPRecipeBase &R : *ExitVPBB) {
+    auto *IR = dyn_cast<VPIRInstruction>(&R);
+    if (!IR)
+      continue;
+    auto *ExitPhi = dyn_cast<PHINode>(&IR->getInstruction());
+    if (!ExitPhi)
+      break;
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ayalz wrote:

A separate VPIRPhi subclass of VIPIRInstruction dedicated to phi's would arguably model the distinction between the two more accurately, and help simplify their documentation, operand behavior, execute(), keeping phi's together, iterating over them, etc., but this can be considered as a follow-up.

https://github.com/llvm/llvm-project/pull/100735