[llvm] [VPlan] Introduce child regions as VPlan transform. (PR #129402)

[Florian Hahn via llvm-commits]

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@@ -130,43 +98,23 @@ void PlainCFGBuilder::fixHeaderPhis() {
     auto *VPPhi = cast<VPWidenPHIRecipe>(VPVal);
     assert(VPPhi->getNumOperands() == 0 &&
            "Expected VPInstruction with no operands.");
-
-    Loop *L = LI->getLoopFor(Phi->getParent());
-    assert(isHeaderBB(Phi->getParent(), L));
+    assert(isHeaderBB(Phi->getParent(), LI->getLoopFor(Phi->getParent())));
     // For header phis, make sure the incoming value from the loop
     // predecessor is the first operand of the recipe.
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fhahn wrote:

I dropped the comment, I think at this point the header phis are not really special (the fixed predecessor order comes when we introduce the corresponding regions)

https://github.com/llvm/llvm-project/pull/129402