[llvm] [VPlan] Simplify Plan's entry in removeBranchOnConst. (PR #154510)

[via llvm-commits]

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@@ -2352,9 +2352,9 @@ EpilogueVectorizerMainLoop::createIterationCountCheck(ElementCount VF,
 /// VPBB are moved to the end of the newly created VPIRBasicBlock. VPBB must
 /// have a single predecessor, which is rewired to the new VPIRBasicBlock. All
 /// successors of VPBB, if any, are rewired to the new VPIRBasicBlock.
-static VPIRBasicBlock *replaceVPBBWithIRVPBB(VPBasicBlock *VPBB,
+static VPIRBasicBlock *replaceVPBBWithIRVPBB(VPlan &Plan, VPBasicBlock *VPBB,
                                              BasicBlock *IRBB) {
-  VPIRBasicBlock *IRVPBB = VPBB->getPlan()->createVPIRBasicBlock(IRBB);
+  VPIRBasicBlock *IRVPBB = Plan.createVPIRBasicBlock(IRBB);
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ayalz wrote:

This change is needed because VPBB may no longer be reachable from Plan's entry. VPBB must still have a single predecessor, as documented above, but that pred might be pred free? If only some callers pass an unreachable VPBB, Plan could be an optional parameter, to keep other callers intact.

https://github.com/llvm/llvm-project/pull/154510