[llvm] [VPlan] Add BranchOnMultiCond, use for early exit plans. (PR #172750)

[via llvm-commits]

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@@ -391,20 +391,21 @@ static bool hasDuplicates(const SmallVectorImpl<VPBlockBase *> &VPBlockVec) {
 bool VPlanVerifier::verifyBlock(const VPBlockBase *VPB) {
   auto *VPBB = dyn_cast<VPBasicBlock>(VPB);
   // Check block's condition bit.
-  if (!isa<VPIRBasicBlock>(VPB)) {
+  if (VPBB && !isa<VPIRBasicBlock>(VPB)) {
+    // VPRegionBlocks can have multiple successors (e.g., with
+    // BranchOnTwoConds) without needing a terminator, so only check
+    // VPBasicBlocks.
     if (VPB->getNumSuccessors() > 1 ||
-        (VPBB && VPBB->getParent() && VPBB->isExiting() &&
+        (VPBB->getParent() && VPBB->isExiting() &&
          !VPBB->getParent()->isReplicator())) {
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ayalz wrote:

Perhaps accounting for implicit backedge when counting successors of latch VPBB's is worth a public API.

https://github.com/llvm/llvm-project/pull/172750