[llvm] [VPlan] Add VPIRBasicBlock, use to model pre-preheader. (PR #93398)

[Florian Hahn via llvm-commits]

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@@ -442,6 +442,58 @@ VPBasicBlock::createEmptyBasicBlock(VPTransformState::CFGState &CFG) {
   return NewBB;
 }
 
+void VPIRWrapperBlock::execute(VPTransformState *State) {
+  for (VPBlockBase *PredVPBlock : getHierarchicalPredecessors()) {
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fhahn wrote:

Yes, in the initial version patching up the CFG isn't needed. Removed and added assert.

https://github.com/llvm/llvm-project/pull/93398