[llvm] [VPlan] Replace VPRegionBlock with explicit CFG before execute (NFCI). (PR #117506)

[Florian Hahn via llvm-commits]

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@@ -956,57 +981,57 @@ void VPlan::execute(VPTransformState *State) {
   for (VPBlockBase *Block : RPOT)
     Block->execute(State);
 
-  State->CFG.DTU.flush();
-
-  auto *LoopRegion = getVectorLoopRegion();
-  if (!LoopRegion)
-    return;
-
-  VPBasicBlock *LatchVPBB = LoopRegion->getExitingBasicBlock();
-  BasicBlock *VectorLatchBB = State->CFG.VPBB2IRBB[LatchVPBB];
-
   // Fix the latch value of canonical, reduction and first-order recurrences
   // phis in the vector loop.
-  VPBasicBlock *Header = LoopRegion->getEntryBasicBlock();
-  for (VPRecipeBase &R : Header->phis()) {
-    // Skip phi-like recipes that generate their backedege values themselves.
-    if (isa<VPWidenPHIRecipe>(&R))
+  for (VPBasicBlock *Header :
+       VPBlockUtils::blocksOnly<VPBasicBlock>(vp_depth_first_shallow(Entry))) {
+    if (!Header->isHeader(State->VPDT))
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fhahn wrote:

Yep, moved getSingleLoopHeader to VPlanUtils and used here, thanks

https://github.com/llvm/llvm-project/pull/117506