[llvm] 2d8bcb5 - [VPlan] Lift isUsedByLoadStoreAddr into vputils, operate on VPValue(NFC) (#196415)

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Sat May 9 12:16:05 PDT 2026


Author: Florian Hahn
Date: 2026-05-09T21:16:01+02:00
New Revision: 2d8bcb5fab244bc263e2450857788ef1a5c2b9c1

URL: https://github.com/llvm/llvm-project/commit/2d8bcb5fab244bc263e2450857788ef1a5c2b9c1
DIFF: https://github.com/llvm/llvm-project/commit/2d8bcb5fab244bc263e2450857788ef1a5c2b9c1.diff

LOG: [VPlan] Lift isUsedByLoadStoreAddr into vputils, operate on VPValue(NFC) (#196415)

Extract the helper previously scoped to VPReplicateRecipe::computeCost
and make it available from VPlanUtils so other transforms can query
whether a VPValue is used as part of another load or store's address.

Also relax the input type from VPUser * to VPValue *: the worklist now
tracks VPValues directly, and traversal is gated on the user being a
VPSingleDefRecipe before walking its own users. This is NFC for the
existing caller.

Added: 
    

Modified: 
    llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
    llvm/lib/Transforms/Vectorize/VPlanUtils.cpp
    llvm/lib/Transforms/Vectorize/VPlanUtils.h

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
index d04b5edcfc212..11a91dcd46867 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
@@ -3347,56 +3347,6 @@ static const SCEV *getAddressAccessSCEV(const VPValue *Ptr,
   return vputils::isAddressSCEVForCost(Addr, *PSE.getSE(), L) ? Addr : nullptr;
 }
 
-/// Returns true if \p V is used as part of the address of another load or
-/// store.
-static bool isUsedByLoadStoreAddress(const VPUser *V) {
-  SmallPtrSet<const VPUser *, 4> Seen;
-  SmallVector<const VPUser *> WorkList = {V};
-
-  while (!WorkList.empty()) {
-    auto *Cur = dyn_cast<VPSingleDefRecipe>(WorkList.pop_back_val());
-    if (!Cur || !Seen.insert(Cur).second)
-      continue;
-
-    auto *Blend = dyn_cast<VPBlendRecipe>(Cur);
-    // Skip blends that use V only through a compare by checking if any incoming
-    // value was already visited.
-    if (Blend && none_of(seq<unsigned>(0, Blend->getNumIncomingValues()),
-                         [&](unsigned I) {
-                           return Seen.contains(
-                               Blend->getIncomingValue(I)->getDefiningRecipe());
-                         }))
-      continue;
-
-    for (VPUser *U : Cur->users()) {
-      if (auto *InterleaveR = dyn_cast<VPInterleaveBase>(U))
-        if (InterleaveR->getAddr() == Cur)
-          return true;
-      if (auto *RepR = dyn_cast<VPReplicateRecipe>(U)) {
-        if (RepR->getOpcode() == Instruction::Load &&
-            RepR->getOperand(0) == Cur)
-          return true;
-        if (RepR->getOpcode() == Instruction::Store &&
-            RepR->getOperand(1) == Cur)
-          return true;
-      }
-      if (auto *MemR = dyn_cast<VPWidenMemoryRecipe>(U)) {
-        if (MemR->getAddr() == Cur && MemR->isConsecutive())
-          return true;
-      }
-    }
-
-    // The legacy cost model only supports scalarization loads/stores with phi
-    // addresses, if the phi is directly used as load/store address. Don't
-    // traverse further for Blends.
-    if (Blend)
-      continue;
-
-    append_range(WorkList, Cur->users());
-  }
-  return false;
-}
-
 /// Return true if \p R is a predicated load/store with a loop-invariant address
 /// only masked by the header mask.
 static bool isPredicatedUniformMemOpAfterTailFolding(const VPReplicateRecipe &R,
@@ -3539,7 +3489,7 @@ InstructionCost VPReplicateRecipe::computeCost(ElementCount VF,
     TTI::OperandValueInfo OpInfo = TTI::getOperandInfo(UI->getOperand(0));
     bool PreferVectorizedAddressing = Ctx.TTI.prefersVectorizedAddressing();
     bool UsedByLoadStoreAddress =
-        !PreferVectorizedAddressing && isUsedByLoadStoreAddress(this);
+        !PreferVectorizedAddressing && vputils::isUsedByLoadStoreAddress(this);
     InstructionCost ScalarMemOpCost = Ctx.TTI.getMemoryOpCost(
         UI->getOpcode(), ValTy, Alignment, AS, Ctx.CostKind, OpInfo,
         UsedByLoadStoreAddress ? UI : nullptr);

diff  --git a/llvm/lib/Transforms/Vectorize/VPlanUtils.cpp b/llvm/lib/Transforms/Vectorize/VPlanUtils.cpp
index b776d5c75a849..5b80fa15a5535 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanUtils.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanUtils.cpp
@@ -781,3 +781,54 @@ VPInstruction *vputils::findComputeReductionResult(VPReductionPHIRecipe *PhiR) {
   return vputils::findUserOf<VPInstruction::ComputeReductionResult>(
       cast<VPSingleDefRecipe>(SelR));
 }
+
+bool vputils::isUsedByLoadStoreAddress(const VPValue *V) {
+  SmallPtrSet<const VPValue *, 4> Seen;
+  SmallVector<const VPValue *> WorkList = {V};
+
+  while (!WorkList.empty()) {
+    const VPValue *Cur = WorkList.pop_back_val();
+    if (!Seen.insert(Cur).second)
+      continue;
+
+    auto *Blend = dyn_cast<VPBlendRecipe>(Cur);
+    // Skip blends that use V only through a compare by checking if any incoming
+    // value was already visited.
+    if (Blend && none_of(seq<unsigned>(0, Blend->getNumIncomingValues()),
+                         [&](unsigned I) {
+                           return Seen.contains(Blend->getIncomingValue(I));
+                         }))
+      continue;
+
+    for (VPUser *U : Cur->users()) {
+      if (auto *InterleaveR = dyn_cast<VPInterleaveBase>(U))
+        if (InterleaveR->getAddr() == Cur)
+          return true;
+      if (auto *RepR = dyn_cast<VPReplicateRecipe>(U)) {
+        if (RepR->getOpcode() == Instruction::Load &&
+            RepR->getOperand(0) == Cur)
+          return true;
+        if (RepR->getOpcode() == Instruction::Store &&
+            RepR->getOperand(1) == Cur)
+          return true;
+      }
+      if (auto *MemR = dyn_cast<VPWidenMemoryRecipe>(U)) {
+        if (MemR->getAddr() == Cur && MemR->isConsecutive())
+          return true;
+      }
+    }
+
+    // The legacy cost model only supports scalarization loads/stores with phi
+    // addresses, if the phi is directly used as load/store address. Don't
+    // traverse further for Blends.
+    if (Blend)
+      continue;
+
+    // Only traverse further through users that also define a value (and can
+    // thus have their own users walked).
+    for (VPUser *U : Cur->users())
+      if (auto *SDR = dyn_cast<VPSingleDefRecipe>(U))
+        WorkList.push_back(SDR);
+  }
+  return false;
+}

diff  --git a/llvm/lib/Transforms/Vectorize/VPlanUtils.h b/llvm/lib/Transforms/Vectorize/VPlanUtils.h
index ac3a1005c8f24..2a4b8566d8475 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanUtils.h
+++ b/llvm/lib/Transforms/Vectorize/VPlanUtils.h
@@ -159,6 +159,10 @@ VPInstruction *findCanonicalIVIncrement(VPlan &Plan);
 /// mirroring Value::stripPointerCasts.
 GEPNoWrapFlags getGEPFlagsForPtr(VPValue *Ptr);
 
+/// Returns true if \p V is used as part of the address of another load or
+/// store.
+bool isUsedByLoadStoreAddress(const VPValue *V);
+
 /// Find the ComputeReductionResult recipe for \p PhiR, looking through selects
 /// inserted for predicated reductions or tail folding.
 VPInstruction *findComputeReductionResult(VPReductionPHIRecipe *PhiR);


        


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