[VPlan] Move isSingleScalar implementation to VPlanUtils.cpp (NFC)

Move the implementation of vputils::isSingleScalar to VPlanUtils.cpp to
enable code sharing.

Author: fhahn

llvm/lib/Transforms/Vectorize/VPlanUtils.cpp

@@ -89,6 +89,60 @@ const SCEV *vputils::getSCEVExprForVPValue(VPValue *V, ScalarEvolution &SE) {
       .Default([&SE](const VPRecipeBase *) { return SE.getCouldNotCompute(); });
 }
 
+bool vputils::isSingleScalar(const VPValue *VPV) {
+  auto PreservesUniformity = [](unsigned Opcode) -> bool {
+    if (Instruction::isBinaryOp(Opcode) || Instruction::isCast(Opcode))
+      return true;
+    switch (Opcode) {
+    case Instruction::GetElementPtr:
+    case Instruction::ICmp:
+    case Instruction::FCmp:
+    case Instruction::Select:
+    case VPInstruction::Not:
+    case VPInstruction::Broadcast:
+    case VPInstruction::PtrAdd:
+      return true;
+    default:
+      return false;
+    }
+  };
+
+  // A live-in must be uniform across the scope of VPlan.
+  if (VPV->isLiveIn())
+    return true;
+
+  if (auto *Rep = dyn_cast<VPReplicateRecipe>(VPV)) {
+    const VPRegionBlock *RegionOfR = Rep->getRegion();
+    // Don't consider recipes in replicate regions as uniform yet; their first
+    // lane cannot be accessed when executing the replicate region for other
+    // lanes.
+    if (RegionOfR && RegionOfR->isReplicator())
+      return false;
+    return Rep->isSingleScalar() || (PreservesUniformity(Rep->getOpcode()) &&
+                                     all_of(Rep->operands(), isSingleScalar));
+  }
+  if (isa<VPWidenGEPRecipe, VPDerivedIVRecipe, VPBlendRecipe,
+          VPWidenSelectRecipe>(VPV))
+    return all_of(VPV->getDefiningRecipe()->operands(), isSingleScalar);
+  if (auto *WidenR = dyn_cast<VPWidenRecipe>(VPV)) {
+    return PreservesUniformity(WidenR->getOpcode()) &&
+           all_of(WidenR->operands(), isSingleScalar);
+  }
+  if (auto *VPI = dyn_cast<VPInstruction>(VPV))
+    return VPI->isSingleScalar() || VPI->isVectorToScalar() ||
+           (PreservesUniformity(VPI->getOpcode()) &&
+            all_of(VPI->operands(), isSingleScalar));
+  if (isa<VPPartialReductionRecipe>(VPV))
+    return false;
+  if (isa<VPReductionRecipe>(VPV))
+    return true;
+  if (auto *Expr = dyn_cast<VPExpressionRecipe>(VPV))
+    return Expr->isSingleScalar();
+
+  // VPExpandSCEVRecipes must be placed in the entry and are always uniform.
+  return isa<VPExpandSCEVRecipe>(VPV);
+}
+
 bool vputils::isUniformAcrossVFsAndUFs(VPValue *V) {
   // Live-ins are uniform.
   if (V->isLiveIn())

llvm/lib/Transforms/Vectorize/VPlanUtils.h

@@ -41,59 +41,7 @@ const SCEV *getSCEVExprForVPValue(VPValue *V, ScalarEvolution &SE);
 
 /// Returns true if \p VPV is a single scalar, either because it produces the
 /// same value for all lanes or only has its first lane used.
-inline bool isSingleScalar(const VPValue *VPV) {
-  auto PreservesUniformity = [](unsigned Opcode) -> bool {
-    if (Instruction::isBinaryOp(Opcode) || Instruction::isCast(Opcode))
-      return true;
-    switch (Opcode) {
-    case Instruction::GetElementPtr:
-    case Instruction::ICmp:
-    case Instruction::FCmp:
-    case Instruction::Select:
-    case VPInstruction::Not:
-    case VPInstruction::Broadcast:
-    case VPInstruction::PtrAdd:
-      return true;
-    default:
-      return false;
-    }
-  };
-
-  // A live-in must be uniform across the scope of VPlan.
-  if (VPV->isLiveIn())
-    return true;
-
-  if (auto *Rep = dyn_cast<VPReplicateRecipe>(VPV)) {
-    const VPRegionBlock *RegionOfR = Rep->getRegion();
-    // Don't consider recipes in replicate regions as uniform yet; their first
-    // lane cannot be accessed when executing the replicate region for other
-    // lanes.
-    if (RegionOfR && RegionOfR->isReplicator())
-      return false;
-    return Rep->isSingleScalar() || (PreservesUniformity(Rep->getOpcode()) &&
-                                     all_of(Rep->operands(), isSingleScalar));
-  }
-  if (isa<VPWidenGEPRecipe, VPDerivedIVRecipe, VPBlendRecipe,
-          VPWidenSelectRecipe>(VPV))
-    return all_of(VPV->getDefiningRecipe()->operands(), isSingleScalar);
-  if (auto *WidenR = dyn_cast<VPWidenRecipe>(VPV)) {
-    return PreservesUniformity(WidenR->getOpcode()) &&
-           all_of(WidenR->operands(), isSingleScalar);
-  }
-  if (auto *VPI = dyn_cast<VPInstruction>(VPV))
-    return VPI->isSingleScalar() || VPI->isVectorToScalar() ||
-           (PreservesUniformity(VPI->getOpcode()) &&
-            all_of(VPI->operands(), isSingleScalar));
-  if (isa<VPPartialReductionRecipe>(VPV))
-    return false;
-  if (isa<VPReductionRecipe>(VPV))
-    return true;
-  if (auto *Expr = dyn_cast<VPExpressionRecipe>(VPV))
-    return Expr->isSingleScalar();
-
-  // VPExpandSCEVRecipes must be placed in the entry and are alway uniform.
-  return isa<VPExpandSCEVRecipe>(VPV);
-}
+bool isSingleScalar(const VPValue *VPV);
 
 /// Return true if \p V is a header mask in \p Plan.
 bool isHeaderMask(const VPValue *V, const VPlan &Plan);