[VPlan] Introduce vputils::onlyScalarValuesUsed (NFC) (#153577)

Author: artagnon

llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp

@@ -517,10 +517,7 @@ static void removeRedundantCanonicalIVs(VPlan &Plan) {
     // everything WidenNewIV's users need. That is, WidenOriginalIV will
     // generate a vector phi or all users of WidenNewIV demand the first lane
     // only.
-    if (any_of(WidenOriginalIV->users(),
-               [WidenOriginalIV](VPUser *U) {
-                 return !U->usesScalars(WidenOriginalIV);
-               }) ||
+    if (!vputils::onlyScalarValuesUsed(WidenOriginalIV) ||
         vputils::onlyFirstLaneUsed(WidenNewIV)) {
       WidenNewIV->replaceAllUsesWith(WidenOriginalIV);
       WidenNewIV->eraseFromParent();
@@ -1263,9 +1260,7 @@ static void narrowToSingleScalarRecipes(VPlan &Plan) {
       // scalar results used. In the latter case, we would introduce extra
       // broadcasts.
       if (!vputils::isSingleScalar(RepOrWidenR) ||
-          any_of(RepOrWidenR->users(), [RepOrWidenR](VPUser *U) {
-            return !U->usesScalars(RepOrWidenR);
-          }))
+          !vputils::onlyScalarValuesUsed(RepOrWidenR))
         continue;
 
       auto *Clone = new VPReplicateRecipe(RepOrWidenR->getUnderlyingInstr(),
@@ -3216,8 +3211,7 @@ void VPlanTransforms::materializeBroadcasts(VPlan &Plan) {
 
   auto *VectorPreheader = Plan.getVectorPreheader();
   for (VPValue *VPV : VPValues) {
-    if (all_of(VPV->users(),
-               [VPV](VPUser *U) { return U->usesScalars(VPV); }) ||
+    if (vputils::onlyScalarValuesUsed(VPV) ||
         (VPV->isLiveIn() && VPV->getLiveInIRValue() &&
          isa<Constant>(VPV->getLiveInIRValue())))
       continue;
@@ -3373,7 +3367,7 @@ void VPlanTransforms::materializeVFAndVFxUF(VPlan &Plan, VPBasicBlock *VectorPH,
   // For users of the runtime VF, compute it as VF * vscale, and VFxUF as (VF *
   // vscale) * UF.
   VPValue *RuntimeVF = Builder.createElementCount(TCTy, VFEC);
-  if (any_of(VF.users(), [&VF](VPUser *U) { return !U->usesScalars(&VF); })) {
+  if (!vputils::onlyScalarValuesUsed(&VF)) {
     VPValue *BC = Builder.createNaryOp(VPInstruction::Broadcast, RuntimeVF);
     VF.replaceUsesWithIf(
         BC, [&VF](VPUser &U, unsigned) { return !U.usesScalars(&VF); });

llvm/lib/Transforms/Vectorize/VPlanUtils.cpp

@@ -24,6 +24,11 @@ bool vputils::onlyFirstPartUsed(const VPValue *Def) {
                 [Def](const VPUser *U) { return U->onlyFirstPartUsed(Def); });
 }
 
+bool vputils::onlyScalarValuesUsed(const VPValue *Def) {
+  return all_of(Def->users(),
+                [Def](const VPUser *U) { return U->usesScalars(Def); });
+}
+
 VPValue *vputils::getOrCreateVPValueForSCEVExpr(VPlan &Plan, const SCEV *Expr,
                                                 ScalarEvolution &SE) {
   if (auto *Expanded = Plan.getSCEVExpansion(Expr))

llvm/lib/Transforms/Vectorize/VPlanUtils.h

@@ -25,6 +25,9 @@ bool onlyFirstLaneUsed(const VPValue *Def);
 /// Returns true if only the first part of \p Def is used.
 bool onlyFirstPartUsed(const VPValue *Def);
 
+/// Returns true if only scalar values of \p Def are used by all users.
+bool onlyScalarValuesUsed(const VPValue *Def);
+
 /// Get or create a VPValue that corresponds to the expansion of \p Expr. If \p
 /// Expr is a SCEVConstant or SCEVUnknown, return a VPValue wrapping the live-in
 /// value. Otherwise return a VPExpandSCEVRecipe to expand \p Expr. If \p Plan's