[PATCH] D125029: [VPlan] Exit earlier when trying to widen with scalar VFs.

[Florian Hahn via Phabricator via llvm-commits]

This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
fhahn marked 2 inline comments as done.
Closed by commit rGc6e45ea0743b: [VPlan] Exit earlier when trying to widen with scalar VFs. (authored by fhahn).

Changed prior to commit:
  https://reviews.llvm.org/D125029?vs=431246&id=431926#toc

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D125029/new/

https://reviews.llvm.org/D125029

Files:
  llvm/lib/Transforms/Vectorize/LoopVectorize.cpp


Index: llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
===================================================================
--- llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -8137,8 +8137,6 @@
          "Must be called with either a load or store");
 
   auto willWiden = [&](ElementCount VF) -> bool {
-    if (VF.isScalar())
-      return false;
     LoopVectorizationCostModel::InstWidening Decision =
         CM.getWideningDecision(I, VF);
     assert(Decision != LoopVectorizationCostModel::CM_Unknown &&
@@ -8335,8 +8333,6 @@
     return nullptr;
 
   auto willWiden = [&](ElementCount VF) -> bool {
-    if (VF.isScalar())
-       return false;
     Intrinsic::ID ID = getVectorIntrinsicIDForCall(CI, TLI);
     // The following case may be scalarized depending on the VF.
     // The flag shows whether we use Intrinsic or a usual Call for vectorized
@@ -8550,14 +8546,8 @@
 VPRecipeBuilder::tryToCreateWidenRecipe(Instruction *Instr,
                                         ArrayRef<VPValue *> Operands,
                                         VFRange &Range, VPlanPtr &Plan) {
-  // First, check for specific widening recipes that deal with calls, memory
-  // operations, inductions and Phi nodes.
-  if (auto *CI = dyn_cast<CallInst>(Instr))
-    return toVPRecipeResult(tryToWidenCall(CI, Operands, Range));
-
-  if (isa<LoadInst>(Instr) || isa<StoreInst>(Instr))
-    return toVPRecipeResult(tryToWidenMemory(Instr, Operands, Range, Plan));
-
+  // First, check for specific widening recipes that deal with inductions, Phi
+  // nodes, calls and memory operations.
   VPRecipeBase *Recipe;
   if (auto Phi = dyn_cast<PHINode>(Instr)) {
     if (Phi->getParent() != OrigLoop->getHeader())
@@ -8595,6 +8585,17 @@
                                                Range, *Plan)))
     return toVPRecipeResult(Recipe);
 
+  // All widen recipes below deal only with VF > 1.
+  if (LoopVectorizationPlanner::getDecisionAndClampRange(
+          [&](ElementCount VF) { return VF.isScalar(); }, Range))
+    return nullptr;
+
+  if (auto *CI = dyn_cast<CallInst>(Instr))
+    return toVPRecipeResult(tryToWidenCall(CI, Operands, Range));
+
+  if (isa<LoadInst>(Instr) || isa<StoreInst>(Instr))
+    return toVPRecipeResult(tryToWidenMemory(Instr, Operands, Range, Plan));
+
   if (!shouldWiden(Instr, Range))
     return nullptr;
 


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