[llvm] 9129e7b - [LV] Replace OrigPHIsToFix in native with VPlan traversal. (NFC)

[Florian Hahn via llvm-commits]

Author: Florian Hahn
Date: 2022-06-13T22:20:58+01:00
New Revision: 9129e7bb541b8f83a0acefe541b6887837178d8e

URL: https://github.com/llvm/llvm-project/commit/9129e7bb541b8f83a0acefe541b6887837178d8e
DIFF: https://github.com/llvm/llvm-project/commit/9129e7bb541b8f83a0acefe541b6887837178d8e.diff

LOG: [LV] Replace OrigPHIsToFix in native with VPlan traversal. (NFC)

OrigPHIsToFix is only used in the native path. Collecting phis can be
replaced by iterating over the plan. This also removes another
unnecessary use of a late getVPValue.

This also reduces the coupling between ILV and the VPlan utilities.

Added: 
    

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

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 70a8fd89dfbb..677633a9ae88 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -515,8 +515,8 @@ class InnerLoopVectorizer {
   void setDebugLocFromInst(const Value *V,
                            Optional<IRBuilderBase *> CustomBuilder = None);
 
-  /// Fix the non-induction PHIs in the OrigPHIsToFix vector.
-  void fixNonInductionPHIs(VPTransformState &State);
+  /// Fix the non-induction PHIs in \p Plan.
+  void fixNonInductionPHIs(VPlan &Plan, VPTransformState &State);
 
   /// Returns true if the reordering of FP operations is not allowed, but we are
   /// able to vectorize with strict in-order reductions for the given RdxDesc.
@@ -741,10 +741,6 @@ class InnerLoopVectorizer {
   // so we can later fix-up the external users of the induction variables.
   DenseMap<PHINode *, Value *> IVEndValues;
 
-  // Vector of original scalar PHIs whose corresponding widened PHIs need to be
-  // fixed up at the end of vector code generation.
-  SmallVector<PHINode *, 8> OrigPHIsToFix;
-
   /// BFI and PSI are used to check for profile guided size optimizations.
   BlockFrequencyInfo *BFI;
   ProfileSummaryInfo *PSI;
@@ -3666,11 +3662,8 @@ void InnerLoopVectorizer::fixVectorizedLoop(VPTransformState &State,
     truncateToMinimalBitwidths(State);
 
   // Fix widened non-induction PHIs by setting up the PHI operands.
-  if (OrigPHIsToFix.size()) {
-    assert(EnableVPlanNativePath &&
-           "Unexpected non-induction PHIs for fixup in non VPlan-native path");
-    fixNonInductionPHIs(State);
-  }
+  if (EnableVPlanNativePath)
+    fixNonInductionPHIs(Plan, State);
 
   // At this point every instruction in the original loop is widened to a
   // vector form. Now we need to fix the recurrences in the loop. These PHI
@@ -4166,17 +4159,23 @@ void InnerLoopVectorizer::sinkScalarOperands(Instruction *PredInst) {
   } while (Changed);
 }
 
-void InnerLoopVectorizer::fixNonInductionPHIs(VPTransformState &State) {
-  for (PHINode *OrigPhi : OrigPHIsToFix) {
-    VPWidenPHIRecipe *VPPhi =
-        cast<VPWidenPHIRecipe>(State.Plan->getVPValue(OrigPhi));
-    PHINode *NewPhi = cast<PHINode>(State.get(VPPhi, 0));
-    // Make sure the builder has a valid insert point.
-    Builder.SetInsertPoint(NewPhi);
-    for (unsigned i = 0; i < VPPhi->getNumOperands(); ++i) {
-      VPValue *Inc = VPPhi->getIncomingValue(i);
-      VPBasicBlock *VPBB = VPPhi->getIncomingBlock(i);
-      NewPhi->addIncoming(State.get(Inc, 0), State.CFG.VPBB2IRBB[VPBB]);
+void InnerLoopVectorizer::fixNonInductionPHIs(VPlan &Plan,
+                                              VPTransformState &State) {
+  auto Iter = depth_first(
+      VPBlockRecursiveTraversalWrapper<VPBlockBase *>(Plan.getEntry()));
+  for (VPBasicBlock *VPBB : VPBlockUtils::blocksOnly<VPBasicBlock>(Iter)) {
+    for (VPRecipeBase &P : VPBB->phis()) {
+      VPWidenPHIRecipe *VPPhi = dyn_cast<VPWidenPHIRecipe>(&P);
+      if (!VPPhi)
+        continue;
+      PHINode *NewPhi = cast<PHINode>(State.get(VPPhi, 0));
+      // Make sure the builder has a valid insert point.
+      Builder.SetInsertPoint(NewPhi);
+      for (unsigned i = 0; i < VPPhi->getNumOperands(); ++i) {
+        VPValue *Inc = VPPhi->getIncomingValue(i);
+        VPBasicBlock *VPBB = VPPhi->getIncomingBlock(i);
+        NewPhi->addIncoming(State.get(Inc, 0), State.CFG.VPBB2IRBB[VPBB]);
+      }
     }
   }
 }
@@ -4200,7 +4199,6 @@ void InnerLoopVectorizer::widenPHIInstruction(Instruction *PN,
                     : VectorType::get(PN->getType(), State.VF);
   Value *VecPhi = Builder.CreatePHI(VecTy, PN->getNumOperands(), "vec.phi");
   State.set(PhiR, VecPhi, 0);
-  OrigPHIsToFix.push_back(cast<PHINode>(PN));
 }
 
 /// A helper function for checking whether an integer division-related