1 files changed, 58 insertions, 16 deletions

diff --git a/llvm/lib/Transforms/Vectorize/VPlan.h b/llvm/lib/Transforms/Vectorize/VPlan.h
index 707a826..77577b5 100644
--- a/llvm/lib/Transforms/Vectorize/VPlan.h
+++ b/llvm/lib/Transforms/Vectorize/VPlan.h
@@ -242,6 +242,15 @@ struct VPTransformState {
   ElementCount VF;
   unsigned UF;
 
+  /// If EVL (Explicit Vector Length) is not nullptr, then EVL must be a valid
+  /// value set during plan transformation, possibly a default value = whole
+  /// vector register length. EVL is created only if TTI prefers predicated
+  /// vectorization, thus if EVL is not nullptr it also implies preference for
+  /// predicated vectorization.
+  /// TODO: this is a temporarily solution, the EVL must be explicitly used by
+  /// the recipes and must be removed here.
+  VPValue *EVL = nullptr;
+
   /// Hold the indices to generate specific scalar instructions. Null indicates
   /// that all instances are to be generated, using either scalar or vector
   /// instructions.
@@ -346,11 +355,7 @@ struct VPTransformState {
   /// This includes both the original MDs from \p From and additional ones (\see
   /// addNewMetadata).  Use this for *newly created* instructions in the vector
   /// loop.
-  void addMetadata(Instruction *To, Instruction *From);
-
-  /// Similar to the previous function but it adds the metadata to a
-  /// vector of instructions.
-  void addMetadata(ArrayRef<Value *> To, Instruction *From);
+  void addMetadata(Value *To, Instruction *From);
 
   /// Set the debug location in the builder using the debug location \p DL.
   void setDebugLocFrom(DebugLoc DL);
@@ -1163,6 +1168,7 @@ public:
     SLPLoad,
     SLPStore,
     ActiveLaneMask,
+    ExplicitVectorLength,
     CalculateTripCountMinusVF,
     // Increment the canonical IV separately for each unrolled part.
     CanonicalIVIncrementForPart,
@@ -2493,6 +2499,45 @@ public:
 #endif
 };
 
+/// A recipe for generating the phi node for the current index of elements,
+/// adjusted in accordance with EVL value. It starts at the start value of the
+/// canonical induction and gets incremented by EVL in each iteration of the
+/// vector loop.
+class VPEVLBasedIVPHIRecipe : public VPHeaderPHIRecipe {
+public:
+  VPEVLBasedIVPHIRecipe(VPValue *StartIV, DebugLoc DL)
+      : VPHeaderPHIRecipe(VPDef::VPEVLBasedIVPHISC, nullptr, StartIV, DL) {}
+
+  ~VPEVLBasedIVPHIRecipe() override = default;
+
+  VPEVLBasedIVPHIRecipe *clone() override {
+    llvm_unreachable("cloning not implemented yet");
+  }
+
+  VP_CLASSOF_IMPL(VPDef::VPEVLBasedIVPHISC)
+
+  static inline bool classof(const VPHeaderPHIRecipe *D) {
+    return D->getVPDefID() == VPDef::VPEVLBasedIVPHISC;
+  }
+
+  /// Generate phi for handling IV based on EVL over iterations correctly.
+  /// TODO: investigate if it can share the code with VPCanonicalIVPHIRecipe.
+  void execute(VPTransformState &State) override;
+
+  /// Returns true if the recipe only uses the first lane of operand \p Op.
+  bool onlyFirstLaneUsed(const VPValue *Op) const override {
+    assert(is_contained(operands(), Op) &&
+           "Op must be an operand of the recipe");
+    return true;
+  }
+
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+  /// Print the recipe.
+  void print(raw_ostream &O, const Twine &Indent,
+             VPSlotTracker &SlotTracker) const override;
+#endif
+};
+
 /// A Recipe for widening the canonical induction variable of the vector loop.
 class VPWidenCanonicalIVRecipe : public VPSingleDefRecipe {
 public:
@@ -2526,8 +2571,8 @@ public:
   }
 };
 
-/// A recipe for converting the canonical IV value to the corresponding value of
-/// an IV with different start and step values, using Start + CanonicalIV *
+/// A recipe for converting the input value \p IV value to the corresponding
+/// value of an IV with different start and step values, using Start + IV *
 /// Step.
 class VPDerivedIVRecipe : public VPSingleDefRecipe {
   /// Kind of the induction.
@@ -2545,16 +2590,16 @@ public:
             Start, CanonicalIV, Step) {}
 
   VPDerivedIVRecipe(InductionDescriptor::InductionKind Kind,
-                    const FPMathOperator *FPBinOp, VPValue *Start,
-                    VPCanonicalIVPHIRecipe *CanonicalIV, VPValue *Step)
-      : VPSingleDefRecipe(VPDef::VPDerivedIVSC, {Start, CanonicalIV, Step}),
-        Kind(Kind), FPBinOp(FPBinOp) {}
+                    const FPMathOperator *FPBinOp, VPValue *Start, VPValue *IV,
+                    VPValue *Step)
+      : VPSingleDefRecipe(VPDef::VPDerivedIVSC, {Start, IV, Step}), Kind(Kind),
+        FPBinOp(FPBinOp) {}
 
   ~VPDerivedIVRecipe() override = default;
 
   VPRecipeBase *clone() override {
-    return new VPDerivedIVRecipe(Kind, FPBinOp, getStartValue(),
-                                 getCanonicalIV(), getStepValue());
+    return new VPDerivedIVRecipe(Kind, FPBinOp, getStartValue(), getOperand(1),
+                                 getStepValue());
   }
 
   VP_CLASSOF_IMPL(VPDef::VPDerivedIVSC)
@@ -2574,9 +2619,6 @@ public:
   }
 
   VPValue *getStartValue() const { return getOperand(0); }
-  VPCanonicalIVPHIRecipe *getCanonicalIV() const {
-    return cast<VPCanonicalIVPHIRecipe>(getOperand(1));
-  }
   VPValue *getStepValue() const { return getOperand(2); }
 
   /// Returns true if the recipe only uses the first lane of operand \p Op.