Addressed comments + rebase

Author: nikolaypanchenko

llvm/lib/Transforms/Vectorize/VPlan.h

@@ -1476,7 +1476,8 @@ class VPWidenEVLRecipe : public VPWidenRecipe {
   VPValue *getEVL() { return getOperand(getNumOperands() - 1); }
   const VPValue *getEVL() const { return getOperand(getNumOperands() - 1); }
 
-  /// Produce widened copies of all Ingredients.
+  /// Produce a vp-intrinsic using the opcode and operands of the recipe,
+  /// processing EVL elements.
   void execute(VPTransformState &State) override final;
 
   /// Returns true if the recipe only uses the first lane of operand \p Op.

llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp

@@ -1229,7 +1229,6 @@ void VPWidenEVLRecipe::execute(VPTransformState &State) {
                           "explicit vector length.");
   VPValue *Op0 = getOperand(0);
 
-  // If it's scalar operation, hand translation over to VPWidenRecipe
   assert(State.get(Op0, 0)->getType()->isVectorTy() &&
          "VPWidenEVLRecipe should not be used for scalars");
 
@@ -1256,9 +1255,8 @@ void VPWidenEVLRecipe::execute(VPTransformState &State) {
     VPInst = Builder.createVectorInstruction(Opcode, Ops[0]->getType(), Ops,
                                              "vp.op");
 
-    if (I)
-      if (auto *VecOp = dyn_cast<Instruction>(VPInst))
-        VecOp->copyIRFlags(I);
+    if (auto *VecOp = dyn_cast_or_null<Instruction>(VPInst))
+      VecOp->copyIRFlags(I);
   } else {
     llvm_unreachable("Unsupported opcode in VPWidenEVLRecipe::execute");
   }

llvm/test/Transforms/LoopVectorize/RISCV/vplan-vp-intrinsics.ll

@@ -31,7 +31,7 @@ define void @foo(ptr noalias %a, ptr noalias %b, ptr noalias %c, i64 %N) {
 ; IF-EVL-NEXT:    CLONE ir<[[GEP2:%.+]]> = getelementptr inbounds ir<%c>, vp<[[ST]]>
 ; IF-EVL-NEXT:    vp<[[PTR2:%[0-9]+]]> = vector-pointer ir<[[GEP2]]>
 ; IF-EVL-NEXT:    WIDEN ir<[[LD2:%.+]]> = vp.load vp<[[PTR2]]>, vp<[[EVL]]>
-; IF-EVL-NEXT:    WIDEN-VP ir<[[ADD:%.+]]> = add nsw ir<[[LD2]]>, ir<[[LD1]]>
+; IF-EVL-NEXT:    WIDEN-VP ir<[[ADD:%.+]]> = add nsw ir<[[LD2]]>, ir<[[LD1]]>, vp<[[EVL]]>
 ; IF-EVL-NEXT:    CLONE ir<[[GEP3:%.+]]> = getelementptr inbounds ir<%a>, vp<[[ST]]>
 ; IF-EVL-NEXT:    vp<[[PTR3:%[0-9]+]]> = vector-pointer ir<[[GEP3]]>
 ; IF-EVL-NEXT:    WIDEN vp.store vp<[[PTR3]]>, ir<[[ADD]]>, vp<[[EVL]]>