[VPlan] Improve code in VPInstruction::generate (NFC) (#169470)

Make miscellaneous improvements including inlining some expressions and
re-using the existing State.Builder reference.

Author: artagnon

llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp

@@ -594,10 +594,9 @@ Value *VPInstruction::generate(VPTransformState &State) {
       return Builder.CreateCmp(CmpInst::Predicate::ICMP_ULT, VIVElem0, ScalarTC,
                                Name);
 
-    auto *Int1Ty = Type::getInt1Ty(Builder.getContext());
-    auto PredTy = VectorType::get(
-        Int1Ty, State.VF * cast<ConstantInt>(getOperand(2)->getLiveInIRValue())
-                               ->getZExtValue());
+    ElementCount EC = State.VF.multiplyCoefficientBy(
+        cast<ConstantInt>(getOperand(2)->getLiveInIRValue())->getZExtValue());
+    auto *PredTy = VectorType::get(Builder.getInt1Ty(), EC);
     return Builder.CreateIntrinsic(Intrinsic::get_active_lane_mask,
                                    {PredTy, ScalarTC->getType()},
                                    {VIVElem0, ScalarTC}, nullptr, Name);
@@ -627,7 +626,7 @@ Value *VPInstruction::generate(VPTransformState &State) {
     Value *Step = createStepForVF(Builder, ScalarTC->getType(), State.VF, UF);
     Value *Sub = Builder.CreateSub(ScalarTC, Step);
     Value *Cmp = Builder.CreateICmp(CmpInst::Predicate::ICMP_UGT, ScalarTC, Step);
-    Value *Zero = ConstantInt::get(ScalarTC->getType(), 0);
+    Value *Zero = ConstantInt::getNullValue(ScalarTC->getType());
     return Builder.CreateSelect(Cmp, Sub, Zero);
   }
   case VPInstruction::ExplicitVectorLength: {
@@ -639,11 +638,11 @@ Value *VPInstruction::generate(VPTransformState &State) {
            "Requested vector length should be an integer.");
 
     assert(State.VF.isScalable() && "Expected scalable vector factor.");
-    Value *VFArg = State.Builder.getInt32(State.VF.getKnownMinValue());
+    Value *VFArg = Builder.getInt32(State.VF.getKnownMinValue());
 
-    Value *EVL = State.Builder.CreateIntrinsic(
-        State.Builder.getInt32Ty(), Intrinsic::experimental_get_vector_length,
-        {AVL, VFArg, State.Builder.getTrue()});
+    Value *EVL = Builder.CreateIntrinsic(
+        Builder.getInt32Ty(), Intrinsic::experimental_get_vector_length,
+        {AVL, VFArg, Builder.getTrue()});
     return EVL;
   }
   case VPInstruction::CanonicalIVIncrementForPart: {
@@ -697,8 +696,8 @@ Value *VPInstruction::generate(VPTransformState &State) {
     auto NumOfElements = ElementCount::getFixed(getNumOperands());
     Value *Res = PoisonValue::get(toVectorizedTy(ScalarTy, NumOfElements));
     for (const auto &[Idx, Op] : enumerate(operands()))
-      Res = State.Builder.CreateInsertElement(Res, State.get(Op, true),
-                                              State.Builder.getInt32(Idx));
+      Res = Builder.CreateInsertElement(Res, State.get(Op, true),
+                                        Builder.getInt32(Idx));
     return Res;
   }
   case VPInstruction::ReductionStartVector: {
@@ -711,9 +710,8 @@ Value *VPInstruction::generate(VPTransformState &State) {
     ElementCount VF = State.VF.divideCoefficientBy(
         cast<ConstantInt>(getOperand(2)->getLiveInIRValue())->getZExtValue());
     auto *Iden = Builder.CreateVectorSplat(VF, State.get(getOperand(1), true));
-    Constant *Zero = Builder.getInt32(0);
     return Builder.CreateInsertElement(Iden, State.get(getOperand(0), true),
-                                       Zero);
+                                       Builder.getInt32(0));
   }
   case VPInstruction::ComputeAnyOfResult: {
     // FIXME: The cross-recipe dependency on VPReductionPHIRecipe is temporary
@@ -790,14 +788,12 @@ Value *VPInstruction::generate(VPTransformState &State) {
         if (RecurrenceDescriptor::isMinMaxRecurrenceKind(RK))
           ReducedPartRdx = createMinMaxOp(Builder, RK, ReducedPartRdx, RdxPart);
         else {
-          Instruction::BinaryOps Opcode;
           // For sub-recurrences, each UF's reduction variable is already
           // negative, we need to do: reduce.add(-acc_uf0 + -acc_uf1)
-          if (RK == RecurKind::Sub)
-            Opcode = Instruction::Add;
-          else
-            Opcode =
-                (Instruction::BinaryOps)RecurrenceDescriptor::getOpcode(RK);
+          Instruction::BinaryOps Opcode =
+              RK == RecurKind::Sub
+                  ? Instruction::Add
+                  : (Instruction::BinaryOps)RecurrenceDescriptor::getOpcode(RK);
           ReducedPartRdx =
               Builder.CreateBinOp(Opcode, RdxPart, ReducedPartRdx, "bin.rdx");
         }
@@ -862,7 +858,7 @@ Value *VPInstruction::generate(VPTransformState &State) {
     Value *LaneToExtract = State.get(getOperand(0), true);
     Type *IdxTy = State.TypeAnalysis.inferScalarType(getOperand(0));
     Value *Res = nullptr;
-    Value *RuntimeVF = getRuntimeVF(State.Builder, IdxTy, State.VF);
+    Value *RuntimeVF = getRuntimeVF(Builder, IdxTy, State.VF);
 
     for (unsigned Idx = 1; Idx != getNumOperands(); ++Idx) {
       Value *VectorStart =
@@ -892,8 +888,7 @@ Value *VPInstruction::generate(VPTransformState &State) {
     // If there are multiple operands, create a chain of selects to pick the
     // first operand with an active lane and add the number of lanes of the
     // preceding operands.
-    Value *RuntimeVF =
-        getRuntimeVF(State.Builder, State.Builder.getInt64Ty(), State.VF);
+    Value *RuntimeVF = getRuntimeVF(Builder, Builder.getInt64Ty(), State.VF);
     unsigned LastOpIdx = getNumOperands() - 1;
     Value *Res = nullptr;
     for (int Idx = LastOpIdx; Idx >= 0; --Idx) {