[llvm] [VPlan] Remove the unused CalculateTripCountMinusVF opcode (NFC) (PR #216675)

[Florian Hahn via llvm-commits]

https://github.com/fhahn created https://github.com/llvm/llvm-project/pull/216675

bcc272b3220f ("[LV] Remove DataAndControlFlowWithoutRuntimeCheck. NFC", #183762) removed the only createNaryOp building this opcode, leaving behind the enum entry and its cases for type inference, operand count, scalar generation, lowering and printing. Nothing constructs it, so no plan can contain it and no test prints it.

>From 97febf919bfca69bec589f6943104af6459f53b8 Mon Sep 17 00:00:00 2001
From: Florian Hahn <flo at fhahn.com>
Date: Sun, 16 Aug 2026 09:44:30 +0100
Subject: [PATCH] [VPlan] Remove the unused CalculateTripCountMinusVF opcode
 (NFC)

bcc272b3220f ("[LV] Remove DataAndControlFlowWithoutRuntimeCheck. NFC", #183762)
removed the only createNaryOp building this opcode, leaving behind the enum entry
and its cases for type inference, operand count, scalar generation, lowering and
printing. Nothing constructs it, so no plan can contain it and no test prints it.
---
 llvm/lib/Transforms/Vectorize/VPlan.h          |  1 -
 llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp | 17 -----------------
 2 files changed, 18 deletions(-)

diff --git a/llvm/lib/Transforms/Vectorize/VPlan.h b/llvm/lib/Transforms/Vectorize/VPlan.h
index b2e87a8f4f52d..4bb18e46c64ad 100644
--- a/llvm/lib/Transforms/Vectorize/VPlan.h
+++ b/llvm/lib/Transforms/Vectorize/VPlan.h
@@ -1257,7 +1257,6 @@ class LLVM_ABI_FOR_TEST VPInstruction : public VPRecipeWithIRFlags,
     // Represents the incoming loop-invariant alias-mask. All memory accesses
     // in the loop must stay within the active lanes.
     IncomingAliasMask,
-    CalculateTripCountMinusVF,
     // Increment the canonical IV separately for each unrolled part.
     CanonicalIVIncrementForPart,
     // Abstract instruction that compares two values and branches. This is
diff --git a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
index 53ab77fbd28b1..b5524948c1bd9 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
@@ -484,7 +484,6 @@ Type *llvm::computeScalarTypeForInstruction(unsigned Opcode,
     assert(Op0Ty->isIntegerTy() && "expected integer operand");
     AssertOperandType(1, Op0Ty);
     return Type::getVoidTy(Ctx);
-  case VPInstruction::CalculateTripCountMinusVF:
   case VPInstruction::CanonicalIVIncrementForPart:
     assert(Op0Ty->isIntegerTy() && "expected integer operand");
     for (unsigned Idx = 1; Idx != Operands.size(); ++Idx)
@@ -666,7 +665,6 @@ unsigned VPInstruction::getNumOperandsForOpcode() const {
   case VPInstruction::PtrAdd:
   case VPInstruction::WidePtrAdd:
   case VPInstruction::WideIVStep:
-  case VPInstruction::CalculateTripCountMinusVF:
   case VPInstruction::ResumeForEpilogue:
   case VPInstruction::ExtractVectorForPart:
     return 2;
@@ -717,7 +715,6 @@ bool VPInstruction::canGenerateScalarForFirstLane() const {
   case VPInstruction::BranchOnCond:
   case VPInstruction::BranchOnTwoConds:
   case VPInstruction::BranchOnCount:
-  case VPInstruction::CalculateTripCountMinusVF:
   case VPInstruction::CanonicalIVIncrementForPart:
   case VPInstruction::PtrAdd:
   case VPInstruction::ExplicitVectorLength:
@@ -852,15 +849,6 @@ Value *VPInstruction::generate(VPTransformState &State) {
     Value *V2 = State.get(getOperand(1));
     return Builder.CreateVectorSpliceRight(V1, V2, 1, Name);
   }
-  case VPInstruction::CalculateTripCountMinusVF: {
-    Value *ScalarTC = State.get(getOperand(0), VPLane(0));
-    Value *VFxUF = State.get(getOperand(1), VPLane(0));
-    Value *Sub = Builder.CreateSub(ScalarTC, VFxUF);
-    Value *Cmp =
-        Builder.CreateICmp(CmpInst::Predicate::ICMP_UGT, ScalarTC, VFxUF);
-    Value *Zero = ConstantInt::getNullValue(ScalarTC->getType());
-    return Builder.CreateSelect(Cmp, Sub, Zero);
-  }
   case VPInstruction::ExplicitVectorLength: {
     // TODO: Restructure this code with an explicit remainder loop, vsetvli can
     // be outside of the main loop.
@@ -1646,7 +1634,6 @@ bool VPInstruction::opcodeMayReadOrWriteFromMemory() const {
   case VPInstruction::Broadcast:
   case VPInstruction::BuildStructVector:
   case VPInstruction::BuildVector:
-  case VPInstruction::CalculateTripCountMinusVF:
   case VPInstruction::CanonicalIVIncrementForPart:
   case VPInstruction::ComputeReductionResult:
   case VPInstruction::ExtractLane:
@@ -1714,7 +1701,6 @@ bool VPInstruction::usesFirstLaneOnly(const VPValue *Op) const {
   case VPInstruction::ActiveLaneMask:
   case VPInstruction::WideActiveLaneMask:
   case VPInstruction::ExplicitVectorLength:
-  case VPInstruction::CalculateTripCountMinusVF:
   case VPInstruction::CanonicalIVIncrementForPart:
   case VPInstruction::BranchOnCount:
   case VPInstruction::BranchOnCond:
@@ -1803,9 +1789,6 @@ void VPInstruction::printRecipe(raw_ostream &O, const Twine &Indent,
   case VPInstruction::BranchOnTwoConds:
     O << "branch-on-two-conds";
     break;
-  case VPInstruction::CalculateTripCountMinusVF:
-    O << "TC > VF ? TC - VF : 0";
-    break;
   case VPInstruction::CanonicalIVIncrementForPart:
     O << "VF * Part +";
     break;