[LoopVectorizer] use TTI.getOperandInfo()

[jonpa]

Summary

Call getOperandInfo() instead of using (near) duplicated code in LoopVectorizationCostModel::getInstructionCost().

This gets the OperandValueKind and OperandValueProperties values for a Value passed as operand to an arithmetic instruction.

getOperandInfo() used to be a static method in TargetTransformInfo.cpp, but is now instead a public member. The method definition has been moved in the .cpp file to above getArithmeticInstrCost(), from the area of the static functions.

[fhahn]

lib/Analysis/TargetTransformInfo.cpp

390

Can TargetTransformInfo:: be dropped now that it is defined as a member function? That might make it slightly easier to read.

[jonpa]

TargetTransformInfo:: name parts removed in member function (did not compile if I also removed it on the return type).

[fhahn]

LGTM

lib/Transforms/Vectorize/LoopVectorize.cpp

5674

There's no need to initialize Op2VK here, it could just take the result of getOperandInfo directly.

[jonpa]

OK, I removed the initializer per your suggestion. I also removed the declarations of Op1VK and Op1VP, since this made the code more compact and also a bit more readable in the sense of which operand is actually being analyzed.

Does this look good to you?

[fhahn]

Great, that was exactly what I has hoping for! LGTM

[jonpa]

Thanks for review!

r343852.

include/llvm/Analysis/TargetTransformInfo.h

public:
   /// performed.
   unsigned getMaxPrefetchIterationsAhead() const;
 
   /// \return The maximum interleave factor that any transform should try to
   /// perform for this target. This number depends on the level of parallelism
   /// and the number of execution units in the CPU.
   unsigned getMaxInterleaveFactor(unsigned VF) const;
 
+  /// Collect properties of V used in cost analyzis, e.g. OP_PowerOf2.
+  OperandValueKind getOperandInfo(Value *V,
+                                  OperandValueProperties &OpProps) const;
+
   /// This is an approximation of reciprocal throughput of a math/logic op.
   /// A higher cost indicates less expected throughput.
   /// From Agner Fog's guides, reciprocal throughput is "the average number of
   /// clock cycles per instruction when the instructions are not part of a
   /// limiting dependency chain."
   /// Therefore, costs should be scaled to account for multiple execution units
   /// on the target that can process this type of instruction. For example, if
   /// there are 5 scalar integer units and 2 vector integer units that can

lib/Analysis/TargetTransformInfo.cpp

 unsigned TargetTransformInfo::getMaxPrefetchIterationsAhead() const {
   return TTIImpl->getMaxPrefetchIterationsAhead();
 }
 
 unsigned TargetTransformInfo::getMaxInterleaveFactor(unsigned VF) const {
   return TTIImpl->getMaxInterleaveFactor(VF);
 }
 
+TargetTransformInfo::OperandValueKind
+TargetTransformInfo::getOperandInfo(Value *V,
+                   TargetTransformInfo::OperandValueProperties &OpProps) const {
+  TargetTransformInfo::OperandValueKind OpInfo =
+      TargetTransformInfo::OK_AnyValue;
+  OpProps = TargetTransformInfo::OP_None;
+
+  if (auto *CI = dyn_cast<ConstantInt>(V)) {
+    if (CI->getValue().isPowerOf2())
+      OpProps = TargetTransformInfo::OP_PowerOf2;
+    return TargetTransformInfo::OK_UniformConstantValue;
+  }
+
+  const Value *Splat = getSplatValue(V);
+
+  // Check for a splat of a constant or for a non uniform vector of constants
+  // and check if the constant(s) are all powers of two.
+  if (isa<ConstantVector>(V) || isa<ConstantDataVector>(V)) {
+    OpInfo = TargetTransformInfo::OK_NonUniformConstantValue;
+    if (Splat) {
+      OpInfo = TargetTransformInfo::OK_UniformConstantValue;
+      if (auto *CI = dyn_cast<ConstantInt>(Splat))
+        if (CI->getValue().isPowerOf2())
+          OpProps = TargetTransformInfo::OP_PowerOf2;
+    } else if (auto *CDS = dyn_cast<ConstantDataSequential>(V)) {
+      OpProps = TargetTransformInfo::OP_PowerOf2;
+      for (unsigned I = 0, E = CDS->getNumElements(); I != E; ++I) {
+        if (auto *CI = dyn_cast<ConstantInt>(CDS->getElementAsConstant(I)))
+          if (CI->getValue().isPowerOf2())
+            continue;
+        OpProps = TargetTransformInfo::OP_None;
+        break;
+      }
+    }
+  }
+
+  // Check for a splat of a uniform value. This is not loop aware, so return
+  // true only for the obviously uniform cases (argument, globalvalue)
+  if (Splat && (isa<Argument>(Splat) || isa<GlobalValue>(Splat)))
+    OpInfo = TargetTransformInfo::OK_UniformValue;
+
+  return OpInfo;
+}
+
 int TargetTransformInfo::getArithmeticInstrCost(
     unsigned Opcode, Type *Ty, OperandValueKind Opd1Info,
     OperandValueKind Opd2Info, OperandValueProperties Opd1PropInfo,
     OperandValueProperties Opd2PropInfo,
     ArrayRef<const Value *> Args) const {
   int Cost = TTIImpl->getArithmeticInstrCost(Opcode, Ty, Opd1Info, Opd2Info,
                                              Opd1PropInfo, Opd2PropInfo, Args);
   assert(Cost >= 0 && "TTI should not produce negative costs!");

 bool TargetTransformInfo::shouldExpandReduction(const IntrinsicInst *II) const {
   return TTIImpl->shouldExpandReduction(II);
 }
 
 int TargetTransformInfo::getInstructionLatency(const Instruction *I) const {
   return TTIImpl->getInstructionLatency(I);
 }
 
-static TargetTransformInfo::OperandValueKind
-getOperandInfo(Value *V, TargetTransformInfo::OperandValueProperties &OpProps) {
-  TargetTransformInfo::OperandValueKind OpInfo =
-      TargetTransformInfo::OK_AnyValue;
-  OpProps = TargetTransformInfo::OP_None;
-
-  if (auto *CI = dyn_cast<ConstantInt>(V)) {
-    if (CI->getValue().isPowerOf2())
-      OpProps = TargetTransformInfo::OP_PowerOf2;
-    return TargetTransformInfo::OK_UniformConstantValue;
-  }
-
-  const Value *Splat = getSplatValue(V);
-
-  // Check for a splat of a constant or for a non uniform vector of constants
-  // and check if the constant(s) are all powers of two.
-  if (isa<ConstantVector>(V) || isa<ConstantDataVector>(V)) {
-    OpInfo = TargetTransformInfo::OK_NonUniformConstantValue;
-    if (Splat) {
-      OpInfo = TargetTransformInfo::OK_UniformConstantValue;
-      if (auto *CI = dyn_cast<ConstantInt>(Splat))
-        if (CI->getValue().isPowerOf2())
-          OpProps = TargetTransformInfo::OP_PowerOf2;
-    } else if (auto *CDS = dyn_cast<ConstantDataSequential>(V)) {
-      OpProps = TargetTransformInfo::OP_PowerOf2;
-      for (unsigned I = 0, E = CDS->getNumElements(); I != E; ++I) {
-        if (auto *CI = dyn_cast<ConstantInt>(CDS->getElementAsConstant(I)))
-          if (CI->getValue().isPowerOf2())
-            continue;
-        OpProps = TargetTransformInfo::OP_None;
-        break;
-      }
-    }
-  }
-
-  // Check for a splat of a uniform value. This is not loop aware, so return
-  // true only for the obviously uniform cases (argument, globalvalue)
-  if (Splat && (isa<Argument>(Splat) || isa<GlobalValue>(Splat)))
-    OpInfo = TargetTransformInfo::OK_UniformValue;
-
-  return OpInfo;
-}
-
 static bool matchPairwiseShuffleMask(ShuffleVectorInst *SI, bool IsLeft,
                                      unsigned Level) {
   // We don't need a shuffle if we just want to have element 0 in position 0 of
   // the vector.
   if (!SI && Level == 0 && IsLeft)
     return true;
   else if (!SI)
     return false;

lib/Transforms/Vectorize/LoopVectorize.cpp

unsigned LoopVectorizationCostModel::getInstructionCost(Instruction *I,
   case Instruction::Xor: {
     // Since we will replace the stride by 1 the multiplication should go away.
     if (I->getOpcode() == Instruction::Mul && isStrideMul(I, Legal))
       return 0;
     // Certain instructions can be cheaper to vectorize if they have a constant
     // second vector operand. One example of this are shifts on x86.
     TargetTransformInfo::OperandValueKind Op1VK =
         TargetTransformInfo::OK_AnyValue;
     TargetTransformInfo::OperandValueKind Op2VK =
         TargetTransformInfo::OK_AnyValue;
     TargetTransformInfo::OperandValueProperties Op1VP =
         TargetTransformInfo::OP_None;
     TargetTransformInfo::OperandValueProperties Op2VP =
         TargetTransformInfo::OP_None;
-    Value *Op2 = I->getOperand(1);
 
-    // Check for a splat or for a non uniform vector of constants.
-    if (isa<ConstantInt>(Op2)) {
-      ConstantInt *CInt = cast<ConstantInt>(Op2);
-      if (CInt && CInt->getValue().isPowerOf2())
-        Op2VP = TargetTransformInfo::OP_PowerOf2;
-      Op2VK = TargetTransformInfo::OK_UniformConstantValue;
-    } else if (isa<ConstantVector>(Op2) || isa<ConstantDataVector>(Op2)) {
-      Op2VK = TargetTransformInfo::OK_NonUniformConstantValue;
-      Constant *SplatValue = cast<Constant>(Op2)->getSplatValue();
-      if (SplatValue) {
-        ConstantInt *CInt = dyn_cast<ConstantInt>(SplatValue);
-        if (CInt && CInt->getValue().isPowerOf2())
-          Op2VP = TargetTransformInfo::OP_PowerOf2;
-        Op2VK = TargetTransformInfo::OK_UniformConstantValue;
-      }
-    } else if (Legal->isUniform(Op2)) {
+    Value *Op2 = I->getOperand(1);
+    Op2VK = TTI.getOperandInfo(Op2, Op2VP);
+    if (Op2VK == TargetTransformInfo::OK_AnyValue && Legal->isUniform(Op2))
       Op2VK = TargetTransformInfo::OK_UniformValue;
-    }
+
     SmallVector<const Value *, 4> Operands(I->operand_values());
     unsigned N = isScalarAfterVectorization(I, VF) ? VF : 1;
     return N * TTI.getArithmeticInstrCost(I->getOpcode(), VectorTy, Op1VK,
                                           Op2VK, Op1VP, Op2VP, Operands);
   }
   case Instruction::Select: {
     SelectInst *SI = cast<SelectInst>(I);
     const SCEV *CondSCEV = SE->getSCEV(SI->getCondition());