[VPlan] Generalize type inference for binary VPInstructions (NFC).

Generalize logic to set the result type for ops where the result type
and the types of all operands match. Use it to support any unary and
binops.

Author: fhahn

llvm/lib/Transforms/Vectorize/VPlanAnalysis.cpp

@@ -9,6 +9,7 @@
 #include "VPlanAnalysis.h"
 #include "VPlan.h"
 #include "llvm/ADT/TypeSwitch.h"
+#include "llvm/IR/Instruction.h"
 
 using namespace llvm;
 
@@ -26,7 +27,24 @@ Type *VPTypeAnalysis::inferScalarTypeForRecipe(const VPBlendRecipe *R) {
 }
 
 Type *VPTypeAnalysis::inferScalarTypeForRecipe(const VPInstruction *R) {
-  switch (R->getOpcode()) {
+  // Set the result type from the first operand, check if the types for all
+  // other operands match and cache them.
+  auto SetResultTyFromOp = [this, R]() {
+    Type *ResTy = inferScalarType(R->getOperand(0));
+    for (unsigned Op = 1; Op != R->getNumOperands(); ++Op) {
+      VPValue *OtherV = R->getOperand(Op);
+      assert(inferScalarType(OtherV) == ResTy &&
+             "different types inferred for different operands");
+      CachedTypes[OtherV] = ResTy;
+    }
+    return ResTy;
+  };
+
+  unsigned Opcode = R->getOpcode();
+  if (Instruction::isBinaryOp(Opcode) || Instruction::isUnaryOp(Opcode))
+    return SetResultTyFromOp();
+
+  switch (Opcode) {
   case Instruction::Select: {
     Type *ResTy = inferScalarType(R->getOperand(1));
     VPValue *OtherV = R->getOperand(2);
@@ -35,28 +53,16 @@ Type *VPTypeAnalysis::inferScalarTypeForRecipe(const VPInstruction *R) {
     CachedTypes[OtherV] = ResTy;
     return ResTy;
   }
-  case Instruction::Or:
   case Instruction::ICmp:
-  case VPInstruction::FirstOrderRecurrenceSplice: {
-    Type *ResTy = inferScalarType(R->getOperand(0));
-    VPValue *OtherV = R->getOperand(1);
-    assert(inferScalarType(OtherV) == ResTy &&
-           "different types inferred for different operands");
-    CachedTypes[OtherV] = ResTy;
-    return ResTy;
-  }
+  case VPInstruction::FirstOrderRecurrenceSplice:
+  case VPInstruction::Not:
+    return SetResultTyFromOp();
   case VPInstruction::ExtractFromEnd: {
     Type *BaseTy = inferScalarType(R->getOperand(0));
     if (auto *VecTy = dyn_cast<VectorType>(BaseTy))
       return VecTy->getElementType();
     return BaseTy;
   }
-  case VPInstruction::Not: {
-    Type *ResTy = inferScalarType(R->getOperand(0));
-    assert(IntegerType::get(Ctx, 1) == ResTy &&
-           "unexpected scalar type inferred for operand");
-    return ResTy;
-  }
   case VPInstruction::LogicalAnd:
     return IntegerType::get(Ctx, 1);
   case VPInstruction::PtrAdd: