[InstCombine] Make InstCombiner::OptAndOp take a BinaryOperator instead of an Instruction.

The callers have already performed the necessary cast before calling. This allows us to remove a comment that says the instruction must be a BinaryOperator and make it explicit in the argument type.

Had to add a default case to the switch because BinaryOperator::getOpcode() returns a BinaryOps enum.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299339 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/InstCombine/InstCombineAndOrXor.cpp

@@ -137,9 +137,8 @@ Value *InstCombiner::SimplifyBSwap(BinaryOperator &I) {
 }
 
 /// This handles expressions of the form ((val OP C1) & C2).  Where
-/// the Op parameter is 'OP', OpRHS is 'C1', and AndRHS is 'C2'.  Op is
-/// guaranteed to be a binary operator.
-Instruction *InstCombiner::OptAndOp(Instruction *Op,
+/// the Op parameter is 'OP', OpRHS is 'C1', and AndRHS is 'C2'.
+Instruction *InstCombiner::OptAndOp(BinaryOperator *Op,
                                     ConstantInt *OpRHS,
                                     ConstantInt *AndRHS,
                                     BinaryOperator &TheAnd) {
@@ -149,6 +148,7 @@ Instruction *InstCombiner::OptAndOp(Instruction *Op,
     Together = ConstantExpr::getAnd(AndRHS, OpRHS);
 
   switch (Op->getOpcode()) {
+  default: break;
   case Instruction::Xor:
     if (Op->hasOneUse()) {
       // (X ^ C1) & C2 --> (X & C2) ^ (C1&C2)

lib/Transforms/InstCombine/InstCombineInternal.h

@@ -650,7 +650,7 @@ private:
                             SelectPatternFlavor SPF2, Value *C);
   Instruction *foldSelectInstWithICmp(SelectInst &SI, ICmpInst *ICI);
 
-  Instruction *OptAndOp(Instruction *Op, ConstantInt *OpRHS,
+  Instruction *OptAndOp(BinaryOperator *Op, ConstantInt *OpRHS,
                         ConstantInt *AndRHS, BinaryOperator &TheAnd);
 
   Value *insertRangeTest(Value *V, const APInt &Lo, const APInt &Hi,