add some random notes.

llvm-svn: 131862

llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp

@@ -40,6 +40,11 @@ static Value *simplifyValueKnownNonZero(Value *V, InstCombiner &IC) {
     return IC.Builder->CreateShl(One, A);
   }
   
+  // TODO: Lots more we could do here:
+  //    "1 >> X" could get an "isexact" bit.
+  //    If V is a phi node, we can call this on each of its operands.
+  //    "select cond, X, 0" can simplify to "X".
+  
   return 0;
 }