Index: llvm/lib/Transforms/Scalar/Reassociate.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/Reassociate.cpp
+++ llvm/lib/Transforms/Scalar/Reassociate.cpp
@@ -12,10 +12,10 @@
 // For example: 4 + (x + 5) -> x + (4 + 5)
 //
 // In the implementation of this algorithm, constants are assigned rank = 0,
-// function arguments are rank = 1, and other values are assigned ranks
-// corresponding to the reverse post order traversal of current function
-// (starting at 2), which effectively gives values in deep loops higher rank
-// than values not in loops.
+// the ith function arguments are rank = i + 1, and other values are assigned
+// ranks corresponding to the reverse post order traversal of current function
+// (starting at rank(the last function argument) << 16), which effectively gives
+// values in deep loops higher rank than values not in loops.
 //
 //===----------------------------------------------------------------------===//