Summary:
This patch introduces `AAValueConstantRange`, which answers a possible range for integer value in a specific program point.
One of the motivations is propagating existing `range` metadata. (I think we need to change the situation that `range` metadata cannot be put to Argument).
The state is a tuple of `ConstantRange` and it is initialized to (known, assumed) = ([-∞, +∞], empty).
Currently, AAValueConstantRange is created in `getAssumedConstant` method when `AAValueSimplify` returns `nullptr`(worst state).
Supported
- BinaryOperator(add, sub, ...)
- CmpInst(icmp eq, ...)
- !range metadata
`AAValueConstantRange` is not intended to extend to polyhedral range value analysis.
Reviewers: jdoerfert, sstefan1
Reviewed By: jdoerfert
Subscribers: phosek, davezarzycki, baziotis, hiraditya, javed.absar, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71620
188f9a348d