[all-commits] [llvm/llvm-project] 188f9a: [Attributor] AAValueConstantRange: Value range ana...

[Hideto Ueno via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 188f9a348dc545bf9a420d998ad37761bddd7285
      https://github.com/llvm/llvm-project/commit/188f9a348dc545bf9a420d998ad37761bddd7285
  Author: Hideto Ueno <uenoku.tokotoko at gmail.com>
  Date:   2020-01-15 (Wed, 15 Jan 2020)

  Changed paths:
    M llvm/include/llvm/Transforms/IPO/Attributor.h
    M llvm/lib/Transforms/IPO/Attributor.cpp
    M llvm/test/Transforms/Attributor/IPConstantProp/return-constant.ll
    M llvm/test/Transforms/Attributor/IPConstantProp/solve-after-each-resolving-undefs-for-function.ll
    M llvm/test/Transforms/Attributor/dereferenceable-1.ll
    A llvm/test/Transforms/Attributor/lvi-after-jumpthreading.ll
    A llvm/test/Transforms/Attributor/lvi-for-ashr.ll
    A llvm/test/Transforms/Attributor/range.ll
    M llvm/test/Transforms/Attributor/value-simplify.ll

  Log Message:
  -----------
  [Attributor] AAValueConstantRange: Value range analysis using constant range

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