[all-commits] [llvm/llvm-project] b285b3: [Attributor] Detect possibly unbounded cycles in f...

[omar ahmed via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: b285b333dcd04dc79cb864e7178d56b74815caec
      https://github.com/llvm/llvm-project/commit/b285b333dcd04dc79cb864e7178d56b74815caec
  Author: omarahmed1111 <omarpirate2010 at yahoo.com>
  Date:   2020-03-13 (Fri, 13 Mar 2020)

  Changed paths:
    M llvm/include/llvm/Analysis/MustExecute.h
    M llvm/lib/Analysis/MustExecute.cpp
    M llvm/lib/Transforms/IPO/Attributor.cpp
    M llvm/test/Transforms/Attributor/read_write_returned_arguments_scc.ll
    M llvm/test/Transforms/Attributor/willreturn.ll

  Log Message:
  -----------
  [Attributor] Detect possibly unbounded cycles in functions

This patch add mayContainUnboundedCycle helper function which checks whether a function has any cycle which we don't know if it is bounded or not.
Loops with maximum trip count are considered bounded, any other cycle not.
It also contains some fixed tests and some added tests contain bounded and
unbounded loops and non-loop cycles.

Reviewed By: jdoerfert, uenoku, baziotis

Differential Revision: https://reviews.llvm.org/D74691