[PATCH] D68789: [LoopNest]: Analysis to discover properties of a loop nest.

[Michael Kruse via Phabricator via llvm-commits]

Meinersbur accepted this revision.
Meinersbur added a comment.
This revision is now accepted and ready to land.

LGTM



================
Comment at: llvm/include/llvm/Analysis/LoopNestAnalysis.h:34-35
+
+  /// Return true if the given loops \p OuterLoop and \p InnerLoop are
+  /// perfectly nested with respect to each other, and false otherwise.
+  static bool arePerfectlyNested(const Loop &OuterLoop, const Loop &InnerLoop,
----------------
etiotto wrote:
> Meinersbur wrote:
> > Could you clarify whether this allows other perfectly nested loops between outer and inner? Eg.
> > ```
> > for outer:
> >    for middle:
> >       for inner:
> > ```
> > 
> Added example in a comment. 
What I meant is what does it return for:
```
for i
  for j
    for k
```
`arePerfectlyNested(loop_i, loop_k, SE) == ?`


================
Comment at: llvm/include/llvm/Analysis/LoopNestAnalysis.h:86
+  /// Return the number of loops in the nest.
+  unsigned getNumLoops() const { return Loops.size(); }
+
----------------
[style] `SmallVector::size()` is of type `size_t`, why not also return `size_t`?


================
Comment at: llvm/include/llvm/Analysis/LoopNestAnalysis.h:113
+  unsigned getNestDepth() const {
+    return (Loops.back()->getLoopDepth() - Loops.front()->getLoopDepth() + 1);
+  }
----------------
[suggestion] Add an assertion ensuring that the result would not be negative.


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https://reviews.llvm.org/D68789