[Mlir-commits] [mlir] [MLIR][Affine] Check dependences during MDG init (PR #156422)

[Uday Bondhugula]

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@@ -153,9 +153,17 @@ struct MemRefDependenceGraph {
 
   MemRefDependenceGraph(Block &block) : block(block) {}
 
-  // Initializes the dependence graph based on operations in `block'.
-  // Returns true on success, false otherwise.
-  bool init();
+  // Initializes the data dependence graph by walking operations in the MDG's
+  // `block`. A `Node` is created for every top-level op except for
+  // side-effect-free operations with zero results and no regions. Assigns each
+  // node in the graph a node id based on the order in block. Fails if certain
+  // kinds of operations, for which `Node` creation isn't supported, are
+  // encountered (unknown region holding ops). If `fullAffineDependences` is
+  // set, affine memory dependence analysis is performed before concluding that
+  // conflicting affine memory accesses lead to a dependence check; otherwise, a
+  // pair of conflicting affine memory accesses (where one of them is a store
+  // and they are to the same memref) always leads to an edge (conservatively).
+  bool init(bool fullAffineDependences = true);
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bondhugula wrote:

"memory-based" dependences are implied here. Data dependence analysis is the same in this context.

https://github.com/llvm/llvm-project/pull/156422