[Mlir-commits] [mlir] [mlir][IR] Fix inconsistency in block/op dominance (PR #115413)

[Matthias Springer]

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@@ -176,9 +176,14 @@ class DominanceInfo : public detail::DominanceInfoBase</*IsPostDom=*/false> {
   /// Return true if the specified block A properly dominates block B, i.e.: if
   /// block A contains block B, or if the region which contains block A also
   /// contains block B or some parent of block B and block A dominates that
-  /// block in that kind of region. In an SSACFG region, block A dominates
-  /// block B if all control flow paths from the entry block to block B flow
-  /// through block A. In a Graph region, all blocks dominate all other blocks.
+  /// block in that kind of region.
+  ///
+  /// In an SSACFG region, block A dominates block B if all control flow paths
+  /// from the entry block to block B flow through block A.
+  ///
+  /// Graph regions have only a single block. To be consistent with "proper
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matthias-springer wrote:

Note: This could also go the other way. We could say that an operation does not dominate itself in a graph region. But I find the current definition a bit more intuitive. (Considering that "dominance" does not exist in a graph region, so it does not matter at all which ops we are "comparing" in the same region.)


https://github.com/llvm/llvm-project/pull/115413