[llvm-branch-commits] [mlir] [mlir][omp] Improve canonloop/iv naming (PR #159773)

[Michael Kruse via llvm-branch-commits]

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@@ -77,6 +77,177 @@ struct LLVMPointerPointerLikeModel
 };
 } // namespace
 
+/// Generate a name of a canonical loop nest of the format
+/// `<prefix>(_s<num>_r<num>)*` that describes its nesting inside parent
+/// operations (`_r<num>`) and that operation's region (`_s<num>`). The region
+/// number is omitted if the parent operation has just one region. If a loop
+/// nest just consists of canonical loops nested inside each other, also uses
+/// `d<num>` where <num> is the nesting depth of the loop.
+static std::string generateLoopNestingName(StringRef prefix,
+                                           CanonicalLoopOp op) {
+  struct Component {
+    // An region argument of an operation
+    Operation *parentOp;
+    size_t regionInOpIdx;
+    bool isOnlyRegionInOp;
+    bool skipRegion;
+
+    // An operation somewhere in a parent region
+    Operation *thisOp;
+    Region *parentRegion;
+    size_t opInRegionIdx;
+    bool isOnlyOpInRegion;
+    bool skipOp;
+    int depth = -1;
+  };
+  SmallVector<Component> components;
+
+  // Gather a list of parent regions and operations, and the position within
+  // their parent
+  Operation *o = op.getOperation();
+  while (o) {
+    if (o->hasTrait<mlir::OpTrait::IsIsolatedFromAbove>())
+      break;
+
+    // Operation within a region
+    Region *r = o->getParentRegion();
+    if (!r)
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Meinersbur wrote:

A freshly create operation is not yet in any region/block. There is also `Operation::remove` to remove an operation from a region/block. There might be situations such as calling `dump()` on it, when it is not (yet) connected to a parent region. 

https://github.com/llvm/llvm-project/pull/159773