[Mlir-commits] [mlir] [mlir][gpu] Disjoint patterns for lowering clustered subgroup reduce (PR #109158)

[Jakub Kuderski]

================
@@ -262,19 +273,31 @@ struct ScalarSubgroupReduceToShuffles final
 private:
   unsigned subgroupSize = 0;
   unsigned shuffleBitwidth = 0;
+  bool matchClustered;
 };
 
 /// Lowers vector gpu subgroup reductions to a series of shuffles.
 struct VectorSubgroupReduceToShuffles final
     : OpRewritePattern<gpu::SubgroupReduceOp> {
   VectorSubgroupReduceToShuffles(MLIRContext *ctx, unsigned subgroupSize,
-                                 unsigned shuffleBitwidth,
+                                 unsigned shuffleBitwidth, bool matchClustered,
                                  PatternBenefit benefit)
       : OpRewritePattern(ctx, benefit), subgroupSize(subgroupSize),
-        shuffleBitwidth(shuffleBitwidth) {}
+        shuffleBitwidth(shuffleBitwidth), matchClustered(matchClustered) {}
 
   LogicalResult matchAndRewrite(gpu::SubgroupReduceOp op,
                                 PatternRewriter &rewriter) const override {
+    if (op.getClusterSize().has_value() != matchClustered) {
+      if (matchClustered)
+        return rewriter.notifyMatchFailure(
+            op, "op is non-clustered but pattern is configured to only match "
+                "clustered ops");
+      else
+        return rewriter.notifyMatchFailure(
+            op, "op is clustered but pattern is configured to only match "
+                "non-clustered ops");
----------------
kuhar wrote:

```suggestion
      if (matchClustered) {
        return rewriter.notifyMatchFailure(
            op, "op is non-clustered but pattern is configured to only match "
                "clustered ops");
      } else {
        return rewriter.notifyMatchFailure(
            op, "op is clustered but pattern is configured to only match "
                "non-clustered ops");
     }
```

https://github.com/llvm/llvm-project/pull/109158