[Mlir-commits] [mlir] [MLIR][XeGPU] Add uniform values distribution pattern (PR #176737)

[Charitha Saumya]

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@@ -1208,6 +1213,71 @@ struct LoadDistribution final : public gpu::WarpDistributionPattern {
   }
 };
 
+// Sink SG-uniform ops. An op is uniform if any of the following is none
+// of its operands/results has a distribution layout attribute.
+// Non-uniform vectors are handled by dedicated patterns.
+// This pattern must have a higher priority than distribution patterns,
+// because a distributable shape may be logically intended as uniform.
+struct SinkUniformOps final : public gpu::WarpDistributionPattern {
+  using gpu::WarpDistributionPattern::WarpDistributionPattern;
+  LogicalResult matchAndRewrite(gpu::WarpExecuteOnLane0Op warpOp,
+                                PatternRewriter &rewriter) const override {
+    // Take the last op
+    Operation *warpRegionPreYieldOp = warpOp.getTerminator()->getPrevNode();
+    // Any ops with nested regions must be handled carefully in dedicated
+    // patterns.
+    if (!warpRegionPreYieldOp || warpRegionPreYieldOp->getNumRegions())
+      return failure();
+    int operandIdx = -1;
+    if (warpRegionPreYieldOp->getNumResults()) {
+      OpOperand *operand = getWarpResult(
+          warpOp, [&](Operation *op) { return warpRegionPreYieldOp == op; });
+      if (!operand)
+        return failure();
+      operandIdx = operand->getOperandNumber();
+      if (warpRegionPreYieldOp->getResult(0).getType() !=
+          warpOp.getResult(operandIdx).getType())
+        return rewriter.notifyMatchFailure(warpOp,
+                                           "The op result is not uniform.");
+    }
+
+    // The op must have at least no layout-based operands or results.
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charithaintc wrote:

fix the comment?

https://github.com/llvm/llvm-project/pull/176737