[Mlir-commits] [mlir] [MLIR][XeGPU][TransformOps] Add get_desc_op (PR #166801)

[Jianhui Li]

================
@@ -111,6 +155,28 @@ setDescLayout(transform::TransformRewriter &rewriter,
   return newDescOp;
 }
 
+DiagnosedSilenceableFailure
+transform::GetDescOp::apply(transform::TransformRewriter &rewriter,
+                            transform::TransformResults &results,
+                            transform::TransformState &state) {
+
+  auto targetValues = state.getPayloadValues(getTarget());
+  if (!llvm::hasSingleElement(targetValues)) {
+    return emitDefiniteFailure()
+           << "requires exactly one target value handle (got "
+           << llvm::range_size(targetValues) << ")";
+  }
+
+  auto maybeDescOp =
+      findProducerOfType<xegpu::CreateNdDescOp>(*targetValues.begin());
+  if (!maybeDescOp) {
+    return emitSilenceableFailure(getLoc()) << "Could not find descriptor op.";
----------------
Jianhui-Li wrote:

Actually user may write a program like below, and findProducerOfType will miss it since it only searches along operand(0).  
A_desc = Create_nd_tdesc : <1024x1024xbf16>
A = Load_nd A_desc : <1024x1024xbf16>
Bias = load bias_memref : <1024xbf16>
Bias_bcast = broadcast Bias: <1024x1024xbf16>
A_Bias = add Bias_bcast, A  //A tensor is used as 2nd parameter. 
C = DPAS A_Bias, ...  

I don't think it worths to complicate findProducerOfType(). Maybe the message can add a hint, like "Could not find a matching descriptor op when walking the producer chain of the first operand.";

https://github.com/llvm/llvm-project/pull/166801