[Mlir-commits] [mlir] [MLIR][XeGPU] Add unroll patterns and blocking pass for XeGPU [2/N] (PR #140163)

[Chao Chen]

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@@ -0,0 +1,330 @@
+//===---- XeGPUBlocking.cpp ---- XeGPU Blocking Pass ----------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "mlir/Dialect/XeGPU/Transforms/Passes.h"
+
+#include "mlir/Dialect/GPU/IR/GPUDialect.h"
+#include "mlir/Dialect/Vector/Transforms/VectorTransforms.h"
+#include "mlir/Dialect/XeGPU/IR/XeGPU.h"
+#include "mlir/Dialect/XeGPU/Transforms/Transforms.h"
+#include "mlir/Dialect/XeGPU/Utils/XeGPUUtils.h"
+#include "mlir/Interfaces/LoopLikeInterface.h"
+#include "mlir/Pass/Pass.h"
+#include "mlir/Pass/PassManager.h"
+#include "mlir/Transforms/DialectConversion.h"
+#include "mlir/Transforms/GreedyPatternRewriteDriver.h"
+
+namespace mlir {
+namespace xegpu {
+#define GEN_PASS_DEF_XEGPUBLOCKING
+#include "mlir/Dialect/XeGPU/Transforms/Passes.h.inc"
+} // namespace xegpu
+} // namespace mlir
+
+#define DEBUG_TYPE "xegpu-blocking"
+#define DBGS() (llvm::dbgs() << "[" DEBUG_TYPE "]: ")
+#define LDBG(X) LLVM_DEBUG(DBGS() << X << "\n")
+
+using namespace mlir;
+
+namespace {
+
+// reslove the unrealized conversion cast ops generated when doing SCF
+// Structural Type Conversion. It will have two formats, N:1 vector
+// cast and 1:N vector cast. vector::insert_strided_slice ops will be
+// used for the first case, and vector::extract_strided_slice ops will be
+// used for the second case.
+static void
+resolveUnrealizedConversionCastOp(UnrealizedConversionCastOp castOp) {
+  ValueRange inputs = castOp.getInputs();
+  ValueRange outputs = castOp.getOutputs();
+
+  if (inputs.size() == 1 && outputs.size() == 1) {
+    castOp->replaceAllUsesWith(inputs);
+    castOp->erase();
+  }
+
+  VectorType inputTy = dyn_cast<VectorType>(inputs[0].getType());
+  VectorType outputTy = dyn_cast<VectorType>(outputs[0].getType());
+  if (inputTy && outputTy) {
+    OpBuilder builder(castOp);
+    // unpack
+    if (inputs.size() > 1 && outputs.size() == 1) {
+      ArrayRef<int64_t> shape = outputTy.getShape();
+      Value result = xegpu::createVectorWithShapeFromValues(
+          builder, castOp.getLoc(), inputs, shape);
+      castOp->replaceAllUsesWith(ValueRange(result));
+      castOp->erase();
+    }
+
+    // pack
+    if (castOp.getNumResults() > 1 && castOp.getNumOperands() == 1) {
+      ArrayRef<int64_t> tileShape = outputTy.getShape();
+      SmallVector<Value> results = xegpu::extractVectorsWithShapeFromValue(
+          builder, castOp.getLoc(), inputs[0], tileShape);
+      castOp->replaceAllUsesWith(results);
+      castOp->erase();
+    }
+  }
+}
+
+/// Unroll XeGPU ops to their instruction-level representation.
+class XeGPUBlockingPass final
+    : public xegpu::impl::XeGPUBlockingBase<XeGPUBlockingPass> {
+public:
+  void runOnOperation() override;
+
+private:
+  // Get the tile shape for a given value. If the value has a layout
+  // attribute and it is an SG layout, return the inst_data as the tile shape
+  // if inst_data is available; otherwise, return the original shape of the
+  // value. If the value does not have an SG layout, return std::nullopt.
+  std::optional<SmallVector<int64_t>>
+  getTileShape(TypedValue<ShapedType> value) const;
+
+  std::optional<SmallVector<int64_t>> getTileShape(OpOperand &operand) const;
+
+  std::optional<SmallVector<int64_t>> getTileShape(OpResult result) const;
+
+  // Get the tile shape for a given operation.
+  std::optional<SmallVector<int64_t>> getTileShape(Operation *op) const;
+
+  // Determine if the operation requires unrolling. Return false if all operands
+  // and results have tile shapes identical to their original types. Otherwise,
+  // return true.
+  bool needsUnroll(Operation *op) const;
+};
+} // namespace
+
+std::optional<SmallVector<int64_t>>
+XeGPUBlockingPass::getTileShape(TypedValue<ShapedType> value) const {
+  assert(value && "value must be non-null");
+  xegpu::LayoutAttr layout = xegpu::getLayoutAttr(value);
----------------
chencha3 wrote:

I removed an unused interface. For the rest two, I didn't find a good way unify them. It seems I cannot use template to cover `OpOperand &` and `OpResult`. any suggestions?

https://github.com/llvm/llvm-project/pull/140163