[mlir][linalg] Improve codegen when tiling PadTensor evenly

[springerm]

Summary

Produce simpler IR with more static type information and fewer affine expressions.

Depends On D105529

[springerm]

rebase

[springerm]

rebase

[springerm]

rebase

[springerm]

fix test

mlir/lib/Dialect/Linalg/Transforms/Tiling.cpp

void mlir::linalg::populateLinalgTilingCanonicalizationPatterns(
   AffineApplyOp::getCanonicalizationPatterns(patterns, ctx);
   AffineForOp::getCanonicalizationPatterns(patterns, ctx);
   AffineMinOp::getCanonicalizationPatterns(patterns, ctx);
   AffineMaxOp::getCanonicalizationPatterns(patterns, ctx);
   scf::ForOp::getCanonicalizationPatterns(patterns, ctx);
   scf::ParallelOp::getCanonicalizationPatterns(patterns, ctx);
   ConstantIndexOp::getCanonicalizationPatterns(patterns, ctx);
   tensor::ExtractSliceOp::getCanonicalizationPatterns(patterns, ctx);
+  tensor::InsertSliceOp::getCanonicalizationPatterns(patterns, ctx);
   memref::SubViewOp::getCanonicalizationPatterns(patterns, ctx);
   tensor::CastOp::getCanonicalizationPatterns(patterns, ctx);
   memref::ViewOp::getCanonicalizationPatterns(patterns, ctx);
   PadTensorOp::getCanonicalizationPatterns(patterns, ctx);
   ctx->getLoadedDialect<LinalgDialect>()->getCanonicalizationPatterns(patterns);
   CanonicalizationPatternList<
 #define GET_OP_LIST
 #include "mlir/Dialect/Linalg/IR/LinalgStructuredOps.cpp.inc"
static void applyPadTensorOpTilingToLoopPatterns(
     ArrayRef<StringRef> distributionTypes = {}) {
   auto options = LinalgTilingOptions()
                      .setTileSizes(tileSizes)
                      .setLoopType(loopType)
                      .setDistributionTypes(distributionTypes);
   MLIRContext *ctx = funcOp.getContext();
   RewritePatternSet patterns(ctx);
   patterns.add<PadTensorOpTilingPattern>(patterns.getContext(), options);
-  patterns.add<ExtractSliceOfPadTensorSwapPattern>(patterns.getContext());
+  patterns.add<AffineMinSCFCanonicalizationPattern>(patterns.getContext());
   (void)applyPatternsAndFoldGreedily(funcOp, std::move(patterns));
   (void)applyPatternsAndFoldGreedily(
       funcOp, getLinalgTilingCanonicalizationPatterns(ctx));
   // Drop the marker.
   funcOp.walk([](PadTensorOp op) {
     op->removeAttr(LinalgTransforms::kLinalgTransformMarker);
   });
+  // Apply swap pattern after generating loop nest and running
+  // canonicalizations.
+  patterns.clear();
+  patterns.add<ExtractSliceOfPadTensorSwapPattern>(patterns.getContext());
+  (void)applyPatternsAndFoldGreedily(funcOp, std::move(patterns));
+  (void)applyPatternsAndFoldGreedily(
+      funcOp, getLinalgTilingCanonicalizationPatterns(ctx));
 }
 
 namespace {
 struct LinalgTilingPass : public LinalgTilingBase<LinalgTilingPass> {
   LinalgTilingPass() = default;
   LinalgTilingPass(ArrayRef<int64_t> sizes) { tileSizes = sizes; }
 
   void runOnFunction() override {

mlir/test/Dialect/Linalg/tile-pad-tensor-op.mlir

func @static_pad_tensor(%input_tensor: tensor<7x9xf32>,
                         %pad_value: f32) -> tensor<15x16xf32> {
   %0 = linalg.pad_tensor %input_tensor, %output_tensor
     low[3, 4] high[5, 3] {
     ^bb0(%arg1: index, %arg2: index):
       linalg.yield %pad_value : f32
     } : tensor<7x9xf32> to tensor<15x16xf32>
   return %0 : tensor<15x16xf32>
 }
+
+// -----
+
+// TILE1-LABEL: func @static_pad_tile_evenly(
+//  TILE1-SAME:     %[[IN:.*]]: tensor<7x9xf32>, %[[OUT:.*]]: tensor<14x15xf32>
+//   TILE1-DAG:   %[[C0:.*]] = constant 0 : index
+//   TILE1-DAG:   %[[C3:.*]] = constant 3 : index
+//   TILE1-DAG:   %[[C15:.*]] = constant 15 : index
+//       TILE1:   %[[RESULT:.*]] = scf.for %[[IV:.*]] = %[[C0]] to %[[C15]] step %[[C3]] iter_args(%[[INNER_OUT:.*]] =
+//       TILE1:     %[[R2:.*]] = scf.if
+//       TILE1:       %[[GEN:.*]] = tensor.generate
+//       TILE1:       scf.yield %[[GEN]] : tensor<14x3xf32>
+//       TILE1:     else
+//       TILE1:       %[[SLICE:.*]] = tensor.extract_slice %arg0[0, %{{.*}}] [7, %{{.*}}] [1, 1] : tensor<7x9xf32> to tensor<7x?xf32>
+//       TILE1:       %[[PAD:.*]] = linalg.pad_tensor %8 low[0, 0] high[7, %{{.*}}]
+//       TILE1:       %[[CAST:.*]] = tensor.cast %[[PAD]] : tensor<14x?xf32> to tensor<14x3xf32>
+//       TILE1:       scf.yield %[[CAST]] : tensor<14x3xf32>
+//       TILE1:     %[[R3:.*]] = tensor.insert_slice %[[R2]] into %[[INNER_OUT]][0, %[[IV]]] [14, 3] [1, 1] : tensor<14x3xf32> into tensor<14x15xf32>
+//       TILE1:     scf.yield %[[R3]] : tensor<14x15xf32>
+//       TILE1:   return %[[RESULT]] : tensor<14x15xf32>
+func @static_pad_tile_evenly(%input_tensor: tensor<7x9xf32>,
+                             %output_tensor: tensor<14x15xf32>,
+                             %pad_value: f32) -> tensor<14x15xf32> {
+  %0 = linalg.pad_tensor %input_tensor, %output_tensor
+    low[0, 0] high[7, 6] {
+    ^bb0(%arg1: index, %arg2: index):
+      linalg.yield %pad_value : f32
+    } : tensor<7x9xf32> to tensor<14x15xf32>
+  return %0 : tensor<14x15xf32>
+}