[MLIR] Don't drop attached discardable attributes (#111261)

The creation of pack op was dropping discardable attributes.

Author: pashu123

mlir/lib/Dialect/Tensor/IR/TensorOps.cpp

@@ -4337,11 +4337,16 @@ LogicalResult PackOp::canonicalize(PackOp packOp, PatternRewriter &rewriter) {
       dest =
           rewriter.create<tensor::CastOp>(loc, newDestType, packOp.getDest());
     }
-    Value newOp = rewriter.create<tensor::PackOp>(
-        loc, source, dest, packOp.getInnerDimsPos(), packOp.getMixedTiles(),
-        packOp.getPaddingValue(), packOp.getOuterDimsPerm());
+    auto clonedPackOp = cast<PackOp>(rewriter.clone(*packOp));
+    Value res = clonedPackOp.getResult();
+    rewriter.startOpModification(clonedPackOp);
+    clonedPackOp.getSourceMutable().assign(source);
+    clonedPackOp.getDestMutable().assign(dest);
+    res.setType(dest.getType());
+    rewriter.finalizeOpModification(clonedPackOp);
+
     rewriter.replaceOpWithNewOp<tensor::CastOp>(
-        packOp, packOp.getResult().getType(), newOp);
+        packOp, packOp.getResult().getType(), clonedPackOp);
     return success();
   }
 

mlir/test/Dialect/Tensor/canonicalize.mlir

@@ -2357,7 +2357,7 @@ func.func @unpack_pack_with_padding_no_canonicalization(%t: tensor<256x512xbf16>
   %tensor_empty = tensor.empty() : tensor<4x16x64x32xbf16>
   %tensor_empty1 = tensor.empty() : tensor<224x512xbf16>
   %packed = tensor.pack %t outer_dims_perm = [0, 1] inner_dims_pos = [0, 1] inner_tiles = [64, 32] into %tensor_empty : tensor<256x512xbf16> -> tensor<4x16x64x32xbf16>
-  %unpacked = tensor.unpack %packed inner_dims_pos = [0, 1] inner_tiles = [64, 32] into %tensor_empty1 : tensor<4x16x64x32xbf16> -> tensor<224x512xbf16> 
+  %unpacked = tensor.unpack %packed inner_dims_pos = [0, 1] inner_tiles = [64, 32] into %tensor_empty1 : tensor<4x16x64x32xbf16> -> tensor<224x512xbf16>
   return %unpacked : tensor<224x512xbf16>
 }
 
@@ -2707,3 +2707,14 @@ func.func @test_destination_multiple_result(%arg0: tensor<2x2xf32>, %arg1: tenso
   %0:2 = test.destination_style_op ins(%cast : tensor<?x2xf32>) outs(%cast_0 : tensor<?x2xf32>) -> tensor<?x2xf32>, index
   return %0#1 : index
 }
+
+// -----
+
+// CHECK-LABEL:   func.func @pack_dont_drop_attributes(
+// CHECK: tensor.pack {{.*}}  {test_attr}
+func.func @pack_dont_drop_attributes(%arg0: tensor<?x?x?xf16>, %arg1: tensor<128x?x100x16x1xf16>) -> tensor<128x?x100x16x1xf16> {
+  %c32_i64 = arith.constant 32 : i64
+  %cst = arith.constant 0.000000e+00 : f16
+  %pack = tensor.pack %arg0 padding_value(%cst : f16) outer_dims_perm = [0, 1, 2] inner_dims_pos = [1, 2] inner_tiles = [16, 1] into %arg1 {test_attr} : tensor<?x?x?xf16> -> tensor<128x?x100x16x1xf16>
+  return %pack : tensor<128x?x100x16x1xf16>
+}