[mlir][vector] Drop inner unit dims for xWrite on dynamic shapes. (#80725)

This is part of
66347e5

The regression in downstream projects is about transfer_read patterns,
which needs more investigation. Add the support for transfer_write for
now.

Author: hanhanW

mlir/lib/Dialect/Vector/Transforms/VectorTransforms.cpp

@@ -1318,7 +1318,7 @@ class DropInnerMostUnitDimsTransferWrite
       return failure();
 
     auto srcType = dyn_cast<MemRefType>(writeOp.getSource().getType());
-    if (!srcType || !srcType.hasStaticShape())
+    if (!srcType)
       return failure();
 
     if (!writeOp.getPermutationMap().isMinorIdentity())
@@ -1341,20 +1341,23 @@ class DropInnerMostUnitDimsTransferWrite
         VectorType::get(targetType.getShape().drop_back(dimsToDrop),
                         targetType.getElementType());
 
+    Location loc = writeOp.getLoc();
+    SmallVector<OpFoldResult> sizes =
+        memref::getMixedSizes(rewriter, loc, writeOp.getSource());
+    SmallVector<OpFoldResult> offsets(srcType.getRank(),
+                                      rewriter.getIndexAttr(0));
+    SmallVector<OpFoldResult> strides(srcType.getRank(),
+                                      rewriter.getIndexAttr(1));
     MemRefType resultMemrefType =
         getMemRefTypeWithDroppingInnerDims(rewriter, srcType, dimsToDrop);
-    SmallVector<int64_t> offsets(srcType.getRank(), 0);
-    SmallVector<int64_t> strides(srcType.getRank(), 1);
     ArrayAttr inBoundsAttr =
         writeOp.getInBounds()
             ? rewriter.getArrayAttr(
                   writeOp.getInBoundsAttr().getValue().drop_back(dimsToDrop))
             : ArrayAttr();
 
-    Location loc = writeOp.getLoc();
     Value rankedReducedView = rewriter.create<memref::SubViewOp>(
-        loc, resultMemrefType, writeOp.getSource(), offsets, srcType.getShape(),
-        strides);
+        loc, resultMemrefType, writeOp.getSource(), offsets, sizes, strides);
     auto permMap = getTransferMinorIdentityMap(
         cast<ShapedType>(rankedReducedView.getType()), resultTargetVecType);
 

mlir/test/Dialect/Vector/vector-transfer-collapse-inner-most-dims.mlir

@@ -119,6 +119,27 @@ func.func @drop_inner_most_dim_for_transfer_write(%arg0: memref<1x512x16x1xf32,
 
 // -----
 
+func.func @outer_dyn_drop_inner_most_dim_for_transfer_write(%arg0: memref<?x512x16x1xf32, strided<[8192, 16, 1, 1], offset: ?>>, %arg1: vector<1x16x16x1xf32>, %arg2: index) {
+  %c0 = arith.constant 0 : index
+  vector.transfer_write %arg1, %arg0[%arg2, %c0, %c0, %c0]
+    {in_bounds = [true, true, true, true]}
+    : vector<1x16x16x1xf32>, memref<?x512x16x1xf32, strided<[8192, 16, 1, 1], offset: ?>>
+  return
+}
+// CHECK:      func.func @outer_dyn_drop_inner_most_dim_for_transfer_write
+// CHECK-SAME:   %[[DEST:[a-zA-Z0-9]+]]
+// CHECK-SAME:   %[[VEC:[a-zA-Z0-9]+]]
+// CHECK-SAME:   %[[IDX:[a-zA-Z0-9]+]]
+//  CHECK-DAG:   %[[C0:.+]] = arith.constant 0 : index
+//  CHECK-DAG:   %[[D0:.+]] = memref.dim %[[SRC]], %[[C0]]
+// CHECK:        %[[SUBVIEW:.+]] = memref.subview %[[DEST]][0, 0, 0, 0] [%[[D0]], 512, 16, 1]
+// CHECK-SAME:     memref<?x512x16x1xf32, strided<[8192, 16, 1, 1], offset: ?>> to memref<?x512x16xf32, strided<[8192, 16, 1], offset: ?>>
+// CHECK:        %[[CAST:.+]] = vector.shape_cast %[[VEC]] : vector<1x16x16x1xf32> to vector<1x16x16xf32>
+// CHECK:        vector.transfer_write %[[CAST]], %[[SUBVIEW]]
+// CHECK-SAME:     [%[[IDX]], %[[C0]], %[[C0]]]
+
+// -----
+
 func.func @non_unit_strides(%arg0: memref<512x16x1xf32, strided<[8192, 16, 4], offset: ?>>, %arg1: vector<16x16x1xf32>, %arg2: index) {
   %c0 = arith.constant 0 : index
   vector.transfer_write %arg1, %arg0[%arg2, %c0, %c0]