[Mlir-commits] [mlir] [MLIR] Legalize certain `vector.transfer_read` ops of scalable vectors (PR #143146)

[Nicolas Vasilache]

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@@ -0,0 +1,257 @@
+// RUN: mlir-opt --arm-sve-legalize-vector-storage --split-input-file %s | FileCheck %s
+
+
+// Test the `LegalizeTransferRead` pattern
+// (mlir/lib/Dialect/ArmSVE/Transforms/LegalizeVectorStorage.cpp)
+
+// -----
+
+// This is the base case, unremarkable in any way, except that it's our main
+// motivating example and use case.
+
+// CHECK-LABEL:       @base_case
+// CHECK-SAME:          %[[I:.+]]: index, %[[J:.+]]: index, %[[M:.+]]:
+// CHECK:               %[[PAD:.+]] = arith.constant 0 : i8
+// CHECK:               %[[C0:.+]] = arith.constant 0 : index
+// CHECK:               %[[COLLAPSE:.+]] = memref.collapse_shape %[[M]]
+// CHECK-SAME{LITERAL}:   [[0], [1], [2, 3]]
+// CHECK-SAME:            : memref<?x?x?x8xi8> into memref<?x?x?xi8>
+// CHECK-NEXT:          %[[T0:.+]] = vector.transfer_read %[[COLLAPSE]][%[[I]], %[[J]], %[[C0]]], %[[PAD]] {in_bounds = [true]}
+// CHECK-SAME:            : memref<?x?x?xi8>, vector<[32]xi8>
+// CHECK-NEXT:          %[[T1:.+]] = vector.shape_cast %[[T0]] : vector<[32]xi8> to vector<[4]x8xi8>
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nicolasvasilache wrote:

For my own education: what does mean in scalable world ?
Seems like it encodes (32 * vscale) -> (4*vscale) x 8 but I am not "seeing" it.
Is there something I can read to refresh my mental model here?

https://github.com/llvm/llvm-project/pull/143146