[Mlir-commits] [mlir] [mlir] Compose expand of collapse to cast (PR #172864)

[llvmlistbot at llvm.org]

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@@ -1193,6 +1193,42 @@ func.func @collapse_expand_fold_to_cast(%m: memref<?xf32, strided<[1]>, 3>, %sz0
 
 // -----
 
+// CHECK-LABEL: func @expand_collapse_fold_to_cast(
+//  CHECK-SAME:     %[[m:.*]]: memref<1x3x2x384xui8, strided<[1179648, 768, 384, 1]>>
+//       CHECK:   %[[casted:.*]] = memref.cast %[[m]] : memref<1x3x2x384xui8, strided<[1179648, 768, 384, 1]>> to memref<1x3x2x384xui8, strided<[2304, 768, 384, 1]>>
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MaheshRavishankar wrote:

I am not sure this cast is valid. It is changing the strides of the outer-most dimension... If you think of access into the memrefs using `sum(index[i] * stride[i])` for the same indices, `%casted` and `%m` are accessing different strides. I am not sure this is valid. Actually looking at the input, this is an interesting case. By themselves the operations are valid, but they cannot be folded into a cast operation.

https://github.com/llvm/llvm-project/pull/172864