[Mlir-commits] [mlir] [mlir][linalg] Restrict linalg.pack to not have artificial padding. (PR #149624)

[Ege Beysel]

================
@@ -220,6 +243,29 @@ struct FoldPadWithPackOp : public OpRewritePattern<PackOp> {
       if (!isEqualConstantIntOrValue(paddingValue, constantPaddingValue))
         return failure();
 
+    // Folding is not allowed if it introduces artificial padding.
+    RankedTensorType unpackedType = packOp.getSourceType();
+    SmallVector<int64_t> outerShapeWithoutTranspose =
+        getPackedOuterShapeWithoutTransposition(packOp);
+    for (auto [pos, tileSize, high] :
+         llvm::zip_equal(packOp.getInnerDimsPos(), packOp.getStaticInnerTiles(),
+                         padOp.getMixedHighPad())) {
+      if (unpackedType.isDynamicDim(pos))
+        return failure();
+      if (ShapedType::isDynamic(outerShapeWithoutTranspose[pos]))
+        return failure();
+      if (ShapedType::isDynamic(tileSize))
----------------
egebeysel wrote:

Oh, I stand corrected. Thanks!

I was confused by the `verifyCompatibleShape`. One thing I noticed, when we have dynamic inner tile sizes, any result shape is essentially legal, right? including

```mlir
%pack = linalg.pack ... inner_tiles = [%tile] : tensor<7xf32> into tensor<8x?xf32>
```
I know this is also pretty artificial as well, but I don't think `verifyCompatibleShape` checks anything on that regard? 

https://github.com/llvm/llvm-project/pull/149624