[Mlir-commits] [mlir] [MLIR] VectorEmulateNarrowType to support loading of unaligned vectors (PR #113411)

[Han-Chung Wang]

================
@@ -214,19 +264,19 @@ struct ConvertVectorMaskedStore final
     // Load the whole data and use arith.select to handle the corner cases.
     // E.g., given these input values:
     //
-    //   %mask = [1, 1, 1, 0, 0, 0]
-    //   %0[%c0, %c0] contains [0x1, 0x2, 0x3, 0x4, 0x5, 0x6]
-    //   %value_to_store = [0x7, 0x8, 0x9, 0xA, 0xB, 0xC]
+    //   %mask = [0, 1, 1, 1, 1, 1, 0, 0]
----------------
hanhanW wrote:

I honestly don't know if this is a valid mask or not. Because the vector dialect operations (vector.constant_mask, vector.create_mask) do not create such mask. E.g.,

```
// create a constant vector mask of size 4x3xi1 with elements in range
// 0 <= row <= 2 and 0 <= col <= 1 are set to 1 (others to 0).
%1 = vector.constant_mask [3, 2] : vector<4x3xi1>

print %1
              columns
            0    1    2
          |------------
        0 | 1    1    0
  rows  1 | 1    1    0
        2 | 1    1    0
        3 | 0    0    0
```

and

```
// create a constant vector mask of size 4x3xi1 with elements in range
// 0 <= row <= 2 and 0 <= col <= 1 are set to 1 (others to 0).
%1 = vector.constant_mask [3, 2] : vector<4x3xi1>

print %1
              columns
            0    1    2
          |------------
        0 | 1    1    0
  rows  1 | 1    1    0
        2 | 1    1    0
        3 | 0    0    0
```

Can we have zeros before ones in a mask? (perhaps @dcaballe and @banach-space know?)

https://github.com/llvm/llvm-project/pull/113411