[Mlir-commits] [mlir] [mlir][vector] Clarify the semantics of BroadcastOp (PR #101928)

[Andrzej Warzyński]

================
@@ -2391,12 +2391,28 @@ mlir::vector::isBroadcastableTo(Type srcType, VectorType dstVectorType,
   // (all leading dimensions are simply duplicated).
   int64_t lead = dstRank - srcRank;
   for (int64_t r = 0; r < srcRank; ++r) {
+    bool mismatch = false;
----------------
banach-space wrote:

Naming is hard ... Here's an attempt to explain:

1.  `mismatch` - bool to model whether a mismatch in dims has been found. I am introducing this to be able to replace logic like this:
```cpp
if (complex_conditions_for_fixed_width_widh_dims || complex_conditions_for_scalable_flags)
  // Do sth when dims mismatch
```

with something like this:
```cpp
if (complex_conditions_for_fixed_width_dims)
  mismatch = true;
  
if (complex_conditions_for_scalable_flags)
  mismatch = true;
  
if (mismatch)
  // Do sth when dims mismatch
```

2. `mismatchingDims` - pointer to the result. If `! = nullptr` then we'll use it to pass the first dimension that mismatched. I'll add `!=nullptr` to disambiguate a bit.


https://github.com/llvm/llvm-project/pull/101928