[Mlir-commits] [mlir] Sub-channel quantized type implementation (PR #120172)

[Sandeep Dasgupta]

================
@@ -228,38 +365,44 @@ static Type parseUniformType(DialectAsmParser &parser) {
     return nullptr;
   }
 
-  // Optionally parse quantized dimension for per-axis quantization.
+  // Optionally parse quantized dimension for per-axis or sub-channel
+  // quantization.
   if (succeeded(parser.parseOptionalColon())) {
-    if (parser.parseInteger(quantizedDimension))
-      return nullptr;
-    isPerAxis = true;
+    if (succeeded(parser.parseOptionalLBrace())) {
+      isSubChannel = true;
+      if (parseBlockSizeInfoUntilRBrace(parser, quantizedDimensions,
----------------
sdasgup3 wrote:

That is a good point!

>> parseCommaSeparatedListUntil

I could not find `` defined in `DialectAsmParser` ([ref](https://github.com/llvm/llvm-project/blob/12fe5ae88cce0e3a8de47ed766425cbf8505ab87/mlir/include/mlir/IR/DialectImplementation.h#L56) and [ref](https://github.com/llvm/llvm-project/blob/12fe5ae88cce0e3a8de47ed766425cbf8505ab87/mlir/include/mlir/IR/OpImplementation.h#L805)

>> parseCommaSeparatedList

The problem with just using this one is if we pass on a explicitly specified delimiter, then empty list is allowed. But the sub-channel types expects the block-info to be non-empty. To mitigate the above two limitations, we have implemented our own version of  `parseCommaSeparatedListUntil` as follows using the second API you suggested. 

```
static ParseResult
parseBlockSizeInfoUntilRBrace(DialectAsmParser &parser,
                              SmallVectorImpl<int32_t> &quantizedDimensions,
                              SmallVectorImpl<int64_t> &blockSizes) {
  // Empty block-sizes info.
  if (succeeded(parser.parseOptionalRBrace())) {
    return success();
  }

  auto parseBlockSizeElements = [&]() -> ParseResult {
    quantizedDimensions.resize(quantizedDimensions.size() + 1);
    blockSizes.resize(blockSizes.size() + 1);
    if (parser.parseInteger(quantizedDimensions.back()) ||
        parser.parseColon() || parser.parseInteger(blockSizes.back()))
      return failure();
    return success();
  };

  if (parser.parseCommaSeparatedList(parseBlockSizeElements) ||
      parser.parseRBrace()) {
    return failure();
  }

  return success();
}
```
 


https://github.com/llvm/llvm-project/pull/120172