[mlir][tosa] Disable folder for non-int/float/index types in tosa.slice

[NatashaKnk]

Summary

In order to fold, we need to create an ElementsAttr, and those cannot be generated from any type. In particular, currently we need to avoid folding quantized types.

[NatashaKnk]

Fix formatting

[NatashaKnk]

Fix formatting

[jpienaar]

It seems like your latest update removed the functional change (it just shows me the formatting change now)

[jpienaar]

LG, but please add rationale in both description and comment in code.

[NatashaKnk]

fixed ;

[NatashaKnk]

Add comment in code

[NatashaKnk]

Check for output type as well

mlir/lib/Dialect/Tosa/IR/TosaCanonicalizations.cpp

OpFoldResult SubOp::fold(FoldAdaptor adaptor) {
   if (!lhsAttr || !rhsAttr)
     return {};
 
   return binaryFolder<std::minus<APInt>, std::minus<APFloat>>(lhsAttr, rhsAttr,
                                                               lhsTy);
 }
 
 namespace {
-template <typename Cmp> struct ComparisonFold {
+template <typename Cmp>
+struct ComparisonFold {
   ComparisonFold() = default;
   APInt operator()(const APInt &l, const APInt &r) {
     return APInt(1, Cmp()(l, r));
   }
 
   APInt operator()(const APFloat &l, const APFloat &r) {
     return APInt(1, Cmp()(l, r));
   }
if (!inputTy || !outputTy)
     return {};
 
   if (inputTy == outputTy && inputTy.hasStaticShape())
     return getInput();
 
   if (!adaptor.getInput())
     return {};
 
+  // Cannot create an ElementsAttr from non-int/float/index types
+  if (!inputTy.getElementType().isIntOrIndexOrFloat() ||
+      !outputTy.getElementType().isIntOrIndexOrFloat())
+    return {};
+
   auto operand = adaptor.getInput().cast<ElementsAttr>();
   if (operand.isSplat() && outputTy.hasStaticShape()) {
     return SplatElementsAttr::get(outputTy, operand.getSplatValue<Attribute>());
   }
 
   if (inputTy.hasStaticShape() && outputTy.hasStaticShape() &&
       outputTy.getNumElements() == 1) {
     llvm::SmallVector<uint64_t> indices(getStart());