Don't elide splat attributes during printing

[tberghammer]

Summary

A splat attribute have a single element during printing so we should
treat it as such when we decide if we elide it or not based on the flag
intended to elide large attributes.

[mehdi_amini]

mlir/lib/IR/AsmPrinter.cpp

162

I think this expression isn't the most straightforward way to express the logic here, in general ternary aren't great but as subexpression it is rarely a good idea IMO. I rather read something like this:

return attr.isa<SplatElementsAttr>() ||
          (elementsAttrElementLimit.hasValue() &&
         *elementsAttrElementLimit < int64_t(attr.getNumElements()));

[tberghammer]

Improve readability based on review commens

[rriddle]

Thanks!

mlir/lib/IR/AsmPrinter.cpp

 OpPrintingFlags &OpPrintingFlags::useLocalScope() {
   printLocalScope = true;
   return *this;
 }
 
 /// Return if the given ElementsAttr should be elided.
 bool OpPrintingFlags::shouldElideElementsAttr(ElementsAttr attr) const {
   return elementsAttrElementLimit.hasValue() &&
-         *elementsAttrElementLimit < int64_t(attr.getNumElements());
+         *elementsAttrElementLimit < int64_t(attr.getNumElements()) &&
+         !attr.isa<SplatElementsAttr>();
 }
 
 /// Return the size limit for printing large ElementsAttr.
 Optional<int64_t> OpPrintingFlags::getLargeElementsAttrLimit() const {
   return elementsAttrElementLimit;
 }
 
 /// Return if debug information should be printed.

mlir/test/IR/pretty-attributes.mlir

 // CHECK: dense<[1, 2]> : tensor<2xi32>
 "test.non_elided_dense_attr"() {foo.dense_attr = dense<[1, 2]> : tensor<2xi32>} : () -> ()
 
 // CHECK: opaque<"", "0xDEADBEEF"> : vector<1x1x1xf16>
 "test.sparse_attr"() {foo.sparse_attr = sparse<[[1, 2, 3]],  -2.0> : vector<1x1x1xf16>} : () -> ()
 
 // CHECK: opaque<"", "0xDEADBEEF"> : tensor<100xf32>
 "test.opaque_attr"() {foo.opaque_attr = opaque<"", "0xEBFE"> : tensor<100xf32> } : () -> ()
+
+// CHECK: dense<1> : tensor<3xi32>
+"test.dense_splat"() {foo.dense_attr = dense<1> : tensor<3xi32>} : () -> ()