[mlir] OptionalProp<IntProp<uint8_t>> printout empty for 0 and similar values.

[peledins-zimperium]

We have in our op:

arguments = (ins OptionalProp<IntProp<"uint8_t">>:$stuff)
...
let assemblyFormat = [{
        $op (`stuff` $stuff^)?
    }];

When serializing this for stuff==0 we get printout of

stuff

In generated code:
_odsPrinter << (*(getProperties().stuff));
which maps to:

  raw_ostream &operator<<(unsigned char C) {
    if (OutBufCur >= OutBufEnd)
      return write(C);
    *OutBufCur++ = C;
    return *this;
  }

So it ends up printing \0 instead of 0.

uint16_t works, int8_t does not.

For OptionalAttr<I8Attr> this works as expected and prints 0.

[llvmbot]

@llvm/issue-subscribers-mlir

Author: None (peledins-zimperium)

We have in our op:

arguments = (ins OptionalProp<IntProp<"uint8_t">>:$stuff)
...
let assemblyFormat = [{
        $op (`stuff` $stuff^)?
    }];

When serializing this for stuff==0 we get printout of

stuff

In generated code:
_odsPrinter << (*(getProperties().stuff));
which maps to:

  raw_ostream &operator<<(unsigned char C) {
    if (OutBufCur >= OutBufEnd)
      return write(C);
    *OutBufCur++ = C;
    return *this;
  }

So it ends up printing \0 instead of 0.

uint16_t works, int8_t does not.