[llvm-commits] [RFC] Towards an assembler parser for PowerPC

[Ulrich Weigand]

Chris Lattner <clattner at apple.com> wrote on 18.01.2013 20:54:37:

> Right.  All things being equal, it is better to have fewer
> instructions, and to just use one as the canonical (general) form.
> Convenience aliases should be done with InstAlias, which the tblgen
> generated instprinter should pick up for free (at least in the
> simple/common cases).

Hmm, seems like this doesn't currently work for branch instructions,
since the "branch target" operand apparently makes it fall out of
the "simple/common cases".  I'm running into this path in
AsmWriterEmitter::EmitPrintAliasInstruction:

            assert(Rec->isSubClassOf("Operand") && "Unexpected operand!");
            // FIXME: We may need to handle these situations.
            delete IAP;
            IAP = 0;
            CantHandle = true;
            break;

Bye,
Ulrich