llvm dev - Jul 2016 - TableGen change in LLVM 3.9 allows only prefix instruction notation

Hello.
     I am curious why did you changed TableGen to allow in principle only
writing ASM
instructions in prefix notation. I ask because I personally use an assembly
notation that
is infix (I could use a simple preprocessor that changes prefix to infix).

     Just to mention: I found the solution to this - the following part of the
code is
responsible for this from llvm/utils/TableGen/AsmMatcherEmitter.cpp (so it needs
to be
commented to be disabled):
        // The first token of the instruction is the mnemonic, which must be a
        // simple string, not a $foo variable or a singleton register.
        if (AsmOperands.empty())
          PrintFatalError(TheDef->getLoc(),
                        "Instruction '" + TheDef->getName() +
"' has no tokens");

        assert(!AsmOperands[0].Token.empty());
        if (HasMnemonicFirst) {
          Mnemonic = AsmOperands[0].Token;
          if (Mnemonic[0] == '$')
            PrintFatalError(TheDef->getLoc(),
                            "Invalid instruction mnemonic '" +
Mnemonic + "'!");

          // Remove the first operand, it is tracked in the mnemonic field.
          AsmOperands.erase(AsmOperands.begin());
        } else if (AsmOperands[0].Token[0] != '$')
          Mnemonic = AsmOperands[0].Token;

   Thank you,
     Alex

On 15 July 2016 at 05:40, Alex Susu via llvm-dev
<llvm-dev at lists.llvm.org> wrote:
>     I am curious why did you changed TableGen to allow in principle only
> writing ASM instructions in prefix notation. I ask because I personally use
> an assembly notation that is infix (I could use a simple preprocessor that
> changes prefix to infix).
Running "git blame" points at
https://github.com/llvm-mirror/llvm/commit/5ef1349, which gives the
reasoning and suggests you ought to be able to set "HasMnemonicFirst".

Tim.

Hello.
     Tim, thanks for pointing me out to
https://github.com/llvm-mirror/llvm/commit/5ef1349 .
     I followed the example there and:
       - left utils/TableGen/AsmMatcherEmitter.cpp unchanged (no more commenting
of the
lines I said I did comment in the previous email)
       - following Hexagon.td I added in my MyTarget.td file:
         def MyTargetAsmParser : AsmParser {
           bit HasMnemonicFirst = 0;
         }
         [...]
         let AssemblyParsers = [MyTargetAsmParser];

      By doing these steps I was (again) able to use infix ASM instruction
notation.

   Thank you,
     Alex

On 7/15/2016 7:12 PM, Tim Northover wrote:
> On 15 July 2016 at 05:40, Alex Susu via llvm-dev
> <llvm-dev at lists.llvm.org> wrote:
>>      I am curious why did you changed TableGen to allow in principle
only
>> writing ASM instructions in prefix notation. I ask because I personally
use
>> an assembly notation that is infix (I could use a simple preprocessor
that
>> changes prefix to infix).
>
> Running "git blame" points at
> https://github.com/llvm-mirror/llvm/commit/5ef1349, which gives the
> reasoning and suggests you ought to be able to set
"HasMnemonicFirst".
>
> Tim.
>