[llvm-commits] [PATCH] Asm operand parsing improvements

[Bruno Cardoso Lopes]

Does anyone can give me some feedback? :)

On Fri, Jan 28, 2011 at 4:42 PM, Bruno Cardoso Lopes
<bruno.cardoso at gmail.com> wrote:
> ping!
>
> On Wed, Jan 26, 2011 at 11:21 AM, Bruno Cardoso Lopes
> <bruno.cardoso at gmail.com> wrote:
>> Hi,
>>
>> The first attached patch implements support for custom target specific
>> asm parsing of operands. This is useful to avoid adding hacks to
>> AsmParsers whenever something different from an immediate or register
>> appears. The initial motivation was to remove the "mcr" family of
>> hacks from ARMAsmParser, but this is also going to be useful for other
>> ARM system instructions which I'm about to add the correct parsing and
>> encoding once this gets accepted. The second attached patch contains
>> modifications to the ARMAsmParser so that it starts using this
>> mechanism.
>>
>> A quick explanation of how it works (read the first patch for details):
>>
>> A table like the one below is autogenerated for every instruction
>> containing a 'ParserMethod' in its AsmOperandClass:
>>
>> static const OperandMatchEntry OperandMatchTable[20] = {
>>  /* Mnemonic, Operand List Mask, Operand Class, Features */
>>  { "cdp", 29 /* 0, 2, 3, 4 */, MCK_Coproc, Feature_IsThumb|Feature_HasV6 },
>>  { "cdp", 58 /* 1, 3, 4, 5 */, MCK_Coproc, Feature_IsARM },
>>
>> A matcher function very similar (but lot more naive) to
>> MatchInstructionImpl scans the table. After the mnemonic match, the
>> features are checked and if the "to be parsed" operand index is
>> present in the mask, there's a real match. Then, a switch like the one
>> below dispatch the parsing to the custom method provided in
>> 'ParseMethod':
>>
>>  case MCK_Coproc:
>>    return TryParseCoprocessorOperandName(Operands);
>>
>> Ok to commit? Suggestions?
>> Thanks.
>>
>> --
>> Bruno Cardoso Lopes
>> http://www.brunocardoso.cc
>>
>
>
>
> --
> Bruno Cardoso Lopes
> http://www.brunocardoso.cc
>



-- 
Bruno Cardoso Lopes
http://www.brunocardoso.cc