[llvm-commits] [llvm] r78379 - in /llvm/trunk: lib/Target/X86/AsmParser/X86AsmParser.cpp test/MC/AsmParser/labels.s test/MC/AsmParser/x86_instructions.s

[Chris Lattner]

ok!

On Aug 7, 2009, at 10:59 AM, Daniel Dunbar wrote:

> On Fri, Aug 7, 2009 at 9:50 AM, Chris Lattner<clattner at apple.com>  
> wrote:
>> On Aug 7, 2009, at 1:45 AM, Daniel Dunbar wrote:
>>
>> I'm sure you have a ton of ideas :), but it looks pretty straight-
>> forward to break down common conditions into a tree.  Turning the top
>> level into a switch on the # operands also looks pretty obvious :).
>
> Yes, I was hoping it was evident I didn't plan on leaving the matcher
> like this. :)
>
> I'm tempted to just implement a generic tree match generator; it seems
> like there are a number of places we could make use of this. In this
> particular case it should allow the tokens and operands to be matched
> simultaneously.
>
> I was planning on waiting until the major correctness stuff was done,
> though, since it changes the matching a bit. Although I also like
> being able to build the code, so... :)
>
>> The generated code looks great for a first cut though!  Maybe it
>> should include a comment about the instruction being matched?
>
> Err, lets wait until the matcher is done to optimize this  
> dimension. :)
>
> The only place to put a comment about the instruction is when a
> terminal state is reached, at which point the conversion function has
> the instruction name already in it. I can add a comment there if you
> think it adds clarity.
>
>> Is the code intended to handle regclass constraints yet?  For  
>> example,
>> in:
>
> Nope. That is the partial order stuff in the comment at the top of
> AsmMatcherEmitter.cpp, which isn't implemented yet.
>
>> I don't see how it avoids matching things like "mulss %gs, %eax".  Do
>> you intend the matcher to reject this in the future?
>
> Yes, the matcher will reject code which would be ambiguous (and force
> the .td user to resolve it), once things are finished. At least thats
> my current plan. :)
>
> - Daniel
>
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