llvm dev - Nov 2015 - Meaning of IR inline assembly

Hello,

Most of the IR language is correctly explained; but with inline assembly I feel
alone at some point:

define i32 @main(i32 %argc, i8** %argv) #0 {
  ... //some uninteresting bloat here
  call void asm sideeffect "outw %eax, $0",
"imr,~{dirflag},~{fpsr},~{flags}"(i32 %8) #2, !srcloc !2
  ret i32 0
}

I reduced the above code to the offending line containing:
"imr,~{dirflag},~{fpsr},~{flags}".

How should I interpret this? I found no resource on this over the net. Maybe
there are more options like that?
Do you have a link explaining this more in details?

thanks a lot.
-- 
Alex

> On 18.11.2015, at 16:28, AlexandreFressange via llvm-dev <llvm-dev at
lists.llvm.org> wrote:
> 
> I reduced the above code to the offending line containing:
"imr,~{dirflag},~{fpsr},~{flags}".
> 
> How should I interpret this? I found no resource on this over the net.
Maybe there are more options like that?
> Do you have a link explaining this more in details?
It’s called a constraint string and it is documented here:

http://llvm.org/docs/LangRef.html#inline-asm-constraint-string

Cheers,

d
> 
> thanks a lot.
> -- 
> Alex
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev

Thanks, but I could not find the imr, dirflag, fpsr constraints here. Just the
usual gcc/clang inline assembly constraints.
Those one were of my concern, actually :)



-- 
Alex


18.11.2015, 17:11, "David Siegel" <agnat at
icloud.com>:
>>  On 18.11.2015, at 16:28, AlexandreFressange via llvm-dev <llvm-dev
at lists.llvm.org> wrote:
>>
>>  I reduced the above code to the offending line containing:
"imr,~{dirflag},~{fpsr},~{flags}".
>>
>>  How should I interpret this? I found no resource on this over the net.
Maybe there are more options like that?
>>  Do you have a link explaining this more in details?
>
> It’s called a constraint string and it is documented here:
>
> http://llvm.org/docs/LangRef.html#inline-asm-constraint-string
>
> Cheers,
>
> d
>
>>  thanks a lot.
>>  --
>>  Alex
>>  _______________________________________________
>>  LLVM Developers mailing list
>>  llvm-dev at lists.llvm.org
>>  http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev