llvm dev - Jun 2011 - [LLVMdev] LLVM interpreter does not support fmod

It seems llvm interpreter only supports a limited number of external
functions. fmod, in particular is not supported. any reason why it is not
supported ?

"lli -force-interpreter test.bc
LLVM ERROR: Tried to execute an unknown external function: double (double,
double)* fmod
"

-- 
Kind Regards

Xin Tong
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Hi,
> It seems llvm interpreter only supports a limited number of external
> functions. fmod, in particular is not supported. any reason why it is not
> supported ?
> 
> "lli -force-interpreter test.bc
> LLVM ERROR: Tried to execute an unknown external function: double (double,
> double)* fmod
> "
  You can check out the comments in
lib/ExecutionEngine/Interpreter/ExternalFunctions.cpp
to see how LLVM interpreter handle external functions.

  "... If such a wrapper does not exist, and libffi is available, then the
Interpreter will
   attempt to invoke the function using libffi, after finding its address."

I guess you have to configure LLVM with "--enable-libffi" option.

  HTH.

Regards,
chenwj

-- 
Wei-Ren Chen (陳韋任)
Computer Systems Lab, Institute of Information Science,
Academia Sinica, Taiwan (R.O.C.)
Tel:886-2-2788-3799 #1667

On Jun 14, 2011, at 7:57 PM, 陳韋任 wrote:
> Hi,
> 
>> It seems llvm interpreter only supports a limited number of external
>> functions. fmod, in particular is not supported. any reason why it is
not
>> supported ?
>> 
>> "lli -force-interpreter test.bc
>> LLVM ERROR: Tried to execute an unknown external function: double
(double,
>> double)* fmod
>> "
> 
>  You can check out the comments in
lib/ExecutionEngine/Interpreter/ExternalFunctions.cpp
> to see how LLVM interpreter handle external functions.
> 
>  "... If such a wrapper does not exist, and libffi is available, then
the Interpreter will
>   attempt to invoke the function using libffi, after finding its
address."
> 
> I guess you have to configure LLVM with "--enable-libffi" option.
Also note that the interpreter has a ton of limitations, this is just the tip of
the iceberg.  It is far from being production quality.

-Chris