llvm dev - Feb 2008 - [LLVMdev] Removing inlining of library functions

I am interested in analyzing the bytecode code produced for C files.   
By default, inlining of user and library functions (libc) is done. If  
I turn off inlining (-disable-inlining in gccas and gccld) then no  
inlining is done.  I want to be able to inline user code but disallow   
library code to be inlined.

In trying to understand the InlineSimple.cpp code, I see that library  
functions are tagged as having internal linkage, just as other user  
functions in a module, and so these library functions are inlined if  
they satisfy other inlining rules (e.g., strcpy() is quite often  
inlined).

My questions:
- is there a simple way to disallow inlining of library functions?
- in what part of the code tree is the internal linkage attribute  
being set for library functions?

I am using LLVM1.9 (due to a dependency of some C code on gcc3.4) but  
I'd imagine that this functionality hasn't changed much in more recent  
versions.

Thanks,
Cristina

Try adding the gcc 'noinline' attribute to functions you don't
want inlined (see the gcc docs for details).

Ciao,

Duncan.

The defined gcc interface for this is -fno-builtin.  It seems not be  
to be working in llvm-gcc, however.

On Feb 20, 2008, at 6:55 PM, Cristina Cifuentes wrote:
> I am interested in analyzing the bytecode code produced for C files.
> By default, inlining of user and library functions (libc) is done. If
> I turn off inlining (-disable-inlining in gccas and gccld) then no
> inlining is done.  I want to be able to inline user code but disallow
> library code to be inlined.
>
> In trying to understand the InlineSimple.cpp code, I see that library
> functions are tagged as having internal linkage, just as other user
> functions in a module, and so these library functions are inlined if
> they satisfy other inlining rules (e.g., strcpy() is quite often
> inlined).
>
> My questions:
> - is there a simple way to disallow inlining of library functions?
> - in what part of the code tree is the internal linkage attribute
> being set for library functions?
>
> I am using LLVM1.9 (due to a dependency of some C code on gcc3.4) but
> I'd imagine that this functionality hasn't changed much in more
recent
> versions.
>
> Thanks,
> Cristina
>
>
>
>
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev

On Feb 20, 2008, at 6:55 PM, Cristina Cifuentes wrote:
> - in what part of the code tree is the internal linkage attribute
> being set for library functions?

Internalize pass (Transforms/IPO/Internalize.cpp) sets internal  
linkage if the function is not in export list. If you're using 'llvm- 
ld' try  -disable-internalize.

-
Devang

On Thu, 21 Feb 2008, Dale Johannesen wrote:
> The defined gcc interface for this is -fno-builtin.  It seems not be
> to be working in llvm-gcc, however.
Please file a reduced testcase in bugzilla,

-Chris
>
>> I am interested in analyzing the bytecode code produced for C files.
>> By default, inlining of user and library functions (libc) is done. If
>> I turn off inlining (-disable-inlining in gccas and gccld) then no
>> inlining is done.  I want to be able to inline user code but disallow
>> library code to be inlined.
>>
>> In trying to understand the InlineSimple.cpp code, I see that library
>> functions are tagged as having internal linkage, just as other user
>> functions in a module, and so these library functions are inlined if
>> they satisfy other inlining rules (e.g., strcpy() is quite often
>> inlined).
>>
>> My questions:
>> - is there a simple way to disallow inlining of library functions?
>> - in what part of the code tree is the internal linkage attribute
>> being set for library functions?
>>
>> I am using LLVM1.9 (due to a dependency of some C code on gcc3.4) but
>> I'd imagine that this functionality hasn't changed much in more
recent
>> versions.
>>
>> Thanks,
>> Cristina
>>
>>
>>
>>
>> _______________________________________________
>> LLVM Developers mailing list
>> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
-Chris

-- 
http://nondot.org/sabre/
http://llvm.org/

This option doesn't always help as various C library functions
are built-in into the compiler.

Regards,
Cristina




On Feb 21, 2008, at 7:32 PM, Duncan Sands wrote:
> Try adding the gcc 'noinline' attribute to functions you don't
> want inlined (see the gcc docs for details).
>
> Ciao,
>
> Duncan.

On Feb 22, 2008, at 9:30 AM, Devang Patel wrote:
>
> On Feb 20, 2008, at 6:55 PM, Cristina Cifuentes wrote:
>
>> - in what part of the code tree is the internal linkage attribute
>> being set for library functions?
>
>
> Internalize pass (Transforms/IPO/Internalize.cpp) sets internal  
> linkage if the function is not in export list. If you're using
'llvm-
> ld' try  -disable-internalize.
This is equivalent to using the -fno-builtin option in llvm-gcc.

Regards,
Cristina

>
>
> -
> Devang
>
>
>