[LLVMdev] Internalize pass

[Talin]

Reid Kleckner wrote:
> Sounds like LLVM thinks the calling conventions or declarations are
> mismatched.  See:
> http://llvm.org/docs/FAQ.html#callconvwrong
>
>   
BTW, I'm still completely stumped on this issue, and I've put it aside 
to work on other things. But it would be nice to re-enable internalize :)
> Reid
>
> On Sat, Oct 3, 2009 at 1:16 AM, Talin <viridia at gmail.com> wrote:
>   
>> Well, after some investigation I have a few more clues as to what is
>> going on.
>>
>> I have a module which contains a call to an external native function.
>> This native function lives in a static library, and there is an external
>> declaration for it in the module.
>>
>> I find that I can run "llvm-ld -disable-opts -native -l mylibrary
>> test.bc" and it works fine. That is, llvm-ld is able to generate a
>> native object file, and link it against the static library with no problem.
>>
>> However, if I remove the "-disable-opts" line, it seems to replace the
>> call to the native function with "unreachable". I'm not 100% certain of
>> this, but if I replace the native function with a non-native function
>> that does something similar, then it seems to work ok.
>>
>> Chris Lattner wrote:
>>     
>>> On Sep 30, 2009, at 12:06 AM, Talin wrote:
>>>
>>>       
>>>> I'm playing around with different combinations of LTO passes, and
>>>> I've run into a strange problem:
>>>>
>>>> I have a 'main' function that looks like this:
>>>>
>>>> define i32
>>>> @"main(tart.core.Array[tart.core.String])->int"(%"tart.core.Array[tart.core.String]"*
>>>> %args) {
>>>> entry:
>>>>   call void @llvm.dbg.func.start(metadata !0)
>>>>   call void @llvm.dbg.stoppoint(i32 2, i32 19, metadata !1)
>>>>   %integerLimitsTest = call { } @integerLimitsTest() ; <{ }> [#uses=0]
>>>>   call void @llvm.dbg.stoppoint(i32 3, i32 21, metadata !1)
>>>>   %integerToStringTest = call { } @integerToStringTest() ; <{ }>
>>>> [#uses=0]
>>>>   call void @llvm.dbg.stoppoint(i32 4, i32 9, metadata !1)
>>>>   call void @llvm.dbg.region.end(metadata !0)
>>>>   ret i32 0
>>>> }
>>>>
>>>> However, when I add an internalize pass before the other LTO passes,
>>>> the 'main' function turns into this:
>>>>
>>>> define i32 @main(i32, i8** nocapture) nounwind readnone {
>>>> entry:
>>>>   tail call void @llvm.dbg.func.start(metadata !0)
>>>>   tail call void @llvm.dbg.stoppoint(i32 3, i32 21, metadata !1)
>>>>   unreachable
>>>> }
>>>>
>>>> The thing is, there's nothing particularly special or interesting
>>>> about the functions being called from main().
>>>>         
>>> This is likely to not be due to internalize itself.  Internalize marks
>>> functions "internal", which allows other interprocedural optimizers to
>>> have more freedom to change their interfaces etc.  The likely problem
>>> here is that you are calling something from 'main' with mismatching
>>> calling conventions or something like that.  It is hard to say without
>>> a full testcase.
>>>
>>> -Chris
>>>       
>> _______________________________________________
>> LLVM Developers mailing list
>> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>>
>>     
>
>