[cfe-dev] Remove unused types from ASTContext
mats petersson via cfe-dev
cfe-dev at lists.llvm.org
Sun Apr 30 14:00:35 PDT 2017
Like I said, you need those types for most of the compilation process. It's
REALLY hard to keep track of when these things don't matter any longer -
you certainly need types that actually generate code all the way to LLVM-IR
generation. That's for the AST types. IR types, which isn't quite the same
thing.
The latter, you can do by doing "syntax-only" run on the compiler - it
won't generate any LLVM-IR, so memory usage here is "only" AST. Also,
prodcuing LLVM-IR output from the compiler (-S -emit-llvm) and then using
`llc` to compile the IR to machine code, to determine memory usage of the
IR types (obviously with other things).
[In my compiler project, I decided it's so hard to track what is needed
again and what isn't, and decided to NOT free any memory for that reason -
of course, not a particularly great strategy if you want to run it as a
library in something else, but if I really had to, I could probably stick
every object in one or more container(s) and free it all at the end]
--
Mats
On 30 April 2017 at 21:12, mateusz janek <stryku2393 at gmail.com> wrote:
> Sorry for no response, I was quite busy.
>
> Thanks Brian for help with the build (: Also I've tried with the g++-6 and
> it has same problem with the memory usage.
>
> The problem here is caused by creating a lot of template class
> specializations. As Mats partially said and I found in the llvm sources
> here: https://github.com/stryku/llvm/blob/master/include/llvm/
> IR/Type.h#L42 types are stored till the end of program life. AFAIU every
> class specialization is a separate type.
>
> Simpler program that shows my problem is e.g. https://gist.github.com/
> stryku/986bcd6a5d5773ef0e0136a5eca97e20
> There is a lot of specializations of values_container, create_container, create_impl
> etc. Additionally every values_container have a lot of template
> parameters which in fact are also types (built-in types, but still).
>
> For now, I'm playing with llvm and clang sources to understand what's
> going on there and I'll probably try to implement my own mechanism of
> storing a template class specializations.
>
> Thanks for your interest,
> Stryku
>
>
>
> 2017-04-29 0:02 GMT+02:00 Brian Cain <brian.cain at gmail.com>:
>
>>
>> On Fri, Apr 28, 2017 at 6:11 AM, mateusz janek <stryku2393 at gmail.com>
>> wrote:
>>
>>> Did you use CMake? If no, ctai requres clang 4.0 and to be compiled with
>>> flags: `-std=c++1z -ftemplate-backtrace-limit=0 -ftemplate-depth=8096`
>>>
>>>
>> I got it to work with some tweaks to the CMake config. It ran quickly
>> for me, but it did allocate a decent amount of memory on the way. Also I
>> used a nightly build of clang and libc++ (and not libstdc++).
>>
>> 15.85user 0.48system 0:16.38elapsed 99%CPU (0avgtext+0avgdata
>> 4053852maxresident)k
>> 0inputs+24outputs (0major+381214minor)pagefaults 0swaps
>>
>>
>>
>> diff:
>>
>> diff --git a/CMakeLists.txt b/CMakeLists.txt
>> index 0143461..109d975 100644
>> --- a/CMakeLists.txt
>> +++ b/CMakeLists.txt
>> @@ -1,9 +1,9 @@
>> cmake_minimum_required(VERSION 3.5)
>> project(ctai)
>>
>> -add_definitions(-std=c++1z -ftemplate-backtrace-limit=0
>> -ftemplate-depth=1024)
>> -
>> -set(CMAKE_CXX_COMPILER clang++-3.9)
>> +set(CMAKE_CXX_COMPILER clang++-3.9 CACHE STRING "")
>> +set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++1z -stdlib=libc++
>> -ftemplate-backtrace-limit=0 -ftemplate-depth=8192" CACHE STRING "" FORCE)
>> +set(CMAKE_MODULE_LINKER_FLAGS ${CMAKE_MODULE_LINKER_FLAGS} "-std=c++1z
>> -stdlib=libc++" CACHE STRING "" FORCE)
>>
>> set(INCLUDE_FILES
>> register.hpp
>> diff --git a/main.cpp b/main.cpp
>> index b95eb4d..35e6d6f 100644
>> --- a/main.cpp
>> +++ b/main.cpp
>> @@ -30,6 +30,66 @@ using code = decltype(
>> "mov ebx , 1 "
>> "add eax , ebx "
>> "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> + "mov DWORD PTR [ ebp + 4 ] , eax "
>> "jmp .loop_label "
>> ":end_label "
>> "mov eax , DWORD PTR [ ebp + 16 ] "
>> @@ -39,4 +99,4 @@ int main()
>> {
>> std::cout << "15th element of fibonacci series is: " <<
>> cai::execute_code<code>;
>> return 0;
>> -}
>> \ No newline at end of file
>> +}
>>
>>
>>
>>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/cfe-dev/attachments/20170430/8e9743a0/attachment.html>
More information about the cfe-dev
mailing list