[cfe-dev] [LLVMdev] [lldb-dev] RFC: LLVM should require a working C++11 <thread>, <mutex>, and <atomic>

[Vadim Chugunov]

This might be a better question for mingw devs, but apparently these days
GCC itself needs threads for something, and may be built on top of either
win32 or posix threads.

Vadim

PS: I did some more testing, and it looks like when parallel code
generation is actually used (4 threads), the difference becomes >20%.

On Fri, Sep 26, 2014 at 1:01 PM, Yaron Keren <yaron.keren at gmail.com> wrote:

> Hi Vadim,
>
> Yes, exactly, what is the point of having two versions -pthreads and
> -win32threads when you can make -pthreads behave like -win32threads by
> disabling the use of pthreads etc?
>
> Yaron
>
>
> 2014-09-26 22:47 GMT+03:00 Vadim Chugunov <vadimcn at gmail.com>:
>
>> When LLVM's configure finds a usable <pthread.h>, it prefers to use that
>> rather than the home-grown stuff.   However if LLVM is configured with
>> --disable-pthreads, both mingw flavors produce the same results.
>>
>> BTW, I've tried to quantify the slowdown: a quick test indicates that
>> LLVM build that uses pthreads is about 10% slower than the one which
>> doesn't.  This is less that I remember seeing last year (something got
>> optimized?), but still...
>>
>> Vadim
>>
>>
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