[llvm-commits] [llvm] r72148 - /llvm/trunk/include/llvm/System/Atomic.h

[Sebastian Redl]

Sebastian Redl wrote:
> Chris Lattner wrote:
>   
>> On May 19, 2009, at 5:31 PM, Owen Anderson wrote:
>>   
>>     
>>> Author: resistor
>>> Date: Tue May 19 19:31:29 2009
>>> New Revision: 72148
>>>
>>> URL: http://llvm.org/viewvc/llvm-project?rev=72148&view=rev
>>> Log:
>>> We need to include config.h here so that the #defines are set  
>>> properly.
>>>     
>>>       
>> This isn't going to work: LLVM headers can't include config.h, because  
>> it conflicts with other projects that use their own config.h.  Why  
>> does "gcc atomics support" need to be autoconf'd?  Can' you just check  
>> against the gcc version macros?
>>   
>>     
> No, the atomic intrinsics simply disappear when the platform doesn't
> support them, e.g. -march=i386.
>   
Wait, I remembered that wrong. The builtins exist, but GCC tries to
resolve them to library functions, which aren't actually implemented (or
weren't, back in GCC 4.3).

Sebastian