[PATCH] Cygwin: Make gcc-specific code in <sys/cpuset.h> compiler-agnostic

Mark Geisert mark@maxrnd.com
Sun Jul 9 07:58:37 GMT 2023


Hi all,

Brian Inglis wrote:
> On 2023-07-08 15:53, Mark Geisert wrote:
>> Mark Geisert wrote:
>> I got tripped up by misspelling and not being able to link clang{,++} programs 
>> on my test system.  I checked the .o files with objdump: Clang and clang++ both 
>> support __builtin_popcountl, but they emit code for the Hackers Delight 
>> algorithm rather than using the single-instruction popcnt.  Sorry for the 
>> confustion [sic].
> 
> That's what I meant - clang 8 "identifies as" gcc 4, and builtin and intrinsic 
> function support are almost the same (and fairly close to gcc 11) builtin and 
> intrinsic function support.
> 
> And as you mentioned, any support for builtins is better than what we can whip up 
> off the top of our heads (unless you use HD/2!)
> 
> For our purposes, the main differences between clang 8 and current are latest 
> language, library, and processor support, but it also supports useful tools like 
> the analyzer and formatter, which gcc does not provide.
> 
> And it is convenient to be able to run another compiler side by side for 
> comparisons without copying files and remoting to another system.

I now understand what you were getting at.  We are in agreement.  Thanks to your 
persistence and everybody elses comments and to my belatedly getting a working 
clang/clang++ build environment, there is a much smaller v2 patch incoming.
Thanks and Regards All,

..mark



More information about the Cygwin-patches mailing list