On 11 March 2012 09:46, mark florisson <markflorisso...@gmail.com> wrote: > On 10 March 2012 14:00, Stefan Behnel <stefan...@behnel.de> wrote: >> Lisandro Dalcin, 10.03.2012 10:51: >>> On 10 March 2012 03:41, mark florisson wrote: >>>> On 9 March 2012 14:22, Lisandro Dalcin wrote: >>>>> I'm basically experiencing the issues here: >>>>> http://www.cocoabuilder.com/archive/xcode/310299-error-calling-builtin-expect-inside-omp-parallel-for.html >>>>> >>>>> Can you imagine any way to workaround it? >>>> >>>> What a lovely C compiler bug... Did you file a bug report with gcc or >>>> xcode? What version of gcc does Lion ship with? >>>> >>> >>> I'm using a Mac just by accident, no idea (nor motivation) to report >>> bugs to Apple. >>> >>> $ gcc --version >>> i686-apple-darwin11-llvm-gcc-4.2 (GCC) 4.2.1 (Based on Apple Inc. >>> build 5658) (LLVM build 2336.9.00) >>> >>> Could that be the the bug is actually in the LLVM backend? >>> >>>> I suppose the macro would have to be disabled for OS X Lion inside >>>> parallel sections (there seems to be __APPLE__ and __OSX__, I don't >>>> know about detecting the OS X version), that's easy to do (undef and >>>> redefine to no-ops before parallel section and redefine it again after >>>> the section). I'll try fixing it during the sprints next week. >>> >>> Perhaps switching to use a "omp_likely"/"omp_unlikely" macros inside >>> OpenMP blocks would be nicer than defining/undefining? >> >> Could that be coded into the macro or would it require to change the >> generated code? But at least it sounds like it would not impact code in >> functions that are being called from within the OpenMP blocks, would it? >> Just the code straight inside the block. A work-around could still have a >> substantial impact if it requires changes to the generated code. > > Yeah, that's why I suggested the undef/re-def approach around OpenMP > blocks. It's some code bloat, but only for the C preprocessor, so it > should be fine. >
I still feel bad about this. What about just disabling branch prediction if OpenMP is ever used? Or perhaps just protect the definitions of likely/unlikely with some guard, such as users can disable them using a -D definition? -- Lisandro Dalcin --------------- CIMEC (INTEC/CONICET-UNL) Predio CONICET-Santa Fe Colectora RN 168 Km 472, Paraje El Pozo 3000 Santa Fe, Argentina Tel: +54-342-4511594 (ext 1011) Tel/Fax: +54-342-4511169 _______________________________________________ cython-devel mailing list cython-devel@python.org http://mail.python.org/mailman/listinfo/cython-devel
