Christoph Gohlke, 26.08.2012 10:03: > On 8/25/2012 6:51 AM, Stefan Behnel wrote: >> Christoph Gohlke, 25.08.2012 04:07: >>> On 8/24/2012 12:43 PM, Stefan Behnel wrote: >>>> Christoph Gohlke, 24.08.2012 07:20: >>>>> On 64 bit Python 2.7 and 3.2 with msvc9 compiler, python.exe crashes >>>>> during >>>>> `test_slice_assignment (memslice.__test__)`. I tested two computers. The >>>>> Windows executive can not identify in which specific module it >>>>> crashes, and >>>>> neither enabling faulthandler nor building with debug symbols gives any >>>>> useful information. Can anyone reproduce this? It seems compiler specific >>>>> since Python 3.3, which is using msvc10, does not crash. >>>> >>>> Hmm, yes, sounds like a problem with the compiler. Would be good to get >>>> this sorted out, but it's almost impossible to debug something like this >>>> from a distance. >>> >>> Maybe the following simple example is related. It fails (not crash) when >>> compiled with 64 bit msvc9, but does work with 32 bit msvc9 and msvc10 (32 >>> and 64 bit): >>> >>> ``` >>> from cython.view cimport array as cvarray >>> import numpy as np >>> >>> narr = np.arange(8 * 14 * 11).reshape((8, 14, 11)) >>> >>> cdef int[:, :, ::1] a = narr >>> cdef int[:, :, :] b = a[2:8:2, -4:1:-1, 1:3] >>> >>> print narr[2:8:2, -4:1:-1, 1:3].shape >>> print b.shape[0], b.shape[1], b.shape[2] >>> ``` >>> >>> On win-amd64-py2.x the shape of b is (3, 9, 3) but it should be (3, 9, 2) >> >> I'll leave that for the others to comment. > > This failure and the test crash disappear when auto-inlining is disabled, > e.g. using the `/Ob1` compiler switch > <http://msdn.microsoft.com/en-us/library/47238hez%28v=vs.100%29.aspx>
Thanks for figuring that out. > Is there a way to add a C pre-processor `#pragma` to a Cython generated C > file? I don't think so, not in arbitrary places. > I tried `cdef void emit_pragma '#pragma auto_inline(off) //' ()` but > the pragma ends up inside the Python module init function, which fails to > compile with `error C2156: pragma must be outside function`. As a quick fix, we could wrap (or just start) our utility code section with that pragma. It starts after all user code. According to the docs, the pragma only disables automatic inlining in the specific range, not explicitly requested inlining. http://msdn.microsoft.com/en-us/library/ah08w5c3%28v=vs.71%29.aspx We usually know what we consider worth inlining and what doesn't need to be. If we can find out what exact functions trigger this, we can start being more specific about where to enable the pragma, but I think it's ok to enable it on all utility code for now. Could you figure out a suitable preprocessor guard that only enables it for the affected compilers? Stefan _______________________________________________ cython-devel mailing list cython-devel@python.org http://mail.python.org/mailman/listinfo/cython-devel
