On 8/26/2012 2:41 AM, Stefan Behnel wrote:
Stefan Behnel, 26.08.2012 11:36:
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?
How about `#if defined(_WIN64) && (_MSC_VER == 1500)`
A patch would essentially look like this:
diff -r 18fed0dec20e Cython/Compiler/Code.py
--- a/Cython/Compiler/Code.py Sun Aug 26 00:54:01 2012 +0200
+++ b/Cython/Compiler/Code.py Sun Aug 26 11:39:29 2012 +0200
@@ -893,6 +893,8 @@
code.write('\n#line 1 "cython_utility"\n')
code.putln("")
code.putln("/* Runtime support code */")
+ code.putln("#pragma auto_inline(off)")
+ code.putln("")
def finalize_main_c_code(self):
self.close_global_decls()
Stefan
Thanks. I just tried this. The `#pragma auto_inline(off)` line appears
after the MemoryView code and has no effect on that part.
Christoph
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