[issue19537] Fix misalignment in fastsearch_memchr_1char
STINNER Victor added the comment: 2014-03-24 0:30 GMT+01:00 Antoine Pitrou rep...@bugs.python.org: What is the size of the PyASCIIObject on x86/x64 with and without the patch? Haven't tried on x86, but on x86-64 it's the same. If it changes it will probably get detected by the sys.getsizeof() tests. test_sys has been modified: -asciifields = nnbP +asciifields = nn4bP It would like to know if objects are bigger with the change or not. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
Antoine Pitrou added the comment: Look at the commits, not the patch. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
STINNER Victor added the comment: Look at the commits, not the patch. Ah! You wrote Ok, I've committed the patch. Ok, your commit is fine. I would prefered a named field (called padding), but it's fine ;-) -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
Mark Lawrence added the comment: Martin, Larry msg214639 states Fix PyUnicode_DATA() alignment under m68k., your comments please. -- nosy: +BreamoreBoy, larry, loewis ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
Stefan Krah added the comment: Mark Lawrence, stop playing off committers against each other. This is outright trolling. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
Andreas Schwab added the comment:
The attached patch has been tested on
{i586,x86_64,ppc,ppc64,ppc64le,armv6hl,armv7hl,aarch64,m68k}-suse-linux.
--
keywords: +patch
Added file: http://bugs.python.org/file34589/pyasciiobject-align.patch
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[issue19537] Fix misalignment in fastsearch_memchr_1char
Changes by Andreas Schwab sch...@linux-m68k.org: Removed file: http://bugs.python.org/file32554/xx ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
Antoine Pitrou added the comment: Are unnamed struct fields actually valid C? -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
Stefan Krah added the comment: Yes, ยง6.7.2.1: A bit-field declaration with no declarator, but only a colon and a width, indicates an unnamed bit-field. With a footnote: 105) An unnamed bit-field structure member is useful for padding to conform to externally imposed layouts. Unnamed struct members are valid, too: There may be unnamed padding at the end of a structure or union. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
Roundup Robot added the comment: New changeset 004ae1472a43 by Antoine Pitrou in branch '3.4': Issue #19537: Fix PyUnicode_DATA() alignment under m68k. Patch by Andreas Schwab. http://hg.python.org/cpython/rev/004ae1472a43 New changeset 0128b25068de by Antoine Pitrou in branch 'default': Issue #19537: Fix PyUnicode_DATA() alignment under m68k. Patch by Andreas Schwab. http://hg.python.org/cpython/rev/0128b25068de -- nosy: +python-dev ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
Antoine Pitrou added the comment: Ok, I've committed the patch, then. Thank you, Andreas. -- resolution: - fixed stage: needs patch - committed/rejected status: open - closed ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
STINNER Victor added the comment: What is the size of the PyASCIIObject on x86/x64 with and without the patch? GCC and Visual Studio provide attributes to align structures. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
Antoine Pitrou added the comment: What is the size of the PyASCIIObject on x86/x64 with and without the patch? Haven't tried on x86, but on x86-64 it's the same. If it changes it will probably get detected by the sys.getsizeof() tests. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
STINNER Victor added the comment: If you compile Python with GCC, we can maybe try something with __attribute__ ((aligned (sizeof(void * attribute. The attribute can be used on a structure field. The problem is that we don't care of the alignment of header attributes, only of data, but data is not a field but the data just after the structure. Or is it possible to GCC to get a structure size aligned on 4 bytes? For the explicit padding: how do you compute the size of the padding? How about disabling the fast-path in FASTSEARCH if data is not aligned? (You might get non-aligned if even if structure is correctly aligned, it may happen if the memory allocator does not align memory blocks. I don't know if Python may get unaligned memory blocks.) -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
Serhiy Storchaka added the comment: I think that adding __attribute__ ((aligned (sizeof(void * to the PyObject type (or to the ob_base field) is enough. If first byte of structure is aligned, then first byte past the structure should be aligned too. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
Serhiy Storchaka added the comment: Antoine, if sizeof(PyUnicodeObject) is 38, the start of UCS4 unicode string is not aligned. This should be fixed. -- stage: patch review - needs patch ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
Antoine Pitrou added the comment: Antoine, if sizeof(PyUnicodeObject) is 38, the start of UCS4 unicode string is not aligned. This should be fixed. Probably. Does anyone want to propose a patch? -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
Andreas Schwab added the comment: How about adding explicit padding to the bitfield in PyASCIIObject? -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
Antoine Pitrou added the comment: How about adding explicit padding to the bitfield in PyASCIIObject? That sounds ok to me, but it must be explicitly for 68k (or use a sufficiently smart scheme not to affect already aligned architectures). -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
Stefan Krah added the comment: (gdb) p sizeof(PyASCIIObject) $1 = 22 If the only issue is that the size should be 24 instead of 22, could we perhaps add an unused uint16_t to the struct just for this architecture? -- nosy: +skrah ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
Serhiy Storchaka added the comment: What is sizeof(PyUnicodeObject)? -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
Andreas Schwab added the comment: (gdb) p sizeof(PyUnicodeObject) $1 = 38 -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
Changes by STINNER Victor victor.stin...@gmail.com: -- nosy: +haypo ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
Changes by Stefan Krah stefan-use...@bytereef.org: -- nosy: -skrah ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
Changes by Stefan Krah stefan-use...@bytereef.org: -- nosy: +skrah ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
Serhiy Storchaka added the comment: Current code assumes that PyUnicode_DATA() is aligned to PyUnicode_KIND() bytes. If this is not true on some platform it will be easer to add a padding than rewrite a code. A lot of code depends on this assumption. See also issue14422. I afraid that proposed patch may slow down a search. -- nosy: +pitrou ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
Antoine Pitrou added the comment: I don't understand in which concrete situation the current code could be wrong. The start of the unicode string should always be aligned, due to how unicode objects are allocated. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
Andreas Schwab added the comment: (gdb) p sizeof(PyASCIIObject) $1 = 22 -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
Stefan Krah added the comment: Andreas Schwab rep...@bugs.python.org wrote: (gdb) p sizeof(PyASCIIObject) $1 = 22 m68k again? ;) -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
Andreas Schwab added the comment: There is nothing wrong with that. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
New submission from Andreas Schwab: sizeof(foo) is never a good approximation for the alignment of foo -- components: Interpreter Core files: xx messages: 202487 nosy: schwab priority: normal severity: normal status: open title: Fix misalignment in fastsearch_memchr_1char type: behavior versions: Python 3.3 Added file: http://bugs.python.org/file32554/xx ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19537] Fix misalignment in fastsearch_memchr_1char
Changes by Serhiy Storchaka storch...@gmail.com: -- nosy: +serhiy.storchaka stage: - patch review versions: +Python 3.4 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19537 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
