[Python-Dev] Shorter float repr in Python 3.1? (original) (raw)

"Martin v. Löwis" martin at v.loewis.de
Tue Apr 14 19:55:36 CEST 2009

Is it true that to produce a working universal/fat build of Python, one has to first regenerate configure and pyconfig.h.in using autoconf version >= 2.62? If not, then I don't understand how the ACCBIGENDIAN autoconf macro can be giving the right results.

The outcome of AC_C_BIGENDIAN isn't used on OSX. Depending on the exact version you look at, things might work differently; in trunk, Include/pymacconfig.h should be used, which does

#if defined(APPLE)

undef WORDS_BIGENDIAN

#ifdef BIG_ENDIAN #define WORDS_BIGENDIAN 1 #endif /* __BIG_ENDIAN */ #endif

Earlier versions included that ifdef block directly in pyconfig.h.in.

In case it isn't clear how this works: GCC predefines BIG_ENDIAN on PPC but not on x86; for universal binaries, two (or more) separate preprocessor (and compiler runs) are done.

HTH, Martin

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