From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Pouiller?= Date: Wed, 9 Nov 2016 10:25:07 +0100 Subject: [Buildroot] [PATCH 1/2] python: fix double format detection Message-ID: <20161109092508.4503-1-jezz@sysmic.org> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net Python is not able to detect if compiler double representation is compliant with IEE754: checking whether C doubles are little-endian IEEE 754 binary64... no checking whether C doubles are big-endian IEEE 754 binary64... no checking whether C doubles are ARM mixed-endian IEEE 754 binary64... no Accordingly 'legacy' mode isused. It is possible to check this at runtime by check if 'sys.float_repr_style' contains 'short' or 'legacy'. Calculus correctness is not garanteed with 'legacy'. Problem is better described here: http://stackoverflow.com/questions/29920294/what-causes-pythons-float-repr-style-to-use-legacy https://bugs.python.org/issue7117 However, all gcc architecture use a representation compliant with IEE754. So, we can enable it unconditionnaly. Signed-off-by: J?r?me Pouiller --- package/python/python.mk | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/package/python/python.mk b/package/python/python.mk index cc65376..0191d59 100644 --- a/package/python/python.mk +++ b/package/python/python.mk @@ -140,6 +140,13 @@ PYTHON_CONF_ENV += \ ac_cv_prog_HAS_HG=/bin/false \ ac_cv_prog_SVNVERSION=/bin/false +# GCC is always complient with IEEE754 +ifeq ($(call qstrip,$(BR2_ENDIAN)),LITTLE) +PYTHON_CONF_ENV += ac_cv_little_endian_double=yes +else +PYTHON_CONF_ENV += ac_cv_big_endian_double=yes +endif + PYTHON_CONF_OPTS += \ --without-cxx-main \ --without-doc-strings \ -- 2.9.3