| Message ID | 1337116550-12175-1-git-send-email-yann.morin.1998@free.fr |
|---|---|
| State | Accepted |
| Commit | cb30e130519fcb50e1a2e0d7a02aa628e52ed24c |
| Headers | show |
On 05/15/12 23:15, Yann E. MORIN wrote: > Decimal floats were introduced circa gcc-4.2 or -4.3, and requires > the floating-point environement fenv.h in the C library. > > The uClibc .config file used by crosstool-NG to build uClibc is the > same as used by the internal buildroot mechanism, and explcitly > disables fenv support. > > The quick workaround is to simply disable decimal floats in all > crosstool-NG config files. Wouldn't it be better to enable FENV in buildroot's uClibc config? I remember there were some packages that had problems with it too. Regards, Arnout
>>>>> "Arnout" == Arnout Vandecappelle <arnout@mind.be> writes: Arnout> On 05/15/12 23:15, Yann E. MORIN wrote: >> Decimal floats were introduced circa gcc-4.2 or -4.3, and requires >> the floating-point environement fenv.h in the C library. >> >> The uClibc .config file used by crosstool-NG to build uClibc is the >> same as used by the internal buildroot mechanism, and explcitly >> disables fenv support. >> >> The quick workaround is to simply disable decimal floats in all >> crosstool-NG config files. Arnout> Wouldn't it be better to enable FENV in buildroot's uClibc config? It's afaik only available for i386, and even then I believe some things are missing.
On Wednesday 16 May 2012 09:40:37 Peter Korsgaard wrote: > >>>>> "Arnout" == Arnout Vandecappelle <arnout@mind.be> writes: > > Arnout> On 05/15/12 23:15, Yann E. MORIN wrote: > >> Decimal floats were introduced circa gcc-4.2 or -4.3, and requires > >> the floating-point environement fenv.h in the C library. > >> > >> The uClibc .config file used by crosstool-NG to build uClibc is the > >> same as used by the internal buildroot mechanism, and explcitly > >> disables fenv support. > >> > >> The quick workaround is to simply disable decimal floats in all > >> crosstool-NG config files. > > Arnout> Wouldn't it be better to enable FENV in buildroot's uClibc config? I did not want to impact the internal backend, thus the workaround is limited to the crosstool-NG backend. This limits the impact for the now-woon-to-be-released next version of BR. Switching to enabling fenv by default can be done in the next cycle. > It's afaik only available for i386, and even then I believe some things > are missing. khem told me yesterday on IRC that uClibc had a working fenv for all supported architectures, with no _known_ problems (which does not mean there is none, just that none is known so far): http://ibot.rikers.org/%23uclibc/20120515.html.gz @ 20:20:25 - 20:56.17 Regards, Yann E. MORIN.
>>>>> "Yann" == Yann E MORIN <yann.morin.1998@free.fr> writes: Arnout> Wouldn't it be better to enable FENV in buildroot's uClibc config? Yann> I did not want to impact the internal backend, thus the workaround is Yann> limited to the crosstool-NG backend. This limits the impact for the Yann> now-woon-to-be-released next version of BR. Yann> Switching to enabling fenv by default can be done in the next cycle. Agreed, lets keep it simple for now. >> It's afaik only available for i386, and even then I believe some things >> are missing. Yann> khem told me yesterday on IRC that uClibc had a working fenv for all Yann> supported architectures, with no _known_ problems (which does not mean Yann> there is none, just that none is known so far): Yann> http://ibot.rikers.org/%23uclibc/20120515.html.gz @ 20:20:25 - 20:56.17 Yes, I saw that as well, but looking at the uClibc sources I only see .c files for i386 and sh4.
>>>>> "Yann" == Yann E MORIN <yann.morin.1998@free.fr> writes:
Yann> Decimal floats were introduced circa gcc-4.2 or -4.3, and requires
Yann> the floating-point environement fenv.h in the C library.
Yann> The uClibc .config file used by crosstool-NG to build uClibc is the
Yann> same as used by the internal buildroot mechanism, and explcitly
Yann> disables fenv support.
Yann> The quick workaround is to simply disable decimal floats in all
Yann> crosstool-NG config files.
Yann> In the long run, it might be better to check this situation, and/or
Yann> add code and/or options in crosstool-NG to handle this (but it is
Yann> much more involved, and this workaround is sane).
Committed, thanks.
diff --git a/toolchain/toolchain-crosstool-ng/crosstool-ng.config-eglibc b/toolchain/toolchain-crosstool-ng/crosstool-ng.config-eglibc index c1ab679..4488d02 100644 --- a/toolchain/toolchain-crosstool-ng/crosstool-ng.config-eglibc +++ b/toolchain/toolchain-crosstool-ng/crosstool-ng.config-eglibc @@ -273,8 +273,8 @@ CT_CC_LANG_CXX=y # gcc other options # CT_CC_ENABLE_CXX_FLAGS="" -CT_CC_CORE_EXTRA_CONFIG_ARRAY="" -CT_CC_EXTRA_CONFIG_ARRAY="" +CT_CC_CORE_EXTRA_CONFIG_ARRAY="--disable-decimal-float" +CT_CC_EXTRA_CONFIG_ARRAY="--disable-decimal-float" CT_CC_STATIC_LIBSTDCXX=y # diff --git a/toolchain/toolchain-crosstool-ng/crosstool-ng.config-glibc b/toolchain/toolchain-crosstool-ng/crosstool-ng.config-glibc index 4a555c7..46a636b 100644 --- a/toolchain/toolchain-crosstool-ng/crosstool-ng.config-glibc +++ b/toolchain/toolchain-crosstool-ng/crosstool-ng.config-glibc @@ -273,8 +273,8 @@ CT_CC_LANG_CXX=y # gcc other options # CT_CC_ENABLE_CXX_FLAGS="" -CT_CC_CORE_EXTRA_CONFIG_ARRAY="" -CT_CC_EXTRA_CONFIG_ARRAY="" +CT_CC_CORE_EXTRA_CONFIG_ARRAY="--disable-decimal-float" +CT_CC_EXTRA_CONFIG_ARRAY="--disable-decimal-float" CT_CC_STATIC_LIBSTDCXX=y # diff --git a/toolchain/toolchain-crosstool-ng/crosstool-ng.config-uClibc b/toolchain/toolchain-crosstool-ng/crosstool-ng.config-uClibc index 0e442f0..437f455 100644 --- a/toolchain/toolchain-crosstool-ng/crosstool-ng.config-uClibc +++ b/toolchain/toolchain-crosstool-ng/crosstool-ng.config-uClibc @@ -272,8 +272,8 @@ CT_CC_LANG_CXX=y # gcc other options # CT_CC_ENABLE_CXX_FLAGS="" -CT_CC_CORE_EXTRA_CONFIG_ARRAY="" -CT_CC_EXTRA_CONFIG_ARRAY="" +CT_CC_CORE_EXTRA_CONFIG_ARRAY="--disable-decimal-float" +CT_CC_EXTRA_CONFIG_ARRAY="--disable-decimal-float" CT_CC_STATIC_LIBSTDCXX=y #
Decimal floats were introduced circa gcc-4.2 or -4.3, and requires the floating-point environement fenv.h in the C library. The uClibc .config file used by crosstool-NG to build uClibc is the same as used by the internal buildroot mechanism, and explcitly disables fenv support. The quick workaround is to simply disable decimal floats in all crosstool-NG config files. In the long run, it might be better to check this situation, and/or add code and/or options in crosstool-NG to handle this (but it is much more involved, and this workaround is sane). Reported-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> CC: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr> --- .../crosstool-ng.config-eglibc | 4 ++-- .../crosstool-ng.config-glibc | 4 ++-- .../crosstool-ng.config-uClibc | 4 ++-- 3 files changed, 6 insertions(+), 6 deletions(-)