Re: [Patch] Fix libstdc++ build when using uclibc instead of glibc
On 07/01/16 13:37 -0800, Steve Ellcey wrote: On Thu, 2016-01-07 at 20:56 +0100, Bernhard Reutner-Fischer wrote: On January 7, 2016 12:23:49 PM GMT+01:00, Jonathan Wakely wrote: >On 07/01/16 07:28 +0100, Marc Glisse wrote: >>On Wed, 6 Jan 2016, Jonathan Wakely wrote: >> >>>On 06/01/16 12:45 -0800, Steve Ellcey wrote: On Wed, 2016-01-06 at 20:34 +, Jonathan Wakely wrote: >On 05/01/16 14:43 -0800, Steve Ellcey wrote: >>While trying to build GCC with uclibc instead of glibc I ran into >a build >>failure in libstdc++. uclibc doesn't seem to provide the >isfinite function uClibc provides an infinite macro. Make sure to enable C99 math though. (You mean isfinite, not infinite, right? C99 doesn't define an "infinite" macro.) OK? TIA, But is there any reason to use the infinite macro instead of the __builtin_isfinite function? I think that if I used the infinite macro The isfinite macro doesn't exist in C++, if the C library defines it we #undef it in , because the C++ standard requires those C99 math functions to be real functions, not macros. So that's a good reason to use the builtin :-) (Currently if you #include instead of then you get the macro, because comes from the C library, but I'm in the process of fixing that so the C++ library will provide its own wrapper that does the #undef.) I would also have to check for NAN since NAN is neither finite nor infinite. Here is what I tested last night with no failures. Is this version OK to checkin? Yes, this is OK, thanks.
Re: [Patch] Fix libstdc++ build when using uclibc instead of glibc
On Thu, 2016-01-07 at 20:56 +0100, Bernhard Reutner-Fischer wrote:
> On January 7, 2016 12:23:49 PM GMT+01:00, Jonathan Wakely
> wrote:
> >On 07/01/16 07:28 +0100, Marc Glisse wrote:
> >>On Wed, 6 Jan 2016, Jonathan Wakely wrote:
> >>
> >>>On 06/01/16 12:45 -0800, Steve Ellcey wrote:
> On Wed, 2016-01-06 at 20:34 +, Jonathan Wakely wrote:
> >On 05/01/16 14:43 -0800, Steve Ellcey wrote:
> >>While trying to build GCC with uclibc instead of glibc I ran into
> >a build
> >>failure in libstdc++. uclibc doesn't seem to provide the
> >isfinite function
>
> uClibc provides an infinite macro. Make sure to enable C99 math though.
>
> OK?
>
> TIA,
But is there any reason to use the infinite macro instead of the
__builtin_isfinite function? I think that if I used the infinite macro
I would also have to check for NAN since NAN is neither finite nor
infinite. Here is what I tested last night with no failures. Is this
version OK to checkin?
Steve Ellcey
sell...@imgtec.com
2016-01-07 Steve Ellcey
* include/ext/random.tcc: Use __builtin_isfinite instead of
std::isfinite.
diff --git a/libstdc++-v3/include/ext/random.tcc
b/libstdc++-v3/include/ext/random.tcc
index a9c5a2b..52350e8 100644
--- a/libstdc++-v3/include/ext/random.tcc
+++ b/libstdc++-v3/include/ext/random.tcc
@@ -1570,7 +1570,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
return __t; });
__norm = std::sqrt(__sum);
}
- while (__norm == _RealType(0) || ! std::isfinite(__norm));
+ while (__norm == _RealType(0) || ! __builtin_isfinite(__norm));
std::transform(__ret.begin(), __ret.end(), __ret.begin(),
[__norm](_RealType __val){ return __val / __norm; });
Re: [Patch] Fix libstdc++ build when using uclibc instead of glibc
On 06/01/16 12:45 -0800, Steve Ellcey wrote: On Wed, 2016-01-06 at 20:34 +, Jonathan Wakely wrote: On 05/01/16 14:43 -0800, Steve Ellcey wrote: >While trying to build GCC with uclibc instead of glibc I ran into a build >failure in libstdc++. uclibc doesn't seem to provide the isfinite function >like glibc does so that means that libstdc++ doesn't have std::isfinite. > >This in turn caused include/ext/random.tcc to not compile because it uses >std::isfinite. I can easily see how this might be considered a uclibc >bug but given that it is the only build problem I ran into I was hoping >we could fix it in libstdc++ by using __builtin_finite instead of Shouldn't that be __builtin_isfinite not __builtin_finite ? You are right. For some reason I thought that isfinite was implemented as __builtin_finite and that there was no __builtin_isfinite. I am not sure why I thought that but it does not seem to be the case. I will update my patch, retest, and resubmit. Thanks. Regarding the substance of the patch, the usual approach would be to gate the relevant parts of (or even the whole thing) on the presence of std::isinfinite, but that would presumably disable the functionality completely for uclibc. If using the builtin works reliably then I'm OK with that. However, I would expect that for un-optimized code the builtin will just emit a call to isfinite() in the C library, and so if uclibc doesn't define that at all then that will result in a linker error. If uclibc does define that function then we should figure out why libstdc++ fails to see it, and see if we can fix that, so that std::isfinite() gets declared and the existing code in starts working. i.e. I'd like to be sure there isn't some deeper underlying problem that should be addressed, rather than just working around it.
Re: [Patch] Fix libstdc++ build when using uclibc instead of glibc
On Wed, 2016-01-06 at 20:34 +, Jonathan Wakely wrote: > On 05/01/16 14:43 -0800, Steve Ellcey wrote: > >While trying to build GCC with uclibc instead of glibc I ran into a build > >failure in libstdc++. uclibc doesn't seem to provide the isfinite function > >like glibc does so that means that libstdc++ doesn't have std::isfinite. > > > >This in turn caused include/ext/random.tcc to not compile because it uses > >std::isfinite. I can easily see how this might be considered a uclibc > >bug but given that it is the only build problem I ran into I was hoping > >we could fix it in libstdc++ by using __builtin_finite instead of > > Shouldn't that be __builtin_isfinite not __builtin_finite ? You are right. For some reason I thought that isfinite was implemented as __builtin_finite and that there was no __builtin_isfinite. I am not sure why I thought that but it does not seem to be the case. I will update my patch, retest, and resubmit. Steve Ellcey sell...@imgtec.com
Re: [Patch] Fix libstdc++ build when using uclibc instead of glibc
On 05/01/16 14:43 -0800, Steve Ellcey wrote:
While trying to build GCC with uclibc instead of glibc I ran into a build
failure in libstdc++. uclibc doesn't seem to provide the isfinite function
like glibc does so that means that libstdc++ doesn't have std::isfinite.
This in turn caused include/ext/random.tcc to not compile because it uses
std::isfinite. I can easily see how this might be considered a uclibc
bug but given that it is the only build problem I ran into I was hoping
we could fix it in libstdc++ by using __builtin_finite instead of
Shouldn't that be __builtin_isfinite not __builtin_finite ?
std::isfinite. This fixes my uclibc build and also worked for glibc
with no regressions.
OK to checkin?
Steve Ellcey
sell...@imgtec.com
2016-01-05 Steve Ellcey
* include/ext/random.tcc: Use __builtin_finite instead of
std::isfinite.
diff --git a/libstdc++-v3/include/ext/random.tcc
b/libstdc++-v3/include/ext/random.tcc
index a9c5a2b..3467823 100644
--- a/libstdc++-v3/include/ext/random.tcc
+++ b/libstdc++-v3/include/ext/random.tcc
@@ -1570,7 +1570,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
return __t; });
__norm = std::sqrt(__sum);
}
- while (__norm == _RealType(0) || ! std::isfinite(__norm));
+ while (__norm == _RealType(0) || ! __builtin_finite(__norm));
std::transform(__ret.begin(), __ret.end(), __ret.begin(),
[__norm](_RealType __val){ return __val / __norm; });
[Patch] Fix libstdc++ build when using uclibc instead of glibc
While trying to build GCC with uclibc instead of glibc I ran into a build
failure in libstdc++. uclibc doesn't seem to provide the isfinite function
like glibc does so that means that libstdc++ doesn't have std::isfinite.
This in turn caused include/ext/random.tcc to not compile because it uses
std::isfinite. I can easily see how this might be considered a uclibc
bug but given that it is the only build problem I ran into I was hoping
we could fix it in libstdc++ by using __builtin_finite instead of
std::isfinite. This fixes my uclibc build and also worked for glibc
with no regressions.
OK to checkin?
Steve Ellcey
sell...@imgtec.com
2016-01-05 Steve Ellcey
* include/ext/random.tcc: Use __builtin_finite instead of
std::isfinite.
diff --git a/libstdc++-v3/include/ext/random.tcc
b/libstdc++-v3/include/ext/random.tcc
index a9c5a2b..3467823 100644
--- a/libstdc++-v3/include/ext/random.tcc
+++ b/libstdc++-v3/include/ext/random.tcc
@@ -1570,7 +1570,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
return __t; });
__norm = std::sqrt(__sum);
}
- while (__norm == _RealType(0) || ! std::isfinite(__norm));
+ while (__norm == _RealType(0) || ! __builtin_finite(__norm));
std::transform(__ret.begin(), __ret.end(), __ret.begin(),
[__norm](_RealType __val){ return __val / __norm; });
