For std::isinf, the standard requires effectively calling isinf as
double from Libc for integral types. But integral types are never
infinite; we don't need to call Libc to return false.
Also short-circuit other functions where Libc won't have interesting
answers: signbit, fpclassify, isfinite, isnan, and isnormal.
I added correctness tests for integral types since we're no longer
deferring to Libc.
In review it was pointed out that in future revisions of the C++
standard we may add more types to std::is_arithmetic (e.g.,
std::is_fixed_point). I'll leave it to a future commit to hack this to
allow using math functions on those. We'll need to change things like
__libcpp_fpclassify anyway, so I'm not sure anything here would really
be future-proof.
https://reviews.llvm.org/D31561
rdar://problem/31361223
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@301060 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
GLIBC recently removed the incorrect `int isinf(double)` and `int isnan(double)` overloads in C++11 and greater. This causes previously `XFAIL: linux` tests to start passing.
Since there is no longer a way to 'XFAIL' the tests I choose to simply tolerate this bug.
See https://sourceware.org/bugzilla/show_bug.cgi?id=19439
Reviewers: rsmith, mclow.lists, EricWF
Subscribers: jroelofs, cfe-commits
Differential Revision: http://reviews.llvm.org/D19835
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@271060 91177308-0d34-0410-b5e6-96231b3b80d8
