On 29/09/16 10:10 +0100, Jonathan Wakely wrote:
On 29/09/16 10:54 +0200, Rainer Orth wrote:
Hi Jonathan,
This adds the new 3D std::hypot() functions. This implementation seems
to be faster than the naïve sqrt(x*x + y*y + z*z) implementation, or
hypot(hypot(x, y), z), and should be a bit more accurate at very large
or very small values due to reducing the arguments by the largest one.
Improvements welcome though, as this is not my forte.
The test might not be very good, but tests some small integer values
and some other values where accuracy is lost for one or other of the
alternative implementations mentioned above. If this FAILs for some
32-bit targets we might need to adjust the tolerances or the
dg-options.
* doc/xml/manual/status_cxx2017.xml: Update status.
* include/c_global/cmath (hypot): Add three-dimensional overloads.
* testsuite/26_numerics/headers/cmath/hypot.cc: New.
Tested powerpc64le-linux and x86_64-linux, committed to trunk.
the new test currently FAILs on Solaris 12 (both SPARC and x86):
+FAIL: 26_numerics/headers/cmath/hypot.cc (test for excess errors)
+WARNING: 26_numerics/headers/cmath/hypot.cc compilation failed to produce execu
table
Excess errors:
/vol/gcc/src/hg/trunk/local/libstdc++-v3/testsuite/26_numerics/headers/cmath/hypot.cc:38:
error: no matching function for call to 'hypot(double, double, double)'
/vol/gcc/src/hg/trunk/local/libstdc++-v3/testsuite/26_numerics/headers/cmath/hypot.cc:38:
error: no matching function for call to 'hypot(double, double, double)'
/vol/gcc/src/hg/trunk/local/libstdc++-v3/testsuite/26_numerics/headers/cmath/hypot.cc:38:
error: template argument 2 is invalid
and many more.
That would suggest Solaris uses include/c_std/cmath (where I forgot to
add the new overloads) rather than include/c_global/cmath ... is that
right?
Alternatively it's using c_global/cmath but _GLIBCXX_USE_C99_MATH_TR1
is not defined, as the new overloads are inside that block. I thought
that was defined for Solaris though, which is why we have the
__CORRECT_ISO_CPP11_MATH_H_PROTO there in that file.
Once again I wish we had a Solaris machine in the compile farm, or it
was possible to install a Solaris VM and get OS updates without paying
Oracle for the privilege.
