tree edf2485adc0bb6e3e6ebda6e20c2a4df7d9426d2
parent 6878e852d1d26cca0abee3013822311cd894ca3e
author Mikhail Maltsev <mikhail.maltsev@arm.com> 1519054896 +0000
committer Mikhail Maltsev <mikhail.maltsev@arm.com> 1519054896 +0000

[libcxx] Improve accuracy of complex asinh and acosh

Summary:
Currently std::asinh and std::acosh use std::pow to compute x^2. This
results in a significant error when computing e.g. asinh(i) or
acosh(-1).

This patch expresses x^2 directly via x.real() and x.imag(), like it
is done in libstdc++/glibc, and adds tests that checks the accuracy.

Reviewers: EricWF, mclow.lists

Reviewed By: mclow.lists

Subscribers: christof, cfe-commits

Differential Revision: https://reviews.llvm.org/D41629

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@325510 91177308-0d34-0410-b5e6-96231b3b80d8