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1//===-- Implementation header for atanhf ------------------------*- C++ -*-===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef LLVM_LIBC_SRC___SUPPORT_MATH_ATANHF_H10#define LLVM_LIBC_SRC___SUPPORT_MATH_ATANHF_H11 12#include "acoshf_utils.h"13#include "src/__support/FPUtil/FEnvImpl.h"14#include "src/__support/FPUtil/FPBits.h"15#include "src/__support/macros/config.h"16#include "src/__support/macros/optimization.h" // LIBC_UNLIKELY17 18namespace LIBC_NAMESPACE_DECL {19 20namespace math {21 22LIBC_INLINE static constexpr float atanhf(float x) {23 using namespace acoshf_internal;24 using FPBits = typename fputil::FPBits<float>;25 26 FPBits xbits(x);27 Sign sign = xbits.sign();28 uint32_t x_abs = xbits.abs().uintval();29 30 // |x| >= 1.031 if (LIBC_UNLIKELY(x_abs >= 0x3F80'0000U)) {32 if (xbits.is_nan()) {33 if (xbits.is_signaling_nan()) {34 fputil::raise_except_if_required(FE_INVALID);35 return FPBits::quiet_nan().get_val();36 }37 return x;38 }39 // |x| == 1.040 if (x_abs == 0x3F80'0000U) {41 fputil::set_errno_if_required(ERANGE);42 fputil::raise_except_if_required(FE_DIVBYZERO);43 return FPBits::inf(sign).get_val();44 } else {45 fputil::set_errno_if_required(EDOM);46 fputil::raise_except_if_required(FE_INVALID);47 return FPBits::quiet_nan().get_val();48 }49 }50 51 // |x| < ~0.1052 if (LIBC_UNLIKELY(x_abs <= 0x3dcc'0000U)) {53 // |x| <= 2^-2654 if (LIBC_UNLIKELY(x_abs <= 0x3280'0000U)) {55 return static_cast<float>(LIBC_UNLIKELY(x_abs == 0)56 ? x57 : (x + 0x1.5555555555555p-2 * x * x * x));58 }59 60 double xdbl = x;61 double x2 = xdbl * xdbl;62 // Pure Taylor series.63 double pe = fputil::polyeval(x2, 0.0, 0x1.5555555555555p-2,64 0x1.999999999999ap-3, 0x1.2492492492492p-3,65 0x1.c71c71c71c71cp-4, 0x1.745d1745d1746p-4);66 return static_cast<float>(fputil::multiply_add(xdbl, pe, xdbl));67 }68 double xdbl = x;69 return static_cast<float>(0.5 * log_eval((xdbl + 1.0) / (xdbl - 1.0)));70}71 72} // namespace math73 74} // namespace LIBC_NAMESPACE_DECL75 76#endif // LLVM_LIBC_SRC___SUPPORT_MATH_ATANHF_H77