87 lines · c
1//===-- Implementation header for acoshf ------------------------*- 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_ACOSHF_H10#define LLVM_LIBC_SRC___SUPPORT_MATH_ACOSHF_H11 12#include "acoshf_utils.h"13#include "src/__support/FPUtil/FEnvImpl.h"14#include "src/__support/FPUtil/FPBits.h"15#include "src/__support/FPUtil/multiply_add.h"16#include "src/__support/FPUtil/sqrt.h"17#include "src/__support/macros/config.h"18#include "src/__support/macros/optimization.h" // LIBC_UNLIKELY19 20namespace LIBC_NAMESPACE_DECL {21 22namespace math {23 24LIBC_INLINE static constexpr float acoshf(float x) {25 using namespace acoshf_internal;26 using FPBits_t = typename fputil::FPBits<float>;27 FPBits_t xbits(x);28 29 if (LIBC_UNLIKELY(x <= 1.0f)) {30 if (x == 1.0f)31 return 0.0f;32 // x < 1.33 fputil::set_errno_if_required(EDOM);34 fputil::raise_except_if_required(FE_INVALID);35 return FPBits_t::quiet_nan().get_val();36 }37 38#ifndef LIBC_MATH_HAS_SKIP_ACCURATE_PASS39 uint32_t x_u = xbits.uintval();40 if (LIBC_UNLIKELY(x_u >= 0x4f8ffb03)) {41 if (LIBC_UNLIKELY(xbits.is_inf_or_nan()))42 return x;43 44 // Helper functions to set results for exceptional cases.45 auto round_result_slightly_down = [](float r) -> float {46 volatile float tmp = r;47 tmp = tmp - 0x1.0p-25f;48 return tmp;49 };50 auto round_result_slightly_up = [](float r) -> float {51 volatile float tmp = r;52 tmp = tmp + 0x1.0p-25f;53 return tmp;54 };55 56 switch (x_u) {57 case 0x4f8ffb03: // x = 0x1.1ff606p32f58 return round_result_slightly_up(0x1.6fdd34p4f);59 case 0x5c569e88: // x = 0x1.ad3d1p57f60 return round_result_slightly_up(0x1.45c146p5f);61 case 0x5e68984e: // x = 0x1.d1309cp61f62 return round_result_slightly_up(0x1.5c9442p5f);63 case 0x655890d3: // x = 0x1.b121a6p75f64 return round_result_slightly_down(0x1.a9a3f2p5f);65 case 0x6eb1a8ec: // x = 0x1.6351d8p94f66 return round_result_slightly_down(0x1.08b512p6f);67 case 0x7997f30a: // x = 0x1.2fe614p116f68 return round_result_slightly_up(0x1.451436p6f);69 }70 }71#else72 if (LIBC_UNLIKELY(xbits.is_inf_or_nan()))73 return x;74#endif // !LIBC_MATH_HAS_SKIP_ACCURATE_PASS75 76 double x_d = static_cast<double>(x);77 // acosh(x) = log(x + sqrt(x^2 - 1))78 return static_cast<float>(log_eval(79 x_d + fputil::sqrt<double>(fputil::multiply_add(x_d, x_d, -1.0))));80}81 82} // namespace math83 84} // namespace LIBC_NAMESPACE_DECL85 86#endif // LLVM_LIBC_SRC___SUPPORT_MATH_ACOSHF_H87