1 //===-- Half-precision cosh(x) function -----------------------------------===// 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-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "src/math/coshf16.h" 10 #include "expxf16.h" 11 #include "hdr/errno_macros.h" 12 #include "hdr/fenv_macros.h" 13 #include "src/__support/FPUtil/FEnvImpl.h" 14 #include "src/__support/FPUtil/FPBits.h" 15 #include "src/__support/FPUtil/except_value_utils.h" 16 #include "src/__support/FPUtil/rounding_mode.h" 17 #include "src/__support/common.h" 18 #include "src/__support/macros/config.h" 19 #include "src/__support/macros/optimization.h" 20 21 namespace LIBC_NAMESPACE_DECL { 22 23 static constexpr fputil::ExceptValues<float16, 9> COSHF16_EXCEPTS_POS = {{ 24 // x = 0x1.6ap-5, coshf16(x) = 0x1p+0 (RZ) 25 {0x29a8U, 0x3c00U, 1U, 0U, 1U}, 26 // x = 0x1.8c4p+0, coshf16(x) = 0x1.3a8p+1 (RZ) 27 {0x3e31U, 0x40eaU, 1U, 0U, 0U}, 28 // x = 0x1.994p+0, coshf16(x) = 0x1.498p+1 (RZ) 29 {0x3e65U, 0x4126U, 1U, 0U, 0U}, 30 // x = 0x1.b6p+0, coshf16(x) = 0x1.6d8p+1 (RZ) 31 {0x3ed8U, 0x41b6U, 1U, 0U, 1U}, 32 // x = 0x1.aap+1, coshf16(x) = 0x1.be8p+3 (RZ) 33 {0x42a8U, 0x4afaU, 1U, 0U, 1U}, 34 // x = 0x1.cc4p+1, coshf16(x) = 0x1.23cp+4 (RZ) 35 {0x4331U, 0x4c8fU, 1U, 0U, 0U}, 36 // x = 0x1.288p+2, coshf16(x) = 0x1.9b4p+5 (RZ) 37 {0x44a2U, 0x526dU, 1U, 0U, 0U}, 38 // x = 0x1.958p+2, coshf16(x) = 0x1.1a4p+8 (RZ) 39 {0x4656U, 0x5c69U, 1U, 0U, 0U}, 40 // x = 0x1.5fp+3, coshf16(x) = 0x1.c54p+14 (RZ) 41 {0x497cU, 0x7715U, 1U, 0U, 1U}, 42 }}; 43 44 static constexpr fputil::ExceptValues<float16, 4> COSHF16_EXCEPTS_NEG = {{ 45 // x = -0x1.6ap-5, coshf16(x) = 0x1p+0 (RZ) 46 {0xa9a8U, 0x3c00U, 1U, 0U, 1U}, 47 // x = -0x1.b6p+0, coshf16(x) = 0x1.6d8p+1 (RZ) 48 {0xbed8U, 0x41b6U, 1U, 0U, 1U}, 49 // x = -0x1.288p+2, coshf16(x) = 0x1.9b4p+5 (RZ) 50 {0xc4a2U, 0x526dU, 1U, 0U, 0U}, 51 // x = -0x1.5fp+3, coshf16(x) = 0x1.c54p+14 (RZ) 52 {0xc97cU, 0x7715U, 1U, 0U, 1U}, 53 }}; 54 55 LLVM_LIBC_FUNCTION(float16, coshf16, (float16 x)) { 56 using FPBits = fputil::FPBits<float16>; 57 FPBits x_bits(x); 58 59 uint16_t x_u = x_bits.uintval(); 60 uint16_t x_abs = x_u & 0x7fffU; 61 62 // When |x| >= acosh(2^16), or x is NaN. 63 if (LIBC_UNLIKELY(x_abs >= 0x49e5U)) { 64 // cosh(NaN) = NaN 65 if (x_bits.is_nan()) { 66 if (x_bits.is_signaling_nan()) { 67 fputil::raise_except_if_required(FE_INVALID); 68 return FPBits::quiet_nan().get_val(); 69 } 70 71 return x; 72 } 73 74 // When |x| >= acosh(2^16). 75 if (x_abs >= 0x49e5U) { 76 // cosh(+/-inf) = +inf 77 if (x_bits.is_inf()) 78 return FPBits::inf().get_val(); 79 80 switch (fputil::quick_get_round()) { 81 case FE_TONEAREST: 82 case FE_UPWARD: 83 fputil::set_errno_if_required(ERANGE); 84 fputil::raise_except_if_required(FE_OVERFLOW | FE_INEXACT); 85 return FPBits::inf().get_val(); 86 default: 87 return FPBits::max_normal().get_val(); 88 } 89 } 90 } 91 92 if (x_bits.is_pos()) { 93 if (auto r = COSHF16_EXCEPTS_POS.lookup(x_u); LIBC_UNLIKELY(r.has_value())) 94 return r.value(); 95 } else { 96 if (auto r = COSHF16_EXCEPTS_NEG.lookup(x_u); LIBC_UNLIKELY(r.has_value())) 97 return r.value(); 98 } 99 100 return eval_sinh_or_cosh</*IsSinh=*/false>(x); 101 } 102 103 } // namespace LIBC_NAMESPACE_DECL 104