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| 1 | +//===-- Multiplication of IEEE 754 floating-point numbers -------*- 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-exception |
| 6 | +// |
| 7 | +//===----------------------------------------------------------------------===// |
| 8 | + |
| 9 | +#ifndef LLVM_LIBC_SRC___SUPPORT_FPUTIL_GENERIC_MUL_H |
| 10 | +#define LLVM_LIBC_SRC___SUPPORT_FPUTIL_GENERIC_MUL_H |
| 11 | + |
| 12 | +#include "hdr/errno_macros.h" |
| 13 | +#include "hdr/fenv_macros.h" |
| 14 | +#include "src/__support/CPP/bit.h" |
| 15 | +#include "src/__support/CPP/type_traits.h" |
| 16 | +#include "src/__support/FPUtil/BasicOperations.h" |
| 17 | +#include "src/__support/FPUtil/FEnvImpl.h" |
| 18 | +#include "src/__support/FPUtil/FPBits.h" |
| 19 | +#include "src/__support/FPUtil/dyadic_float.h" |
| 20 | +#include "src/__support/macros/attributes.h" |
| 21 | +#include "src/__support/macros/config.h" |
| 22 | +#include "src/__support/macros/optimization.h" |
| 23 | + |
| 24 | +namespace LIBC_NAMESPACE_DECL { |
| 25 | +namespace fputil::generic { |
| 26 | + |
| 27 | +template <typename OutType, typename InType> |
| 28 | +LIBC_INLINE cpp::enable_if_t<cpp::is_floating_point_v<OutType> && |
| 29 | + cpp::is_floating_point_v<InType> && |
| 30 | + sizeof(OutType) <= sizeof(InType), |
| 31 | + OutType> |
| 32 | +mul(InType x, InType y) { |
| 33 | + using OutFPBits = FPBits<OutType>; |
| 34 | + using OutStorageType = typename OutFPBits::StorageType; |
| 35 | + using InFPBits = FPBits<InType>; |
| 36 | + using InStorageType = typename InFPBits::StorageType; |
| 37 | + // The product of two p-digit numbers is a 2p-digit number. |
| 38 | + using DyadicFloat = |
| 39 | + DyadicFloat<cpp::bit_ceil(2 * static_cast<size_t>(InFPBits::SIG_LEN))>; |
| 40 | + |
| 41 | + InFPBits x_bits(x); |
| 42 | + InFPBits y_bits(y); |
| 43 | + |
| 44 | + Sign result_sign = x_bits.sign() == y_bits.sign() ? Sign::POS : Sign::NEG; |
| 45 | + |
| 46 | + if (LIBC_UNLIKELY(x_bits.is_inf_or_nan() || y_bits.is_inf_or_nan() || |
| 47 | + x_bits.is_zero() || y_bits.is_zero())) { |
| 48 | + if (x_bits.is_nan() || y_bits.is_nan()) { |
| 49 | + if (x_bits.is_signaling_nan() || y_bits.is_signaling_nan()) |
| 50 | + raise_except_if_required(FE_INVALID); |
| 51 | + |
| 52 | + if (x_bits.is_quiet_nan()) { |
| 53 | + InStorageType x_payload = static_cast<InStorageType>(getpayload(x)); |
| 54 | + if ((x_payload & ~(OutFPBits::FRACTION_MASK >> 1)) == 0) |
| 55 | + return OutFPBits::quiet_nan(x_bits.sign(), |
| 56 | + static_cast<OutStorageType>(x_payload)) |
| 57 | + .get_val(); |
| 58 | + } |
| 59 | + |
| 60 | + if (y_bits.is_quiet_nan()) { |
| 61 | + InStorageType y_payload = static_cast<InStorageType>(getpayload(y)); |
| 62 | + if ((y_payload & ~(OutFPBits::FRACTION_MASK >> 1)) == 0) |
| 63 | + return OutFPBits::quiet_nan(y_bits.sign(), |
| 64 | + static_cast<OutStorageType>(y_payload)) |
| 65 | + .get_val(); |
| 66 | + } |
| 67 | + |
| 68 | + return OutFPBits::quiet_nan().get_val(); |
| 69 | + } |
| 70 | + |
| 71 | + if (x_bits.is_inf()) { |
| 72 | + if (y_bits.is_zero()) { |
| 73 | + set_errno_if_required(EDOM); |
| 74 | + raise_except_if_required(FE_INVALID); |
| 75 | + return OutFPBits::quiet_nan().get_val(); |
| 76 | + } |
| 77 | + |
| 78 | + return OutFPBits::inf(result_sign).get_val(); |
| 79 | + } |
| 80 | + |
| 81 | + if (y_bits.is_inf()) { |
| 82 | + if (x_bits.is_zero()) { |
| 83 | + set_errno_if_required(EDOM); |
| 84 | + raise_except_if_required(FE_INVALID); |
| 85 | + return OutFPBits::quiet_nan().get_val(); |
| 86 | + } |
| 87 | + |
| 88 | + return OutFPBits::inf(result_sign).get_val(); |
| 89 | + } |
| 90 | + |
| 91 | + // Now either x or y is zero, and the other one is finite. |
| 92 | + return OutFPBits::zero(result_sign).get_val(); |
| 93 | + } |
| 94 | + |
| 95 | + DyadicFloat xd(x); |
| 96 | + DyadicFloat yd(y); |
| 97 | + |
| 98 | + DyadicFloat result = quick_mul(xd, yd); |
| 99 | + return result.template as<OutType, /*ShouldSignalExceptions=*/true>(); |
| 100 | +} |
| 101 | + |
| 102 | +} // namespace fputil::generic |
| 103 | +} // namespace LIBC_NAMESPACE_DECL |
| 104 | + |
| 105 | +#endif // LLVM_LIBC_SRC___SUPPORT_FPUTIL_GENERIC_MUL_H |
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