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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-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef LLVM_LIBC_SRC___SUPPORT_FPUTIL_GENERIC_MUL_H10#define LLVM_LIBC_SRC___SUPPORT_FPUTIL_GENERIC_MUL_H11 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 24namespace LIBC_NAMESPACE_DECL {25namespace fputil::generic {26 27template <typename OutType, typename InType>28LIBC_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>32mul(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 = x_bits.get_mantissa();54 x_payload >>= InFPBits::FRACTION_LEN - OutFPBits::FRACTION_LEN;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 = y_bits.get_mantissa();62 y_payload >>= InFPBits::FRACTION_LEN - OutFPBits::FRACTION_LEN;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::generic103} // namespace LIBC_NAMESPACE_DECL104 105#endif // LLVM_LIBC_SRC___SUPPORT_FPUTIL_GENERIC_MUL_H106