[libc-commits] [libc] [libc][math][c23] Add {f, d}mul{l, f128} and f16mul{, f, l, f128} C23 math functions (PR #98972)

[via libc-commits]

================
@@ -0,0 +1,120 @@
+//===-- Division of IEEE 754 floating-point numbers -------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC___SUPPORT_FPUTIL_GENERIC_MUL_H
+#define LLVM_LIBC_SRC___SUPPORT_FPUTIL_GENERIC_MUL_H
+
+#include "hdr/errno_macros.h"
+#include "hdr/fenv_macros.h"
+#include "src/__support/CPP/bit.h"
+#include "src/__support/CPP/type_traits.h"
+#include "src/__support/FPUtil/BasicOperations.h"
+#include "src/__support/FPUtil/FEnvImpl.h"
+#include "src/__support/FPUtil/FPBits.h"
+#include "src/__support/FPUtil/dyadic_float.h"
+#include "src/__support/macros/attributes.h"
+#include "src/__support/macros/config.h"
+#include "src/__support/macros/optimization.h"
+
+namespace LIBC_NAMESPACE_DECL {
+namespace fputil::generic {
+
+template <typename OutType, typename InType>
+LIBC_INLINE cpp::enable_if_t<cpp::is_floating_point_v<OutType> &&
+                                 cpp::is_floating_point_v<InType> &&
+                                 sizeof(OutType) <= sizeof(InType),
+                             OutType>
+mul(InType x, InType y) {
+  using OutFPBits = FPBits<OutType>;
+  using OutStorageType = typename OutFPBits::StorageType;
+  using InFPBits = FPBits<InType>;
+  using InStorageType = typename InFPBits::StorageType;
+  // The product of two p-digit numbers is a 2p-digit number.
+  using DyadicFloat = DyadicFloat<cpp::bit_ceil(
+      2 * static_cast<size_t>(InFPBits::FRACTION_LEN))>;
----------------
lntue wrote:

nit: it should be `InFPBits::SIG_LEN`.

https://github.com/llvm/llvm-project/pull/98972