[libc-commits] [libc] [libc][math][C23] add software float16 support (PR #184283)

[via libc-commits]

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@@ -0,0 +1,127 @@
+//===-- Definition of float16 data type. ------------------------*- 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_FLOAT16_H
+#define LLVM_LIBC_SRC___SUPPORT_FPUTIL_FLOAT16_H
+
+#include "src/__support/macros/properties/types.h"
+
+#ifdef LIBC_USE_SOFT_FLOAT16
+
+#include "hdr/stdint_proxy.h"
+#include "src/__support/CPP/type_traits.h"
+#include "src/__support/FPUtil/cast.h"
+#include "src/__support/FPUtil/comparison_operations.h"
+#include "src/__support/FPUtil/dyadic_float.h"
+#include "src/__support/FPUtil/generic/add_sub.h"
+#include "src/__support/FPUtil/generic/div.h"
+#include "src/__support/FPUtil/generic/mul.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+namespace fputil {
+
+struct Float16 {
+  uint16_t bits;
+
+  LIBC_INLINE Float16() = default;
+
+  template <typename T>
+  LIBC_INLINE constexpr explicit Float16(T value)
+      : bits(static_cast<uint16_t>(0U)) {
+    if constexpr (cpp::is_floating_point_v<T>) {
+      bits = fputil::cast<Float16>(value).bits;
+    } else if constexpr (cpp::is_integral_v<T>) {
+      Sign sign = Sign::POS;
+
+      if constexpr (cpp::is_signed_v<T>) {
+        if (value < 0) {
+          sign = Sign::NEG;
+          value = -value;
+        }
+      }
+
+      fputil::DyadicFloat<cpp::numeric_limits<cpp::make_unsigned_t<T>>::digits>
+          xd(sign, 0, value);
+      bits = xd.template as<Float16, /*ShouldSignalExceptions=*/true>().bits;
+
+    } else if constexpr (cpp::is_convertible_v<T, Float16>) {
+      bits = value.operator Float16().bits;
+    }
+  }
+
+  template <cpp::enable_if_t<fputil::get_fp_type<float>() ==
+                                 fputil::FPType::IEEE754_Binary32,
+                             int> = 0>
+  LIBC_INLINE constexpr operator float() const {
+    return fputil::cast<float>(*this);
+  }
+
+  template <typename T, cpp::enable_if_t<cpp::is_integral_v<T>, int> = 0>
+  LIBC_INLINE constexpr explicit operator T() const {
+    return static_cast<T>(static_cast<float>(*this));
+  }
+
+  LIBC_INLINE bool operator==(Float16 other) const {
+    return fputil::equals(*this, other);
+  }
+
+  LIBC_INLINE bool operator!=(Float16 other) const {
+    return !fputil::equals(*this, other);
+  }
+
+  LIBC_INLINE bool operator<(Float16 other) const {
+    return fputil::less_than(*this, other);
+  }
+
+  LIBC_INLINE bool operator<=(Float16 other) const {
+    return fputil::less_than_or_equals(*this, other);
+  }
+
+  LIBC_INLINE bool operator>(Float16 other) const {
+    return fputil::greater_than(*this, other);
+  }
+
+  LIBC_INLINE bool operator>=(Float16 other) const {
+    return fputil::greater_than_or_equals(*this, other);
+  }
+
+  LIBC_INLINE constexpr Float16 operator-() const {
+    fputil::FPBits<float16> result(*this);
+    result.set_sign(result.is_pos() ? Sign::NEG : Sign::POS);
+    return result.get_val();
+  }
+
+  LIBC_INLINE Float16 operator+(Float16 other) const {
+    return fputil::generic::add<Float16>(*this, other);
+  }
+
+  LIBC_INLINE Float16 operator-(Float16 other) const {
+    return fputil::generic::sub<Float16>(*this, other);
+  }
+
+  LIBC_INLINE Float16 operator*(Float16 other) const {
+    return fputil::generic::mul<float16>(*this, other);
+  }
+
+  LIBC_INLINE Float16 operator/(Float16 other) const {
+    return fputil::generic::div<float16>(*this, other);
+  }
+
----------------
Sukumarsawant wrote:

can you add other compound assignment operators and smoke tests for it ?

https://github.com/llvm/llvm-project/pull/184283