[libc][math][c23] Add llroundf16 C23 math function

Author: overmighty

libc/config/linux/aarch64/entrypoints.txt

@@ -501,6 +501,7 @@ if(LIBC_TYPES_HAS_FLOAT16)
     # math.h C23 _Float16 entrypoints
     libc.src.math.fabsf16
     libc.src.math.llrintf16
+    libc.src.math.llroundf16
     libc.src.math.lrintf16
     libc.src.math.lroundf16
     libc.src.math.nearbyintf16

libc/config/linux/x86_64/entrypoints.txt

@@ -534,6 +534,7 @@ if(LIBC_TYPES_HAS_FLOAT16)
     # math.h C23 _Float16 entrypoints
     libc.src.math.fabsf16
     libc.src.math.llrintf16
+    libc.src.math.llroundf16
     libc.src.math.lrintf16
     libc.src.math.lroundf16
     libc.src.math.nearbyintf16

libc/docs/math/index.rst

@@ -176,7 +176,7 @@ Basic Operations
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
 | llrint           | |check|          | |check|         | |check|                | |check|              | |check|                | 7.12.9.5               | F.10.6.5                   |
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
-| llround          | |check|          | |check|         | |check|                |                      | |check|                | 7.12.9.7               | F.10.6.7                   |
+| llround          | |check|          | |check|         | |check|                | |check|              | |check|                | 7.12.9.7               | F.10.6.7                   |
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
 | logb             | |check|          | |check|         | |check|                |                      | |check|                | 7.12.6.17              | F.10.3.17                  |
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+

libc/spec/stdc.td

@@ -576,6 +576,7 @@ def StdC : StandardSpec<"stdc"> {
           FunctionSpec<"llround", RetValSpec<LongLongType>, [ArgSpec<DoubleType>]>,
           FunctionSpec<"llroundf", RetValSpec<LongLongType>, [ArgSpec<FloatType>]>,
           FunctionSpec<"llroundl", RetValSpec<LongLongType>, [ArgSpec<LongDoubleType>]>,
+          GuardedFunctionSpec<"llroundf16", RetValSpec<LongLongType>, [ArgSpec<Float16Type>], "LIBC_TYPES_HAS_FLOAT16">,
           GuardedFunctionSpec<"llroundf128", RetValSpec<LongLongType>, [ArgSpec<Float128Type>], "LIBC_TYPES_HAS_FLOAT128">,
 
           FunctionSpec<"rint", RetValSpec<DoubleType>, [ArgSpec<DoubleType>]>,

libc/src/math/CMakeLists.txt

@@ -229,6 +229,7 @@ add_math_entrypoint_object(llrintf128)
 add_math_entrypoint_object(llround)
 add_math_entrypoint_object(llroundf)
 add_math_entrypoint_object(llroundl)
+add_math_entrypoint_object(llroundf16)
 add_math_entrypoint_object(llroundf128)
 
 add_math_entrypoint_object(lrint)

libc/src/math/generic/CMakeLists.txt

@@ -561,6 +561,19 @@ add_entrypoint_object(
     libc.src.__support.FPUtil.nearest_integer_operations
 )
 
+add_entrypoint_object(
+  llroundf16
+  SRCS
+    llroundf16.cpp
+  HDRS
+    ../llroundf16.h
+  COMPILE_OPTIONS
+    -O3
+  DEPENDS
+    libc.src.__support.macros.properties.types
+    libc.src.__support.FPUtil.nearest_integer_operations
+)
+
 add_entrypoint_object(
   llroundf128
   SRCS

libc/src/math/generic/llroundf16.cpp

@@ -0,0 +1,19 @@
+//===-- Implementation of llroundf16 function -----------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/math/llroundf16.h"
+#include "src/__support/FPUtil/NearestIntegerOperations.h"
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(long long, llroundf16, (float16 x)) {
+  return fputil::round_to_signed_integer<float128, long long>(x);
+}
+
+} // namespace LIBC_NAMESPACE

libc/src/math/llroundf16.h

@@ -0,0 +1,20 @@
+//===-- Implementation header for llroundf16 --------------------*- 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_MATH_LLROUNDF16_H
+#define LLVM_LIBC_SRC_MATH_LLROUNDF16_H
+
+#include "src/__support/macros/properties/types.h"
+
+namespace LIBC_NAMESPACE {
+
+long long llroundf16(float16 x);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_MATH_LLROUNDF16_H

libc/test/src/math/smoke/CMakeLists.txt

@@ -565,6 +565,22 @@ add_fp_unittest(
     libc.src.__support.FPUtil.fp_bits
 )
 
+add_fp_unittest(
+  llroundf16_test
+  SUITE
+    libc-math-smoke-tests
+  SRCS
+    llroundf16_test.cpp
+  HDRS
+    RoundToIntegerTest.h
+  DEPENDS
+    libc.src.errno.errno
+    libc.src.math.llroundf16
+    libc.src.__support.CPP.algorithm
+    libc.src.__support.FPUtil.fenv_impl
+    libc.src.__support.FPUtil.fp_bits
+)
+
 add_fp_unittest(
   llroundf128_test
   SUITE

libc/test/src/math/smoke/llroundf16_test.cpp

@@ -0,0 +1,13 @@
+//===-- Unittests for llroundf16 ------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "RoundToIntegerTest.h"
+
+#include "src/math/llroundf16.h"
+
+LIST_ROUND_TO_INTEGER_TESTS(float16, long long, LIBC_NAMESPACE::llroundf16)