[libc][math][c23] Add rintf16 MPFR unit tests

Author: overmighty

libc/test/src/math/CMakeLists.txt

@@ -549,6 +549,7 @@ add_fp_unittest(
     RIntTest.h
   DEPENDS
     libc.src.math.rint
+    libc.src.__support.CPP.algorithm
     libc.src.__support.FPUtil.fenv_impl
     libc.src.__support.FPUtil.fp_bits
 )
@@ -564,6 +565,7 @@ add_fp_unittest(
     RIntTest.h
   DEPENDS
     libc.src.math.rintf
+    libc.src.__support.CPP.algorithm
     libc.src.__support.FPUtil.fenv_impl
     libc.src.__support.FPUtil.fp_bits
 )
@@ -579,6 +581,23 @@ add_fp_unittest(
     RIntTest.h
   DEPENDS
     libc.src.math.rintl
+    libc.src.__support.CPP.algorithm
+    libc.src.__support.FPUtil.fenv_impl
+    libc.src.__support.FPUtil.fp_bits
+)
+
+add_fp_unittest(
+  rintf16_test
+  NEED_MPFR
+  SUITE
+    libc-math-unittests
+  SRCS
+    rintf16_test.cpp
+  HDRS
+    RIntTest.h
+  DEPENDS
+    libc.src.math.rintf16
+    libc.src.__support.CPP.algorithm
     libc.src.__support.FPUtil.fenv_impl
     libc.src.__support.FPUtil.fp_bits
 )

libc/test/src/math/RIntTest.h

@@ -9,6 +9,7 @@
 #ifndef LLVM_LIBC_TEST_SRC_MATH_RINTTEST_H
 #define LLVM_LIBC_TEST_SRC_MATH_RINTTEST_H
 
+#include "src/__support/CPP/algorithm.h"
 #include "src/__support/FPUtil/FEnvImpl.h"
 #include "src/__support/FPUtil/FPBits.h"
 #include "test/UnitTest/FEnvSafeTest.h"
@@ -101,8 +102,10 @@ class RIntTestTemplate : public LIBC_NAMESPACE::testing::FEnvSafeTest {
   }
 
   void testSubnormalRange(RIntFunc func) {
-    constexpr StorageType COUNT = 100'001;
-    constexpr StorageType STEP = (MAX_SUBNORMAL - MIN_SUBNORMAL) / COUNT;
+    constexpr int COUNT = 100'001;
+    constexpr StorageType STEP = LIBC_NAMESPACE::cpp::max(
+        static_cast<StorageType>((MAX_SUBNORMAL - MIN_SUBNORMAL) / COUNT),
+        StorageType(1));
     for (StorageType i = MIN_SUBNORMAL; i <= MAX_SUBNORMAL; i += STEP) {
       T x = FPBits(i).get_val();
       for (int mode : ROUNDING_MODES) {
@@ -114,13 +117,16 @@ class RIntTestTemplate : public LIBC_NAMESPACE::testing::FEnvSafeTest {
   }
 
   void testNormalRange(RIntFunc func) {
-    constexpr StorageType COUNT = 100'001;
-    constexpr StorageType STEP = (MAX_NORMAL - MIN_NORMAL) / COUNT;
+    constexpr int COUNT = 100'001;
+    constexpr StorageType STEP = LIBC_NAMESPACE::cpp::max(
+        static_cast<StorageType>((MAX_NORMAL - MIN_NORMAL) / COUNT),
+        StorageType(1));
     for (StorageType i = MIN_NORMAL; i <= MAX_NORMAL; i += STEP) {
-      T x = FPBits(i).get_val();
+      FPBits xbits(i);
+      T x = xbits.get_val();
       // In normal range on x86 platforms, the long double implicit 1 bit can be
       // zero making the numbers NaN. We will skip them.
-      if (isnan(x)) {
+      if (xbits.is_nan()) {
         continue;
       }
 

libc/test/src/math/rintf16_test.cpp

@@ -0,0 +1,13 @@
+//===-- Unittests for rintf16 ---------------------------------------------===//
+//
+// 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 "RIntTest.h"
+
+#include "src/math/rintf16.h"
+
+LIST_RINT_TESTS(float16, LIBC_NAMESPACE::rintf16)

libc/utils/MPFRWrapper/MPFRUtils.cpp

@@ -1104,6 +1104,7 @@ template <typename T> T round(T x, RoundingMode mode) {
 template float round<float>(float, RoundingMode);
 template double round<double>(double, RoundingMode);
 template long double round<long double>(long double, RoundingMode);
+template float16 round<float16>(float16, RoundingMode);
 
 } // namespace mpfr
 } // namespace testing