add exhaustive test for atanpif16

Author: hulxv

libc/test/src/math/CMakeLists.txt

@@ -2143,6 +2143,17 @@ add_fp_unittest(
     libc.src.__support.FPUtil.fp_bits
 )
 
+add_fp_unittest(
+  atanpif16_test
+  NEED_MPFR
+  SUITE
+    libc-math-unittests
+  SRCS
+    atanpif16_test.cpp
+  DEPENDS
+    libc.src.math.atanpif16
+)
+
 add_fp_unittest(
   fmul_test
   NEED_MPFR

libc/test/src/math/atanpif16_test.cpp

@@ -0,0 +1,40 @@
+//===-- Exhaustive test for atanpif16 -------------------------------------===//
+//
+// 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/atanpif16.h"
+#include "test/UnitTest/FPMatcher.h"
+#include "test/UnitTest/Test.h"
+#include "utils/MPFRWrapper/MPFRUtils.h"
+
+using LlvmLibcAtanpif16Test = LIBC_NAMESPACE::testing::FPTest<float16>;
+
+namespace mpfr = LIBC_NAMESPACE::testing::mpfr;
+
+// Range: [0, Inf]
+static constexpr uint16_t POS_START = 0x0000U;
+static constexpr uint16_t POS_STOP = 0x7c00U;
+
+// Range: [-Inf, 0]
+static constexpr uint16_t NEG_START = 0x8000U;
+static constexpr uint16_t NEG_STOP = 0xfc00U;
+
+TEST_F(LlvmLibcAtanpif16Test, PositiveRange) {
+  for (uint16_t v = POS_START; v <= POS_STOP; ++v) {
+    float16 x = FPBits(v).get_val();
+    EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Atanpi, x,
+                                   LIBC_NAMESPACE::atanpif16(x), 0.5);
+  }
+}
+
+TEST_F(LlvmLibcAtanpif16Test, NegativeRange) {
+  for (uint16_t v = NEG_START; v <= NEG_STOP; ++v) {
+    float16 x = FPBits(v).get_val();
+    EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Atanpi, x,
+                                   LIBC_NAMESPACE::atanpif16(x), 0.5);
+  }
+}

libc/utils/MPFRWrapper/MPCommon.cpp

@@ -106,6 +106,12 @@ MPFRNumber MPFRNumber::atanh() const {
   return result;
 }
 
+MPFRNumber MPFRNumber::atanpi() const {
+  MPFRNumber result(*this);
+  mpfr_atanpi(result.value, value, mpfr_rounding);
+  return result;
+}
+
 MPFRNumber MPFRNumber::cbrt() const {
   MPFRNumber result(*this);
   mpfr_cbrt(result.value, value, mpfr_rounding);

libc/utils/MPFRWrapper/MPCommon.h

@@ -187,6 +187,7 @@ class MPFRNumber {
   MPFRNumber atan() const;
   MPFRNumber atan2(const MPFRNumber &b);
   MPFRNumber atanh() const;
+  MPFRNumber atanpi() const;
   MPFRNumber cbrt() const;
   MPFRNumber ceil() const;
   MPFRNumber cos() const;

libc/utils/MPFRWrapper/MPFRUtils.cpp

@@ -40,6 +40,8 @@ unary_operation(Operation op, InputType input, unsigned int precision,
     return mpfrInput.atan();
   case Operation::Atanh:
     return mpfrInput.atanh();
+  case Operation::Atanpi:
+    return mpfrInput.atanpi();
   case Operation::Cbrt:
     return mpfrInput.cbrt();
   case Operation::Ceil:

libc/utils/MPFRWrapper/MPFRUtils.h

@@ -32,6 +32,7 @@ enum class Operation : int {
   Asinh,
   Atan,
   Atanh,
+  Atanpi,
   Cbrt,
   Ceil,
   Cos,