[libc][math][c23] Add f16sqrtf C23 math function (#95251)

Part of #95250.

6 files changed, 108 insertions, 36 deletions

diff --git a/libc/test/src/math/exhaustive/CMakeLists.txt b/libc/test/src/math/exhaustive/CMakeLists.txt
index 938e519..34df872 100644
--- a/libc/test/src/math/exhaustive/CMakeLists.txt
+++ b/libc/test/src/math/exhaustive/CMakeLists.txt
@@ -420,3 +420,18 @@ add_fp_unittest(
   LINK_LIBRARIES
     -lpthread
 )
+
+add_fp_unittest(
+  f16sqrtf_test
+  NO_RUN_POSTBUILD
+  NEED_MPFR
+  SUITE
+    libc_math_exhaustive_tests
+  SRCS
+    f16sqrtf_test.cpp
+  DEPENDS
+    .exhaustive_test
+    libc.src.math.f16sqrtf
+  LINK_LIBRARIES
+    -lpthread
+)
diff --git a/libc/test/src/math/exhaustive/exhaustive_test.h b/libc/test/src/math/exhaustive/exhaustive_test.h
index c4ae382..13e2727 100644
--- a/libc/test/src/math/exhaustive/exhaustive_test.h
+++ b/libc/test/src/math/exhaustive/exhaustive_test.h
@@ -35,16 +35,16 @@
 //   LlvmLibcUnaryOpExhaustiveMathTest<FloatType, Op, Func>.
 namespace mpfr = LIBC_NAMESPACE::testing::mpfr;
 
-template <typename T> using UnaryOp = T(T);
+template <typename OutType, typename InType = OutType>
+using UnaryOp = OutType(InType);
 
-template <typename T, mpfr::Operation Op, UnaryOp<T> Func>
+template <typename OutType, typename InType, mpfr::Operation Op,
+          UnaryOp<OutType, InType> Func>
 struct UnaryOpChecker : public virtual LIBC_NAMESPACE::testing::Test {
-  using FloatType = T;
+  using FloatType = InType;
   using FPBits = LIBC_NAMESPACE::fputil::FPBits<FloatType>;
   using StorageType = typename FPBits::StorageType;
 
-  static constexpr UnaryOp<FloatType> *FUNC = Func;
-
   // Check in a range, return the number of failures.
   uint64_t check(StorageType start, StorageType stop,
                  mpfr::RoundingMode rounding) {
@@ -57,11 +57,11 @@ struct UnaryOpChecker : public virtual LIBC_NAMESPACE::testing::Test {
       FPBits xbits(bits);
       FloatType x = xbits.get_val();
       bool correct =
-          TEST_MPFR_MATCH_ROUNDING_SILENTLY(Op, x, FUNC(x), 0.5, rounding);
+          TEST_MPFR_MATCH_ROUNDING_SILENTLY(Op, x, Func(x), 0.5, rounding);
       failed += (!correct);
       // Uncomment to print out failed values.
       // if (!correct) {
-      //   TEST_MPFR_MATCH(Op::Operation, x, Op::func(x), 0.5, rounding);
+      //   EXPECT_MPFR_MATCH_ROUNDING(Op, x, Func(x), 0.5, rounding);
       // }
     } while (bits++ < stop);
     return failed;
@@ -169,4 +169,9 @@ struct LlvmLibcExhaustiveMathTest
 
 template <typename FloatType, mpfr::Operation Op, UnaryOp<FloatType> Func>
 using LlvmLibcUnaryOpExhaustiveMathTest =
-    LlvmLibcExhaustiveMathTest<UnaryOpChecker<FloatType, Op, Func>>;
+    LlvmLibcExhaustiveMathTest<UnaryOpChecker<FloatType, FloatType, Op, Func>>;
+
+template <typename OutType, typename InType, mpfr::Operation Op,
+          UnaryOp<OutType, InType> Func>
+using LlvmLibcUnaryNarrowingOpExhaustiveMathTest =
+    LlvmLibcExhaustiveMathTest<UnaryOpChecker<OutType, InType, Op, Func>>;
diff --git a/libc/test/src/math/exhaustive/f16sqrtf_test.cpp b/libc/test/src/math/exhaustive/f16sqrtf_test.cpp
new file mode 100644
index 0000000..3a42ff8
--- /dev/null
+++ b/libc/test/src/math/exhaustive/f16sqrtf_test.cpp
@@ -0,0 +1,25 @@
+//===-- Exhaustive test for f16sqrtf --------------------------------------===//
+//
+// 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 "exhaustive_test.h"
+#include "src/math/f16sqrtf.h"
+#include "utils/MPFRWrapper/MPFRUtils.h"
+
+namespace mpfr = LIBC_NAMESPACE::testing::mpfr;
+
+using LlvmLibcF16sqrtfExhaustiveTest =
+    LlvmLibcUnaryNarrowingOpExhaustiveMathTest<
+        float16, float, mpfr::Operation::Sqrt, LIBC_NAMESPACE::f16sqrtf>;
+
+// Range: [0, Inf];
+static constexpr uint32_t POS_START = 0x0000'0000U;
+static constexpr uint32_t POS_STOP = 0x7f80'0000U;
+
+TEST_F(LlvmLibcF16sqrtfExhaustiveTest, PostiveRange) {
+  test_full_range_all_roundings(POS_START, POS_STOP);
+}
diff --git a/libc/test/src/math/smoke/CMakeLists.txt b/libc/test/src/math/smoke/CMakeLists.txt
index 68cd412..3bb87d2 100644
--- a/libc/test/src/math/smoke/CMakeLists.txt
+++ b/libc/test/src/math/smoke/CMakeLists.txt
@@ -2504,9 +2504,10 @@ add_fp_unittest(
     libc-math-smoke-tests
   SRCS
     sqrtf_test.cpp
+  HDRS
+    SqrtTest.h
   DEPENDS
     libc.src.math.sqrtf
-    libc.src.__support.FPUtil.fp_bits
 )
 
 add_fp_unittest(
@@ -2515,9 +2516,10 @@ add_fp_unittest(
     libc-math-smoke-tests
   SRCS
     sqrt_test.cpp
+  HDRS
+    SqrtTest.h
   DEPENDS
     libc.src.math.sqrt
-    libc.src.__support.FPUtil.fp_bits
 )
 
 add_fp_unittest(
@@ -2526,9 +2528,10 @@ add_fp_unittest(
     libc-math-smoke-tests
   SRCS
     sqrtl_test.cpp
+  HDRS
+    SqrtTest.h
   DEPENDS
     libc.src.math.sqrtl
-    libc.src.__support.FPUtil.fp_bits
 )
 
 add_fp_unittest(
@@ -2537,9 +2540,10 @@ add_fp_unittest(
     libc-math-smoke-tests
   SRCS
     sqrtf128_test.cpp
+  HDRS
+    SqrtTest.h
   DEPENDS
     libc.src.math.sqrtf128
-    libc.src.__support.FPUtil.fp_bits
 )
 
 add_fp_unittest(
@@ -2548,9 +2552,9 @@ add_fp_unittest(
     libc-math-smoke-tests
   SRCS
     generic_sqrtf_test.cpp
+  HDRS
+    SqrtTest.h
   DEPENDS
-    libc.src.math.sqrtf
-    libc.src.__support.FPUtil.fp_bits
     libc.src.__support.FPUtil.generic.sqrt
   COMPILE_OPTIONS
     -O3
@@ -2562,9 +2566,9 @@ add_fp_unittest(
     libc-math-smoke-tests
   SRCS
     generic_sqrt_test.cpp
+  HDRS
+    SqrtTest.h
   DEPENDS
-    libc.src.math.sqrt
-    libc.src.__support.FPUtil.fp_bits
     libc.src.__support.FPUtil.generic.sqrt
   COMPILE_OPTIONS
     -O3
@@ -2576,9 +2580,9 @@ add_fp_unittest(
     libc-math-smoke-tests
   SRCS
     generic_sqrtl_test.cpp
+  HDRS
+    SqrtTest.h
   DEPENDS
-    libc.src.math.sqrtl
-    libc.src.__support.FPUtil.fp_bits
     libc.src.__support.FPUtil.generic.sqrt
   COMPILE_OPTIONS
     -O3
@@ -2590,9 +2594,9 @@ add_fp_unittest(
     libc-math-smoke-tests
   SRCS
     generic_sqrtf128_test.cpp
+  HDRS
+    SqrtTest.h
   DEPENDS
-    libc.src.math.sqrtf128
-    libc.src.__support.FPUtil.fp_bits
     libc.src.__support.FPUtil.generic.sqrt
   COMPILE_OPTIONS
     -O3
@@ -3543,3 +3547,15 @@ add_fp_unittest(
   DEPENDS
     libc.src.math.totalordermagf16
 )
+
+add_fp_unittest(
+  f16sqrtf_test
+  SUITE
+    libc-math-smoke-tests
+  SRCS
+    f16sqrtf_test.cpp
+  HDRS
+    SqrtTest.h
+  DEPENDS
+    libc.src.math.f16sqrtf
+)
diff --git a/libc/test/src/math/smoke/SqrtTest.h b/libc/test/src/math/smoke/SqrtTest.h
index 8afacaf..ce9f2f8 100644
--- a/libc/test/src/math/smoke/SqrtTest.h
+++ b/libc/test/src/math/smoke/SqrtTest.h
@@ -6,37 +6,35 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "src/__support/CPP/bit.h"
 #include "test/UnitTest/FEnvSafeTest.h"
 #include "test/UnitTest/FPMatcher.h"
 #include "test/UnitTest/Test.h"
 
-#include "hdr/math_macros.h"
-
-template <typename T>
+template <typename OutType, typename InType>
 class SqrtTest : public LIBC_NAMESPACE::testing::FEnvSafeTest {
 
-  DECLARE_SPECIAL_CONSTANTS(T)
-
-  static constexpr StorageType HIDDEN_BIT =
-      StorageType(1) << LIBC_NAMESPACE::fputil::FPBits<T>::FRACTION_LEN;
+  DECLARE_SPECIAL_CONSTANTS(OutType)
 
 public:
-  typedef T (*SqrtFunc)(T);
+  typedef OutType (*SqrtFunc)(InType);
 
   void test_special_numbers(SqrtFunc func) {
     ASSERT_FP_EQ(aNaN, func(aNaN));
     ASSERT_FP_EQ(inf, func(inf));
     ASSERT_FP_EQ(aNaN, func(neg_inf));
-    ASSERT_FP_EQ(0.0, func(0.0));
-    ASSERT_FP_EQ(-0.0, func(-0.0));
-    ASSERT_FP_EQ(aNaN, func(T(-1.0)));
-    ASSERT_FP_EQ(T(1.0), func(T(1.0)));
-    ASSERT_FP_EQ(T(2.0), func(T(4.0)));
-    ASSERT_FP_EQ(T(3.0), func(T(9.0)));
+    ASSERT_FP_EQ(zero, func(zero));
+    ASSERT_FP_EQ(neg_zero, func(neg_zero));
+    ASSERT_FP_EQ(aNaN, func(InType(-1.0)));
+    ASSERT_FP_EQ(OutType(1.0), func(InType(1.0)));
+    ASSERT_FP_EQ(OutType(2.0), func(InType(4.0)));
+    ASSERT_FP_EQ(OutType(3.0), func(InType(9.0)));
   }
 };
 
 #define LIST_SQRT_TESTS(T, func)                                               \
-  using LlvmLibcSqrtTest = SqrtTest<T>;                                        \
+  using LlvmLibcSqrtTest = SqrtTest<T, T>;                                     \
+  TEST_F(LlvmLibcSqrtTest, SpecialNumbers) { test_special_numbers(&func); }
+
+#define LIST_NARROWING_SQRT_TESTS(OutType, InType, func)                       \
+  using LlvmLibcSqrtTest = SqrtTest<OutType, InType>;                          \
   TEST_F(LlvmLibcSqrtTest, SpecialNumbers) { test_special_numbers(&func); }
diff --git a/libc/test/src/math/smoke/f16sqrtf_test.cpp b/libc/test/src/math/smoke/f16sqrtf_test.cpp
new file mode 100644
index 0000000..36231ae
--- /dev/null
+++ b/libc/test/src/math/smoke/f16sqrtf_test.cpp
@@ -0,0 +1,13 @@
+//===-- Unittests for f16sqrtf --------------------------------------------===//
+//
+// 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 "SqrtTest.h"
+
+#include "src/math/f16sqrtf.h"
+
+LIST_NARROWING_SQRT_TESTS(float16, float, LIBC_NAMESPACE::f16sqrtf)