[libc][math][c23] Add {getpayload,setpayload,setpayloadsig}f16 C23 math functions (#95159)

Part of #93566.

21 files changed, 519 insertions, 2 deletions

diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
index dfed6ac..aa223a6 100644
--- a/libc/config/linux/aarch64/entrypoints.txt
+++ b/libc/config/linux/aarch64/entrypoints.txt
@@ -522,6 +522,7 @@ if(LIBC_TYPES_HAS_FLOAT16)
     libc.src.math.frexpf16
     libc.src.math.fromfpf16
     libc.src.math.fromfpxf16
+    libc.src.math.getpayloadf16
     libc.src.math.ilogbf16
     libc.src.math.llogbf16
     libc.src.math.llrintf16
@@ -544,6 +545,8 @@ if(LIBC_TYPES_HAS_FLOAT16)
     libc.src.math.rintf16
     libc.src.math.roundf16
     libc.src.math.roundevenf16
+    libc.src.math.setpayloadf16
+    libc.src.math.setpayloadsigf16
     libc.src.math.totalorderf16
     libc.src.math.totalordermagf16
     libc.src.math.truncf16
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index cfe3516..ab7f572 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -555,6 +555,7 @@ if(LIBC_TYPES_HAS_FLOAT16)
     libc.src.math.frexpf16
     libc.src.math.fromfpf16
     libc.src.math.fromfpxf16
+    libc.src.math.getpayloadf16
     libc.src.math.ilogbf16
     libc.src.math.llogbf16
     libc.src.math.llrintf16
@@ -574,6 +575,8 @@ if(LIBC_TYPES_HAS_FLOAT16)
     libc.src.math.rintf16
     libc.src.math.roundf16
     libc.src.math.roundevenf16
+    libc.src.math.setpayloadf16
+    libc.src.math.setpayloadsigf16
     libc.src.math.totalorderf16
     libc.src.math.totalordermagf16
     libc.src.math.truncf16
diff --git a/libc/docs/c23.rst b/libc/docs/c23.rst
index 4134bef..b9a2424 100644
--- a/libc/docs/c23.rst
+++ b/libc/docs/c23.rst
@@ -44,8 +44,9 @@ Additions:
   * compoundn*
   * totalorder* |check|
   * totalordermag* |check|
-  * getpayload*
-  * setpayload*
+  * getpayload* |check|
+  * setpayload* |check|
+  * setpayloadsig* |check|
   * iscannonical
   * issignaling
   * issubnormal
diff --git a/libc/docs/math/index.rst b/libc/docs/math/index.rst
index 293edd1..c9b1238 100644
--- a/libc/docs/math/index.rst
+++ b/libc/docs/math/index.rst
@@ -170,6 +170,8 @@ Basic Operations
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
 | fsub             | N/A              |                 |                        | N/A                  |                        | 7.12.14.2              | F.10.11                    |
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
+| getpayload       |                  |                 |                        | |check|              |                        | F.10.13.1              | N/A                        |
++------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
 | ilogb            | |check|          | |check|         | |check|                | |check|              | |check|                | 7.12.6.8               | F.10.3.8                   |
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
 | ldexp            | |check|          | |check|         | |check|                |                      | |check|                | 7.12.6.9               | F.10.3.9                   |
@@ -212,6 +214,10 @@ Basic Operations
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
 | scalbn           | |check|          | |check|         | |check|                |                      | |check|                | 7.12.6.19              | F.10.3.19                  |
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
+| setpayload       |                  |                 |                        | |check|              |                        | F.10.13.2              | N/A                        |
++------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
+| setpayloadsig    |                  |                 |                        | |check|              |                        | F.10.13.3              | N/A                        |
++------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
 | totalorder       |                  |                 |                        | |check|              |                        | F.10.12.1              | N/A                        |
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
 | totalordermag    |                  |                 |                        | |check|              |                        | F.10.12.2              | N/A                        |
diff --git a/libc/spec/stdc.td b/libc/spec/stdc.td
index f9c79ee..f0b36f82 100644
--- a/libc/spec/stdc.td
+++ b/libc/spec/stdc.td
@@ -716,6 +716,12 @@ def StdC : StandardSpec<"stdc"> {
 
           GuardedFunctionSpec<"totalordermagf16", RetValSpec<IntType>, [ArgSpec<Float16Ptr>, ArgSpec<Float16Ptr>], "LIBC_TYPES_HAS_FLOAT16">,
 
+          GuardedFunctionSpec<"getpayloadf16", RetValSpec<Float16Type>, [ArgSpec<Float16Ptr>], "LIBC_TYPES_HAS_FLOAT16">,
+
+          GuardedFunctionSpec<"setpayloadf16", RetValSpec<IntType>, [ArgSpec<Float16Ptr>, ArgSpec<Float16Type>], "LIBC_TYPES_HAS_FLOAT16">,
+
+          GuardedFunctionSpec<"setpayloadsigf16", RetValSpec<IntType>, [ArgSpec<Float16Ptr>, ArgSpec<Float16Type>], "LIBC_TYPES_HAS_FLOAT16">,
+
           GuardedFunctionSpec<"f16sqrtf", RetValSpec<Float16Type>, [ArgSpec<FloatType>], "LIBC_TYPES_HAS_FLOAT16">,
       ]
   >;
diff --git a/libc/src/__support/FPUtil/BasicOperations.h b/libc/src/__support/FPUtil/BasicOperations.h
index beb8e48..17eee7b 100644
--- a/libc/src/__support/FPUtil/BasicOperations.h
+++ b/libc/src/__support/FPUtil/BasicOperations.h
@@ -265,6 +265,48 @@ totalordermag(T x, T y) {
   return FPBits<T>(x).abs().uintval() <= FPBits<T>(y).abs().uintval();
 }
 
+template <typename T>
+LIBC_INLINE cpp::enable_if_t<cpp::is_floating_point_v<T>, T> getpayload(T x) {
+  using FPBits = FPBits<T>;
+  FPBits x_bits(x);
+
+  if (!x_bits.is_nan())
+    return T(-1.0);
+
+  return T(x_bits.uintval() & (FPBits::FRACTION_MASK >> 1));
+}
+
+template <bool IsSignaling, typename T>
+LIBC_INLINE cpp::enable_if_t<cpp::is_floating_point_v<T>, bool>
+setpayload(T &res, T pl) {
+  using FPBits = FPBits<T>;
+  FPBits pl_bits(pl);
+
+  // Signaling NaNs don't have the mantissa's MSB set to 1, so they need a
+  // non-zero payload to distinguish them from infinities.
+  if (!IsSignaling && pl_bits.is_zero()) {
+    res = FPBits::quiet_nan(Sign::POS).get_val();
+    return false;
+  }
+
+  int pl_exp = pl_bits.get_exponent();
+
+  if (pl_bits.is_neg() || pl_exp < 0 || pl_exp >= FPBits::FRACTION_LEN - 1 ||
+      ((pl_bits.get_mantissa() << pl_exp) & FPBits::FRACTION_MASK) != 0) {
+    res = T(0.0);
+    return true;
+  }
+
+  using StorageType = typename FPBits::StorageType;
+  StorageType v(pl_bits.get_explicit_mantissa() >> (FPBits::SIG_LEN - pl_exp));
+
+  if constexpr (IsSignaling)
+    res = FPBits::signaling_nan(Sign::POS, v).get_val();
+  else
+    res = FPBits::quiet_nan(Sign::POS, v).get_val();
+  return false;
+}
+
 } // namespace fputil
 } // namespace LIBC_NAMESPACE
 
diff --git a/libc/src/math/CMakeLists.txt b/libc/src/math/CMakeLists.txt
index 4472367..92e0cd2 100644
--- a/libc/src/math/CMakeLists.txt
+++ b/libc/src/math/CMakeLists.txt
@@ -210,6 +210,8 @@ add_math_entrypoint_object(fromfpxl)
 add_math_entrypoint_object(fromfpxf16)
 add_math_entrypoint_object(fromfpxf128)
 
+add_math_entrypoint_object(getpayloadf16)
+
 add_math_entrypoint_object(hypot)
 add_math_entrypoint_object(hypotf)
 
@@ -350,6 +352,10 @@ add_math_entrypoint_object(scalbnf)
 add_math_entrypoint_object(scalbnl)
 add_math_entrypoint_object(scalbnf128)
 
+add_math_entrypoint_object(setpayloadf16)
+
+add_math_entrypoint_object(setpayloadsigf16)
+
 add_math_entrypoint_object(sincos)
 add_math_entrypoint_object(sincosf)
 
diff --git a/libc/src/math/generic/CMakeLists.txt b/libc/src/math/generic/CMakeLists.txt
index aa0069d..f509b97 100644
--- a/libc/src/math/generic/CMakeLists.txt
+++ b/libc/src/math/generic/CMakeLists.txt
@@ -3603,6 +3603,45 @@ add_entrypoint_object(
 )
 
 add_entrypoint_object(
+  getpayloadf16
+  SRCS
+    getpayloadf16.cpp
+  HDRS
+    ../getpayloadf16.h
+  DEPENDS
+    libc.src.__support.macros.properties.types
+    libc.src.__support.FPUtil.basic_operations
+  COMPILE_OPTIONS
+    -O3
+)
+
+add_entrypoint_object(
+  setpayloadf16
+  SRCS
+    setpayloadf16.cpp
+  HDRS
+    ../setpayloadf16.h
+  DEPENDS
+    libc.src.__support.macros.properties.types
+    libc.src.__support.FPUtil.basic_operations
+  COMPILE_OPTIONS
+    -O3
+)
+
+add_entrypoint_object(
+  setpayloadsigf16
+  SRCS
+    setpayloadsigf16.cpp
+  HDRS
+    ../setpayloadsigf16.h
+  DEPENDS
+    libc.src.__support.macros.properties.types
+    libc.src.__support.FPUtil.basic_operations
+  COMPILE_OPTIONS
+    -O3
+)
+
+add_entrypoint_object(
   f16fmaf
   SRCS
     f16fmaf.cpp
diff --git a/libc/src/math/generic/getpayloadf16.cpp b/libc/src/math/generic/getpayloadf16.cpp
new file mode 100644
index 0000000..0923226
--- /dev/null
+++ b/libc/src/math/generic/getpayloadf16.cpp
@@ -0,0 +1,19 @@
+//===-- Implementation of getpayloadf16 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/getpayloadf16.h"
+#include "src/__support/FPUtil/BasicOperations.h"
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(float16, getpayloadf16, (const float16 *x)) {
+  return fputil::getpayload(*x);
+}
+
+} // namespace LIBC_NAMESPACE
diff --git a/libc/src/math/generic/setpayloadf16.cpp b/libc/src/math/generic/setpayloadf16.cpp
new file mode 100644
index 0000000..98fc239
--- /dev/null
+++ b/libc/src/math/generic/setpayloadf16.cpp
@@ -0,0 +1,19 @@
+//===-- Implementation of setpayloadf16 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/setpayloadf16.h"
+#include "src/__support/FPUtil/BasicOperations.h"
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(int, setpayloadf16, (float16 * res, float16 pl)) {
+  return static_cast<int>(fputil::setpayload</*IsSignaling=*/false>(*res, pl));
+}
+
+} // namespace LIBC_NAMESPACE
diff --git a/libc/src/math/generic/setpayloadsigf16.cpp b/libc/src/math/generic/setpayloadsigf16.cpp
new file mode 100644
index 0000000..c79620f
--- /dev/null
+++ b/libc/src/math/generic/setpayloadsigf16.cpp
@@ -0,0 +1,19 @@
+//===-- Implementation of setpayloadsigf16 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/setpayloadsigf16.h"
+#include "src/__support/FPUtil/BasicOperations.h"
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(int, setpayloadsigf16, (float16 * res, float16 pl)) {
+  return static_cast<int>(fputil::setpayload</*IsSignaling=*/true>(*res, pl));
+}
+
+} // namespace LIBC_NAMESPACE
diff --git a/libc/src/math/getpayloadf16.h b/libc/src/math/getpayloadf16.h
new file mode 100644
index 0000000..1349dfd
--- /dev/null
+++ b/libc/src/math/getpayloadf16.h
@@ -0,0 +1,20 @@
+//===-- Implementation header for getpayloadf16 -----------------*- 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_GETPAYLOADF16_H
+#define LLVM_LIBC_SRC_MATH_GETPAYLOADF16_H
+
+#include "src/__support/macros/properties/types.h"
+
+namespace LIBC_NAMESPACE {
+
+float16 getpayloadf16(const float16 *x);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_MATH_GETPAYLOADF16_H
diff --git a/libc/src/math/setpayloadf16.h b/libc/src/math/setpayloadf16.h
new file mode 100644
index 0000000..8705e28
--- /dev/null
+++ b/libc/src/math/setpayloadf16.h
@@ -0,0 +1,20 @@
+//===-- Implementation header for setpayloadf16 -----------------*- 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_SETPAYLOADF16_H
+#define LLVM_LIBC_SRC_MATH_SETPAYLOADF16_H
+
+#include "src/__support/macros/properties/types.h"
+
+namespace LIBC_NAMESPACE {
+
+int setpayloadf16(float16 *res, float16 pl);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_MATH_SETPAYLOADF16_H
diff --git a/libc/src/math/setpayloadsigf16.h b/libc/src/math/setpayloadsigf16.h
new file mode 100644
index 0000000..ee9bc38
--- /dev/null
+++ b/libc/src/math/setpayloadsigf16.h
@@ -0,0 +1,20 @@
+//===-- Implementation header for setpayloadsigf16 --------------*- 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_SETPAYLOADSIGF16_H
+#define LLVM_LIBC_SRC_MATH_SETPAYLOADSIGF16_H
+
+#include "src/__support/macros/properties/types.h"
+
+namespace LIBC_NAMESPACE {
+
+int setpayloadsigf16(float16 *res, float16 pl);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_MATH_SETPAYLOADSIGF16_H
diff --git a/libc/test/src/math/smoke/CMakeLists.txt b/libc/test/src/math/smoke/CMakeLists.txt
index a67d043..bd8de18 100644
--- a/libc/test/src/math/smoke/CMakeLists.txt
+++ b/libc/test/src/math/smoke/CMakeLists.txt
@@ -3554,6 +3554,42 @@ add_fp_unittest(
 )
 
 add_fp_unittest(
+  getpayloadf16_test
+  SUITE
+    libc-math-smoke-tests
+  SRCS
+    getpayloadf16_test.cpp
+  HDRS
+    GetPayloadTest.h
+  DEPENDS
+    libc.src.math.getpayloadf16
+)
+
+add_fp_unittest(
+  setpayloadf16_test
+  SUITE
+    libc-math-smoke-tests
+  SRCS
+    setpayloadf16_test.cpp
+  HDRS
+    SetPayloadTest.h
+  DEPENDS
+    libc.src.math.setpayloadf16
+)
+
+add_fp_unittest(
+  setpayloadsigf16_test
+  SUITE
+    libc-math-smoke-tests
+  SRCS
+    setpayloadsigf16_test.cpp
+  HDRS
+    SetPayloadSigTest.h
+  DEPENDS
+    libc.src.math.setpayloadsigf16
+)
+
+add_fp_unittest(
   f16fmaf_test
   SUITE
     libc-math-smoke-tests
diff --git a/libc/test/src/math/smoke/GetPayloadTest.h b/libc/test/src/math/smoke/GetPayloadTest.h
new file mode 100644
index 0000000..6e30de7
--- /dev/null
+++ b/libc/test/src/math/smoke/GetPayloadTest.h
@@ -0,0 +1,70 @@
+//===-- Utility class to test different flavors of getpayload ---*- 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 LIBC_TEST_SRC_MATH_SMOKE_GETPAYLOADTEST_H
+#define LIBC_TEST_SRC_MATH_SMOKE_GETPAYLOADTEST_H
+
+#include "test/UnitTest/FEnvSafeTest.h"
+#include "test/UnitTest/FPMatcher.h"
+#include "test/UnitTest/Test.h"
+
+template <typename T>
+class GetPayloadTestTemplate : public LIBC_NAMESPACE::testing::FEnvSafeTest {
+
+  DECLARE_SPECIAL_CONSTANTS(T)
+
+public:
+  typedef T (*GetPayloadFunc)(const T *);
+
+  T funcWrapper(GetPayloadFunc func, T x) { return func(&x); }
+
+  void testNonNaNs(GetPayloadFunc func) {
+    EXPECT_FP_EQ(T(-1.0), funcWrapper(func, T(0.0)));
+    EXPECT_FP_EQ(T(-1.0), funcWrapper(func, T(-0.0)));
+    EXPECT_FP_EQ(T(-1.0), funcWrapper(func, T(0.1)));
+    EXPECT_FP_EQ(T(-1.0), funcWrapper(func, T(-0.1)));
+    EXPECT_FP_EQ(T(-1.0), funcWrapper(func, T(123.38)));
+    EXPECT_FP_EQ(T(-1.0), funcWrapper(func, T(-123.38)));
+    EXPECT_FP_EQ(T(-1.0), funcWrapper(func, inf));
+    EXPECT_FP_EQ(T(-1.0), funcWrapper(func, neg_inf));
+  }
+
+  void testNaNs(GetPayloadFunc func) {
+    EXPECT_FP_EQ(T(0.0), funcWrapper(func, aNaN));
+    EXPECT_FP_EQ(T(0.0), funcWrapper(func, neg_aNaN));
+
+    T default_snan_payload = StorageType(1) << (FPBits::SIG_LEN - 2);
+    EXPECT_FP_EQ(default_snan_payload, funcWrapper(func, sNaN));
+    EXPECT_FP_EQ(default_snan_payload, funcWrapper(func, neg_sNaN));
+
+    T qnan_42 = FPBits::quiet_nan(Sign::POS, 0x42).get_val();
+    T neg_qnan_42 = FPBits::quiet_nan(Sign::NEG, 0x42).get_val();
+    T snan_42 = FPBits::signaling_nan(Sign::POS, 0x42).get_val();
+    T neg_snan_42 = FPBits::signaling_nan(Sign::NEG, 0x42).get_val();
+    EXPECT_FP_EQ(T(0x42.0p+0), funcWrapper(func, qnan_42));
+    EXPECT_FP_EQ(T(0x42.0p+0), funcWrapper(func, neg_qnan_42));
+    EXPECT_FP_EQ(T(0x42.0p+0), funcWrapper(func, snan_42));
+    EXPECT_FP_EQ(T(0x42.0p+0), funcWrapper(func, neg_snan_42));
+
+    T qnan_123 = FPBits::quiet_nan(Sign::POS, 0x123).get_val();
+    T neg_qnan_123 = FPBits::quiet_nan(Sign::NEG, 0x123).get_val();
+    T snan_123 = FPBits::signaling_nan(Sign::POS, 0x123).get_val();
+    T neg_snan_123 = FPBits::signaling_nan(Sign::NEG, 0x123).get_val();
+    EXPECT_FP_EQ(T(0x123.0p+0), funcWrapper(func, qnan_123));
+    EXPECT_FP_EQ(T(0x123.0p+0), funcWrapper(func, neg_qnan_123));
+    EXPECT_FP_EQ(T(0x123.0p+0), funcWrapper(func, snan_123));
+    EXPECT_FP_EQ(T(0x123.0p+0), funcWrapper(func, neg_snan_123));
+  }
+};
+
+#define LIST_GETPAYLOAD_TESTS(T, func)                                         \
+  using LlvmLibcGetPayloadTest = GetPayloadTestTemplate<T>;                    \
+  TEST_F(LlvmLibcGetPayloadTest, NonNaNs) { testNonNaNs(&func); }              \
+  TEST_F(LlvmLibcGetPayloadTest, NaNs) { testNaNs(&func); }
+
+#endif // LIBC_TEST_SRC_MATH_SMOKE_GETPAYLOADTEST_H
diff --git a/libc/test/src/math/smoke/SetPayloadSigTest.h b/libc/test/src/math/smoke/SetPayloadSigTest.h
new file mode 100644
index 0000000..7ec3ac0
--- /dev/null
+++ b/libc/test/src/math/smoke/SetPayloadSigTest.h
@@ -0,0 +1,74 @@
+//===-- Utility class to test flavors of setpayloadsig ----------*- 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 LIBC_TEST_SRC_MATH_SMOKE_SETPAYLOADSIGTEST_H
+#define LIBC_TEST_SRC_MATH_SMOKE_SETPAYLOADSIGTEST_H
+
+#include "test/UnitTest/FEnvSafeTest.h"
+#include "test/UnitTest/FPMatcher.h"
+#include "test/UnitTest/Test.h"
+
+template <typename T>
+class SetPayloadSigTestTemplate : public LIBC_NAMESPACE::testing::FEnvSafeTest {
+
+  DECLARE_SPECIAL_CONSTANTS(T)
+
+public:
+  typedef int (*SetPayloadSigFunc)(T *, T);
+
+  void testInvalidPayloads(SetPayloadSigFunc func) {
+    T res;
+
+    EXPECT_EQ(1, func(&res, T(aNaN)));
+    EXPECT_EQ(1, func(&res, T(neg_aNaN)));
+    EXPECT_EQ(1, func(&res, T(inf)));
+    EXPECT_EQ(1, func(&res, T(neg_inf)));
+    EXPECT_EQ(1, func(&res, T(0.0)));
+    EXPECT_EQ(1, func(&res, T(-0.0)));
+    EXPECT_EQ(1, func(&res, T(0.1)));
+    EXPECT_EQ(1, func(&res, T(-0.1)));
+    EXPECT_EQ(1, func(&res, T(-1.0)));
+    EXPECT_EQ(1, func(&res, T(0x42.1p+0)));
+    EXPECT_EQ(1, func(&res, T(-0x42.1p+0)));
+    EXPECT_EQ(1, func(&res, T(StorageType(1) << (FPBits::FRACTION_LEN - 1))));
+  }
+
+  void testValidPayloads(SetPayloadSigFunc func) {
+    T res;
+
+    EXPECT_EQ(0, func(&res, T(1.0)));
+    EXPECT_TRUE(FPBits(res).is_signaling_nan());
+    EXPECT_EQ(FPBits::signaling_nan(Sign::POS, 1).uintval(),
+              FPBits(res).uintval());
+
+    EXPECT_EQ(0, func(&res, T(0x42.0p+0)));
+    EXPECT_TRUE(FPBits(res).is_signaling_nan());
+    EXPECT_EQ(FPBits::signaling_nan(Sign::POS, 0x42).uintval(),
+              FPBits(res).uintval());
+
+    EXPECT_EQ(0, func(&res, T(0x123.0p+0)));
+    EXPECT_TRUE(FPBits(res).is_signaling_nan());
+    EXPECT_EQ(FPBits::signaling_nan(Sign::POS, 0x123).uintval(),
+              FPBits(res).uintval());
+
+    EXPECT_EQ(0, func(&res, T(FPBits::FRACTION_MASK >> 1)));
+    EXPECT_TRUE(FPBits(res).is_signaling_nan());
+    EXPECT_EQ(
+        FPBits::signaling_nan(Sign::POS, FPBits::FRACTION_MASK >> 1).uintval(),
+        FPBits(res).uintval());
+  }
+};
+
+#define LIST_SETPAYLOADSIG_TESTS(T, func)                                      \
+  using LlvmLibcSetPayloadSigTest = SetPayloadSigTestTemplate<T>;              \
+  TEST_F(LlvmLibcSetPayloadSigTest, InvalidPayloads) {                         \
+    testInvalidPayloads(&func);                                                \
+  }                                                                            \
+  TEST_F(LlvmLibcSetPayloadSigTest, ValidPayloads) { testValidPayloads(&func); }
+
+#endif // LIBC_TEST_SRC_MATH_SMOKE_SETPAYLOADSIGTEST_H
diff --git a/libc/test/src/math/smoke/SetPayloadTest.h b/libc/test/src/math/smoke/SetPayloadTest.h
new file mode 100644
index 0000000..4b0dacf
--- /dev/null
+++ b/libc/test/src/math/smoke/SetPayloadTest.h
@@ -0,0 +1,75 @@
+//===-- Utility class to test different flavors of setpayload ---*- 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 LIBC_TEST_SRC_MATH_SMOKE_SETPAYLOADTEST_H
+#define LIBC_TEST_SRC_MATH_SMOKE_SETPAYLOADTEST_H
+
+#include "test/UnitTest/FEnvSafeTest.h"
+#include "test/UnitTest/FPMatcher.h"
+#include "test/UnitTest/Test.h"
+
+template <typename T>
+class SetPayloadTestTemplate : public LIBC_NAMESPACE::testing::FEnvSafeTest {
+
+  DECLARE_SPECIAL_CONSTANTS(T)
+
+public:
+  typedef int (*SetPayloadFunc)(T *, T);
+
+  void testInvalidPayloads(SetPayloadFunc func) {
+    T res;
+
+    EXPECT_EQ(1, func(&res, T(aNaN)));
+    EXPECT_EQ(1, func(&res, T(neg_aNaN)));
+    EXPECT_EQ(1, func(&res, T(inf)));
+    EXPECT_EQ(1, func(&res, T(neg_inf)));
+    EXPECT_EQ(1, func(&res, T(0.1)));
+    EXPECT_EQ(1, func(&res, T(-0.1)));
+    EXPECT_EQ(1, func(&res, T(-1.0)));
+    EXPECT_EQ(1, func(&res, T(0x42.1p+0)));
+    EXPECT_EQ(1, func(&res, T(-0x42.1p+0)));
+    EXPECT_EQ(1, func(&res, T(StorageType(1) << (FPBits::FRACTION_LEN - 1))));
+  }
+
+  void testValidPayloads(SetPayloadFunc func) {
+    T res;
+
+    EXPECT_EQ(0, func(&res, T(0.0)));
+    EXPECT_TRUE(FPBits(res).is_quiet_nan());
+    EXPECT_EQ(FPBits(aNaN).uintval(), FPBits(res).uintval());
+
+    EXPECT_EQ(0, func(&res, T(1.0)));
+    EXPECT_TRUE(FPBits(res).is_quiet_nan());
+    EXPECT_EQ(FPBits::quiet_nan(Sign::POS, 1).uintval(), FPBits(res).uintval());
+
+    EXPECT_EQ(0, func(&res, T(0x42.0p+0)));
+    EXPECT_TRUE(FPBits(res).is_quiet_nan());
+    EXPECT_EQ(FPBits::quiet_nan(Sign::POS, 0x42).uintval(),
+              FPBits(res).uintval());
+
+    EXPECT_EQ(0, func(&res, T(0x123.0p+0)));
+    EXPECT_TRUE(FPBits(res).is_quiet_nan());
+    EXPECT_EQ(FPBits::quiet_nan(Sign::POS, 0x123).uintval(),
+              FPBits(res).uintval());
+
+    EXPECT_EQ(0, func(&res, T(FPBits::FRACTION_MASK >> 1)));
+    EXPECT_TRUE(FPBits(res).is_quiet_nan());
+    EXPECT_EQ(
+        FPBits::quiet_nan(Sign::POS, FPBits::FRACTION_MASK >> 1).uintval(),
+        FPBits(res).uintval());
+  }
+};
+
+#define LIST_SETPAYLOAD_TESTS(T, func)                                         \
+  using LlvmLibcSetPayloadTest = SetPayloadTestTemplate<T>;                    \
+  TEST_F(LlvmLibcSetPayloadTest, InvalidPayloads) {                            \
+    testInvalidPayloads(&func);                                                \
+  }                                                                            \
+  TEST_F(LlvmLibcSetPayloadTest, ValidPayloads) { testValidPayloads(&func); }
+
+#endif // LIBC_TEST_SRC_MATH_SMOKE_SETPAYLOADTEST_H
diff --git a/libc/test/src/math/smoke/getpayloadf16_test.cpp b/libc/test/src/math/smoke/getpayloadf16_test.cpp
new file mode 100644
index 0000000..385b047
--- /dev/null
+++ b/libc/test/src/math/smoke/getpayloadf16_test.cpp
@@ -0,0 +1,13 @@
+//===-- Unittests for getpayloadf16 ---------------------------------------===//
+//
+// 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 "GetPayloadTest.h"
+
+#include "src/math/getpayloadf16.h"
+
+LIST_GETPAYLOAD_TESTS(float16, LIBC_NAMESPACE::getpayloadf16)
diff --git a/libc/test/src/math/smoke/setpayloadf16_test.cpp b/libc/test/src/math/smoke/setpayloadf16_test.cpp
new file mode 100644
index 0000000..ccf5370
--- /dev/null
+++ b/libc/test/src/math/smoke/setpayloadf16_test.cpp
@@ -0,0 +1,13 @@
+//===-- Unittests for setpayloadf16 ---------------------------------------===//
+//
+// 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 "SetPayloadTest.h"
+
+#include "src/math/setpayloadf16.h"
+
+LIST_SETPAYLOAD_TESTS(float16, LIBC_NAMESPACE::setpayloadf16)
diff --git a/libc/test/src/math/smoke/setpayloadsigf16_test.cpp b/libc/test/src/math/smoke/setpayloadsigf16_test.cpp
new file mode 100644
index 0000000..9f786e6
--- /dev/null
+++ b/libc/test/src/math/smoke/setpayloadsigf16_test.cpp
@@ -0,0 +1,13 @@
+//===-- Unittests for setpayloadsigf16 ------------------------------------===//
+//
+// 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 "SetPayloadSigTest.h"
+
+#include "src/math/setpayloadsigf16.h"
+
+LIST_SETPAYLOADSIG_TESTS(float16, LIBC_NAMESPACE::setpayloadsigf16)