[libc][math][c++23] Add {get,set}payloadbf16 and setpayloadsigbf16 math functions (#153994)

krishna2803 · web-flow · commit de6bd152b904 · 2025-08-23T01:02:02.000+05:30
This PR adds the following basic math functions for BFloat16 type along
with the tests:
- getpayloadbf16
- setpayloadbf16
- setpayloadsigbf16

---------

Signed-off-by: Krishna Pandey &lt;kpandey81930@gmail.com&gt;
diff --git a/libc/config/baremetal/aarch64/entrypoints.txt b/libc/config/baremetal/aarch64/entrypoints.txt
@@ -787,12 +787,15 @@ list(APPEND TARGET_LIBM_ENTRYPOINTS
   libc.src.math.fminimum_numbf16
   libc.src.math.fromfpbf16
   libc.src.math.fromfpxbf16
+  libc.src.math.getpayloadbf16
   libc.src.math.nextafterbf16
   libc.src.math.nextdownbf16
   libc.src.math.nexttowardbf16
   libc.src.math.nextupbf16
   libc.src.math.roundbf16
   libc.src.math.roundevenbf16
+  libc.src.math.setpayloadbf16
+  libc.src.math.setpayloadsigbf16
   libc.src.math.truncbf16
   libc.src.math.ufromfpbf16
   libc.src.math.ufromfpxbf16
diff --git a/libc/config/baremetal/arm/entrypoints.txt b/libc/config/baremetal/arm/entrypoints.txt
@@ -790,12 +790,15 @@ list(APPEND TARGET_LIBM_ENTRYPOINTS
   libc.src.math.fminimum_numbf16
   libc.src.math.fromfpbf16
   libc.src.math.fromfpxbf16
+  libc.src.math.getpayloadbf16
   libc.src.math.nextafterbf16
   libc.src.math.nextdownbf16
   libc.src.math.nexttowardbf16
   libc.src.math.nextupbf16
   libc.src.math.roundbf16
   libc.src.math.roundevenbf16
+  libc.src.math.setpayloadbf16
+  libc.src.math.setpayloadsigbf16
   libc.src.math.truncbf16
   libc.src.math.ufromfpbf16
   libc.src.math.ufromfpxbf16
diff --git a/libc/config/baremetal/riscv/entrypoints.txt b/libc/config/baremetal/riscv/entrypoints.txt
@@ -790,12 +790,15 @@ list(APPEND TARGET_LIBM_ENTRYPOINTS
   libc.src.math.fminimum_numbf16
   libc.src.math.fromfpbf16
   libc.src.math.fromfpxbf16
+  libc.src.math.getpayloadbf16
   libc.src.math.nextafterbf16
   libc.src.math.nextdownbf16
   libc.src.math.nexttowardbf16
   libc.src.math.nextupbf16
   libc.src.math.roundbf16
   libc.src.math.roundevenbf16
+  libc.src.math.setpayloadbf16
+  libc.src.math.setpayloadsigbf16
   libc.src.math.truncbf16
   libc.src.math.ufromfpbf16
   libc.src.math.ufromfpxbf16
diff --git a/libc/config/darwin/aarch64/entrypoints.txt b/libc/config/darwin/aarch64/entrypoints.txt
@@ -620,12 +620,15 @@ list(APPEND TARGET_LIBM_ENTRYPOINTS
   libc.src.math.fminimum_numbf16
   libc.src.math.fromfpbf16
   libc.src.math.fromfpxbf16
+  libc.src.math.getpayloadbf16
   libc.src.math.nextafterbf16
   libc.src.math.nextdownbf16
   libc.src.math.nexttowardbf16
   libc.src.math.nextupbf16
   libc.src.math.roundbf16
   libc.src.math.roundevenbf16
+  libc.src.math.setpayloadbf16
+  libc.src.math.setpayloadsigbf16
   libc.src.math.truncbf16
   libc.src.math.ufromfpbf16
   libc.src.math.ufromfpxbf16
diff --git a/libc/config/darwin/x86_64/entrypoints.txt b/libc/config/darwin/x86_64/entrypoints.txt
@@ -263,12 +263,15 @@ list(APPEND TARGET_LIBM_ENTRYPOINTS
   libc.src.math.fminimum_numbf16
   libc.src.math.fromfpbf16
   libc.src.math.fromfpxbf16
+  libc.src.math.getpayloadbf16
   libc.src.math.nextafterbf16
   libc.src.math.nextdownbf16
   libc.src.math.nexttowardbf16
   libc.src.math.nextupbf16
   libc.src.math.roundbf16
   libc.src.math.roundevenbf16
+  libc.src.math.setpayloadbf16
+  libc.src.math.setpayloadsigbf16
   libc.src.math.truncbf16
   libc.src.math.ufromfpbf16
   libc.src.math.ufromfpxbf16
diff --git a/libc/config/gpu/amdgpu/entrypoints.txt b/libc/config/gpu/amdgpu/entrypoints.txt
@@ -646,12 +646,15 @@ list(APPEND TARGET_LIBM_ENTRYPOINTS
   libc.src.math.fminimum_numbf16
   libc.src.math.fromfpbf16
   libc.src.math.fromfpxbf16
+  libc.src.math.getpayloadbf16
   libc.src.math.nextafterbf16
   libc.src.math.nextdownbf16
   libc.src.math.nexttowardbf16
   libc.src.math.nextupbf16
   libc.src.math.roundbf16
   libc.src.math.roundevenbf16
+  libc.src.math.setpayloadbf16
+  libc.src.math.setpayloadsigbf16
   libc.src.math.truncbf16
   libc.src.math.ufromfpbf16
   libc.src.math.ufromfpxbf16
diff --git a/libc/config/gpu/nvptx/entrypoints.txt b/libc/config/gpu/nvptx/entrypoints.txt
@@ -648,12 +648,15 @@ list(APPEND TARGET_LIBM_ENTRYPOINTS
   libc.src.math.fminimum_numbf16
   libc.src.math.fromfpbf16
   libc.src.math.fromfpxbf16
+  libc.src.math.getpayloadbf16
   libc.src.math.nextafterbf16
   libc.src.math.nextdownbf16
   libc.src.math.nexttowardbf16
   libc.src.math.nextupbf16
   libc.src.math.roundbf16
   libc.src.math.roundevenbf16
+  libc.src.math.setpayloadbf16
+  libc.src.math.setpayloadsigbf16
   libc.src.math.truncbf16
   libc.src.math.ufromfpbf16
   libc.src.math.ufromfpxbf16
diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
@@ -875,12 +875,15 @@ list(APPEND TARGET_LIBM_ENTRYPOINTS
   libc.src.math.fminimum_numbf16
   libc.src.math.fromfpbf16
   libc.src.math.fromfpxbf16
+  libc.src.math.getpayloadbf16
   libc.src.math.nextafterbf16
   libc.src.math.nextdownbf16
   libc.src.math.nexttowardbf16
   libc.src.math.nextupbf16
   libc.src.math.roundbf16
   libc.src.math.roundevenbf16
+  libc.src.math.setpayloadbf16
+  libc.src.math.setpayloadsigbf16
   libc.src.math.truncbf16
   libc.src.math.ufromfpbf16
   libc.src.math.ufromfpxbf16
diff --git a/libc/config/linux/arm/entrypoints.txt b/libc/config/linux/arm/entrypoints.txt
@@ -490,12 +490,15 @@ list(APPEND TARGET_LIBM_ENTRYPOINTS
   libc.src.math.fminimum_numbf16
   libc.src.math.fromfpbf16
   libc.src.math.fromfpxbf16
+  libc.src.math.getpayloadbf16
   libc.src.math.nextafterbf16
   libc.src.math.nextdownbf16
   libc.src.math.nexttowardbf16
   libc.src.math.nextupbf16
   libc.src.math.roundbf16
   libc.src.math.roundevenbf16
+  libc.src.math.setpayloadbf16
+  libc.src.math.setpayloadsigbf16
   libc.src.math.truncbf16
   libc.src.math.ufromfpbf16
   libc.src.math.ufromfpxbf16
diff --git a/libc/config/linux/riscv/entrypoints.txt b/libc/config/linux/riscv/entrypoints.txt
@@ -893,11 +893,15 @@ list(APPEND TARGET_LIBM_ENTRYPOINTS
   libc.src.math.fminimum_numbf16
   libc.src.math.fromfpbf16
   libc.src.math.fromfpxbf16
+  libc.src.math.getpayloadbf16
   libc.src.math.nextafterbf16
   libc.src.math.nextdownbf16
   libc.src.math.nexttowardbf16
+  libc.src.math.nextupbf16
   libc.src.math.roundbf16
   libc.src.math.roundevenbf16
+  libc.src.math.setpayloadbf16
+  libc.src.math.setpayloadsigbf16
   libc.src.math.truncbf16
   libc.src.math.ufromfpbf16
   libc.src.math.ufromfpxbf16
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
@@ -926,12 +926,15 @@ list(APPEND TARGET_LIBM_ENTRYPOINTS
   libc.src.math.fminimum_numbf16
   libc.src.math.fromfpbf16
   libc.src.math.fromfpxbf16
+  libc.src.math.getpayloadbf16
   libc.src.math.nextafterbf16
   libc.src.math.nextdownbf16
   libc.src.math.nexttowardbf16
   libc.src.math.nextupbf16
   libc.src.math.roundbf16
   libc.src.math.roundevenbf16
+  libc.src.math.setpayloadbf16
+  libc.src.math.setpayloadsigbf16
   libc.src.math.truncbf16
   libc.src.math.ufromfpbf16
   libc.src.math.ufromfpxbf16
diff --git a/libc/config/windows/entrypoints.txt b/libc/config/windows/entrypoints.txt
@@ -336,12 +336,15 @@ list(APPEND TARGET_LIBM_ENTRYPOINTS
   libc.src.math.fminimum_numbf16
   libc.src.math.fromfpbf16
   libc.src.math.fromfpxbf16
+  libc.src.math.getpayloadbf16
   libc.src.math.nextafterbf16
   libc.src.math.nextdownbf16
   libc.src.math.nexttowardbf16
   libc.src.math.nextupbf16
   libc.src.math.roundbf16
   libc.src.math.roundevenbf16
+  libc.src.math.setpayloadbf16
+  libc.src.math.setpayloadsigbf16
   libc.src.math.truncbf16
   libc.src.math.ufromfpbf16
   libc.src.math.ufromfpxbf16
diff --git a/libc/docs/headers/math/index.rst b/libc/docs/headers/math/index.rst
@@ -187,7 +187,7 @@ Basic Operations
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+------------------------+----------------------------+
 | fsub             | N/A              | |check|         | |check|                | N/A                  | |check|\*              | N/A                    | 7.12.14.2              | F.10.11                    |
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+------------------------+----------------------------+
-| getpayload       | |check|          | |check|         | |check|                | |check|              | |check|                |                        | F.10.13.1              | N/A                        |
+| getpayload       | |check|          | |check|         | |check|                | |check|              | |check|                | |check|                | F.10.13.1              | N/A                        |
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+------------------------+----------------------------+
 | ilogb            | |check|          | |check|         | |check|                | |check|              | |check|                |                        | 7.12.6.8               | F.10.3.8                   |
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+------------------------+----------------------------+
@@ -237,9 +237,9 @@ Basic Operations
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+------------------------+----------------------------+
 | scalbn           | |check|          | |check|         | |check|                | |check|              | |check|                |                        | 7.12.6.19              | F.10.3.19                  |
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+------------------------+----------------------------+
-| setpayload       | |check|          | |check|         | |check|                | |check|              | |check|                |                        | F.10.13.2              | N/A                        |
+| setpayload       | |check|          | |check|         | |check|                | |check|              | |check|                | |check|                | F.10.13.2              | N/A                        |
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+------------------------+----------------------------+
-| setpayloadsig    | |check|          | |check|         | |check|                | |check|              | |check|                |                        | F.10.13.3              | N/A                        |
+| setpayloadsig    | |check|          | |check|         | |check|                | |check|              | |check|                | |check|                | F.10.13.3              | N/A                        |
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+------------------------+----------------------------+
 | totalorder       | |check|          | |check|         | |check|                | |check|              | |check|                |                        | F.10.12.1              | N/A                        |
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+------------------------+----------------------------+
diff --git a/libc/src/__support/FPUtil/bfloat16.h b/libc/src/__support/FPUtil/bfloat16.h
@@ -29,8 +29,6 @@ struct BFloat16 {
 
   LIBC_INLINE BFloat16() = default;
 
-  LIBC_INLINE constexpr explicit BFloat16(uint16_t bits) : bits(bits) {}
-
   template <typename T> LIBC_INLINE constexpr explicit BFloat16(T value) {
     if constexpr (cpp::is_floating_point_v<T>) {
       bits = fputil::cast<bfloat16>(value).bits;
diff --git a/libc/src/math/CMakeLists.txt b/libc/src/math/CMakeLists.txt
@@ -332,6 +332,7 @@ add_math_entrypoint_object(getpayloadf)
 add_math_entrypoint_object(getpayloadl)
 add_math_entrypoint_object(getpayloadf16)
 add_math_entrypoint_object(getpayloadf128)
+add_math_entrypoint_object(getpayloadbf16)
 
 add_math_entrypoint_object(hypot)
 add_math_entrypoint_object(hypotf)
@@ -509,12 +510,14 @@ add_math_entrypoint_object(setpayloadf)
 add_math_entrypoint_object(setpayloadl)
 add_math_entrypoint_object(setpayloadf16)
 add_math_entrypoint_object(setpayloadf128)
+add_math_entrypoint_object(setpayloadbf16)
 
 add_math_entrypoint_object(setpayloadsig)
 add_math_entrypoint_object(setpayloadsigf)
 add_math_entrypoint_object(setpayloadsigl)
 add_math_entrypoint_object(setpayloadsigf16)
 add_math_entrypoint_object(setpayloadsigf128)
+add_math_entrypoint_object(setpayloadsigbf16)
 
 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
@@ -4609,6 +4609,20 @@ add_entrypoint_object(
     libc.src.__support.FPUtil.basic_operations
 )
 
+add_entrypoint_object(
+  getpayloadbf16
+  SRCS
+    getpayloadbf16.cpp
+  HDRS
+    ../getpayloadbf16.h
+  DEPENDS
+    libc.src.__support.common
+    libc.src.__support.FPUtil.basic_operations
+    libc.src.__support.FPUtil.bfloat16
+    libc.src.__support.macros.config
+    libc.src.__support.macros.properties.types
+)
+
 add_entrypoint_object(
   setpayload
   SRCS
@@ -4661,6 +4675,20 @@ add_entrypoint_object(
     libc.src.__support.FPUtil.basic_operations
 )
 
+add_entrypoint_object(
+  setpayloadbf16
+  SRCS
+    setpayloadbf16.cpp
+  HDRS
+    ../setpayloadbf16.h
+  DEPENDS
+    libc.src.__support.common
+    libc.src.__support.FPUtil.basic_operations
+    libc.src.__support.FPUtil.bfloat16
+    libc.src.__support.macros.config
+    libc.src.__support.macros.properties.types
+)
+
 add_entrypoint_object(
   setpayloadsig
   SRCS
@@ -4713,6 +4741,20 @@ add_entrypoint_object(
     libc.src.__support.FPUtil.basic_operations
 )
 
+add_entrypoint_object(
+  setpayloadsigbf16
+  SRCS
+    setpayloadsigbf16.cpp
+  HDRS
+    ../setpayloadsigbf16.h
+  DEPENDS
+    libc.src.__support.common
+    libc.src.__support.FPUtil.basic_operations
+    libc.src.__support.FPUtil.bfloat16
+    libc.src.__support.macros.config
+    libc.src.__support.macros.properties.types
+)
+
 add_entrypoint_object(
   f16add
   SRCS
diff --git a/libc/src/math/generic/getpayloadbf16.cpp b/libc/src/math/generic/getpayloadbf16.cpp
@@ -0,0 +1,21 @@
+//===-- Implementation of getpayloadbf16 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/getpayloadbf16.h"
+#include "src/__support/FPUtil/BasicOperations.h"
+#include "src/__support/FPUtil/bfloat16.h"
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(bfloat16, getpayloadbf16, (const bfloat16 *x)) {
+  return fputil::getpayload(*x);
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/math/generic/setpayloadbf16.cpp b/libc/src/math/generic/setpayloadbf16.cpp
@@ -0,0 +1,21 @@
+//===-- Implementation of setpayloadbf16 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/setpayloadbf16.h"
+#include "src/__support/FPUtil/BasicOperations.h"
+#include "src/__support/FPUtil/bfloat16.h"
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, setpayloadbf16, (bfloat16 * res, bfloat16 pl)) {
+  return static_cast<int>(fputil::setpayload</*IsSignaling=*/false>(*res, pl));
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/math/generic/setpayloadsigbf16.cpp b/libc/src/math/generic/setpayloadsigbf16.cpp
@@ -0,0 +1,21 @@
+//===-- Implementation of setpayloadsigbf16 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/setpayloadsigbf16.h"
+#include "src/__support/FPUtil/BasicOperations.h"
+#include "src/__support/FPUtil/bfloat16.h"
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, setpayloadsigbf16, (bfloat16 * res, bfloat16 pl)) {
+  return static_cast<int>(fputil::setpayload</*IsSignaling=*/true>(*res, pl));
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/math/getpayloadbf16.h b/libc/src/math/getpayloadbf16.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for getpayloadbf16 ----------------*- 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_GETPAYLOADBF16_H
+#define LLVM_LIBC_SRC_MATH_GETPAYLOADBF16_H
+
+#include "src/__support/macros/config.h"
+#include "src/__support/macros/properties/types.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+bfloat16 getpayloadbf16(const bfloat16 *x);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_MATH_GETPAYLOADBF16_H
diff --git a/libc/src/math/setpayloadbf16.h b/libc/src/math/setpayloadbf16.h
diff --git a/libc/src/math/setpayloadsigbf16.h b/libc/src/math/setpayloadsigbf16.h
diff --git a/libc/test/src/math/smoke/CMakeLists.txt b/libc/test/src/math/smoke/CMakeLists.txt
diff --git a/libc/test/src/math/smoke/GetPayloadTest.h b/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
diff --git a/libc/test/src/math/smoke/SetPayloadTest.h b/libc/test/src/math/smoke/SetPayloadTest.h
diff --git a/libc/test/src/math/smoke/getpayloadbf16_test.cpp b/libc/test/src/math/smoke/getpayloadbf16_test.cpp
diff --git a/libc/test/src/math/smoke/setpayloadbf16_test.cpp b/libc/test/src/math/smoke/setpayloadbf16_test.cpp
diff --git a/libc/test/src/math/smoke/setpayloadsigbf16_test.cpp b/libc/test/src/math/smoke/setpayloadsigbf16_test.cpp
