[libc][math][c++23] Add bf16{add,sub}{,f,l,f128} math functions (#152774)

This PR adds implements following basic math functions for BFloat16 type
along with the tests:
- bf16add
- bf16addf
- bf16addl
- bf16addf128
- bf16sub
- bf16subf
- bf16subl
- bf16subf128

---------

Signed-off-by: Krishna Pandey <[email protected]>

Author: krishna2803

libc/config/linux/x86_64/entrypoints.txt

@@ -896,13 +896,27 @@ endif()
 list(APPEND TARGET_LIBM_ENTRYPOINTS
   # bfloat16 entrypoints
   libc.src.math.ceilbf16
+  libc.src.math.bf16add
+  libc.src.math.bf16addf
+  libc.src.math.bf16addl
+  libc.src.math.bf16sub
+  libc.src.math.bf16subf
+  libc.src.math.bf16subl
   libc.src.math.fabsbf16
   libc.src.math.floorbf16
   libc.src.math.roundbf16
   libc.src.math.roundevenbf16
   libc.src.math.truncbf16
 )
 
+if(LIBC_TYPES_HAS_FLOAT128)
+  list(APPEND TARGET_LIBM_ENTRYPOINTS
+    # math.h C++23 mixed bfloat16 and _Float128 entrypoints
+    libc.src.math.bf16addf128
+    libc.src.math.bf16subf128
+  )
+endif()
+
 if(LIBC_COMPILER_HAS_FIXED_POINT)
   list(APPEND TARGET_LIBM_ENTRYPOINTS
     # stdfix.h _Fract and _Accum entrypoints

libc/src/math/CMakeLists.txt

@@ -563,3 +563,13 @@ add_math_entrypoint_object(ufromfpxf)
 add_math_entrypoint_object(ufromfpxl)
 add_math_entrypoint_object(ufromfpxf16)
 add_math_entrypoint_object(ufromfpxf128)
+
+add_math_entrypoint_object(bf16add)
+add_math_entrypoint_object(bf16addf)
+add_math_entrypoint_object(bf16addl)
+add_math_entrypoint_object(bf16addf128)
+
+add_math_entrypoint_object(bf16sub)
+add_math_entrypoint_object(bf16subf)
+add_math_entrypoint_object(bf16subl)
+add_math_entrypoint_object(bf16subf128)

libc/src/math/bf16add.h

@@ -0,0 +1,21 @@
+//===-- Implementation header for bf16add -----------------------*- 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_BF16ADD_H
+#define LLVM_LIBC_SRC_MATH_BF16ADD_H
+
+#include "src/__support/macros/config.h"
+#include "src/__support/macros/properties/types.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+bfloat16 bf16add(double x, double y);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_MATH_BF16ADD_H

libc/src/math/bf16addf.h

@@ -0,0 +1,21 @@
+//===-- Implementation header for bf16addf ----------------------*- 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_BF16ADDF_H
+#define LLVM_LIBC_SRC_MATH_BF16ADDF_H
+
+#include "src/__support/macros/config.h"
+#include "src/__support/macros/properties/types.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+bfloat16 bf16addf(float x, float y);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_MATH_BF16ADDF_H

libc/src/math/bf16addf128.h

@@ -0,0 +1,21 @@
+//===-- Implementation header for bf16addf128 -------------------*- 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_BF16ADDF128_H
+#define LLVM_LIBC_SRC_MATH_BF16ADDF128_H
+
+#include "src/__support/macros/config.h"
+#include "src/__support/macros/properties/types.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+bfloat16 bf16addf128(float128 x, float128 y);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_MATH_BF16ADDF128_H

libc/src/math/bf16addl.h

@@ -0,0 +1,21 @@
+//===-- Implementation header for bf16addl ----------------------*- 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_BF16ADDL_H
+#define LLVM_LIBC_SRC_MATH_BF16ADDL_H
+
+#include "src/__support/macros/config.h"
+#include "src/__support/macros/properties/types.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+bfloat16 bf16addl(long double x, long double y);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_MATH_BF16ADDL_H

libc/src/math/bf16sub.h

@@ -0,0 +1,21 @@
+//===-- Implementation header for bf16sub -----------------------*- 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_BF16SUB_H
+#define LLVM_LIBC_SRC_MATH_BF16SUB_H
+
+#include "src/__support/macros/config.h"
+#include "src/__support/macros/properties/types.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+bfloat16 bf16sub(double x, double y);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_MATH_BF16SUB_H

libc/src/math/bf16subf.h

@@ -0,0 +1,21 @@
+//===-- Implementation header for bf16subf ----------------------*- 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_BF16SUBF_H
+#define LLVM_LIBC_SRC_MATH_BF16SUBF_H
+
+#include "src/__support/macros/config.h"
+#include "src/__support/macros/properties/types.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+bfloat16 bf16subf(float x, float y);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_MATH_BF16SUBF_H

libc/src/math/bf16subf128.h

@@ -0,0 +1,21 @@
+//===-- Implementation header for bf16subf128 -------------------*- 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_BF16SUBF128_H
+#define LLVM_LIBC_SRC_MATH_BF16SUBF128_H
+
+#include "src/__support/macros/config.h"
+#include "src/__support/macros/properties/types.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+bfloat16 bf16subf128(float128 x, float128 y);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_MATH_BF16SUBF128_H

libc/src/math/bf16subl.h

@@ -0,0 +1,21 @@
+//===-- Implementation header for bf16subl ----------------------*- 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_BF16SUBL_H
+#define LLVM_LIBC_SRC_MATH_BF16SUBL_H
+
+#include "src/__support/macros/config.h"
+#include "src/__support/macros/properties/types.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+bfloat16 bf16subl(long double x, long double y);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_MATH_BF16SUBL_H