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[libc][math][c++23] Add {,u}fromfp{,x}bf16 math functions #153992

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Merged
merged 5 commits into from
Aug 19, 2025
Merged

[libc][math][c++23] Add {,u}fromfp{,x}bf16 math functions #153992

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b58785d
feat: implement {,u}fromfp{,x}bf16 math functions
krishna2803 Aug 16, 2025
0a2b527
chore: add tests for {,u}fromfp{,x}bf16 math functions
krishna2803 Aug 16, 2025
baaf0e0
chore: update entrypoints
krishna2803 Aug 16, 2025
733f4f1
chore: update docs
krishna2803 Aug 16, 2025
ecb6d7f
style: clang-format
krishna2803 Aug 17, 2025
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4 changes: 4 additions & 0 deletions libc/config/baremetal/aarch64/entrypoints.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -785,9 +785,13 @@ list(APPEND TARGET_LIBM_ENTRYPOINTS
libc.src.math.fminimum_magbf16
libc.src.math.fminimum_mag_numbf16
libc.src.math.fminimum_numbf16
libc.src.math.fromfpbf16
libc.src.math.fromfpxbf16
libc.src.math.roundbf16
libc.src.math.roundevenbf16
libc.src.math.truncbf16
libc.src.math.ufromfpbf16
libc.src.math.ufromfpxbf16
)

if(LIBC_TYPES_HAS_FLOAT128)
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4 changes: 4 additions & 0 deletions libc/config/baremetal/arm/entrypoints.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -788,9 +788,13 @@ list(APPEND TARGET_LIBM_ENTRYPOINTS
libc.src.math.fminimum_magbf16
libc.src.math.fminimum_mag_numbf16
libc.src.math.fminimum_numbf16
libc.src.math.fromfpbf16
libc.src.math.fromfpxbf16
libc.src.math.roundbf16
libc.src.math.roundevenbf16
libc.src.math.truncbf16
libc.src.math.ufromfpbf16
libc.src.math.ufromfpxbf16
)

if(LIBC_TYPES_HAS_FLOAT128)
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4 changes: 4 additions & 0 deletions libc/config/baremetal/riscv/entrypoints.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -788,9 +788,13 @@ list(APPEND TARGET_LIBM_ENTRYPOINTS
libc.src.math.fminimum_magbf16
libc.src.math.fminimum_mag_numbf16
libc.src.math.fminimum_numbf16
libc.src.math.fromfpbf16
libc.src.math.fromfpxbf16
libc.src.math.roundbf16
libc.src.math.roundevenbf16
libc.src.math.truncbf16
libc.src.math.ufromfpbf16
libc.src.math.ufromfpxbf16
)

if(LIBC_TYPES_HAS_FLOAT128)
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4 changes: 4 additions & 0 deletions libc/config/darwin/aarch64/entrypoints.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -618,9 +618,13 @@ list(APPEND TARGET_LIBM_ENTRYPOINTS
libc.src.math.fminimum_magbf16
libc.src.math.fminimum_mag_numbf16
libc.src.math.fminimum_numbf16
libc.src.math.fromfpbf16
libc.src.math.fromfpxbf16
libc.src.math.roundbf16
libc.src.math.roundevenbf16
libc.src.math.truncbf16
libc.src.math.ufromfpbf16
libc.src.math.ufromfpxbf16
)

if(LIBC_TYPES_HAS_FLOAT128)
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5 changes: 4 additions & 1 deletion libc/config/darwin/x86_64/entrypoints.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -261,10 +261,13 @@ list(APPEND TARGET_LIBM_ENTRYPOINTS
libc.src.math.fminimum_magbf16
libc.src.math.fminimum_mag_numbf16
libc.src.math.fminimum_numbf16

libc.src.math.fromfpbf16
libc.src.math.fromfpxbf16
libc.src.math.roundbf16
libc.src.math.roundevenbf16
libc.src.math.truncbf16
libc.src.math.ufromfpbf16
libc.src.math.ufromfpxbf16
)

set(TARGET_LLVMLIBC_ENTRYPOINTS
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4 changes: 4 additions & 0 deletions libc/config/gpu/amdgpu/entrypoints.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -644,9 +644,13 @@ list(APPEND TARGET_LIBM_ENTRYPOINTS
libc.src.math.fminimum_magbf16
libc.src.math.fminimum_mag_numbf16
libc.src.math.fminimum_numbf16
libc.src.math.fromfpbf16
libc.src.math.fromfpxbf16
libc.src.math.roundbf16
libc.src.math.roundevenbf16
libc.src.math.truncbf16
libc.src.math.ufromfpbf16
libc.src.math.ufromfpxbf16
)

set(TARGET_LLVMLIBC_ENTRYPOINTS
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4 changes: 4 additions & 0 deletions libc/config/gpu/nvptx/entrypoints.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -645,9 +645,13 @@ list(APPEND TARGET_LIBM_ENTRYPOINTS
libc.src.math.fminimum_magbf16
libc.src.math.fminimum_mag_numbf16
libc.src.math.fminimum_numbf16
libc.src.math.fromfpbf16
libc.src.math.fromfpxbf16
libc.src.math.roundbf16
libc.src.math.roundevenbf16
libc.src.math.truncbf16
libc.src.math.ufromfpbf16
libc.src.math.ufromfpxbf16
)

set(TARGET_LLVMLIBC_ENTRYPOINTS
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4 changes: 4 additions & 0 deletions libc/config/linux/aarch64/entrypoints.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -872,9 +872,13 @@ list(APPEND TARGET_LIBM_ENTRYPOINTS
libc.src.math.fminimum_magbf16
libc.src.math.fminimum_mag_numbf16
libc.src.math.fminimum_numbf16
libc.src.math.fromfpbf16
libc.src.math.fromfpxbf16
libc.src.math.roundbf16
libc.src.math.roundevenbf16
libc.src.math.truncbf16
libc.src.math.ufromfpbf16
libc.src.math.ufromfpxbf16
)

if(LIBC_TYPES_HAS_FLOAT128)
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4 changes: 4 additions & 0 deletions libc/config/linux/arm/entrypoints.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -488,9 +488,13 @@ list(APPEND TARGET_LIBM_ENTRYPOINTS
libc.src.math.fminimum_magbf16
libc.src.math.fminimum_mag_numbf16
libc.src.math.fminimum_numbf16
libc.src.math.fromfpbf16
libc.src.math.fromfpxbf16
libc.src.math.roundbf16
libc.src.math.roundevenbf16
libc.src.math.truncbf16
libc.src.math.ufromfpbf16
libc.src.math.ufromfpxbf16
)

set(TARGET_LLVMLIBC_ENTRYPOINTS
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4 changes: 4 additions & 0 deletions libc/config/linux/riscv/entrypoints.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -891,9 +891,13 @@ list(APPEND TARGET_LIBM_ENTRYPOINTS
libc.src.math.fminimum_magbf16
libc.src.math.fminimum_mag_numbf16
libc.src.math.fminimum_numbf16
libc.src.math.fromfpbf16
libc.src.math.fromfpxbf16
libc.src.math.roundbf16
libc.src.math.roundevenbf16
libc.src.math.truncbf16
libc.src.math.ufromfpbf16
libc.src.math.ufromfpxbf16
)

if(LIBC_TYPES_HAS_FLOAT128)
Expand Down
4 changes: 4 additions & 0 deletions libc/config/linux/x86_64/entrypoints.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -923,9 +923,13 @@ list(APPEND TARGET_LIBM_ENTRYPOINTS
libc.src.math.fminimum_magbf16
libc.src.math.fminimum_mag_numbf16
libc.src.math.fminimum_numbf16
libc.src.math.fromfpbf16
libc.src.math.fromfpxbf16
libc.src.math.roundbf16
libc.src.math.roundevenbf16
libc.src.math.truncbf16
libc.src.math.ufromfpbf16
libc.src.math.ufromfpxbf16
)

if(LIBC_TYPES_HAS_FLOAT128)
Expand Down
4 changes: 4 additions & 0 deletions libc/config/windows/entrypoints.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -334,9 +334,13 @@ list(APPEND TARGET_LIBM_ENTRYPOINTS
libc.src.math.fminimum_magbf16
libc.src.math.fminimum_mag_numbf16
libc.src.math.fminimum_numbf16
libc.src.math.fromfpbf16
libc.src.math.fromfpxbf16
libc.src.math.roundbf16
libc.src.math.roundevenbf16
libc.src.math.truncbf16
libc.src.math.ufromfpbf16
libc.src.math.ufromfpxbf16
)

set(TARGET_LLVMLIBC_ENTRYPOINTS
Expand Down
8 changes: 4 additions & 4 deletions libc/docs/headers/math/index.rst
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Original file line number Diff line number Diff line change
Expand Up @@ -181,9 +181,9 @@ Basic Operations
+------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+------------------------+----------------------------+
| frexp | |check| | |check| | |check| | |check| | |check| | | 7.12.6.7 | F.10.3.7 |
+------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+------------------------+----------------------------+
| fromfp | |check| | |check| | |check| | |check| | |check| | | 7.12.9.10 | F.10.6.10 |
| fromfp | |check| | |check| | |check| | |check| | |check| | |check| | 7.12.9.10 | F.10.6.10 |
+------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+------------------------+----------------------------+
| fromfpx | |check| | |check| | |check| | |check| | |check| | | 7.12.9.11 | F.10.6.11 |
| fromfpx | |check| | |check| | |check| | |check| | |check| | |check| | 7.12.9.11 | F.10.6.11 |
+------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+------------------------+----------------------------+
| fsub | N/A | |check| | |check| | N/A | |check|\* | N/A | 7.12.14.2 | F.10.11 |
+------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+------------------------+----------------------------+
Expand Down Expand Up @@ -247,9 +247,9 @@ Basic Operations
+------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+------------------------+----------------------------+
| trunc | |check| | |check| | |check| | |check| | |check| | |check| | 7.12.9.9 | F.10.6.9 |
+------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+------------------------+----------------------------+
| ufromfp | |check| | |check| | |check| | |check| | |check| | | 7.12.9.10 | F.10.6.10 |
| ufromfp | |check| | |check| | |check| | |check| | |check| | |check| | 7.12.9.10 | F.10.6.10 |
+------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+------------------------+----------------------------+
| ufromfpx | |check| | |check| | |check| | |check| | |check| | | 7.12.9.11 | F.10.6.11 |
| ufromfpx | |check| | |check| | |check| | |check| | |check| | |check| | 7.12.9.11 | F.10.6.11 |
+------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+------------------------+----------------------------+

Higher Math Functions
Expand Down
4 changes: 4 additions & 0 deletions libc/src/math/CMakeLists.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -312,12 +312,14 @@ add_math_entrypoint_object(fromfpf)
add_math_entrypoint_object(fromfpl)
add_math_entrypoint_object(fromfpf16)
add_math_entrypoint_object(fromfpf128)
add_math_entrypoint_object(fromfpbf16)

add_math_entrypoint_object(fromfpx)
add_math_entrypoint_object(fromfpxf)
add_math_entrypoint_object(fromfpxl)
add_math_entrypoint_object(fromfpxf16)
add_math_entrypoint_object(fromfpxf128)
add_math_entrypoint_object(fromfpxbf16)

add_math_entrypoint_object(fsub)
add_math_entrypoint_object(fsubl)
Expand Down Expand Up @@ -567,12 +569,14 @@ add_math_entrypoint_object(ufromfpf)
add_math_entrypoint_object(ufromfpl)
add_math_entrypoint_object(ufromfpf16)
add_math_entrypoint_object(ufromfpf128)
add_math_entrypoint_object(ufromfpbf16)

add_math_entrypoint_object(ufromfpx)
add_math_entrypoint_object(ufromfpxf)
add_math_entrypoint_object(ufromfpxl)
add_math_entrypoint_object(ufromfpxf16)
add_math_entrypoint_object(ufromfpxf128)
add_math_entrypoint_object(ufromfpxbf16)

add_math_entrypoint_object(bf16add)
add_math_entrypoint_object(bf16addf)
Expand Down
21 changes: 21 additions & 0 deletions libc/src/math/fromfpbf16.h
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@@ -0,0 +1,21 @@
//===-- Implementation header for fromfpbf16 --------------------*- 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_FROMFPBF16_H
#define LLVM_LIBC_SRC_MATH_FROMFPBF16_H

#include "src/__support/macros/config.h"
#include "src/__support/macros/properties/types.h"

namespace LIBC_NAMESPACE_DECL {

bfloat16 fromfpbf16(bfloat16 x, int rnd, unsigned int width);

} // namespace LIBC_NAMESPACE_DECL

#endif // LLVM_LIBC_SRC_MATH_FROMFPBF16_H
21 changes: 21 additions & 0 deletions libc/src/math/fromfpxbf16.h
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@@ -0,0 +1,21 @@
//===-- Implementation header for fromfpxbf16 -------------------*- 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_FROMFPXBF16_H
#define LLVM_LIBC_SRC_MATH_FROMFPXBF16_H

#include "src/__support/macros/config.h"
#include "src/__support/macros/properties/types.h"

namespace LIBC_NAMESPACE_DECL {

bfloat16 fromfpxbf16(bfloat16 x, int rnd, unsigned int width);

} // namespace LIBC_NAMESPACE_DECL

#endif // LLVM_LIBC_SRC_MATH_FROMFPXBF16_H
56 changes: 56 additions & 0 deletions libc/src/math/generic/CMakeLists.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -3745,6 +3745,20 @@ add_entrypoint_object(
libc.src.__support.FPUtil.nearest_integer_operations
)

add_entrypoint_object(
fromfpbf16
SRCS
fromfpbf16.cpp
HDRS
../fromfpbf16.h
DEPENDS
libc.src.__support.common
libc.src.__support.FPUtil.bfloat16
libc.src.__support.FPUtil.nearest_integer_operations
libc.src.__support.macros.config
libc.src.__support.macros.properties.types
)

add_entrypoint_object(
fromfpx
SRCS
Expand Down Expand Up @@ -3797,6 +3811,20 @@ add_entrypoint_object(
libc.src.__support.FPUtil.nearest_integer_operations
)

add_entrypoint_object(
fromfpxbf16
SRCS
fromfpxbf16.cpp
HDRS
../fromfpxbf16.h
DEPENDS
libc.src.__support.common
libc.src.__support.FPUtil.bfloat16
libc.src.__support.FPUtil.nearest_integer_operations
libc.src.__support.macros.config
libc.src.__support.macros.properties.types
)

add_entrypoint_object(
ufromfp
SRCS
Expand Down Expand Up @@ -3849,6 +3877,20 @@ add_entrypoint_object(
libc.src.__support.FPUtil.nearest_integer_operations
)

add_entrypoint_object(
ufromfpbf16
SRCS
ufromfpbf16.cpp
HDRS
../ufromfpbf16.h
DEPENDS
libc.src.__support.common
libc.src.__support.FPUtil.bfloat16
libc.src.__support.FPUtil.nearest_integer_operations
libc.src.__support.macros.config
libc.src.__support.macros.properties.types
)

add_entrypoint_object(
ufromfpx
SRCS
Expand Down Expand Up @@ -3901,6 +3943,20 @@ add_entrypoint_object(
libc.src.__support.FPUtil.nearest_integer_operations
)

add_entrypoint_object(
ufromfpxbf16
SRCS
ufromfpxbf16.cpp
HDRS
../ufromfpxbf16.h
DEPENDS
libc.src.__support.common
libc.src.__support.FPUtil.bfloat16
libc.src.__support.FPUtil.nearest_integer_operations
libc.src.__support.macros.config
libc.src.__support.macros.properties.types
)

add_entrypoint_object(
coshf
SRCS
Expand Down
22 changes: 22 additions & 0 deletions libc/src/math/generic/fromfpbf16.cpp
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@@ -0,0 +1,22 @@
//===-- Implementation of fromfpbf16 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/fromfpbf16.h"
#include "src/__support/FPUtil/NearestIntegerOperations.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, fromfpbf16,
(bfloat16 x, int rnd, unsigned int width)) {
return fputil::fromfp</*IsSigned=*/true>(x, rnd, width);
}

} // namespace LIBC_NAMESPACE_DECL
22 changes: 22 additions & 0 deletions libc/src/math/generic/fromfpxbf16.cpp
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@@ -0,0 +1,22 @@
//===-- Implementation of fromfpxbf16 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/fromfpxbf16.h"
#include "src/__support/FPUtil/NearestIntegerOperations.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, fromfpxbf16,
(bfloat16 x, int rnd, unsigned int width)) {
return fputil::fromfpx</*IsSigned=*/true>(x, rnd, width);
}

} // namespace LIBC_NAMESPACE_DECL
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