[libc-commits] [compiler-rt] [libc] [llvm] [Compiler-rt][builtins] introduce libc math routines (PR #197950)
via libc-commits
libc-commits at lists.llvm.org
Fri May 22 11:04:19 PDT 2026
https://github.com/hulxv updated https://github.com/llvm/llvm-project/pull/197950
>From 78326c920eadd4d7a511cace2d645f2615422075 Mon Sep 17 00:00:00 2001
From: hulxv <hulxxv at gmail.com>
Date: Sun, 17 May 2026 02:12:46 +0300
Subject: [PATCH 1/6] [Compiler-rt][builtins] introduce libc math routines
---
.github/workflows/libc-overlay-tests.yml | 9 ++++-
compiler-rt/lib/builtins/CMakeLists.txt | 17 +++++++++-
.../lib/builtins/{addtf3.c => addtf3.cpp} | 20 ++++++++---
compiler-rt/lib/builtins/fp_libc_config.h | 12 +++++++
compiler-rt/lib/builtins/int_lib.h | 14 ++++++--
libc/shared/builtins.h | 16 +++++++++
libc/shared/builtins/addtf3.h | 29 ++++++++++++++++
libc/src/__support/CMakeLists.txt | 1 +
libc/src/__support/FPUtil/dyadic_float.h | 3 ++
libc/src/__support/builtins/CMakeLists.txt | 9 +++++
libc/src/__support/builtins/addtf3.h | 33 +++++++++++++++++++
11 files changed, 154 insertions(+), 9 deletions(-)
rename compiler-rt/lib/builtins/{addtf3.c => addtf3.cpp} (67%)
create mode 100644 compiler-rt/lib/builtins/fp_libc_config.h
create mode 100644 libc/shared/builtins.h
create mode 100644 libc/shared/builtins/addtf3.h
create mode 100644 libc/src/__support/builtins/CMakeLists.txt
create mode 100644 libc/src/__support/builtins/addtf3.h
diff --git a/.github/workflows/libc-overlay-tests.yml b/.github/workflows/libc-overlay-tests.yml
index f63150983aa03..2974634cb6d3e 100644
--- a/.github/workflows/libc-overlay-tests.yml
+++ b/.github/workflows/libc-overlay-tests.yml
@@ -109,9 +109,16 @@ jobs:
--parallel
--target libc
- - name: Test
+ - name: Test libc
run: >
cmake
--build ${{ steps.strings.outputs.build-output-dir }}
--parallel
--target check-libc
+
+ - name: Test Compiler-rt builtins
+ run: >
+ cmake
+ --build ${{ steps.strings.outputs.build-output-dir }}
+ --parallel
+ --target check-builtins
diff --git a/compiler-rt/lib/builtins/CMakeLists.txt b/compiler-rt/lib/builtins/CMakeLists.txt
index 3fa21578c86ad..2843d0870f39c 100644
--- a/compiler-rt/lib/builtins/CMakeLists.txt
+++ b/compiler-rt/lib/builtins/CMakeLists.txt
@@ -215,7 +215,7 @@ set(BF16_SOURCES
)
set(GENERIC_TF_SOURCES
- addtf3.c
+ addtf3.cpp
comparetf2.c
divtc3.c
divtf3.c
@@ -243,6 +243,21 @@ set(GENERIC_TF_SOURCES
trunctfsf2.c
)
+option(COMPILER_RT_USE_LIBC_MATH
+ "Use LLVM libc math routines for floating-point builtins" OFF)
+
+if(COMPILER_RT_USE_LIBC_MATH)
+ set(LLVM_LIBC_SRC_DIR "${CMAKE_CURRENT_SOURCE_DIR}/../../../libc"
+ CACHE PATH "Path to LLVM libc source directory")
+
+ if(NOT EXISTS "${LLVM_LIBC_SRC_DIR}/src/__support/FPUtil/FPBits.h")
+ message(FATAL_ERROR "LLVM libc not found at ${LLVM_LIBC_SRC_DIR}")
+ endif()
+
+ include_directories(SYSTEM ${LLVM_LIBC_SRC_DIR})
+ add_definitions(-DCOMPILER_RT_USE_LIBC_MATH)
+endif()
+
option(COMPILER_RT_EXCLUDE_ATOMIC_BUILTIN
"Skip the atomic builtin (these should normally be provided by a shared library)"
On)
diff --git a/compiler-rt/lib/builtins/addtf3.c b/compiler-rt/lib/builtins/addtf3.cpp
similarity index 67%
rename from compiler-rt/lib/builtins/addtf3.c
rename to compiler-rt/lib/builtins/addtf3.cpp
index 2cb3a4d591917..f8d0f72a4357d 100644
--- a/compiler-rt/lib/builtins/addtf3.c
+++ b/compiler-rt/lib/builtins/addtf3.cpp
@@ -13,11 +13,23 @@
#define QUAD_PRECISION
#include "fp_lib.h"
-#if defined(CRT_HAS_TF_MODE)
-#include "fp_add_impl.inc"
+#ifdef COMPILER_RT_USE_LIBC_MATH
+
+#include "fp_libc_config.h"
+#include "int_lib.h"
+#include "shared/builtins/addtf3.h"
COMPILER_RT_ABI fp_t __addtf3(fp_t a, fp_t b) {
- return __addXf3__(a, b);
+ return LIBC_NAMESPACE::shared::addtf3(a, b);
}
-#endif
+#else
+
+#include "fp_add_impl.inc"
+#if defined(CRT_HAS_TF_MODE)
+
+COMPILER_RT_ABI fp_t __addtf3(fp_t a, fp_t b) { return __addXf3__(a, b); }
+
+#endif // defined(CRT_HAS_TF_MODE)
+
+#endif // COMPILER_RT_USE_LIBC_MATH
\ No newline at end of file
diff --git a/compiler-rt/lib/builtins/fp_libc_config.h b/compiler-rt/lib/builtins/fp_libc_config.h
new file mode 100644
index 0000000000000..1dc69a9f95167
--- /dev/null
+++ b/compiler-rt/lib/builtins/fp_libc_config.h
@@ -0,0 +1,12 @@
+#ifndef FP_LIBC_CONFIG_H
+#define FP_LIBC_CONFIG_H
+
+#ifndef LIBC_COPT_PUBLIC_PACKAGING
+#define LIBC_COPT_PUBLIC_PACKAGING
+#endif
+
+#ifndef LIBC_NAMESPACE
+#define LIBC_NAMESPACE __llvm_libc_rt
+#endif
+
+#endif
\ No newline at end of file
diff --git a/compiler-rt/lib/builtins/int_lib.h b/compiler-rt/lib/builtins/int_lib.h
index 629c3065da6a0..8e76985134d94 100644
--- a/compiler-rt/lib/builtins/int_lib.h
+++ b/compiler-rt/lib/builtins/int_lib.h
@@ -20,14 +20,22 @@
// ABI macro definitions
+// In C++ translation units we must give compiler-rt entry points C linkage so
+// that their symbol names are not mangled. C TUs are unaffected.
+#ifdef __cplusplus
+#define COMPILER_RT_C_LINKAGE extern "C"
+#else
+#define COMPILER_RT_C_LINKAGE
+#endif
+
#if __ARM_EABI__
#ifdef COMPILER_RT_ARMHF_TARGET
-#define COMPILER_RT_ABI
+#define COMPILER_RT_ABI COMPILER_RT_C_LINKAGE
#else
-#define COMPILER_RT_ABI __attribute__((__pcs__("aapcs")))
+#define COMPILER_RT_ABI COMPILER_RT_C_LINKAGE __attribute__((__pcs__("aapcs")))
#endif
#else
-#define COMPILER_RT_ABI
+#define COMPILER_RT_ABI COMPILER_RT_C_LINKAGE
#endif
#define AEABI_RTABI __attribute__((__pcs__("aapcs")))
diff --git a/libc/shared/builtins.h b/libc/shared/builtins.h
new file mode 100644
index 0000000000000..157b6622cbcff
--- /dev/null
+++ b/libc/shared/builtins.h
@@ -0,0 +1,16 @@
+//===-- Compiler-runtime builtin primitives ---------------------*- 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_SHARED_BUILTINS_H
+#define LLVM_LIBC_SHARED_BUILTINS_H
+
+#include "libc_common.h"
+
+#include "builtins/addtf3.h"
+
+#endif // LLVM_LIBC_SHARED_BUILTINS_H
diff --git a/libc/shared/builtins/addtf3.h b/libc/shared/builtins/addtf3.h
new file mode 100644
index 0000000000000..5dfda22d929b7
--- /dev/null
+++ b/libc/shared/builtins/addtf3.h
@@ -0,0 +1,29 @@
+//===-- Shared __addtf3 function -------------------------------*- 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_SHARED_BUILTINS_ADDTF3_H
+#define LLVM_LIBC_SHARED_BUILTINS_ADDTF3_H
+
+#include "include/llvm-libc-types/float128.h"
+
+#ifdef LIBC_TYPES_HAS_FLOAT128
+
+#include "shared/libc_common.h"
+#include "src/__support/builtins/addtf3.h"
+
+namespace LIBC_NAMESPACE_DECL {
+namespace shared {
+
+using builtins::addtf3;
+
+} // namespace shared
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LIBC_TYPES_HAS_FLOAT128
+
+#endif // LLVM_LIBC_SHARED_BUILTINS_ADDTF3_H
diff --git a/libc/src/__support/CMakeLists.txt b/libc/src/__support/CMakeLists.txt
index ada489046ef9e..0246bcd8f01b6 100644
--- a/libc/src/__support/CMakeLists.txt
+++ b/libc/src/__support/CMakeLists.txt
@@ -470,6 +470,7 @@ add_subdirectory(wchar)
add_subdirectory(wctype)
add_subdirectory(math)
+add_subdirectory(builtins)
if(LIBC_COMPILER_HAS_EXT_VECTOR_TYPE)
add_subdirectory(mathvec)
endif()
diff --git a/libc/src/__support/FPUtil/dyadic_float.h b/libc/src/__support/FPUtil/dyadic_float.h
index 8ce041247716b..04e7c0c34859b 100644
--- a/libc/src/__support/FPUtil/dyadic_float.h
+++ b/libc/src/__support/FPUtil/dyadic_float.h
@@ -415,6 +415,9 @@ template <size_t Bits> struct DyadicFloat {
if constexpr (cpp::is_same_v<T, bfloat16>
#if defined(LIBC_TYPES_HAS_FLOAT16) && !defined(__LIBC_USE_FLOAT16_CONVERSION)
|| cpp::is_same_v<T, float16>
+#endif
+#if defined(LIBC_TYPES_HAS_FLOAT128)
+ || cpp::is_same_v<T, float128>
#endif
)
return generic_as<T, ShouldSignalExceptions>();
diff --git a/libc/src/__support/builtins/CMakeLists.txt b/libc/src/__support/builtins/CMakeLists.txt
new file mode 100644
index 0000000000000..c4982887d0a7c
--- /dev/null
+++ b/libc/src/__support/builtins/CMakeLists.txt
@@ -0,0 +1,9 @@
+add_header_library(
+ addtf3
+ HDRS
+ addtf3.h
+ DEPENDS
+ libc.include.llvm-libc-types.float128
+ libc.src.__support.FPUtil.generic.add_sub
+ libc.src.__support.macros.config
+)
diff --git a/libc/src/__support/builtins/addtf3.h b/libc/src/__support/builtins/addtf3.h
new file mode 100644
index 0000000000000..f2c5b5332e877
--- /dev/null
+++ b/libc/src/__support/builtins/addtf3.h
@@ -0,0 +1,33 @@
+//===-- Implementation header for __addtf3 ----------------------*- 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___SUPPORT_BUILTINS_ADDTF3_H
+#define LLVM_LIBC_SRC___SUPPORT_BUILTINS_ADDTF3_H
+
+#include "include/llvm-libc-types/float128.h"
+
+#ifdef LIBC_TYPES_HAS_FLOAT128
+
+#include "src/__support/FPUtil/generic/add_sub.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+namespace builtins {
+
+// Same-precision quad-precision addition.
+// Mirrors the compiler-rt __addtf3 ABI: a + b at float128 precision.
+LIBC_INLINE float128 addtf3(float128 x, float128 y) {
+ return fputil::generic::add<float128>(x, y);
+}
+
+} // namespace builtins
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LIBC_TYPES_HAS_FLOAT128
+
+#endif // LLVM_LIBC_SRC___SUPPORT_BUILTINS_ADDTF3_H
>From c1fc00bcf16b05df96ff36214b9ea0f5887793ae Mon Sep 17 00:00:00 2001
From: hulxv <hulxxv at gmail.com>
Date: Mon, 18 May 2026 20:58:47 +0300
Subject: [PATCH 2/6] fix the ci
---
.../compiler-rt-libc-builtins-tests.yml | 57 +++++++++++++++++++
.github/workflows/libc-overlay-tests.yml | 9 +--
2 files changed, 58 insertions(+), 8 deletions(-)
create mode 100644 .github/workflows/compiler-rt-libc-builtins-tests.yml
diff --git a/.github/workflows/compiler-rt-libc-builtins-tests.yml b/.github/workflows/compiler-rt-libc-builtins-tests.yml
new file mode 100644
index 0000000000000..613a932b9ce50
--- /dev/null
+++ b/.github/workflows/compiler-rt-libc-builtins-tests.yml
@@ -0,0 +1,57 @@
+# Pre-commit CI for the compiler-rt + LLVM-libc builtins integration.
+name: compiler-rt + libc Builtins Tests
+permissions:
+ contents: read
+on:
+ pull_request:
+ branches: ["main"]
+ paths:
+ - "compiler-rt/lib/builtins/**"
+ - "compiler-rt/test/builtins/**"
+ - "libc/shared/builtins.h"
+ - "libc/shared/builtins/**"
+ - "libc/src/__support/builtins/**"
+ - "libc/src/__support/FPUtil/**"
+ - ".github/workflows/compiler-rt-libc-builtins-tests.yml"
+
+jobs:
+ build:
+ name: builtins (${{ matrix.os }})
+ runs-on: ${{ matrix.os }}
+ container:
+ image: ${{ (startsWith(matrix.os, 'ubuntu-24.04-arm') && 'ghcr.io/llvm/arm64v8/libc-ubuntu-24.04') || 'ghcr.io/llvm/libc-ubuntu-24.04' }}
+ options: >-
+ --privileged
+ strategy:
+ fail-fast: false
+ matrix:
+ os: [ubuntu-24.04, ubuntu-24.04-arm]
+
+ steps:
+ - uses: actions/checkout at de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+ with:
+ persist-credentials: false
+
+ - name: Configure CMake
+ shell: bash
+ run: |
+ cmake \
+ -B /__w/llvm-project/llvm-project/build \
+ -S /__w/llvm-project/llvm-project/llvm \
+ -G Ninja \
+ -DCMAKE_C_COMPILER=clang-23 \
+ -DCMAKE_CXX_COMPILER=clang++-23 \
+ -DCMAKE_BUILD_TYPE=Release \
+ -DLLVM_ENABLE_ASSERTIONS=ON \
+ -DLLVM_ENABLE_PROJECTS=clang \
+ -DLLVM_ENABLE_RUNTIMES="libc;compiler-rt" \
+ -DCOMPILER_RT_USE_LIBC_MATH=ON \
+ -DCOMPILER_RT_INCLUDE_TESTS=ON
+
+ - name: Test compiler-rt builtins
+ shell: bash
+ run: |
+ cmake \
+ --build /__w/llvm-project/llvm-project/build \
+ --parallel \
+ --target check-builtins
diff --git a/.github/workflows/libc-overlay-tests.yml b/.github/workflows/libc-overlay-tests.yml
index 2974634cb6d3e..f63150983aa03 100644
--- a/.github/workflows/libc-overlay-tests.yml
+++ b/.github/workflows/libc-overlay-tests.yml
@@ -109,16 +109,9 @@ jobs:
--parallel
--target libc
- - name: Test libc
+ - name: Test
run: >
cmake
--build ${{ steps.strings.outputs.build-output-dir }}
--parallel
--target check-libc
-
- - name: Test Compiler-rt builtins
- run: >
- cmake
- --build ${{ steps.strings.outputs.build-output-dir }}
- --parallel
- --target check-builtins
>From ea0bb8cfb14d9e1567ac86f00f5d11f47b3e36b2 Mon Sep 17 00:00:00 2001
From: hulxv <hulxxv at gmail.com>
Date: Tue, 19 May 2026 23:17:19 +0300
Subject: [PATCH 3/6] keep c builtin file
---
compiler-rt/lib/builtins/CMakeLists.txt | 19 ++++++++++++-------
compiler-rt/lib/builtins/addtf3.c | 23 +++++++++++++++++++++++
compiler-rt/lib/builtins/addtf3.cpp | 17 ++---------------
3 files changed, 37 insertions(+), 22 deletions(-)
create mode 100644 compiler-rt/lib/builtins/addtf3.c
diff --git a/compiler-rt/lib/builtins/CMakeLists.txt b/compiler-rt/lib/builtins/CMakeLists.txt
index 2843d0870f39c..015b87e4061e6 100644
--- a/compiler-rt/lib/builtins/CMakeLists.txt
+++ b/compiler-rt/lib/builtins/CMakeLists.txt
@@ -215,7 +215,7 @@ set(BF16_SOURCES
)
set(GENERIC_TF_SOURCES
- addtf3.cpp
+ addtf3.c
comparetf2.c
divtc3.c
divtf3.c
@@ -247,15 +247,20 @@ option(COMPILER_RT_USE_LIBC_MATH
"Use LLVM libc math routines for floating-point builtins" OFF)
if(COMPILER_RT_USE_LIBC_MATH)
- set(LLVM_LIBC_SRC_DIR "${CMAKE_CURRENT_SOURCE_DIR}/../../../libc"
- CACHE PATH "Path to LLVM libc source directory")
-
- if(NOT EXISTS "${LLVM_LIBC_SRC_DIR}/src/__support/FPUtil/FPBits.h")
- message(FATAL_ERROR "LLVM libc not found at ${LLVM_LIBC_SRC_DIR}")
+ include(FindLibcCommonUtils)
+ if(NOT TARGET llvm-libc-common-utilities)
+ message(FATAL_ERROR "LLVM libc is not found at ${libc_path}.")
endif()
- include_directories(SYSTEM ${LLVM_LIBC_SRC_DIR})
+ get_target_property(_libc_include_dirs llvm-libc-common-utilities
+ INTERFACE_INCLUDE_DIRECTORIES)
+ include_directories(SYSTEM ${_libc_include_dirs})
add_definitions(-DCOMPILER_RT_USE_LIBC_MATH)
+
+ # Swap the legacy soft-float .c builtins for the libc-backed .cpp
+ # implementations (which delegate to LIBC_NAMESPACE::shared::*).
+ list(REMOVE_ITEM GENERIC_TF_SOURCES addtf3.c)
+ list(APPEND GENERIC_TF_SOURCES addtf3.cpp)
endif()
option(COMPILER_RT_EXCLUDE_ATOMIC_BUILTIN
diff --git a/compiler-rt/lib/builtins/addtf3.c b/compiler-rt/lib/builtins/addtf3.c
new file mode 100644
index 0000000000000..2cb3a4d591917
--- /dev/null
+++ b/compiler-rt/lib/builtins/addtf3.c
@@ -0,0 +1,23 @@
+//===-- lib/addtf3.c - Quad-precision addition --------------------*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements quad-precision soft-float addition.
+//
+//===----------------------------------------------------------------------===//
+
+#define QUAD_PRECISION
+#include "fp_lib.h"
+
+#if defined(CRT_HAS_TF_MODE)
+#include "fp_add_impl.inc"
+
+COMPILER_RT_ABI fp_t __addtf3(fp_t a, fp_t b) {
+ return __addXf3__(a, b);
+}
+
+#endif
diff --git a/compiler-rt/lib/builtins/addtf3.cpp b/compiler-rt/lib/builtins/addtf3.cpp
index f8d0f72a4357d..ded906bac2ab0 100644
--- a/compiler-rt/lib/builtins/addtf3.cpp
+++ b/compiler-rt/lib/builtins/addtf3.cpp
@@ -1,4 +1,4 @@
-//===-- lib/addtf3.c - Quad-precision addition --------------------*- C -*-===//
+//===-- lib/addtf3.cpp - Quad-precision addition (libc-backed) --*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
@@ -6,15 +6,13 @@
//
//===----------------------------------------------------------------------===//
//
-// This file implements quad-precision soft-float addition.
+// __addtf3 implemented on top of LLVM-libc's shared::addtf3 instruction.
//
//===----------------------------------------------------------------------===//
#define QUAD_PRECISION
#include "fp_lib.h"
-#ifdef COMPILER_RT_USE_LIBC_MATH
-
#include "fp_libc_config.h"
#include "int_lib.h"
#include "shared/builtins/addtf3.h"
@@ -22,14 +20,3 @@
COMPILER_RT_ABI fp_t __addtf3(fp_t a, fp_t b) {
return LIBC_NAMESPACE::shared::addtf3(a, b);
}
-
-#else
-
-#include "fp_add_impl.inc"
-#if defined(CRT_HAS_TF_MODE)
-
-COMPILER_RT_ABI fp_t __addtf3(fp_t a, fp_t b) { return __addXf3__(a, b); }
-
-#endif // defined(CRT_HAS_TF_MODE)
-
-#endif // COMPILER_RT_USE_LIBC_MATH
\ No newline at end of file
>From 820f4984e351d2609e4349a5b9ecafa8dd88d6c3 Mon Sep 17 00:00:00 2001
From: hulxv <hulxxv at gmail.com>
Date: Wed, 20 May 2026 01:32:08 +0300
Subject: [PATCH 4/6] nits
---
.github/workflows/compiler-rt-libc-builtins-tests.yml | 8 ++++----
compiler-rt/lib/builtins/fp_libc_config.h | 4 ----
2 files changed, 4 insertions(+), 8 deletions(-)
diff --git a/.github/workflows/compiler-rt-libc-builtins-tests.yml b/.github/workflows/compiler-rt-libc-builtins-tests.yml
index 613a932b9ce50..a6436eab150f8 100644
--- a/.github/workflows/compiler-rt-libc-builtins-tests.yml
+++ b/.github/workflows/compiler-rt-libc-builtins-tests.yml
@@ -36,15 +36,15 @@ jobs:
shell: bash
run: |
cmake \
- -B /__w/llvm-project/llvm-project/build \
- -S /__w/llvm-project/llvm-project/llvm \
+ -B build \
+ -S llvm \
-G Ninja \
-DCMAKE_C_COMPILER=clang-23 \
-DCMAKE_CXX_COMPILER=clang++-23 \
-DCMAKE_BUILD_TYPE=Release \
-DLLVM_ENABLE_ASSERTIONS=ON \
-DLLVM_ENABLE_PROJECTS=clang \
- -DLLVM_ENABLE_RUNTIMES="libc;compiler-rt" \
+ -DLLVM_ENABLE_RUNTIMES="compiler-rt" \
-DCOMPILER_RT_USE_LIBC_MATH=ON \
-DCOMPILER_RT_INCLUDE_TESTS=ON
@@ -52,6 +52,6 @@ jobs:
shell: bash
run: |
cmake \
- --build /__w/llvm-project/llvm-project/build \
+ --build build \
--parallel \
--target check-builtins
diff --git a/compiler-rt/lib/builtins/fp_libc_config.h b/compiler-rt/lib/builtins/fp_libc_config.h
index 1dc69a9f95167..827bc7aed9f82 100644
--- a/compiler-rt/lib/builtins/fp_libc_config.h
+++ b/compiler-rt/lib/builtins/fp_libc_config.h
@@ -1,10 +1,6 @@
#ifndef FP_LIBC_CONFIG_H
#define FP_LIBC_CONFIG_H
-#ifndef LIBC_COPT_PUBLIC_PACKAGING
-#define LIBC_COPT_PUBLIC_PACKAGING
-#endif
-
#ifndef LIBC_NAMESPACE
#define LIBC_NAMESPACE __llvm_libc_rt
#endif
>From 124431895832c45e0dd4c06151800aad5b530531 Mon Sep 17 00:00:00 2001
From: hulxv <hulxxv at gmail.com>
Date: Fri, 22 May 2026 19:00:06 +0300
Subject: [PATCH 5/6] some nits
---
compiler-rt/lib/builtins/addtf3.cpp | 2 +-
compiler-rt/lib/builtins/fp_libc_config.h | 2 ++
compiler-rt/lib/builtins/int_lib.h | 14 +++-----------
libc/shared/builtins/addtf3.h | 6 ++++++
4 files changed, 12 insertions(+), 12 deletions(-)
diff --git a/compiler-rt/lib/builtins/addtf3.cpp b/compiler-rt/lib/builtins/addtf3.cpp
index ded906bac2ab0..ae4dbd5772cfb 100644
--- a/compiler-rt/lib/builtins/addtf3.cpp
+++ b/compiler-rt/lib/builtins/addtf3.cpp
@@ -17,6 +17,6 @@
#include "int_lib.h"
#include "shared/builtins/addtf3.h"
-COMPILER_RT_ABI fp_t __addtf3(fp_t a, fp_t b) {
+extern "C" COMPILER_RT_ABI fp_t __addtf3(fp_t a, fp_t b) {
return LIBC_NAMESPACE::shared::addtf3(a, b);
}
diff --git a/compiler-rt/lib/builtins/fp_libc_config.h b/compiler-rt/lib/builtins/fp_libc_config.h
index 827bc7aed9f82..74d7bdbaa4a61 100644
--- a/compiler-rt/lib/builtins/fp_libc_config.h
+++ b/compiler-rt/lib/builtins/fp_libc_config.h
@@ -5,4 +5,6 @@
#define LIBC_NAMESPACE __llvm_libc_rt
#endif
+#define LIBC_MATH (LIBC_MATH_NO_ERRNO | LIBC_MATH_NO_EXCEPT)
+
#endif
\ No newline at end of file
diff --git a/compiler-rt/lib/builtins/int_lib.h b/compiler-rt/lib/builtins/int_lib.h
index 8e76985134d94..629c3065da6a0 100644
--- a/compiler-rt/lib/builtins/int_lib.h
+++ b/compiler-rt/lib/builtins/int_lib.h
@@ -20,22 +20,14 @@
// ABI macro definitions
-// In C++ translation units we must give compiler-rt entry points C linkage so
-// that their symbol names are not mangled. C TUs are unaffected.
-#ifdef __cplusplus
-#define COMPILER_RT_C_LINKAGE extern "C"
-#else
-#define COMPILER_RT_C_LINKAGE
-#endif
-
#if __ARM_EABI__
#ifdef COMPILER_RT_ARMHF_TARGET
-#define COMPILER_RT_ABI COMPILER_RT_C_LINKAGE
+#define COMPILER_RT_ABI
#else
-#define COMPILER_RT_ABI COMPILER_RT_C_LINKAGE __attribute__((__pcs__("aapcs")))
+#define COMPILER_RT_ABI __attribute__((__pcs__("aapcs")))
#endif
#else
-#define COMPILER_RT_ABI COMPILER_RT_C_LINKAGE
+#define COMPILER_RT_ABI
#endif
#define AEABI_RTABI __attribute__((__pcs__("aapcs")))
diff --git a/libc/shared/builtins/addtf3.h b/libc/shared/builtins/addtf3.h
index 5dfda22d929b7..9c39e6e9a8406 100644
--- a/libc/shared/builtins/addtf3.h
+++ b/libc/shared/builtins/addtf3.h
@@ -5,6 +5,12 @@
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
+//
+// This header exposes LLVM-libc's __addtf3 implementation as shared::addtf3
+// so that it can be reused by other LLVM projects, such as compiler-rt's
+// builtins library.
+//
+//===----------------------------------------------------------------------===//
#ifndef LLVM_LIBC_SHARED_BUILTINS_ADDTF3_H
#define LLVM_LIBC_SHARED_BUILTINS_ADDTF3_H
>From 3fdc423850c126c0052e3e4f57a1af7fddc3b58e Mon Sep 17 00:00:00 2001
From: hulxv <hulxxv at gmail.com>
Date: Fri, 22 May 2026 21:03:58 +0300
Subject: [PATCH 6/6] add adddf3
---
compiler-rt/lib/builtins/CMakeLists.txt | 14 ++++++++---
compiler-rt/lib/builtins/adddf3.cpp | 19 ++++++++++++++
libc/shared/builtins.h | 1 +
libc/shared/builtins/adddf3.h | 29 ++++++++++++++++++++++
libc/src/__support/builtins/CMakeLists.txt | 9 +++++++
libc/src/__support/builtins/adddf3.h | 27 ++++++++++++++++++++
6 files changed, 95 insertions(+), 4 deletions(-)
create mode 100644 compiler-rt/lib/builtins/adddf3.cpp
create mode 100644 libc/shared/builtins/adddf3.h
create mode 100644 libc/src/__support/builtins/adddf3.h
diff --git a/compiler-rt/lib/builtins/CMakeLists.txt b/compiler-rt/lib/builtins/CMakeLists.txt
index 015b87e4061e6..ff46a515ce77b 100644
--- a/compiler-rt/lib/builtins/CMakeLists.txt
+++ b/compiler-rt/lib/builtins/CMakeLists.txt
@@ -246,6 +246,14 @@ set(GENERIC_TF_SOURCES
option(COMPILER_RT_USE_LIBC_MATH
"Use LLVM libc math routines for floating-point builtins" OFF)
+# Swap the legacy soft-float <name>.c builtin in <list> for the libc-backed
+# <name>.cpp implementation (which delegates to LIBC_NAMESPACE::shared::*).
+# A macro -- not a function -- so list() mutates the caller's variable.
+macro(use_libc_builtin list_var name)
+ list(REMOVE_ITEM ${list_var} ${name}.c)
+ list(APPEND ${list_var} ${name}.cpp)
+endmacro()
+
if(COMPILER_RT_USE_LIBC_MATH)
include(FindLibcCommonUtils)
if(NOT TARGET llvm-libc-common-utilities)
@@ -257,10 +265,8 @@ if(COMPILER_RT_USE_LIBC_MATH)
include_directories(SYSTEM ${_libc_include_dirs})
add_definitions(-DCOMPILER_RT_USE_LIBC_MATH)
- # Swap the legacy soft-float .c builtins for the libc-backed .cpp
- # implementations (which delegate to LIBC_NAMESPACE::shared::*).
- list(REMOVE_ITEM GENERIC_TF_SOURCES addtf3.c)
- list(APPEND GENERIC_TF_SOURCES addtf3.cpp)
+ use_libc_builtin(GENERIC_TF_SOURCES addtf3)
+ use_libc_builtin(GENERIC_SOURCES adddf3)
endif()
option(COMPILER_RT_EXCLUDE_ATOMIC_BUILTIN
diff --git a/compiler-rt/lib/builtins/adddf3.cpp b/compiler-rt/lib/builtins/adddf3.cpp
new file mode 100644
index 0000000000000..7fd6a722bfeab
--- /dev/null
+++ b/compiler-rt/lib/builtins/adddf3.cpp
@@ -0,0 +1,19 @@
+//===-- lib/adddf3.cpp - Double-precision addition (libc-backed) *- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// __adddf3 implemented on top of LLVM-libc's shared::adddf3 instruction.
+//
+//===----------------------------------------------------------------------===//
+
+#include "fp_libc_config.h"
+#include "int_lib.h"
+#include "shared/builtins/adddf3.h"
+
+extern "C" COMPILER_RT_ABI double __adddf3(double a, double b) {
+ return LIBC_NAMESPACE::shared::adddf3(a, b);
+}
diff --git a/libc/shared/builtins.h b/libc/shared/builtins.h
index 157b6622cbcff..d1812ae357bbc 100644
--- a/libc/shared/builtins.h
+++ b/libc/shared/builtins.h
@@ -11,6 +11,7 @@
#include "libc_common.h"
+#include "builtins/adddf3.h"
#include "builtins/addtf3.h"
#endif // LLVM_LIBC_SHARED_BUILTINS_H
diff --git a/libc/shared/builtins/adddf3.h b/libc/shared/builtins/adddf3.h
new file mode 100644
index 0000000000000..ae27fd8bdd5f5
--- /dev/null
+++ b/libc/shared/builtins/adddf3.h
@@ -0,0 +1,29 @@
+//===-- Shared __adddf3 function -------------------------------*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This header exposes LLVM-libc's __adddf3 implementation as shared::adddf3
+// so that it can be reused by other LLVM projects, such as compiler-rt's
+// builtins library.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SHARED_BUILTINS_ADDDF3_H
+#define LLVM_LIBC_SHARED_BUILTINS_ADDDF3_H
+
+#include "shared/libc_common.h"
+#include "src/__support/builtins/adddf3.h"
+
+namespace LIBC_NAMESPACE_DECL {
+namespace shared {
+
+using builtins::adddf3;
+
+} // namespace shared
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SHARED_BUILTINS_ADDDF3_H
diff --git a/libc/src/__support/builtins/CMakeLists.txt b/libc/src/__support/builtins/CMakeLists.txt
index c4982887d0a7c..384e1d079e54b 100644
--- a/libc/src/__support/builtins/CMakeLists.txt
+++ b/libc/src/__support/builtins/CMakeLists.txt
@@ -7,3 +7,12 @@ add_header_library(
libc.src.__support.FPUtil.generic.add_sub
libc.src.__support.macros.config
)
+
+add_header_library(
+ adddf3
+ HDRS
+ adddf3.h
+ DEPENDS
+ libc.src.__support.FPUtil.generic.add_sub
+ libc.src.__support.macros.config
+)
diff --git a/libc/src/__support/builtins/adddf3.h b/libc/src/__support/builtins/adddf3.h
new file mode 100644
index 0000000000000..e3e907b3164ef
--- /dev/null
+++ b/libc/src/__support/builtins/adddf3.h
@@ -0,0 +1,27 @@
+//===-- Implementation header for __adddf3 ----------------------*- 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___SUPPORT_BUILTINS_ADDDF3_H
+#define LLVM_LIBC_SRC___SUPPORT_BUILTINS_ADDDF3_H
+
+#include "src/__support/FPUtil/generic/add_sub.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+namespace builtins {
+
+// Same-precision double-precision addition.
+// Mirrors the compiler-rt __adddf3 ABI: a + b at double precision.
+LIBC_INLINE double adddf3(double x, double y) {
+ return fputil::generic::add<double>(x, y);
+}
+
+} // namespace builtins
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC___SUPPORT_BUILTINS_ADDDF3_H
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