[libc-commits] [libc] [llvm] [libc][math] Refactor logbf128 to Header Only. (PR #176234)
via libc-commits
libc-commits at lists.llvm.org
Fri Jan 16 13:29:47 PST 2026
https://github.com/AnonMiraj updated https://github.com/llvm/llvm-project/pull/176234
>From d1b8e033a3ee329d4fe6f792d867da83ae23b0ba Mon Sep 17 00:00:00 2001
From: anonmiraj <nabilmalek48 at gmail.com>
Date: Thu, 15 Jan 2026 21:53:14 +0200
Subject: [PATCH 1/2] [libc][math] Refactor logbf128 to Header Only.
---
libc/shared/math.h | 1 +
libc/shared/math/logbf128.h | 30 ++++++++++++++++
libc/src/__support/math/CMakeLists.txt | 9 +++++
libc/src/__support/math/logbf128.h | 34 +++++++++++++++++++
libc/src/math/generic/CMakeLists.txt | 4 +--
libc/src/math/generic/logbf128.cpp | 9 +++--
libc/test/shared/CMakeLists.txt | 1 +
libc/test/shared/shared_math_test.cpp | 2 ++
.../llvm-project-overlay/libc/BUILD.bazel | 13 ++++++-
9 files changed, 95 insertions(+), 8 deletions(-)
create mode 100644 libc/shared/math/logbf128.h
create mode 100644 libc/src/__support/math/logbf128.h
diff --git a/libc/shared/math.h b/libc/shared/math.h
index 2e7bbe1ef13be..b75e60c4f1973 100644
--- a/libc/shared/math.h
+++ b/libc/shared/math.h
@@ -67,6 +67,7 @@
#include "math/ldexpf128.h"
#include "math/ldexpf16.h"
#include "math/log.h"
+#include "math/logbf128.h"
#include "math/rsqrtf.h"
#include "math/rsqrtf16.h"
#include "math/sin.h"
diff --git a/libc/shared/math/logbf128.h b/libc/shared/math/logbf128.h
new file mode 100644
index 0000000000000..c73725460922a
--- /dev/null
+++ b/libc/shared/math/logbf128.h
@@ -0,0 +1,30 @@
+//===-- Shared logbf128 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_MATH_LOGBF128_H
+#define LLVM_LIBC_SHARED_MATH_LOGBF128_H
+
+#include "include/llvm-libc-types/float128.h"
+
+#include "shared/libc_common.h"
+
+#ifdef LIBC_TYPES_HAS_FLOAT128
+
+#include "src/__support/math/logbf128.h"
+
+namespace LIBC_NAMESPACE_DECL {
+namespace shared {
+
+using math::logbf128;
+
+} // namespace shared
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LIBC_TYPES_HAS_FLOAT128
+
+#endif // LLVM_LIBC_SHARED_MATH_LOGBF128_H
diff --git a/libc/src/__support/math/CMakeLists.txt b/libc/src/__support/math/CMakeLists.txt
index b45ccfc0eb3cb..97852c8688182 100644
--- a/libc/src/__support/math/CMakeLists.txt
+++ b/libc/src/__support/math/CMakeLists.txt
@@ -1061,6 +1061,15 @@ add_header_library(
libc.src.__support.macros.optimization
)
+add_header_library(
+ logbf128
+ HDRS
+ logbf128.h
+ DEPENDS
+ libc.src.__support.FPUtil.manipulation_functions
+ libc.src.__support.macros.properties.types
+)
+
add_header_library(
log_range_reduction
HDRS
diff --git a/libc/src/__support/math/logbf128.h b/libc/src/__support/math/logbf128.h
new file mode 100644
index 0000000000000..d18efc5077ade
--- /dev/null
+++ b/libc/src/__support/math/logbf128.h
@@ -0,0 +1,34 @@
+//===-- Implementation header for logbf128-----------------------*- 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_MATH_LOGBF128_H
+#define LLVM_LIBC_SRC___SUPPORT_MATH_LOGBF128_H
+
+#include "include/llvm-libc-types/float128.h"
+
+#ifdef LIBC_TYPES_HAS_FLOAT128
+
+#include "src/__support/FPUtil/ManipulationFunctions.h"
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+namespace math {
+
+LIBC_INLINE static constexpr float128 logbf128(float128 x) {
+ return fputil::logb(x);
+}
+
+} // namespace math
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LIBC_TYPES_HAS_FLOAT128
+
+#endif // LLVM_LIBC_SRC___SUPPORT_MATH_LOGBF128_H
diff --git a/libc/src/math/generic/CMakeLists.txt b/libc/src/math/generic/CMakeLists.txt
index 009a3033083bd..6fb260a7523d4 100644
--- a/libc/src/math/generic/CMakeLists.txt
+++ b/libc/src/math/generic/CMakeLists.txt
@@ -2204,8 +2204,8 @@ add_entrypoint_object(
HDRS
../logbf128.h
DEPENDS
- libc.src.__support.macros.properties.types
- libc.src.__support.FPUtil.manipulation_functions
+ libc.src.__support.math.logbf128
+ libc.src.errno.errno
)
add_entrypoint_object(
diff --git a/libc/src/math/generic/logbf128.cpp b/libc/src/math/generic/logbf128.cpp
index af8348736c9f4..274c19994b3ad 100644
--- a/libc/src/math/generic/logbf128.cpp
+++ b/libc/src/math/generic/logbf128.cpp
@@ -7,12 +7,11 @@
//===----------------------------------------------------------------------===//
#include "src/math/logbf128.h"
-#include "src/__support/FPUtil/ManipulationFunctions.h"
-#include "src/__support/common.h"
-#include "src/__support/macros/config.h"
-
+#include "src/__support/math/logbf128.h"
namespace LIBC_NAMESPACE_DECL {
-LLVM_LIBC_FUNCTION(float128, logbf128, (float128 x)) { return fputil::logb(x); }
+LLVM_LIBC_FUNCTION(float128, logbf128, (float128 x)) {
+ return math::logbf128(x);
+}
} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/test/shared/CMakeLists.txt b/libc/test/shared/CMakeLists.txt
index 58214bf6f88eb..3a9bf9f8d4cf4 100644
--- a/libc/test/shared/CMakeLists.txt
+++ b/libc/test/shared/CMakeLists.txt
@@ -60,6 +60,7 @@ add_fp_unittest(
libc.src.__support.math.fsqrt
libc.src.__support.math.ilogbf16
libc.src.__support.math.log
+ libc.src.__support.math.logbf128
libc.src.__support.math.ldexpf
libc.src.__support.math.ldexpf128
libc.src.__support.math.ldexpf16
diff --git a/libc/test/shared/shared_math_test.cpp b/libc/test/shared/shared_math_test.cpp
index 6b78de0281347..918411efd7096 100644
--- a/libc/test/shared/shared_math_test.cpp
+++ b/libc/test/shared/shared_math_test.cpp
@@ -115,6 +115,8 @@ TEST(LlvmLibcSharedMathTest, AllFloat128) {
LIBC_NAMESPACE::shared::ldexpf128(float128(8), 5));
ASSERT_FP_EQ(float128(-1 * (8 << 5)),
LIBC_NAMESPACE::shared::ldexpf128(float128(-8), 5));
+
+ EXPECT_FP_EQ(float128(0.0), LIBC_NAMESPACE::shared::logbf128(float128(1.0)));
}
#endif // LIBC_TYPES_HAS_FLOAT128
diff --git a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
index 4251f20a5dfcf..f1d390207e45e 100644
--- a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
+++ b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
@@ -2906,6 +2906,14 @@ libc_support_library(
],
)
+libc_support_library(
+ name = "__support_math_logbf128",
+ hdrs = ["src/__support/math/logbf128.h"],
+ deps = [
+ ":__support_fputil_manipulation_functions",
+ ],
+)
+
libc_support_library(
name = "__support_math_exp_constants",
hdrs = ["src/__support/math/exp_constants.h"],
@@ -4546,7 +4554,10 @@ libc_math_function(name = "logbf")
libc_math_function(name = "logbl")
-libc_math_function(name = "logbf128")
+libc_math_function(
+ name = "logbf128",
+ additional_deps = [":__support_math_logbf128"],
+)
libc_math_function(name = "logbf16")
>From 8f473b198f81cd448e74fbe2116a4761cd3bf3a2 Mon Sep 17 00:00:00 2001
From: Anonmiraj <ezzibrahimx at gmail.com>
Date: Fri, 16 Jan 2026 23:29:40 +0200
Subject: [PATCH 2/2] Apply suggestion from @bassiounix
Co-authored-by: Muhammad Bassiouni <60100307+bassiounix at users.noreply.github.com>
---
libc/test/shared/shared_math_test.cpp | 1 -
1 file changed, 1 deletion(-)
diff --git a/libc/test/shared/shared_math_test.cpp b/libc/test/shared/shared_math_test.cpp
index 918411efd7096..84563d851a002 100644
--- a/libc/test/shared/shared_math_test.cpp
+++ b/libc/test/shared/shared_math_test.cpp
@@ -115,7 +115,6 @@ TEST(LlvmLibcSharedMathTest, AllFloat128) {
LIBC_NAMESPACE::shared::ldexpf128(float128(8), 5));
ASSERT_FP_EQ(float128(-1 * (8 << 5)),
LIBC_NAMESPACE::shared::ldexpf128(float128(-8), 5));
-
EXPECT_FP_EQ(float128(0.0), LIBC_NAMESPACE::shared::logbf128(float128(1.0)));
}
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