[libc-commits] [libc] [llvm] [libc][math] Refactor logbf to Header Only. (PR #176222)
via libc-commits
libc-commits at lists.llvm.org
Thu Jan 15 10:59:30 PST 2026
https://github.com/AnonMiraj created https://github.com/llvm/llvm-project/pull/176222
builds with both Clang and GCC 12.2.
Closes https://github.com/llvm/llvm-project/issues/175364.
CC @bassiounix
>From 9f2c1f1869b355b370c539fc17d251f12d708661 Mon Sep 17 00:00:00 2001
From: anonmiraj <nabilmalek48 at gmail.com>
Date: Thu, 15 Jan 2026 20:47:03 +0200
Subject: [PATCH] [libc][math] Refactor logbf to Header Only.
---
libc/shared/math.h | 1 +
libc/shared/math/logbf.h | 25 +++++++++++++++++
libc/src/__support/math/CMakeLists.txt | 9 +++++++
libc/src/__support/math/logbf.h | 27 +++++++++++++++++++
libc/src/math/generic/CMakeLists.txt | 3 ++-
libc/src/math/generic/logbf.cpp | 7 ++---
libc/test/shared/CMakeLists.txt | 1 +
libc/test/shared/shared_math_test.cpp | 1 +
.../llvm-project-overlay/libc/BUILD.bazel | 16 ++++++++++-
9 files changed, 83 insertions(+), 7 deletions(-)
create mode 100644 libc/shared/math/logbf.h
create mode 100644 libc/src/__support/math/logbf.h
diff --git a/libc/shared/math.h b/libc/shared/math.h
index 287f3aea1565a..9c3af982efcb4 100644
--- a/libc/shared/math.h
+++ b/libc/shared/math.h
@@ -65,6 +65,7 @@
#include "math/ldexpf128.h"
#include "math/ldexpf16.h"
#include "math/log.h"
+#include "math/logbf.h"
#include "math/rsqrtf.h"
#include "math/rsqrtf16.h"
#include "math/sin.h"
diff --git a/libc/shared/math/logbf.h b/libc/shared/math/logbf.h
new file mode 100644
index 0000000000000..8b5d3632545f8
--- /dev/null
+++ b/libc/shared/math/logbf.h
@@ -0,0 +1,25 @@
+//===-- Shared logbf 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_LOGBF_H
+#define LLVM_LIBC_SHARED_MATH_LOGBF_H
+
+#include "shared/libc_common.h"
+
+#include "src/__support/math/logbf.h"
+
+namespace LIBC_NAMESPACE_DECL {
+namespace shared {
+
+using math::logbf;
+
+} // namespace shared
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SHARED_MATH_LOGBF_H
diff --git a/libc/src/__support/math/CMakeLists.txt b/libc/src/__support/math/CMakeLists.txt
index 4139a1b1d3444..0b51723f08dba 100644
--- a/libc/src/__support/math/CMakeLists.txt
+++ b/libc/src/__support/math/CMakeLists.txt
@@ -1078,3 +1078,12 @@ add_header_library(
libc.src.__support.math.sincos_eval
libc.src.__support.macros.optimization
)
+
+add_header_library(
+ logbf
+ HDRS
+ logbf.h
+ DEPENDS
+ libc.src.__support.FPUtil.manipulation_functions
+)
+)
diff --git a/libc/src/__support/math/logbf.h b/libc/src/__support/math/logbf.h
new file mode 100644
index 0000000000000..9209fec5e9848
--- /dev/null
+++ b/libc/src/__support/math/logbf.h
@@ -0,0 +1,27 @@
+//===-- Implementation header for logbf------------------------- -*- 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_LOGBF_H
+#define LLVM_LIBC_SRC___SUPPORT_MATH_LOGBF_H
+
+#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 float logbf(float x) { return fputil::logb(x); }
+
+} // namespace math
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC___SUPPORT_MATH_LOGBF_H
diff --git a/libc/src/math/generic/CMakeLists.txt b/libc/src/math/generic/CMakeLists.txt
index 6de4cf376bf02..75cce191c80b0 100644
--- a/libc/src/math/generic/CMakeLists.txt
+++ b/libc/src/math/generic/CMakeLists.txt
@@ -2173,7 +2173,8 @@ add_entrypoint_object(
HDRS
../logbf.h
DEPENDS
- libc.src.__support.FPUtil.manipulation_functions
+ libc.src.__support.math.logbf
+ libc.src.errno.errno
)
add_entrypoint_object(
diff --git a/libc/src/math/generic/logbf.cpp b/libc/src/math/generic/logbf.cpp
index 0dc0251afe290..a2cf5830cee93 100644
--- a/libc/src/math/generic/logbf.cpp
+++ b/libc/src/math/generic/logbf.cpp
@@ -7,12 +7,9 @@
//===----------------------------------------------------------------------===//
#include "src/math/logbf.h"
-#include "src/__support/FPUtil/ManipulationFunctions.h"
-#include "src/__support/common.h"
-#include "src/__support/macros/config.h"
-
+#include "src/__support/math/logbf.h"
namespace LIBC_NAMESPACE_DECL {
-LLVM_LIBC_FUNCTION(float, logbf, (float x)) { return fputil::logb(x); }
+LLVM_LIBC_FUNCTION(float, logbf, (float x)) { return math::logbf(x); }
} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/test/shared/CMakeLists.txt b/libc/test/shared/CMakeLists.txt
index c5955ecfd54cb..5afc5513feb47 100644
--- a/libc/test/shared/CMakeLists.txt
+++ b/libc/test/shared/CMakeLists.txt
@@ -64,4 +64,5 @@ add_fp_unittest(
libc.src.__support.math.rsqrtf
libc.src.__support.math.rsqrtf16
libc.src.__support.math.sin
+ libc.src.__support.math.logbf
)
diff --git a/libc/test/shared/shared_math_test.cpp b/libc/test/shared/shared_math_test.cpp
index 20a98a1a9138c..30211ce2db965 100644
--- a/libc/test/shared/shared_math_test.cpp
+++ b/libc/test/shared/shared_math_test.cpp
@@ -78,6 +78,7 @@ TEST(LlvmLibcSharedMathTest, AllFloat) {
ASSERT_FP_EQ(float(-1 * (8 << 5)), LIBC_NAMESPACE::shared::ldexpf(-8.0f, 5));
EXPECT_FP_EQ(0x1p+0f, LIBC_NAMESPACE::shared::rsqrtf(1.0f));
+ EXPECT_FP_EQ(0x0p+0f, LIBC_NAMESPACE::shared::logbf(1.0f));
}
TEST(LlvmLibcSharedMathTest, AllDouble) {
diff --git a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
index c03c21b834895..9ecbc9e3527df 100644
--- a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
+++ b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
@@ -4524,7 +4524,12 @@ libc_math_function(
libc_math_function(name = "logb")
-libc_math_function(name = "logbf")
+libc_math_function(
+ name = "logbf",
+ additional_deps = [
+ ":__support_math_logbf",
+ ],
+)
libc_math_function(name = "logbl")
@@ -7860,3 +7865,12 @@ libc_function(
":types_wchar_t",
],
)
+
+libc_support_library(
+ name = "__support_math_logbf",
+ hdrs = ["src/__support/math/logbf.h"],
+ deps = [
+ ":__support_common",
+ ":__support_fputil_manipulation_functions",
+ ],
+)
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