[libc-commits] [libc] [llvm] [libc][math] Refactor logbf to Header Only. (PR #176222)
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Fri Jan 16 13:04:59 PST 2026
https://github.com/AnonMiraj updated https://github.com/llvm/llvm-project/pull/176222
>From 7d05cfe9b86488e98eb9e0119903ca54c6ed81d5 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 | 24 +++++++++++++++++
libc/src/__support/math/CMakeLists.txt | 8 ++++++
libc/src/__support/math/logbf.h | 26 +++++++++++++++++++
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, 80 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 2e7bbe1ef13be..9e1e205feb11c 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/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..7a778d59fcead
--- /dev/null
+++ b/libc/shared/math/logbf.h
@@ -0,0 +1,24 @@
+//===-- 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 b45ccfc0eb3cb..0a0a6b1f26d00 100644
--- a/libc/src/__support/math/CMakeLists.txt
+++ b/libc/src/__support/math/CMakeLists.txt
@@ -1061,6 +1061,14 @@ add_header_library(
libc.src.__support.macros.optimization
)
+add_header_library(
+ logbf
+ HDRS
+ logbf.h
+ DEPENDS
+ libc.src.__support.FPUtil.manipulation_functions
+)
+
add_header_library(
log_range_reduction
HDRS
diff --git a/libc/src/__support/math/logbf.h b/libc/src/__support/math/logbf.h
new file mode 100644
index 0000000000000..3d9f6494d2d2d
--- /dev/null
+++ b/libc/src/__support/math/logbf.h
@@ -0,0 +1,26 @@
+//===-- 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 009a3033083bd..7633375e81348 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 58214bf6f88eb..ffb241c999f9d 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.logbf
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..ace9680b479e3 100644
--- a/libc/test/shared/shared_math_test.cpp
+++ b/libc/test/shared/shared_math_test.cpp
@@ -77,6 +77,7 @@ TEST(LlvmLibcSharedMathTest, AllFloat) {
ASSERT_FP_EQ(float(8 << 5), LIBC_NAMESPACE::shared::ldexpf(8.0f, 5));
ASSERT_FP_EQ(float(-1 * (8 << 5)), LIBC_NAMESPACE::shared::ldexpf(-8.0f, 5));
+ EXPECT_FP_EQ(0x0p+0f, LIBC_NAMESPACE::shared::logbf(1.0f));
EXPECT_FP_EQ(0x1p+0f, LIBC_NAMESPACE::shared::rsqrtf(1.0f));
}
diff --git a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
index 4251f20a5dfcf..0418b22c2901d 100644
--- a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
+++ b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
@@ -2906,6 +2906,15 @@ libc_support_library(
],
)
+libc_support_library(
+ name = "__support_math_logbf",
+ hdrs = ["src/__support/math/logbf.h"],
+ deps = [
+ ":__support_common",
+ ":__support_fputil_manipulation_functions",
+ ],
+)
+
libc_support_library(
name = "__support_math_exp_constants",
hdrs = ["src/__support/math/exp_constants.h"],
@@ -4542,7 +4551,12 @@ 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")
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