[libc-commits] [libc] [llvm] [libc][math] Refactor logbf to Header Only. (PR #176222)
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libc-commits at lists.llvm.org
Fri Jan 16 14:09:15 PST 2026
https://github.com/AnonMiraj updated https://github.com/llvm/llvm-project/pull/176222
>From 01397fcd392af6e37436218013fc74e31c299c3a Mon Sep 17 00:00:00 2001
From: anonmiraj <nabilmalek48 at gmail.com>
Date: Thu, 15 Jan 2026 20:47:03 +0200
Subject: [PATCH 1/3] [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 8102ff38584bd..de1f7b0cc0b5d 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/logbf128.h"
#include "math/logbf16.h"
#include "math/rsqrtf.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 5bf0648be02e2..9716a2a3b1ff4 100644
--- a/libc/src/__support/math/CMakeLists.txt
+++ b/libc/src/__support/math/CMakeLists.txt
@@ -1079,6 +1079,14 @@ add_header_library(
libc.src.__support.macros.properties.types
)
+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 11f1e0dd5e8b4..2729c987d6369 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 a2fa0146adadb..51bf25d60451d 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.logbf128
libc.src.__support.math.logbf16
libc.src.__support.math.ldexpf
diff --git a/libc/test/shared/shared_math_test.cpp b/libc/test/shared/shared_math_test.cpp
index baf725b1accc3..8079890357ca0 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(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 6d55f95b02b8f..de7aa4dfa74ab 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_logbf128",
hdrs = ["src/__support/math/logbf128.h"],
@@ -4558,7 +4567,12 @@ 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")
>From 9e7a30ecd566f3716391db42b591b410981137b3 Mon Sep 17 00:00:00 2001
From: Anonmiraj <ezzibrahimx at gmail.com>
Date: Sat, 17 Jan 2026 00:04:19 +0200
Subject: [PATCH 2/3] Apply suggestions from code review
Co-authored-by: Muhammad Bassiouni <60100307+bassiounix at users.noreply.github.com>
---
libc/shared/math/logbf.h | 2 +-
libc/src/__support/math/logbf.h | 2 +-
libc/src/math/generic/logbf.cpp | 1 +
3 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/libc/shared/math/logbf.h b/libc/shared/math/logbf.h
index 7a778d59fcead..559f4bbc327f8 100644
--- a/libc/shared/math/logbf.h
+++ b/libc/shared/math/logbf.h
@@ -1,4 +1,4 @@
-//===-- Shared logbf function------------------------------------*- C++ -*-===//
+//===-- 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.
diff --git a/libc/src/__support/math/logbf.h b/libc/src/__support/math/logbf.h
index 3d9f6494d2d2d..1b0daf92784ed 100644
--- a/libc/src/__support/math/logbf.h
+++ b/libc/src/__support/math/logbf.h
@@ -1,4 +1,4 @@
-//===-- Implementation header for logbf--------------------------*- C++ -*-===//
+//===-- 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.
diff --git a/libc/src/math/generic/logbf.cpp b/libc/src/math/generic/logbf.cpp
index a2cf5830cee93..e319736adc71e 100644
--- a/libc/src/math/generic/logbf.cpp
+++ b/libc/src/math/generic/logbf.cpp
@@ -8,6 +8,7 @@
#include "src/math/logbf.h"
#include "src/__support/math/logbf.h"
+
namespace LIBC_NAMESPACE_DECL {
LLVM_LIBC_FUNCTION(float, logbf, (float x)) { return math::logbf(x); }
>From 62f9f76ac1fd70ad618955d9feb2e763b029b8b4 Mon Sep 17 00:00:00 2001
From: Anonmiraj <ezzibrahimx at gmail.com>
Date: Sat, 17 Jan 2026 00:09:06 +0200
Subject: [PATCH 3/3] Apply suggestion from @bassiounix
Co-authored-by: Muhammad Bassiouni <60100307+bassiounix at users.noreply.github.com>
---
libc/shared/math/logbf.h | 2 --
1 file changed, 2 deletions(-)
diff --git a/libc/shared/math/logbf.h b/libc/shared/math/logbf.h
index 559f4bbc327f8..32665a0f9070b 100644
--- a/libc/shared/math/logbf.h
+++ b/libc/shared/math/logbf.h
@@ -9,8 +9,6 @@
#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 {
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