[libc][math] Refactor logbl to header only (llvm#181659)

Closes llvm#175366

Author: VachanVY

libc/shared/math.h

@@ -117,6 +117,7 @@
 #include "math/logbf.h"
 #include "math/logbf128.h"
 #include "math/logbf16.h"
+#include "math/logbl.h"
 #include "math/logf.h"
 #include "math/logf16.h"
 #include "math/pow.h"

libc/shared/math/logbl.h

@@ -0,0 +1,23 @@
+//===-- Shared logbl 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_LOGBL_H
+#define LLVM_LIBC_SHARED_MATH_LOGBL_H
+
+#include "shared/libc_common.h"
+#include "src/__support/math/logbl.h"
+
+namespace LIBC_NAMESPACE_DECL {
+namespace shared {
+
+using math::logbl;
+
+} // namespace shared
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SHARED_MATH_LOGBL_H

libc/src/__support/math/CMakeLists.txt

@@ -1716,6 +1716,16 @@ add_header_library(
     libc.src.__support.macros.properties.cpu_features
 )
 
+add_header_library(
+  logbl
+  HDRS
+    logbl.h
+  DEPENDS
+    libc.src.__support.FPUtil.manipulation_functions
+    libc.src.__support.common
+    libc.src.__support.macros.config
+)
+
 add_header_library(
   log_range_reduction
   HDRS

libc/src/__support/math/logbl.h

@@ -0,0 +1,26 @@
+//===-- Implementation header for logbl -------------------------*- 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_LOGBL_H
+#define LLVM_LIBC_SRC___SUPPORT_MATH_LOGBL_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 constexpr long double logbl(long double x) {
+  return fputil::logb(x);
+}
+
+} // namespace math
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC___SUPPORT_MATH_LOGBL_H

libc/src/math/generic/CMakeLists.txt

@@ -1999,7 +1999,7 @@ add_entrypoint_object(
   HDRS
     ../logbl.h
   DEPENDS
-    libc.src.__support.FPUtil.manipulation_functions
+    libc.src.__support.math.logbl
 )
 
 add_entrypoint_object(

libc/src/math/generic/logbl.cpp

@@ -7,14 +7,12 @@
 //===----------------------------------------------------------------------===//
 
 #include "src/math/logbl.h"
-#include "src/__support/FPUtil/ManipulationFunctions.h"
-#include "src/__support/common.h"
-#include "src/__support/macros/config.h"
+#include "src/__support/math/logbl.h"
 
 namespace LIBC_NAMESPACE_DECL {
 
 LLVM_LIBC_FUNCTION(long double, logbl, (long double x)) {
-  return fputil::logb(x);
+  return math::logbl(x);
 }
 
 } // namespace LIBC_NAMESPACE_DECL

libc/test/shared/CMakeLists.txt

@@ -114,6 +114,7 @@ add_fp_unittest(
     libc.src.__support.math.llogbf
     libc.src.__support.math.llogbf128
     libc.src.__support.math.llogbf16
+    libc.src.__support.math.logbl
     libc.src.__support.math.logf16    
     libc.src.__support.math.llogbl
     libc.src.__support.math.pow

libc/test/shared/shared_math_test.cpp

@@ -195,6 +195,7 @@ TEST(LlvmLibcSharedMathTest, AllLongDouble) {
   EXPECT_FP_EQ(0x0p+0f, LIBC_NAMESPACE::shared::fsqrtl(0.0L));
   EXPECT_EQ(0, LIBC_NAMESPACE::shared::ilogbl(0x1.p+0L));
   EXPECT_EQ(0L, LIBC_NAMESPACE::shared::llogbl(1.0L));
+  EXPECT_FP_EQ(0x0p+0L, LIBC_NAMESPACE::shared::logbl(1.0L));
   EXPECT_FP_EQ(10.0f, LIBC_NAMESPACE::shared::ffmal(2.0L, 3.0, 4.0L));
 
   long double canonicalizel_cx = 0.0L;

utils/bazel/llvm-project-overlay/libc/BUILD.bazel

@@ -3305,6 +3305,16 @@ libc_support_library(
     ],
 )
 
+libc_support_library(
+    name = "__support_math_logbl",
+    hdrs = ["src/__support/math/logbl.h"],
+    deps = [
+        ":__support_common",
+        ":__support_fputil_manipulation_functions",
+        ":__support_macros_config",
+    ],
+)
+
 libc_support_library(
     name = "__support_math_log10",
     hdrs = ["src/__support/math/log10.h"],
@@ -5399,7 +5409,10 @@ libc_math_function(
     additional_deps = [":__support_math_logbf"],
 )
 
-libc_math_function(name = "logbl")
+libc_math_function(
+    name = "logbl",
+    additional_deps = [":__support_math_logbl"],
+)
 
 libc_math_function(
     name = "logbf128",