[libc-commits] [libc] 930cf1c - [libc] Add implementations of ilogb[f|l].
Siva Chandra Reddy via libc-commits
libc-commits at lists.llvm.org
Thu Nov 5 16:27:56 PST 2020
Author: Siva Chandra Reddy
Date: 2020-11-05T16:27:44-08:00
New Revision: 930cf1cb9fdb77138dedf5ac4afc2ebfc46d63a3
URL: https://github.com/llvm/llvm-project/commit/930cf1cb9fdb77138dedf5ac4afc2ebfc46d63a3
DIFF: https://github.com/llvm/llvm-project/commit/930cf1cb9fdb77138dedf5ac4afc2ebfc46d63a3.diff
LOG: [libc] Add implementations of ilogb[f|l].
Depends on D90805.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D90806
Added:
libc/src/math/ilogb.cpp
libc/src/math/ilogb.h
libc/src/math/ilogbf.cpp
libc/src/math/ilogbf.h
libc/src/math/ilogbl.cpp
libc/src/math/ilogbl.h
libc/test/src/math/ILogbTest.h
libc/test/src/math/ilogb_test.cpp
libc/test/src/math/ilogbf_test.cpp
libc/test/src/math/ilogbl_test.cpp
Modified:
libc/config/linux/aarch64/entrypoints.txt
libc/config/linux/api.td
libc/config/linux/x86_64/entrypoints.txt
libc/spec/stdc.td
libc/src/math/CMakeLists.txt
libc/test/src/math/CMakeLists.txt
libc/utils/FPUtil/CMakeLists.txt
libc/utils/FPUtil/ManipulationFunctions.h
Removed:
################################################################################
diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
index e654d594bce0..a8aeb6dc0021 100644
--- a/libc/config/linux/aarch64/entrypoints.txt
+++ b/libc/config/linux/aarch64/entrypoints.txt
@@ -65,6 +65,9 @@ set(TARGET_LIBM_ENTRYPOINTS
libc.src.math.frexpf
libc.src.math.frexpl
libc.src.math.hypotf
+ libc.src.math.ilogb
+ libc.src.math.ilogbf
+ libc.src.math.ilogbl
libc.src.math.logb
libc.src.math.logbf
libc.src.math.logbl
diff --git a/libc/config/linux/api.td b/libc/config/linux/api.td
index fbeb04086b83..8415e8032d28 100644
--- a/libc/config/linux/api.td
+++ b/libc/config/linux/api.td
@@ -144,6 +144,9 @@ def MathAPI : PublicAPI<"math.h"> {
SimpleMacroDef<"INFINITY", "__builtin_inff()">,
SimpleMacroDef<"NAN", "__builtin_nanf(\"\")">,
+ SimpleMacroDef<"FP_ILOGB0", "(-__INT_MAX__ - 1)">, // INT_MIN
+ SimpleMacroDef<"FP_ILOGBNAN", "__INT_MAX__">,
+
IsFiniteMacro,
IsInfMacro,
IsNanMacro,
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index a67e4084dd5e..f72fb77357f3 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -98,6 +98,9 @@ set(TARGET_LIBM_ENTRYPOINTS
libc.src.math.frexpf
libc.src.math.frexpl
libc.src.math.hypotf
+ libc.src.math.ilogb
+ libc.src.math.ilogbf
+ libc.src.math.ilogbl
libc.src.math.logb
libc.src.math.logbf
libc.src.math.logbl
diff --git a/libc/spec/stdc.td b/libc/spec/stdc.td
index 7d082d28b0eb..de2cbea179cd 100644
--- a/libc/spec/stdc.td
+++ b/libc/spec/stdc.td
@@ -233,6 +233,9 @@ def StdC : StandardSpec<"stdc"> {
Macro<"INFINITY">,
Macro<"NAN">,
+ Macro<"FP_ILOGB0">,
+ Macro<"FP_ILOGBNAN">,
+
Macro<"isfinite">,
Macro<"isinf">,
Macro<"isnan">,
@@ -273,6 +276,10 @@ def StdC : StandardSpec<"stdc"> {
FunctionSpec<"hypotf", RetValSpec<FloatType>, [ArgSpec<FloatType>, ArgSpec<FloatType>]>,
+ FunctionSpec<"ilogb", RetValSpec<IntType>, [ArgSpec<DoubleType>]>,
+ FunctionSpec<"ilogbf", RetValSpec<IntType>, [ArgSpec<FloatType>]>,
+ FunctionSpec<"ilogbl", RetValSpec<IntType>, [ArgSpec<LongDoubleType>]>,
+
FunctionSpec<"logb", RetValSpec<DoubleType>, [ArgSpec<DoubleType>]>,
FunctionSpec<"logbf", RetValSpec<FloatType>, [ArgSpec<FloatType>]>,
FunctionSpec<"logbl", RetValSpec<LongDoubleType>, [ArgSpec<LongDoubleType>]>,
diff --git a/libc/src/math/CMakeLists.txt b/libc/src/math/CMakeLists.txt
index 633a1cdddc54..6c2ff2cc7c62 100644
--- a/libc/src/math/CMakeLists.txt
+++ b/libc/src/math/CMakeLists.txt
@@ -342,6 +342,42 @@ add_entrypoint_object(
-O2
)
+add_entrypoint_object(
+ ilogb
+ SRCS
+ ilogb.cpp
+ HDRS
+ ilogb.h
+ DEPENDS
+ libc.utils.FPUtil.fputil
+ COMPILE_OPTIONS
+ -O2
+)
+
+add_entrypoint_object(
+ ilogbf
+ SRCS
+ ilogbf.cpp
+ HDRS
+ ilogbf.h
+ DEPENDS
+ libc.utils.FPUtil.fputil
+ COMPILE_OPTIONS
+ -O2
+)
+
+add_entrypoint_object(
+ ilogbl
+ SRCS
+ ilogbl.cpp
+ HDRS
+ ilogbl.h
+ DEPENDS
+ libc.utils.FPUtil.fputil
+ COMPILE_OPTIONS
+ -O2
+)
+
add_entrypoint_object(
logb
SRCS
diff --git a/libc/src/math/ilogb.cpp b/libc/src/math/ilogb.cpp
new file mode 100644
index 000000000000..001925b0d481
--- /dev/null
+++ b/libc/src/math/ilogb.cpp
@@ -0,0 +1,16 @@
+//===-- Implementation of ilogb function ----------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/__support/common.h"
+#include "utils/FPUtil/ManipulationFunctions.h"
+
+namespace __llvm_libc {
+
+int LLVM_LIBC_ENTRYPOINT(ilogb)(double x) { return fputil::ilogb(x); }
+
+} // namespace __llvm_libc
diff --git a/libc/src/math/ilogb.h b/libc/src/math/ilogb.h
new file mode 100644
index 000000000000..96672077865a
--- /dev/null
+++ b/libc/src/math/ilogb.h
@@ -0,0 +1,18 @@
+//===-- Implementation header for ilogb -------------------------*- 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_MATH_ILOGB_H
+#define LLVM_LIBC_SRC_MATH_ILOGB_H
+
+namespace __llvm_libc {
+
+int ilogb(double x);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_MATH_ILOGB_H
diff --git a/libc/src/math/ilogbf.cpp b/libc/src/math/ilogbf.cpp
new file mode 100644
index 000000000000..d62b22b5159f
--- /dev/null
+++ b/libc/src/math/ilogbf.cpp
@@ -0,0 +1,16 @@
+//===-- Implementation of ilogbf function ---------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/__support/common.h"
+#include "utils/FPUtil/ManipulationFunctions.h"
+
+namespace __llvm_libc {
+
+int LLVM_LIBC_ENTRYPOINT(ilogbf)(float x) { return fputil::ilogb(x); }
+
+} // namespace __llvm_libc
diff --git a/libc/src/math/ilogbf.h b/libc/src/math/ilogbf.h
new file mode 100644
index 000000000000..1afb76a107c1
--- /dev/null
+++ b/libc/src/math/ilogbf.h
@@ -0,0 +1,18 @@
+//===-- Implementation header for ilogbf ------------------------*- 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_MATH_ILOGBF_H
+#define LLVM_LIBC_SRC_MATH_ILOGBF_H
+
+namespace __llvm_libc {
+
+int ilogbf(float x);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_MATH_ILOGBF_H
diff --git a/libc/src/math/ilogbl.cpp b/libc/src/math/ilogbl.cpp
new file mode 100644
index 000000000000..0ad791f80dfd
--- /dev/null
+++ b/libc/src/math/ilogbl.cpp
@@ -0,0 +1,16 @@
+//===-- Implementation of ilogbl function ---------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/__support/common.h"
+#include "utils/FPUtil/ManipulationFunctions.h"
+
+namespace __llvm_libc {
+
+int LLVM_LIBC_ENTRYPOINT(ilogbl)(long double x) { return fputil::ilogb(x); }
+
+} // namespace __llvm_libc
diff --git a/libc/src/math/ilogbl.h b/libc/src/math/ilogbl.h
new file mode 100644
index 000000000000..4d1cc1995341
--- /dev/null
+++ b/libc/src/math/ilogbl.h
@@ -0,0 +1,18 @@
+//===-- Implementation header for ilogbl ------------------------*- 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_MATH_ILOGBL_H
+#define LLVM_LIBC_SRC_MATH_ILOGBL_H
+
+namespace __llvm_libc {
+
+int ilogbl(long double x);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_MATH_ILOGBL_H
diff --git a/libc/test/src/math/CMakeLists.txt b/libc/test/src/math/CMakeLists.txt
index a90736992f1f..4f8f77e4cf03 100644
--- a/libc/test/src/math/CMakeLists.txt
+++ b/libc/test/src/math/CMakeLists.txt
@@ -370,6 +370,48 @@ add_fp_unittest(
libc.utils.FPUtil.fputil
)
+add_fp_unittest(
+ ilogb_test
+ SUITE
+ libc_math_unittests
+ SRCS
+ ilogb_test.cpp
+ HDRS
+ ILogbTest.h
+ DEPENDS
+ libc.include.math
+ libc.src.math.ilogb
+ libc.utils.FPUtil.fputil
+)
+
+add_fp_unittest(
+ ilogbf_test
+ SUITE
+ libc_math_unittests
+ SRCS
+ ilogbf_test.cpp
+ HDRS
+ ILogbTest.h
+ DEPENDS
+ libc.include.math
+ libc.src.math.ilogbf
+ libc.utils.FPUtil.fputil
+)
+
+add_fp_unittest(
+ ilogbl_test
+ SUITE
+ libc_math_unittests
+ SRCS
+ ilogbl_test.cpp
+ HDRS
+ ILogbTest.h
+ DEPENDS
+ libc.include.math
+ libc.src.math.ilogbl
+ libc.utils.FPUtil.fputil
+)
+
add_fp_unittest(
logb_test
SUITE
diff --git a/libc/test/src/math/ILogbTest.h b/libc/test/src/math/ILogbTest.h
new file mode 100644
index 000000000000..001b419de6cd
--- /dev/null
+++ b/libc/test/src/math/ILogbTest.h
@@ -0,0 +1,108 @@
+//===-- Utility class to test
diff erent flavors of ilogb --------*- 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_TEST_SRC_MATH_ILOGBTEST_H
+#define LLVM_LIBC_TEST_SRC_MATH_ILOGBTEST_H
+
+#include "include/math.h"
+#include "utils/FPUtil/FPBits.h"
+#include "utils/FPUtil/ManipulationFunctions.h"
+#include "utils/UnitTest/Test.h"
+
+#include <limits.h>
+
+class ILogbTest : public __llvm_libc::testing::Test {
+public:
+ template <typename T> struct ILogbFunc { typedef int (*Func)(T); };
+
+ template <typename T>
+ void testSpecialNumbers(typename ILogbFunc<T>::Func func) {
+ EXPECT_EQ(FP_ILOGB0, func(__llvm_libc::fputil::FPBits<T>::zero()));
+ EXPECT_EQ(FP_ILOGB0, func(__llvm_libc::fputil::FPBits<T>::negZero()));
+
+ EXPECT_EQ(FP_ILOGBNAN, func(__llvm_libc::fputil::FPBits<T>::buildNaN(1)));
+
+ EXPECT_EQ(INT_MAX, func(__llvm_libc::fputil::FPBits<T>::inf()));
+ EXPECT_EQ(INT_MAX, func(__llvm_libc::fputil::FPBits<T>::negInf()));
+ }
+
+ template <typename T> void testPowersOfTwo(typename ILogbFunc<T>::Func func) {
+ EXPECT_EQ(0, func(T(1.0)));
+ EXPECT_EQ(0, func(T(-1.0)));
+
+ EXPECT_EQ(1, func(T(2.0)));
+ EXPECT_EQ(1, func(T(-2.0)));
+
+ EXPECT_EQ(2, func(T(4.0)));
+ EXPECT_EQ(2, func(T(-4.0)));
+
+ EXPECT_EQ(3, func(T(8.0)));
+ EXPECT_EQ(3, func(-8.0));
+
+ EXPECT_EQ(4, func(16.0));
+ EXPECT_EQ(4, func(-16.0));
+
+ EXPECT_EQ(5, func(32.0));
+ EXPECT_EQ(5, func(-32.0));
+ }
+
+ template <typename T>
+ void testSomeIntegers(typename ILogbFunc<T>::Func func) {
+ EXPECT_EQ(1, func(T(3.0)));
+ EXPECT_EQ(1, func(T(-3.0)));
+
+ EXPECT_EQ(2, func(T(7.0)));
+ EXPECT_EQ(2, func(T(-7.0)));
+
+ EXPECT_EQ(3, func(T(10.0)));
+ EXPECT_EQ(3, func(T(-10.0)));
+
+ EXPECT_EQ(4, func(T(31.0)));
+ EXPECT_EQ(4, func(-31.0));
+
+ EXPECT_EQ(5, func(55.0));
+ EXPECT_EQ(5, func(-55.0));
+ }
+
+ template <typename T>
+ void testSubnormalRange(typename ILogbFunc<T>::Func func) {
+ using FPBits = __llvm_libc::fputil::FPBits<T>;
+ using UIntType = typename FPBits::UIntType;
+ constexpr UIntType count = 1000001;
+ constexpr UIntType step =
+ (FPBits::maxSubnormal - FPBits::minSubnormal) / count;
+ for (UIntType v = FPBits::minSubnormal; v <= FPBits::maxSubnormal;
+ v += step) {
+ T x = FPBits(v);
+ if (isnan(x) || isinf(x) || x == 0.0)
+ continue;
+
+ int exponent;
+ __llvm_libc::fputil::frexp(x, exponent);
+ ASSERT_EQ(exponent, func(x) + 1);
+ }
+ }
+
+ template <typename T> void testNormalRange(typename ILogbFunc<T>::Func func) {
+ using FPBits = __llvm_libc::fputil::FPBits<T>;
+ using UIntType = typename FPBits::UIntType;
+ constexpr UIntType count = 1000001;
+ constexpr UIntType step = (FPBits::maxNormal - FPBits::minNormal) / count;
+ for (UIntType v = FPBits::minNormal; v <= FPBits::maxNormal; v += step) {
+ T x = FPBits(v);
+ if (isnan(x) || isinf(x) || x == 0.0)
+ continue;
+
+ int exponent;
+ __llvm_libc::fputil::frexp(x, exponent);
+ ASSERT_EQ(exponent, func(x) + 1);
+ }
+ }
+};
+
+#endif // LLVM_LIBC_TEST_SRC_MATH_ILOGBTEST_H
diff --git a/libc/test/src/math/ilogb_test.cpp b/libc/test/src/math/ilogb_test.cpp
new file mode 100644
index 000000000000..cf71ac07be18
--- /dev/null
+++ b/libc/test/src/math/ilogb_test.cpp
@@ -0,0 +1,41 @@
+//===-- Unittests for ilogb -----------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "ILogbTest.h"
+
+#include "include/math.h"
+#include "src/math/ilogb.h"
+#include "utils/CPP/Functional.h"
+#include "utils/FPUtil/FPBits.h"
+#include "utils/FPUtil/ManipulationFunctions.h"
+#include "utils/FPUtil/TestHelpers.h"
+#include "utils/UnitTest/Test.h"
+
+#include <limits.h>
+
+using RunContext = __llvm_libc::testing::RunContext;
+
+TEST_F(ILogbTest, SpecialNumbers_ilogb) {
+ testSpecialNumbers<double>(&__llvm_libc::ilogb);
+}
+
+TEST_F(ILogbTest, PowersOfTwo_ilogb) {
+ testPowersOfTwo<double>(&__llvm_libc::ilogb);
+}
+
+TEST_F(ILogbTest, SomeIntegers_ilogb) {
+ testSomeIntegers<double>(&__llvm_libc::ilogb);
+}
+
+TEST_F(ILogbTest, SubnormalRange_ilogb) {
+ testSubnormalRange<double>(&__llvm_libc::ilogb);
+}
+
+TEST_F(ILogbTest, NormalRange_ilogb) {
+ testNormalRange<double>(&__llvm_libc::ilogb);
+}
diff --git a/libc/test/src/math/ilogbf_test.cpp b/libc/test/src/math/ilogbf_test.cpp
new file mode 100644
index 000000000000..109dddeca7b1
--- /dev/null
+++ b/libc/test/src/math/ilogbf_test.cpp
@@ -0,0 +1,41 @@
+//===-- Unittests for ilogbf ----------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "ILogbTest.h"
+
+#include "include/math.h"
+#include "src/math/ilogbf.h"
+#include "utils/CPP/Functional.h"
+#include "utils/FPUtil/FPBits.h"
+#include "utils/FPUtil/ManipulationFunctions.h"
+#include "utils/FPUtil/TestHelpers.h"
+#include "utils/UnitTest/Test.h"
+
+#include <limits.h>
+
+using RunContext = __llvm_libc::testing::RunContext;
+
+TEST_F(ILogbTest, SpecialNumbers_ilogbf) {
+ testSpecialNumbers<float>(&__llvm_libc::ilogbf);
+}
+
+TEST_F(ILogbTest, PowersOfTwo_ilogbf) {
+ testPowersOfTwo<float>(&__llvm_libc::ilogbf);
+}
+
+TEST_F(ILogbTest, SomeIntegers_ilogbf) {
+ testSomeIntegers<float>(&__llvm_libc::ilogbf);
+}
+
+TEST_F(ILogbTest, SubnormalRange_ilogbf) {
+ testSubnormalRange<float>(&__llvm_libc::ilogbf);
+}
+
+TEST_F(ILogbTest, NormalRange_ilogbf) {
+ testNormalRange<float>(&__llvm_libc::ilogbf);
+}
diff --git a/libc/test/src/math/ilogbl_test.cpp b/libc/test/src/math/ilogbl_test.cpp
new file mode 100644
index 000000000000..6404c6b00fd1
--- /dev/null
+++ b/libc/test/src/math/ilogbl_test.cpp
@@ -0,0 +1,41 @@
+//===-- Unittests for ilogbl ----------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "ILogbTest.h"
+
+#include "include/math.h"
+#include "src/math/ilogbl.h"
+#include "utils/CPP/Functional.h"
+#include "utils/FPUtil/FPBits.h"
+#include "utils/FPUtil/ManipulationFunctions.h"
+#include "utils/FPUtil/TestHelpers.h"
+#include "utils/UnitTest/Test.h"
+
+#include <limits.h>
+
+using RunContext = __llvm_libc::testing::RunContext;
+
+TEST_F(ILogbTest, SpecialNumbers_ilogbl) {
+ testSpecialNumbers<long double>(&__llvm_libc::ilogbl);
+}
+
+TEST_F(ILogbTest, PowersOfTwo_ilogbl) {
+ testPowersOfTwo<long double>(&__llvm_libc::ilogbl);
+}
+
+TEST_F(ILogbTest, SomeIntegers_ilogbl) {
+ testSomeIntegers<long double>(&__llvm_libc::ilogbl);
+}
+
+TEST_F(ILogbTest, SubnormalRange_ilogbl) {
+ testSubnormalRange<long double>(&__llvm_libc::ilogbl);
+}
+
+TEST_F(ILogbTest, NormalRange_ilogbl) {
+ testNormalRange<long double>(&__llvm_libc::ilogbl);
+}
diff --git a/libc/utils/FPUtil/CMakeLists.txt b/libc/utils/FPUtil/CMakeLists.txt
index 8a6cc36a7b51..1c90e017283a 100644
--- a/libc/utils/FPUtil/CMakeLists.txt
+++ b/libc/utils/FPUtil/CMakeLists.txt
@@ -20,6 +20,7 @@ add_header_library(
NearestIntegerOperations.h
NormalFloat.h
DEPENDS
+ libc.include.math
libc.utils.CPP.standalone_cpp
)
diff --git a/libc/utils/FPUtil/ManipulationFunctions.h b/libc/utils/FPUtil/ManipulationFunctions.h
index f233fcdb5244..bfd24c2cc481 100644
--- a/libc/utils/FPUtil/ManipulationFunctions.h
+++ b/libc/utils/FPUtil/ManipulationFunctions.h
@@ -13,8 +13,11 @@
#include "NearestIntegerOperations.h"
#include "NormalFloat.h"
+#include "include/math.h"
#include "utils/CPP/TypeTraits.h"
+#include <limits.h>
+
namespace __llvm_libc {
namespace fputil {
@@ -65,6 +68,35 @@ static inline T copysign(T x, T y) {
return xbits;
}
+template <typename T,
+ cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
+static inline int ilogb(T x) {
+ // TODO: Raise appropriate floating point exceptions and set errno to the
+ // an appropriate error value wherever relevant.
+ FPBits<T> bits(x);
+ if (bits.isZero()) {
+ return FP_ILOGB0;
+ } else if (bits.isNaN()) {
+ return FP_ILOGBNAN;
+ } else if (bits.isInf()) {
+ return INT_MAX;
+ }
+
+ NormalFloat<T> normal(bits);
+ // The C standard does not specify the return value when an exponent is
+ // out of int range. However, XSI conformance required that INT_MAX or
+ // INT_MIN are returned.
+ // NOTE: It is highly unlikely that exponent will be out of int range as
+ // the exponent is only 15 bits wide even for the 128-bit floating point
+ // format.
+ if (normal.exponent > INT_MAX)
+ return INT_MAX;
+ else if (normal.exponent < INT_MIN)
+ return INT_MIN;
+ else
+ return normal.exponent;
+}
+
template <typename T,
cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
static inline T logb(T x) {
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