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[libc][stdbit] implement stdc_first_trailing_one (C23) (llvm#81768)
1 parent de16a05 commit 6297479

24 files changed

+362
-12
lines changed

‎libc/config/linux/x86_64/entrypoints.txt

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@@ -127,6 +127,11 @@ set(TARGET_LIBC_ENTRYPOINTS
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libc.src.stdbit.stdc_first_trailing_zero_ui
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libc.src.stdbit.stdc_first_trailing_zero_ul
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libc.src.stdbit.stdc_first_trailing_zero_ull
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libc.src.stdbit.stdc_first_trailing_one_uc
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libc.src.stdbit.stdc_first_trailing_one_us
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libc.src.stdbit.stdc_first_trailing_one_ui
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libc.src.stdbit.stdc_first_trailing_one_ul
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libc.src.stdbit.stdc_first_trailing_one_ull
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# stdlib.h entrypoints
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libc.src.stdlib.abs

‎libc/docs/stdbit.rst

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@@ -66,11 +66,11 @@ stdc_first_trailing_zero_us |check|
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stdc_first_trailing_zero_ui |check|
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stdc_first_trailing_zero_ul |check|
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stdc_first_trailing_zero_ull |check|
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stdc_first_trailing_one_uc
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stdc_first_trailing_one_us
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stdc_first_trailing_one_ui
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stdc_first_trailing_one_ul
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stdc_first_trailing_one_ull
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stdc_first_trailing_one_uc |check|
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stdc_first_trailing_one_us |check|
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stdc_first_trailing_one_ui |check|
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stdc_first_trailing_one_ul |check|
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stdc_first_trailing_one_ull |check|
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stdc_count_zeros_uc
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stdc_count_zeros_us
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stdc_count_zeros_ui
@@ -121,7 +121,7 @@ stdc_trailing_ones |check|
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stdc_first_leading_zero |check|
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stdc_first_leading_one |check|
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stdc_first_trailing_zero |check|
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stdc_first_trailing_one
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stdc_first_trailing_one |check|
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stdc_count_zeros
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stdc_count_ones
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stdc_has_single_bit

‎libc/include/llvm-libc-macros/stdbit-macros.h

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@@ -116,6 +116,21 @@ inline unsigned stdc_first_trailing_zero(unsigned long x) {
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inline unsigned stdc_first_trailing_zero(unsigned long long x) {
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return stdc_first_trailing_zero_ull(x);
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}
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inline unsigned stdc_first_trailing_one(unsigned char x) {
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return stdc_first_trailing_one_uc(x);
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}
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inline unsigned stdc_first_trailing_one(unsigned short x) {
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return stdc_first_trailing_one_us(x);
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}
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inline unsigned stdc_first_trailing_one(unsigned x) {
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return stdc_first_trailing_one_ui(x);
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}
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inline unsigned stdc_first_trailing_one(unsigned long x) {
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return stdc_first_trailing_one_ul(x);
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}
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inline unsigned stdc_first_trailing_one(unsigned long long x) {
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return stdc_first_trailing_one_ull(x);
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}
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#else
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#define stdc_leading_zeros(x) \
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_Generic((x), \
@@ -166,6 +181,13 @@ inline unsigned stdc_first_trailing_zero(unsigned long long x) {
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unsigned: stdc_first_trailing_zero_ui, \
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unsigned long: stdc_first_trailing_zero_ul, \
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unsigned long long: stdc_first_trailing_zero_ull)(x)
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#define stdc_first_trailing_one(x) \
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_Generic((x), \
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unsigned char: stdc_first_trailing_one_uc, \
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unsigned short: stdc_first_trailing_one_us, \
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unsigned: stdc_first_trailing_one_ui, \
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unsigned long: stdc_first_trailing_one_ul, \
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unsigned long long: stdc_first_trailing_one_ull)(x)
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#endif // __cplusplus
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#endif // __LLVM_LIBC_MACROS_STDBIT_MACROS_H

‎libc/spec/stdc.td

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@@ -783,7 +783,8 @@ def StdC : StandardSpec<"stdc"> {
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Macro<"stdc_trailing_ones">,
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Macro<"stdc_first_leading_zero">,
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Macro<"stdc_first_leading_one">,
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Macro<"stdc_first_trailing_zero">
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Macro<"stdc_first_trailing_zero">,
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Macro<"stdc_first_trailing_one">
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], // Macros
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[], // Types
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[], // Enumerations
@@ -818,11 +819,11 @@ def StdC : StandardSpec<"stdc"> {
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FunctionSpec<"stdc_first_leading_one_ui", RetValSpec<UnsignedIntType>, [ArgSpec<UnsignedIntType>]>,
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FunctionSpec<"stdc_first_leading_one_ul", RetValSpec<UnsignedIntType>, [ArgSpec<UnsignedLongType>]>,
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FunctionSpec<"stdc_first_leading_one_ull", RetValSpec<UnsignedIntType>, [ArgSpec<UnsignedLongLongType>]>,
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FunctionSpec<"stdc_first_trailing_zero_uc", RetValSpec<UnsignedIntType>, [ArgSpec<UnsignedCharType>]>,
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FunctionSpec<"stdc_first_trailing_zero_us", RetValSpec<UnsignedIntType>, [ArgSpec<UnsignedShortType>]>,
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FunctionSpec<"stdc_first_trailing_zero_ui", RetValSpec<UnsignedIntType>, [ArgSpec<UnsignedIntType>]>,
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FunctionSpec<"stdc_first_trailing_zero_ul", RetValSpec<UnsignedIntType>, [ArgSpec<UnsignedLongType>]>,
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FunctionSpec<"stdc_first_trailing_zero_ull", RetValSpec<UnsignedIntType>, [ArgSpec<UnsignedLongLongType>]>,
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FunctionSpec<"stdc_first_trailing_one_uc", RetValSpec<UnsignedIntType>, [ArgSpec<UnsignedCharType>]>,
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FunctionSpec<"stdc_first_trailing_one_us", RetValSpec<UnsignedIntType>, [ArgSpec<UnsignedShortType>]>,
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FunctionSpec<"stdc_first_trailing_one_ui", RetValSpec<UnsignedIntType>, [ArgSpec<UnsignedIntType>]>,
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FunctionSpec<"stdc_first_trailing_one_ul", RetValSpec<UnsignedIntType>, [ArgSpec<UnsignedLongType>]>,
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FunctionSpec<"stdc_first_trailing_one_ull", RetValSpec<UnsignedIntType>, [ArgSpec<UnsignedLongLongType>]>
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] // Functions
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>;
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‎libc/src/__support/CPP/bit.h

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@@ -243,6 +243,11 @@ template <typename T, typename = cpp::enable_if_t<cpp::is_unsigned_v<T>>>
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: countr_zero(static_cast<T>(~value)) + 1;
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}
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template <typename T, typename = cpp::enable_if_t<cpp::is_unsigned_v<T>>>
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[[nodiscard]] LIBC_INLINE constexpr int first_trailing_one(T value) {
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return value == cpp::numeric_limits<T>::max() ? 0 : countr_zero(value) + 1;
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}
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} // namespace LIBC_NAMESPACE::cpp
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#endif // LLVM_LIBC_SRC___SUPPORT_CPP_BIT_H

‎libc/src/stdbit/CMakeLists.txt

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@@ -6,6 +6,7 @@ set(prefixes
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first_leading_zero
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first_leading_one
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first_trailing_zero
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first_trailing_one
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)
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set(suffixes c s i l ll)
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foreach(prefix IN LISTS prefixes)

‎libc/src/stdbit/stdc_first_trailing_one_uc.cpp

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@@ -0,0 +1,21 @@
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//===-- Implementation of stdc_first_trailing_one_uc ----------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "src/stdbit/stdc_first_trailing_one_uc.h"
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#include "src/__support/CPP/bit.h"
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#include "src/__support/common.h"
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namespace LIBC_NAMESPACE {
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LLVM_LIBC_FUNCTION(unsigned, stdc_first_trailing_one_uc,
17+
(unsigned char value)) {
18+
return static_cast<unsigned>(cpp::first_trailing_one(value));
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}
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} // namespace LIBC_NAMESPACE

‎libc/src/stdbit/stdc_first_trailing_one_uc.h

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//===-- Implementation header for stdc_first_trailing_one_uc ---*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_LIBC_SRC_STDBIT_STDC_FIRST_TRAILING_ONE_UC_H
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#define LLVM_LIBC_SRC_STDBIT_STDC_FIRST_TRAILING_ONE_UC_H
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namespace LIBC_NAMESPACE {
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unsigned stdc_first_trailing_one_uc(unsigned char value);
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} // namespace LIBC_NAMESPACE
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#endif // LLVM_LIBC_SRC_STDBIT_STDC_FIRST_TRAILING_ONE_UC_H

‎libc/src/stdbit/stdc_first_trailing_one_ui.cpp

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@@ -0,0 +1,20 @@
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//===-- Implementation of stdc_first_trailing_one_ui ----------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "src/stdbit/stdc_first_trailing_one_ui.h"
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11+
#include "src/__support/CPP/bit.h"
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#include "src/__support/common.h"
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namespace LIBC_NAMESPACE {
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LLVM_LIBC_FUNCTION(unsigned, stdc_first_trailing_one_ui, (unsigned value)) {
17+
return static_cast<unsigned>(cpp::first_trailing_one(value));
18+
}
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} // namespace LIBC_NAMESPACE

‎libc/src/stdbit/stdc_first_trailing_one_ui.h

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//===-- Implementation header for stdc_first_trailing_one_ui ---*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_LIBC_SRC_STDBIT_STDC_FIRST_TRAILING_ONE_UI_H
10+
#define LLVM_LIBC_SRC_STDBIT_STDC_FIRST_TRAILING_ONE_UI_H
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namespace LIBC_NAMESPACE {
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unsigned stdc_first_trailing_one_ui(unsigned value);
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} // namespace LIBC_NAMESPACE
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#endif // LLVM_LIBC_SRC_STDBIT_STDC_FIRST_TRAILING_ONE_UI_H

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