[libc-commits] [libc] [libc] implement stdc_leading_zeros_u* for stdbit.h (PR #79669)

Nick Desaulniers via libc-commits libc-commits at lists.llvm.org
Mon Jan 29 10:27:58 PST 2024


https://github.com/nickdesaulniers updated https://github.com/llvm/llvm-project/pull/79669

>From d6c96e36ab3ec447bfef3a383191821ded8f0c0c Mon Sep 17 00:00:00 2001
From: Nick Desaulniers <ndesaulniers at google.com>
Date: Fri, 26 Jan 2024 12:46:38 -0800
Subject: [PATCH 1/8] [libc] implement stdc_leading_zeros_u* for stdbit.h

- stdbit.stdc_leading_zeros_uc
- stdbit.stdc_leading_zeros_us
- stdbit.stdc_leading_zeros_ui
- stdbit.stdc_leading_zeros_ul
- stdbit.stdc_leading_zeros_ull

Test via:
$ ninja libc-stdbit-tests libc_include_tests
---
 libc/config/linux/x86_64/entrypoints.txt      |  7 +++
 libc/config/linux/x86_64/headers.txt          |  1 +
 libc/include/CMakeLists.txt                   |  9 ++++
 libc/include/llvm-libc-macros/CMakeLists.txt  |  6 +++
 libc/include/llvm-libc-macros/stdbit-macros.h | 19 +++++++
 libc/include/stdbit.h.def                     | 17 +++++++
 libc/spec/spec.td                             |  1 +
 libc/spec/stdc.td                             | 19 ++++++-
 libc/src/CMakeLists.txt                       |  5 +-
 libc/src/stdbit/CMakeLists.txt                | 39 ++++++++++++++
 libc/src/stdbit/stdc_leading_zeros_uc.cpp     | 20 ++++++++
 libc/src/stdbit/stdc_leading_zeros_uc.h       | 18 +++++++
 libc/src/stdbit/stdc_leading_zeros_ui.cpp     | 20 ++++++++
 libc/src/stdbit/stdc_leading_zeros_ui.h       | 18 +++++++
 libc/src/stdbit/stdc_leading_zeros_ul.cpp     | 20 ++++++++
 libc/src/stdbit/stdc_leading_zeros_ul.h       | 18 +++++++
 libc/src/stdbit/stdc_leading_zeros_ull.cpp    | 20 ++++++++
 libc/src/stdbit/stdc_leading_zeros_ull.h      | 18 +++++++
 libc/src/stdbit/stdc_leading_zeros_us.cpp     | 20 ++++++++
 libc/src/stdbit/stdc_leading_zeros_us.h       | 18 +++++++
 libc/test/include/CMakeLists.txt              | 19 +++++++
 libc/test/include/stdbit_test.cpp             | 22 ++++++++
 libc/test/src/CMakeLists.txt                  | 11 ++--
 libc/test/src/stdbit/CMakeLists.txt           | 51 +++++++++++++++++++
 .../src/stdbit/stdc_leading_zeros_uc_test.cpp | 22 ++++++++
 .../src/stdbit/stdc_leading_zeros_ui_test.cpp | 23 +++++++++
 .../src/stdbit/stdc_leading_zeros_ul_test.cpp | 23 +++++++++
 .../stdbit/stdc_leading_zeros_ull_test.cpp    | 24 +++++++++
 .../src/stdbit/stdc_leading_zeros_us_test.cpp | 22 ++++++++
 29 files changed, 522 insertions(+), 8 deletions(-)
 create mode 100644 libc/include/llvm-libc-macros/stdbit-macros.h
 create mode 100644 libc/include/stdbit.h.def
 create mode 100644 libc/src/stdbit/CMakeLists.txt
 create mode 100644 libc/src/stdbit/stdc_leading_zeros_uc.cpp
 create mode 100644 libc/src/stdbit/stdc_leading_zeros_uc.h
 create mode 100644 libc/src/stdbit/stdc_leading_zeros_ui.cpp
 create mode 100644 libc/src/stdbit/stdc_leading_zeros_ui.h
 create mode 100644 libc/src/stdbit/stdc_leading_zeros_ul.cpp
 create mode 100644 libc/src/stdbit/stdc_leading_zeros_ul.h
 create mode 100644 libc/src/stdbit/stdc_leading_zeros_ull.cpp
 create mode 100644 libc/src/stdbit/stdc_leading_zeros_ull.h
 create mode 100644 libc/src/stdbit/stdc_leading_zeros_us.cpp
 create mode 100644 libc/src/stdbit/stdc_leading_zeros_us.h
 create mode 100644 libc/test/include/stdbit_test.cpp
 create mode 100644 libc/test/src/stdbit/CMakeLists.txt
 create mode 100644 libc/test/src/stdbit/stdc_leading_zeros_uc_test.cpp
 create mode 100644 libc/test/src/stdbit/stdc_leading_zeros_ui_test.cpp
 create mode 100644 libc/test/src/stdbit/stdc_leading_zeros_ul_test.cpp
 create mode 100644 libc/test/src/stdbit/stdc_leading_zeros_ull_test.cpp
 create mode 100644 libc/test/src/stdbit/stdc_leading_zeros_us_test.cpp

diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index 3812d9586121e7..e714f0f6cc5ac5 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -91,6 +91,13 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.inttypes.strtoimax
     libc.src.inttypes.strtoumax
 
+    # stdbit.h entrypoints
+    libc.src.stdbit.stdc_leading_zeros_uc
+    libc.src.stdbit.stdc_leading_zeros_us
+    libc.src.stdbit.stdc_leading_zeros_ui
+    libc.src.stdbit.stdc_leading_zeros_ul
+    libc.src.stdbit.stdc_leading_zeros_ull
+
     # stdlib.h entrypoints
     libc.src.stdlib.abs
     libc.src.stdlib.atoi
diff --git a/libc/config/linux/x86_64/headers.txt b/libc/config/linux/x86_64/headers.txt
index d103176897a74a..4009501bc45ce8 100644
--- a/libc/config/linux/x86_64/headers.txt
+++ b/libc/config/linux/x86_64/headers.txt
@@ -15,6 +15,7 @@ set(TARGET_PUBLIC_HEADERS
     libc.include.signal
     libc.include.spawn
     libc.include.setjmp
+    libc.include.stdbit
     libc.include.stdio
     libc.include.stdlib
     libc.include.string
diff --git a/libc/include/CMakeLists.txt b/libc/include/CMakeLists.txt
index 89fffd1022758e..9474bdd3791264 100644
--- a/libc/include/CMakeLists.txt
+++ b/libc/include/CMakeLists.txt
@@ -223,6 +223,15 @@ else()
   message(STATUS "Skipping header signal.h as the target config is missing")
 endif()
 
+add_gen_header(
+  stdbit
+  DEF_FILE stdbit.h.def
+  GEN_HDR stdbit.h
+  DEPENDS
+    .llvm_libc_common_h
+    .llvm-libc-macros.stdbit_macros
+)
+
 add_gen_header(
   stdio
   DEF_FILE stdio.h.def
diff --git a/libc/include/llvm-libc-macros/CMakeLists.txt b/libc/include/llvm-libc-macros/CMakeLists.txt
index 96ee29d7327224..c5a7e742cadd13 100644
--- a/libc/include/llvm-libc-macros/CMakeLists.txt
+++ b/libc/include/llvm-libc-macros/CMakeLists.txt
@@ -111,6 +111,12 @@ add_macro_header(
     signal-macros.h
 )
 
+add_macro_header(
+  stdbit_macros
+  HDR
+    stdbit-macros.h
+)
+
 add_macro_header(
   stdio_macros
   HDR
diff --git a/libc/include/llvm-libc-macros/stdbit-macros.h b/libc/include/llvm-libc-macros/stdbit-macros.h
new file mode 100644
index 00000000000000..183328877c3da8
--- /dev/null
+++ b/libc/include/llvm-libc-macros/stdbit-macros.h
@@ -0,0 +1,19 @@
+//===-- Definition of macros to be used with stdbit functions ----------===//
+//
+// 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_MACROS_STDBIT_MACROS_H
+#define __LLVM_LIBC_MACROS_STDBIT_MACROS_H
+
+#define stdc_leading_zeros(x) _Generic((x), \
+  unsigned char: stdc_leading_zeros_uc, \
+  unsigned short: stdc_leading_zeros_us, \
+  unsigned: stdc_leading_zeros_ui, \
+  unsigned long: stdc_leading_zeros_ul, \
+  unsigned long long: stdc_leading_zeros_ull)(x)
+
+#endif // __LLVM_LIBC_MACROS_STDBIT_MACROS_H
diff --git a/libc/include/stdbit.h.def b/libc/include/stdbit.h.def
new file mode 100644
index 00000000000000..cb79ac1caf049f
--- /dev/null
+++ b/libc/include/stdbit.h.def
@@ -0,0 +1,17 @@
+//===-- C standard library header stdbit.h --------------------------------===//
+//
+// 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_STDBIT_H
+#define LLVM_LIBC_STDBIT_H
+
+#include <__llvm-libc-common.h>
+#include <llvm-libc-macros/stdbit-macros.h>
+
+%%public_api()
+
+#endif // LLVM_LIBC_STDBIT_H
diff --git a/libc/spec/spec.td b/libc/spec/spec.td
index 818cfaee6b61c2..16abf97bf0b1cb 100644
--- a/libc/spec/spec.td
+++ b/libc/spec/spec.td
@@ -50,6 +50,7 @@ def DoubleType : NamedType<"double">;
 def LongDoubleType : NamedType<"long double">;
 def CharType : NamedType<"char">;
 def UnsignedCharType : NamedType<"unsigned char">;
+def UnsignedShortType : NamedType<"unsigned short">;
 
 // TODO: Add compatibility layer to use C23 type _Float128 if possible.
 def Float128Type : NamedType<"__float128">;
diff --git a/libc/spec/stdc.td b/libc/spec/stdc.td
index 43b81c4abaa0e6..b21f620d0766af 100644
--- a/libc/spec/stdc.td
+++ b/libc/spec/stdc.td
@@ -767,6 +767,22 @@ def StdC : StandardSpec<"stdc"> {
       ]
   >;
 
+  HeaderSpec StdBit = HeaderSpec<
+      "stdbit.h",
+      [
+        Macro<"stdc_leading_zeros">
+      ], // Macros
+      [], // Types
+      [], // Enumerations
+      [
+          FunctionSpec<"stdc_leading_zeros_uc", RetValSpec<UnsignedCharType>, [ArgSpec<UnsignedCharType>]>,
+          FunctionSpec<"stdc_leading_zeros_us", RetValSpec<UnsignedShortType>, [ArgSpec<UnsignedShortType>]>,
+          FunctionSpec<"stdc_leading_zeros_ui", RetValSpec<UnsignedIntType>, [ArgSpec<UnsignedIntType>]>,
+          FunctionSpec<"stdc_leading_zeros_ul", RetValSpec<UnsignedLongType>, [ArgSpec<UnsignedLongType>]>,
+          FunctionSpec<"stdc_leading_zeros_ull", RetValSpec<UnsignedLongLongType>, [ArgSpec<UnsignedLongLongType>]>
+      ] // Functions
+  >;
+
   HeaderSpec StdLib = HeaderSpec<
       "stdlib.h",
       [], // Macros
@@ -1141,7 +1157,7 @@ def StdC : StandardSpec<"stdc"> {
       "wchar.h",
       [ // Macros
         Macro<"WEOF">,
-      ], 
+      ],
       [ //Types
         SizeTType,
         WIntType,
@@ -1167,6 +1183,7 @@ def StdC : StandardSpec<"stdc"> {
     Limits,
     Math,
     String,
+    StdBit,
     StdIO,
     StdLib,
     IntTypes,
diff --git a/libc/src/CMakeLists.txt b/libc/src/CMakeLists.txt
index 492f9c5bd50f9b..5211db7bc1f993 100644
--- a/libc/src/CMakeLists.txt
+++ b/libc/src/CMakeLists.txt
@@ -5,9 +5,10 @@ add_subdirectory(errno)
 add_subdirectory(fenv)
 add_subdirectory(inttypes)
 add_subdirectory(math)
-add_subdirectory(string)
-add_subdirectory(stdlib)
+add_subdirectory(stdbit)
 add_subdirectory(stdio)
+add_subdirectory(stdlib)
+add_subdirectory(string)
 add_subdirectory(wchar)
 
 if(${LIBC_TARGET_OS} STREQUAL "linux")
diff --git a/libc/src/stdbit/CMakeLists.txt b/libc/src/stdbit/CMakeLists.txt
new file mode 100644
index 00000000000000..5747a8c2f35318
--- /dev/null
+++ b/libc/src/stdbit/CMakeLists.txt
@@ -0,0 +1,39 @@
+add_entrypoint_object(
+  stdc_leading_zeros_uc
+  SRCS
+    stdc_leading_zeros_uc.cpp
+  HDRS
+    stdc_leading_zeros_uc.h
+)
+
+add_entrypoint_object(
+  stdc_leading_zeros_us
+  SRCS
+    stdc_leading_zeros_us.cpp
+  HDRS
+    stdc_leading_zeros_us.h
+)
+
+add_entrypoint_object(
+  stdc_leading_zeros_ui
+  SRCS
+    stdc_leading_zeros_ui.cpp
+  HDRS
+    stdc_leading_zeros_ui.h
+)
+
+add_entrypoint_object(
+  stdc_leading_zeros_ul
+  SRCS
+    stdc_leading_zeros_ul.cpp
+  HDRS
+    stdc_leading_zeros_ul.h
+)
+
+add_entrypoint_object(
+  stdc_leading_zeros_ull
+  SRCS
+    stdc_leading_zeros_ull.cpp
+  HDRS
+    stdc_leading_zeros_ull.h
+)
diff --git a/libc/src/stdbit/stdc_leading_zeros_uc.cpp b/libc/src/stdbit/stdc_leading_zeros_uc.cpp
new file mode 100644
index 00000000000000..a985700274d259
--- /dev/null
+++ b/libc/src/stdbit/stdc_leading_zeros_uc.cpp
@@ -0,0 +1,20 @@
+//===-- Implementation of stdc_leading_zeros_uc ---------------------------===//
+//
+// 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/stdbit/stdc_leading_zeros_uc.h"
+
+#include "src/__support/CPP/bit.h"
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(unsigned char, stdc_leading_zeros_uc, (unsigned char value)) {
+  return static_cast<unsigned char>(cpp::countl_zero(value));
+}
+
+} // namespace LIBC_NAMESPACE
diff --git a/libc/src/stdbit/stdc_leading_zeros_uc.h b/libc/src/stdbit/stdc_leading_zeros_uc.h
new file mode 100644
index 00000000000000..0622e72b0683ee
--- /dev/null
+++ b/libc/src/stdbit/stdc_leading_zeros_uc.h
@@ -0,0 +1,18 @@
+//===-- Implementation header for stdc_leading_zeros_uc ---------*- 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_STDBIT_STDC_LEADING_ZEROS_UC_H
+#define LLVM_LIBC_SRC_STDBIT_STDC_LEADING_ZEROS_UC_H
+
+namespace LIBC_NAMESPACE {
+
+unsigned char stdc_leading_zeros_uc(unsigned char value);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_STDBIT_STDC_LEADING_ZEROS_UC_H
diff --git a/libc/src/stdbit/stdc_leading_zeros_ui.cpp b/libc/src/stdbit/stdc_leading_zeros_ui.cpp
new file mode 100644
index 00000000000000..99bc0eb70f33bf
--- /dev/null
+++ b/libc/src/stdbit/stdc_leading_zeros_ui.cpp
@@ -0,0 +1,20 @@
+//===-- Implementation of stdc_leading_zeros_ui ---------------------------===//
+//
+// 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/stdbit/stdc_leading_zeros_ui.h"
+
+#include "src/__support/CPP/bit.h"
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(unsigned, stdc_leading_zeros_ui, (unsigned value)) {
+  return static_cast<unsigned>(cpp::countl_zero(value));
+}
+
+} // namespace LIBC_NAMESPACE
diff --git a/libc/src/stdbit/stdc_leading_zeros_ui.h b/libc/src/stdbit/stdc_leading_zeros_ui.h
new file mode 100644
index 00000000000000..14113d486b54a0
--- /dev/null
+++ b/libc/src/stdbit/stdc_leading_zeros_ui.h
@@ -0,0 +1,18 @@
+//===-- Implementation header for stdc_leading_zeros_ui ---------*- 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_STDBIT_STDC_LEADING_ZEROS_UI_H
+#define LLVM_LIBC_SRC_STDBIT_STDC_LEADING_ZEROS_UI_H
+
+namespace LIBC_NAMESPACE {
+
+unsigned stdc_leading_zeros_ui(unsigned value);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_STDBIT_STDC_LEADING_ZEROS_UI_H
diff --git a/libc/src/stdbit/stdc_leading_zeros_ul.cpp b/libc/src/stdbit/stdc_leading_zeros_ul.cpp
new file mode 100644
index 00000000000000..4ce56be04ff358
--- /dev/null
+++ b/libc/src/stdbit/stdc_leading_zeros_ul.cpp
@@ -0,0 +1,20 @@
+//===-- Implementation of stdc_leading_zeros_ul ---------------------------===//
+//
+// 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/stdbit/stdc_leading_zeros_ul.h"
+
+#include "src/__support/CPP/bit.h"
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(unsigned long, stdc_leading_zeros_ul, (unsigned long value)) {
+  return static_cast<unsigned long>(cpp::countl_zero(value));
+}
+
+} // namespace LIBC_NAMESPACE
diff --git a/libc/src/stdbit/stdc_leading_zeros_ul.h b/libc/src/stdbit/stdc_leading_zeros_ul.h
new file mode 100644
index 00000000000000..a1f36299931dc2
--- /dev/null
+++ b/libc/src/stdbit/stdc_leading_zeros_ul.h
@@ -0,0 +1,18 @@
+//===-- Implementation header for stdc_leading_zeros_ul ---------*- 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_STDBIT_STDC_LEADING_ZEROS_UL_H
+#define LLVM_LIBC_SRC_STDBIT_STDC_LEADING_ZEROS_UL_H
+
+namespace LIBC_NAMESPACE {
+
+unsigned long stdc_leading_zeros_ul(unsigned long value);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_STDBIT_STDC_LEADING_ZEROS_UL_H
diff --git a/libc/src/stdbit/stdc_leading_zeros_ull.cpp b/libc/src/stdbit/stdc_leading_zeros_ull.cpp
new file mode 100644
index 00000000000000..5abd6a6e7aab9f
--- /dev/null
+++ b/libc/src/stdbit/stdc_leading_zeros_ull.cpp
@@ -0,0 +1,20 @@
+//===-- Implementation of stdc_leading_zeros_ull --------------------------===//
+//
+// 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/stdbit/stdc_leading_zeros_ull.h"
+
+#include "src/__support/CPP/bit.h"
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(unsigned long long, stdc_leading_zeros_ull, (unsigned long long value)) {
+  return static_cast<unsigned long long>(cpp::countl_zero(value));
+}
+
+} // namespace LIBC_NAMESPACE
diff --git a/libc/src/stdbit/stdc_leading_zeros_ull.h b/libc/src/stdbit/stdc_leading_zeros_ull.h
new file mode 100644
index 00000000000000..b05855b296af0b
--- /dev/null
+++ b/libc/src/stdbit/stdc_leading_zeros_ull.h
@@ -0,0 +1,18 @@
+//===-- Implementation header for stdc_leading_zeros_ull --------*- 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_STDBIT_STDC_LEADING_ZEROS_ULL_H
+#define LLVM_LIBC_SRC_STDBIT_STDC_LEADING_ZEROS_ULL_H
+
+namespace LIBC_NAMESPACE {
+
+unsigned long long stdc_leading_zeros_ull(unsigned long long value);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_STDBIT_STDC_LEADING_ZEROS_ULL_H
diff --git a/libc/src/stdbit/stdc_leading_zeros_us.cpp b/libc/src/stdbit/stdc_leading_zeros_us.cpp
new file mode 100644
index 00000000000000..0c14d5374a9737
--- /dev/null
+++ b/libc/src/stdbit/stdc_leading_zeros_us.cpp
@@ -0,0 +1,20 @@
+//===-- Implementation of stdc_leading_zeros_us ---------------------------===//
+//
+// 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/stdbit/stdc_leading_zeros_us.h"
+
+#include "src/__support/CPP/bit.h"
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(unsigned short, stdc_leading_zeros_us, (unsigned short value)) {
+  return static_cast<unsigned short>(cpp::countl_zero(value));
+}
+
+} // namespace LIBC_NAMESPACE
diff --git a/libc/src/stdbit/stdc_leading_zeros_us.h b/libc/src/stdbit/stdc_leading_zeros_us.h
new file mode 100644
index 00000000000000..c0f62e2be2f02b
--- /dev/null
+++ b/libc/src/stdbit/stdc_leading_zeros_us.h
@@ -0,0 +1,18 @@
+//===-- Implementation header for stdc_leading_zeros_us ---------*- 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_STDBIT_STDC_LEADING_ZEROS_US_H
+#define LLVM_LIBC_SRC_STDBIT_STDC_LEADING_ZEROS_US_H
+
+namespace LIBC_NAMESPACE {
+
+unsigned short stdc_leading_zeros_us(unsigned short value);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_STDBIT_STDC_LEADING_ZEROS_US_H
diff --git a/libc/test/include/CMakeLists.txt b/libc/test/include/CMakeLists.txt
index 183e7ecde719e5..69a08822b06dc6 100644
--- a/libc/test/include/CMakeLists.txt
+++ b/libc/test/include/CMakeLists.txt
@@ -14,3 +14,22 @@ add_libc_test(
     # This is needed because the __containerof macro uses statement expression.
     -Wno-gnu-statement-expression-from-macro-expansion
 )
+
+add_libc_test(
+  stdbit_test
+  SUITE
+    libc_include_tests
+  SRCS
+    stdbit_test.cpp
+  DEPENDS
+    libc.__support.CPP.limits
+    libc.include.llvm-libc-macros.stdbit_macros
+    libc.src.stdbit.stdc_leading_zeros_uc
+    libc.src.stdbit.stdc_leading_zeros_ui
+    libc.src.stdbit.stdc_leading_zeros_ul
+    libc.src.stdbit.stdc_leading_zeros_ull
+    libc.src.stdbit.stdc_leading_zeros_us
+  COMPILE_OPTIONS
+    # stdbit is full of type generic macros implemented via C11 _Generic.
+    -Wno-c11-extensions
+)
diff --git a/libc/test/include/stdbit_test.cpp b/libc/test/include/stdbit_test.cpp
new file mode 100644
index 00000000000000..c2e019d1096ea1
--- /dev/null
+++ b/libc/test/include/stdbit_test.cpp
@@ -0,0 +1,22 @@
+//===-- Unittests for stdbit ----------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDSList-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "test/UnitTest/Test.h"
+
+#include "llvm-libc-macros/stdbit-macros.h"
+#include "src/__support/CPP/limits.h" // UINT_WIDTH
+#include "src/stdbit/stdc_leading_zeros_uc.h"
+#include "src/stdbit/stdc_leading_zeros_ui.h"
+#include "src/stdbit/stdc_leading_zeros_ul.h"
+#include "src/stdbit/stdc_leading_zeros_ull.h"
+#include "src/stdbit/stdc_leading_zeros_us.h"
+
+TEST(LlvmLibcStdbitTest, TypeGenericMacro) {
+  using namespace LIBC_NAMESPACE;
+  EXPECT_EQ(stdc_leading_zeros(0U), static_cast<unsigned>(UINT_WIDTH));
+}
diff --git a/libc/test/src/CMakeLists.txt b/libc/test/src/CMakeLists.txt
index 6bd8ace9ea71af..1f899c729e0abc 100644
--- a/libc/test/src/CMakeLists.txt
+++ b/libc/test/src/CMakeLists.txt
@@ -40,13 +40,14 @@ add_subdirectory(__support)
 add_subdirectory(ctype)
 add_subdirectory(errno)
 add_subdirectory(fenv)
-add_subdirectory(math)
-add_subdirectory(string)
-add_subdirectory(stdlib)
 add_subdirectory(inttypes)
+add_subdirectory(math)
+add_subdirectory(search)
+add_subdirectory(stdbit)
 add_subdirectory(stdio)
+add_subdirectory(stdlib)
+add_subdirectory(string)
 add_subdirectory(wchar)
-add_subdirectory(search)
 
 if(${LIBC_TARGET_OS} STREQUAL "linux")
   add_subdirectory(fcntl)
@@ -113,7 +114,7 @@ add_custom_target(libc-api-test)
 add_dependencies(check-libc libc-api-test)
 
 set(
-  allocator_entrypoints 
+  allocator_entrypoints
     libc.src.stdlib.malloc
     libc.src.stdlib.calloc
     libc.src.stdlib.realloc
diff --git a/libc/test/src/stdbit/CMakeLists.txt b/libc/test/src/stdbit/CMakeLists.txt
new file mode 100644
index 00000000000000..73b32e4ec0caea
--- /dev/null
+++ b/libc/test/src/stdbit/CMakeLists.txt
@@ -0,0 +1,51 @@
+add_custom_target(libc-stdbit-tests)
+
+add_libc_test(
+  stdc_leading_zeros_uc_test
+  SUITE
+    libc-stdbit-tests
+  SRCS
+    stdc_leading_zeros_uc_test.cpp
+  DEPENDS
+    libc.src.stdbit.stdc_leading_zeros_uc
+)
+
+add_libc_test(
+  stdc_leading_zeros_us_test
+  SUITE
+    libc-stdbit-tests
+  SRCS
+    stdc_leading_zeros_us_test.cpp
+  DEPENDS
+    libc.src.stdbit.stdc_leading_zeros_us
+)
+
+add_libc_test(
+  stdc_leading_zeros_ui_test
+  SUITE
+    libc-stdbit-tests
+  SRCS
+    stdc_leading_zeros_ui_test.cpp
+  DEPENDS
+    libc.src.stdbit.stdc_leading_zeros_ui
+)
+
+add_libc_test(
+  stdc_leading_zeros_ul_test
+  SUITE
+    libc-stdbit-tests
+  SRCS
+    stdc_leading_zeros_ul_test.cpp
+  DEPENDS
+    libc.src.stdbit.stdc_leading_zeros_ul
+)
+
+add_libc_test(
+  stdc_leading_zeros_ull_test
+  SUITE
+    libc-stdbit-tests
+  SRCS
+    stdc_leading_zeros_ull_test.cpp
+  DEPENDS
+    libc.src.stdbit.stdc_leading_zeros_ull
+)
diff --git a/libc/test/src/stdbit/stdc_leading_zeros_uc_test.cpp b/libc/test/src/stdbit/stdc_leading_zeros_uc_test.cpp
new file mode 100644
index 00000000000000..76f32dea1896e7
--- /dev/null
+++ b/libc/test/src/stdbit/stdc_leading_zeros_uc_test.cpp
@@ -0,0 +1,22 @@
+//===-- Unittests for stdc_leading_zeros_uc -------------------------------===//
+//
+// 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/stdbit/stdc_leading_zeros_uc.h"
+#include "src/__support/CPP/limits.h"
+#include "test/UnitTest/Test.h"
+
+#define LZ(x) LIBC_NAMESPACE::stdc_leading_zeros_uc((x))
+
+TEST(LlvmLibcStdcLeadingZerosUcTest, Zero) {
+  EXPECT_EQ(LZ(0U), static_cast<unsigned char>(UCHAR_WIDTH));
+}
+
+TEST(LlvmLibcStdcLeadingZerosUcTest, OneHot) {
+  for (unsigned i = 0U; i != UCHAR_WIDTH; ++i)
+    EXPECT_EQ(LZ(1U << i), static_cast<unsigned char>(UCHAR_WIDTH - i - 1));
+}
diff --git a/libc/test/src/stdbit/stdc_leading_zeros_ui_test.cpp b/libc/test/src/stdbit/stdc_leading_zeros_ui_test.cpp
new file mode 100644
index 00000000000000..e1d6653fd3316f
--- /dev/null
+++ b/libc/test/src/stdbit/stdc_leading_zeros_ui_test.cpp
@@ -0,0 +1,23 @@
+//===-- Unittests for stdc_leading_zeros_ui -------------------------------===//
+//
+// 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/stdbit/stdc_leading_zeros_ui.h"
+#include "src/__support/CPP/limits.h"
+#include "test/UnitTest/Test.h"
+#include <stddef.h>
+
+#define LZ(x) LIBC_NAMESPACE::stdc_leading_zeros_ui((x))
+
+TEST(LlvmLibcStdcLeadingZerosUiTest, Zero) {
+  EXPECT_EQ(LZ(0U), static_cast<unsigned>(INT_WIDTH));
+}
+
+TEST(LlvmLibcStdcLeadingZerosUiTest, OneHot) {
+  for (unsigned i = 0U; i != INT_WIDTH; ++i)
+    EXPECT_EQ(LZ(1U << i), INT_WIDTH - i - 1);
+}
diff --git a/libc/test/src/stdbit/stdc_leading_zeros_ul_test.cpp b/libc/test/src/stdbit/stdc_leading_zeros_ul_test.cpp
new file mode 100644
index 00000000000000..fe085533dcb4a3
--- /dev/null
+++ b/libc/test/src/stdbit/stdc_leading_zeros_ul_test.cpp
@@ -0,0 +1,23 @@
+//===-- Unittests for stdc_leading_zeros_ul -------------------------------===//
+//
+// 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/stdbit/stdc_leading_zeros_ul.h"
+#include "src/__support/CPP/limits.h"
+#include "test/UnitTest/Test.h"
+#include <stddef.h>
+
+#define LZ(x) LIBC_NAMESPACE::stdc_leading_zeros_ul((x))
+
+TEST(LlvmLibcStdcLeadingZerosUlTest, Zero) {
+  EXPECT_EQ(LZ(0UL), static_cast<unsigned long>(ULONG_WIDTH));
+}
+
+TEST(LlvmLibcStdcLeadingZerosUlTest, OneHot) {
+  for (unsigned i = 0U; i != ULONG_WIDTH; ++i)
+    EXPECT_EQ(LZ(1UL << i), static_cast<unsigned long>(ULONG_WIDTH - i - 1));
+}
diff --git a/libc/test/src/stdbit/stdc_leading_zeros_ull_test.cpp b/libc/test/src/stdbit/stdc_leading_zeros_ull_test.cpp
new file mode 100644
index 00000000000000..c6ef95dab804b5
--- /dev/null
+++ b/libc/test/src/stdbit/stdc_leading_zeros_ull_test.cpp
@@ -0,0 +1,24 @@
+//===-- Unittests for stdc_leading_zeros_ull -------------------------------===//
+//
+// 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/stdbit/stdc_leading_zeros_ull.h"
+#include "src/__support/CPP/limits.h"
+#include "test/UnitTest/Test.h"
+#include <stddef.h>
+
+#define LZ(x) LIBC_NAMESPACE::stdc_leading_zeros_ull((x))
+
+TEST(LlvmLibcStdcLeadingZerosUllTest, Zero) {
+  EXPECT_EQ(LZ(0ULL), static_cast<unsigned long long>(ULLONG_WIDTH));
+}
+
+TEST(LlvmLibcStdcLeadingZerosUllTest, OneHot) {
+  for (unsigned i = 0U; i != ULLONG_WIDTH; ++i)
+    EXPECT_EQ(LZ(1ULL << i),
+              static_cast<unsigned long long>(ULLONG_WIDTH - i - 1));
+}
diff --git a/libc/test/src/stdbit/stdc_leading_zeros_us_test.cpp b/libc/test/src/stdbit/stdc_leading_zeros_us_test.cpp
new file mode 100644
index 00000000000000..0e50eeae8af383
--- /dev/null
+++ b/libc/test/src/stdbit/stdc_leading_zeros_us_test.cpp
@@ -0,0 +1,22 @@
+//===-- Unittests for stdc_leading_zeros_us -------------------------------===//
+//
+// 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/stdbit/stdc_leading_zeros_us.h"
+#include "src/__support/CPP/limits.h"
+#include "test/UnitTest/Test.h"
+
+#define LZ(x) LIBC_NAMESPACE::stdc_leading_zeros_us((x))
+
+TEST(LlvmLibcStdcLeadingZerosUsTest, Zero) {
+  EXPECT_EQ(LZ(0U), static_cast<unsigned short>(USHRT_WIDTH));
+}
+
+TEST(LlvmLibcStdcLeadingZerosUsTest, OneHot) {
+  for (unsigned i = 0U; i != USHRT_WIDTH; ++i)
+    EXPECT_EQ(LZ(1U << i), static_cast<unsigned short>(USHRT_WIDTH - i - 1));
+}

>From 29581cf1bdadc9768a31223b506bd207d44a1d2d Mon Sep 17 00:00:00 2001
From: Nick Desaulniers <ndesaulniers at google.com>
Date: Fri, 26 Jan 2024 16:09:22 -0800
Subject: [PATCH 2/8] reformat

---
 libc/include/llvm-libc-macros/stdbit-macros.h       | 13 +++++++------
 libc/src/stdbit/stdc_leading_zeros_uc.cpp           |  3 ++-
 libc/src/stdbit/stdc_leading_zeros_ul.cpp           |  3 ++-
 libc/src/stdbit/stdc_leading_zeros_ull.cpp          |  3 ++-
 libc/src/stdbit/stdc_leading_zeros_us.cpp           |  3 ++-
 libc/test/src/stdbit/stdc_leading_zeros_uc_test.cpp |  2 +-
 libc/test/src/stdbit/stdc_leading_zeros_ui_test.cpp |  2 +-
 libc/test/src/stdbit/stdc_leading_zeros_ul_test.cpp |  2 +-
 .../test/src/stdbit/stdc_leading_zeros_ull_test.cpp |  5 +++--
 libc/test/src/stdbit/stdc_leading_zeros_us_test.cpp |  2 +-
 10 files changed, 22 insertions(+), 16 deletions(-)

diff --git a/libc/include/llvm-libc-macros/stdbit-macros.h b/libc/include/llvm-libc-macros/stdbit-macros.h
index 183328877c3da8..febe95fe0a1e3c 100644
--- a/libc/include/llvm-libc-macros/stdbit-macros.h
+++ b/libc/include/llvm-libc-macros/stdbit-macros.h
@@ -9,11 +9,12 @@
 #ifndef __LLVM_LIBC_MACROS_STDBIT_MACROS_H
 #define __LLVM_LIBC_MACROS_STDBIT_MACROS_H
 
-#define stdc_leading_zeros(x) _Generic((x), \
-  unsigned char: stdc_leading_zeros_uc, \
-  unsigned short: stdc_leading_zeros_us, \
-  unsigned: stdc_leading_zeros_ui, \
-  unsigned long: stdc_leading_zeros_ul, \
-  unsigned long long: stdc_leading_zeros_ull)(x)
+#define stdc_leading_zeros(x)                                                  \
+  _Generic((x),                                                                \
+      unsigned char: stdc_leading_zeros_uc,                                    \
+      unsigned short: stdc_leading_zeros_us,                                   \
+      unsigned: stdc_leading_zeros_ui,                                         \
+      unsigned long: stdc_leading_zeros_ul,                                    \
+      unsigned long long: stdc_leading_zeros_ull)(x)
 
 #endif // __LLVM_LIBC_MACROS_STDBIT_MACROS_H
diff --git a/libc/src/stdbit/stdc_leading_zeros_uc.cpp b/libc/src/stdbit/stdc_leading_zeros_uc.cpp
index a985700274d259..8c27043e055bf9 100644
--- a/libc/src/stdbit/stdc_leading_zeros_uc.cpp
+++ b/libc/src/stdbit/stdc_leading_zeros_uc.cpp
@@ -13,7 +13,8 @@
 
 namespace LIBC_NAMESPACE {
 
-LLVM_LIBC_FUNCTION(unsigned char, stdc_leading_zeros_uc, (unsigned char value)) {
+LLVM_LIBC_FUNCTION(unsigned char, stdc_leading_zeros_uc,
+                   (unsigned char value)) {
   return static_cast<unsigned char>(cpp::countl_zero(value));
 }
 
diff --git a/libc/src/stdbit/stdc_leading_zeros_ul.cpp b/libc/src/stdbit/stdc_leading_zeros_ul.cpp
index 4ce56be04ff358..cf21ff449a8bf5 100644
--- a/libc/src/stdbit/stdc_leading_zeros_ul.cpp
+++ b/libc/src/stdbit/stdc_leading_zeros_ul.cpp
@@ -13,7 +13,8 @@
 
 namespace LIBC_NAMESPACE {
 
-LLVM_LIBC_FUNCTION(unsigned long, stdc_leading_zeros_ul, (unsigned long value)) {
+LLVM_LIBC_FUNCTION(unsigned long, stdc_leading_zeros_ul,
+                   (unsigned long value)) {
   return static_cast<unsigned long>(cpp::countl_zero(value));
 }
 
diff --git a/libc/src/stdbit/stdc_leading_zeros_ull.cpp b/libc/src/stdbit/stdc_leading_zeros_ull.cpp
index 5abd6a6e7aab9f..d488559bbd14c2 100644
--- a/libc/src/stdbit/stdc_leading_zeros_ull.cpp
+++ b/libc/src/stdbit/stdc_leading_zeros_ull.cpp
@@ -13,7 +13,8 @@
 
 namespace LIBC_NAMESPACE {
 
-LLVM_LIBC_FUNCTION(unsigned long long, stdc_leading_zeros_ull, (unsigned long long value)) {
+LLVM_LIBC_FUNCTION(unsigned long long, stdc_leading_zeros_ull,
+                   (unsigned long long value)) {
   return static_cast<unsigned long long>(cpp::countl_zero(value));
 }
 
diff --git a/libc/src/stdbit/stdc_leading_zeros_us.cpp b/libc/src/stdbit/stdc_leading_zeros_us.cpp
index 0c14d5374a9737..84df2b842d6950 100644
--- a/libc/src/stdbit/stdc_leading_zeros_us.cpp
+++ b/libc/src/stdbit/stdc_leading_zeros_us.cpp
@@ -13,7 +13,8 @@
 
 namespace LIBC_NAMESPACE {
 
-LLVM_LIBC_FUNCTION(unsigned short, stdc_leading_zeros_us, (unsigned short value)) {
+LLVM_LIBC_FUNCTION(unsigned short, stdc_leading_zeros_us,
+                   (unsigned short value)) {
   return static_cast<unsigned short>(cpp::countl_zero(value));
 }
 
diff --git a/libc/test/src/stdbit/stdc_leading_zeros_uc_test.cpp b/libc/test/src/stdbit/stdc_leading_zeros_uc_test.cpp
index 76f32dea1896e7..ad87c14804e39c 100644
--- a/libc/test/src/stdbit/stdc_leading_zeros_uc_test.cpp
+++ b/libc/test/src/stdbit/stdc_leading_zeros_uc_test.cpp
@@ -6,8 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "src/stdbit/stdc_leading_zeros_uc.h"
 #include "src/__support/CPP/limits.h"
+#include "src/stdbit/stdc_leading_zeros_uc.h"
 #include "test/UnitTest/Test.h"
 
 #define LZ(x) LIBC_NAMESPACE::stdc_leading_zeros_uc((x))
diff --git a/libc/test/src/stdbit/stdc_leading_zeros_ui_test.cpp b/libc/test/src/stdbit/stdc_leading_zeros_ui_test.cpp
index e1d6653fd3316f..a3dde44a8c6630 100644
--- a/libc/test/src/stdbit/stdc_leading_zeros_ui_test.cpp
+++ b/libc/test/src/stdbit/stdc_leading_zeros_ui_test.cpp
@@ -6,8 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "src/stdbit/stdc_leading_zeros_ui.h"
 #include "src/__support/CPP/limits.h"
+#include "src/stdbit/stdc_leading_zeros_ui.h"
 #include "test/UnitTest/Test.h"
 #include <stddef.h>
 
diff --git a/libc/test/src/stdbit/stdc_leading_zeros_ul_test.cpp b/libc/test/src/stdbit/stdc_leading_zeros_ul_test.cpp
index fe085533dcb4a3..1a1df653c88049 100644
--- a/libc/test/src/stdbit/stdc_leading_zeros_ul_test.cpp
+++ b/libc/test/src/stdbit/stdc_leading_zeros_ul_test.cpp
@@ -6,8 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "src/stdbit/stdc_leading_zeros_ul.h"
 #include "src/__support/CPP/limits.h"
+#include "src/stdbit/stdc_leading_zeros_ul.h"
 #include "test/UnitTest/Test.h"
 #include <stddef.h>
 
diff --git a/libc/test/src/stdbit/stdc_leading_zeros_ull_test.cpp b/libc/test/src/stdbit/stdc_leading_zeros_ull_test.cpp
index c6ef95dab804b5..fe5058c4d2f0d3 100644
--- a/libc/test/src/stdbit/stdc_leading_zeros_ull_test.cpp
+++ b/libc/test/src/stdbit/stdc_leading_zeros_ull_test.cpp
@@ -1,4 +1,5 @@
-//===-- Unittests for stdc_leading_zeros_ull -------------------------------===//
+//===-- Unittests for stdc_leading_zeros_ull
+//-------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -6,8 +7,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "src/stdbit/stdc_leading_zeros_ull.h"
 #include "src/__support/CPP/limits.h"
+#include "src/stdbit/stdc_leading_zeros_ull.h"
 #include "test/UnitTest/Test.h"
 #include <stddef.h>
 
diff --git a/libc/test/src/stdbit/stdc_leading_zeros_us_test.cpp b/libc/test/src/stdbit/stdc_leading_zeros_us_test.cpp
index 0e50eeae8af383..8324f3a96922d2 100644
--- a/libc/test/src/stdbit/stdc_leading_zeros_us_test.cpp
+++ b/libc/test/src/stdbit/stdc_leading_zeros_us_test.cpp
@@ -6,8 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "src/stdbit/stdc_leading_zeros_us.h"
 #include "src/__support/CPP/limits.h"
+#include "src/stdbit/stdc_leading_zeros_us.h"
 #include "test/UnitTest/Test.h"
 
 #define LZ(x) LIBC_NAMESPACE::stdc_leading_zeros_us((x))

>From e7f695603e75a40e5a9a9d3aea50eec437e6a07a Mon Sep 17 00:00:00 2001
From: Nick Desaulniers <ndesaulniers at google.com>
Date: Mon, 29 Jan 2024 09:18:07 -0800
Subject: [PATCH 3/8] fix formatting

---
 libc/test/src/stdbit/stdc_leading_zeros_ull_test.cpp | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/libc/test/src/stdbit/stdc_leading_zeros_ull_test.cpp b/libc/test/src/stdbit/stdc_leading_zeros_ull_test.cpp
index fe5058c4d2f0d3..1758821b6e2058 100644
--- a/libc/test/src/stdbit/stdc_leading_zeros_ull_test.cpp
+++ b/libc/test/src/stdbit/stdc_leading_zeros_ull_test.cpp
@@ -1,5 +1,4 @@
-//===-- Unittests for stdc_leading_zeros_ull
-//-------------------------------===//
+//===-- Unittests for stdc_leading_zeros_ull ------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.

>From 48efd947016841898077c2ca44e3137fbd7fc015 Mon Sep 17 00:00:00 2001
From: Nick Desaulniers <ndesaulniers at google.com>
Date: Mon, 29 Jan 2024 09:22:08 -0800
Subject: [PATCH 4/8] remove LZ macro from new tests

---
 libc/test/src/stdbit/stdc_leading_zeros_uc_test.cpp  | 8 ++++----
 libc/test/src/stdbit/stdc_leading_zeros_ui_test.cpp  | 8 ++++----
 libc/test/src/stdbit/stdc_leading_zeros_ul_test.cpp  | 8 ++++----
 libc/test/src/stdbit/stdc_leading_zeros_ull_test.cpp | 7 +++----
 libc/test/src/stdbit/stdc_leading_zeros_us_test.cpp  | 8 ++++----
 5 files changed, 19 insertions(+), 20 deletions(-)

diff --git a/libc/test/src/stdbit/stdc_leading_zeros_uc_test.cpp b/libc/test/src/stdbit/stdc_leading_zeros_uc_test.cpp
index ad87c14804e39c..4e2e1db3bd72b9 100644
--- a/libc/test/src/stdbit/stdc_leading_zeros_uc_test.cpp
+++ b/libc/test/src/stdbit/stdc_leading_zeros_uc_test.cpp
@@ -10,13 +10,13 @@
 #include "src/stdbit/stdc_leading_zeros_uc.h"
 #include "test/UnitTest/Test.h"
 
-#define LZ(x) LIBC_NAMESPACE::stdc_leading_zeros_uc((x))
-
 TEST(LlvmLibcStdcLeadingZerosUcTest, Zero) {
-  EXPECT_EQ(LZ(0U), static_cast<unsigned char>(UCHAR_WIDTH));
+  EXPECT_EQ(LIBC_NAMESPACE::stdc_leading_zeros_uc(0U),
+            static_cast<unsigned char>(UCHAR_WIDTH));
 }
 
 TEST(LlvmLibcStdcLeadingZerosUcTest, OneHot) {
   for (unsigned i = 0U; i != UCHAR_WIDTH; ++i)
-    EXPECT_EQ(LZ(1U << i), static_cast<unsigned char>(UCHAR_WIDTH - i - 1));
+    EXPECT_EQ(LIBC_NAMESPACE::stdc_leading_zeros_uc(1U << i),
+              static_cast<unsigned char>(UCHAR_WIDTH - i - 1));
 }
diff --git a/libc/test/src/stdbit/stdc_leading_zeros_ui_test.cpp b/libc/test/src/stdbit/stdc_leading_zeros_ui_test.cpp
index a3dde44a8c6630..2bd6bb586d7de4 100644
--- a/libc/test/src/stdbit/stdc_leading_zeros_ui_test.cpp
+++ b/libc/test/src/stdbit/stdc_leading_zeros_ui_test.cpp
@@ -11,13 +11,13 @@
 #include "test/UnitTest/Test.h"
 #include <stddef.h>
 
-#define LZ(x) LIBC_NAMESPACE::stdc_leading_zeros_ui((x))
-
 TEST(LlvmLibcStdcLeadingZerosUiTest, Zero) {
-  EXPECT_EQ(LZ(0U), static_cast<unsigned>(INT_WIDTH));
+  EXPECT_EQ(LIBC_NAMESPACE::stdc_leading_zeros_ui(0U),
+            static_cast<unsigned>(INT_WIDTH));
 }
 
 TEST(LlvmLibcStdcLeadingZerosUiTest, OneHot) {
   for (unsigned i = 0U; i != INT_WIDTH; ++i)
-    EXPECT_EQ(LZ(1U << i), INT_WIDTH - i - 1);
+    EXPECT_EQ(LIBC_NAMESPACE::stdc_leading_zeros_ui(1U << i),
+              INT_WIDTH - i - 1);
 }
diff --git a/libc/test/src/stdbit/stdc_leading_zeros_ul_test.cpp b/libc/test/src/stdbit/stdc_leading_zeros_ul_test.cpp
index 1a1df653c88049..9a73aece89acc5 100644
--- a/libc/test/src/stdbit/stdc_leading_zeros_ul_test.cpp
+++ b/libc/test/src/stdbit/stdc_leading_zeros_ul_test.cpp
@@ -11,13 +11,13 @@
 #include "test/UnitTest/Test.h"
 #include <stddef.h>
 
-#define LZ(x) LIBC_NAMESPACE::stdc_leading_zeros_ul((x))
-
 TEST(LlvmLibcStdcLeadingZerosUlTest, Zero) {
-  EXPECT_EQ(LZ(0UL), static_cast<unsigned long>(ULONG_WIDTH));
+  EXPECT_EQ(LIBC_NAMESPACE::stdc_leading_zeros_ul(0UL),
+            static_cast<unsigned long>(ULONG_WIDTH));
 }
 
 TEST(LlvmLibcStdcLeadingZerosUlTest, OneHot) {
   for (unsigned i = 0U; i != ULONG_WIDTH; ++i)
-    EXPECT_EQ(LZ(1UL << i), static_cast<unsigned long>(ULONG_WIDTH - i - 1));
+    EXPECT_EQ(LIBC_NAMESPACE::stdc_leading_zeros_ul(1UL << i),
+              static_cast<unsigned long>(ULONG_WIDTH - i - 1));
 }
diff --git a/libc/test/src/stdbit/stdc_leading_zeros_ull_test.cpp b/libc/test/src/stdbit/stdc_leading_zeros_ull_test.cpp
index 1758821b6e2058..9df2f015f9b6fb 100644
--- a/libc/test/src/stdbit/stdc_leading_zeros_ull_test.cpp
+++ b/libc/test/src/stdbit/stdc_leading_zeros_ull_test.cpp
@@ -11,14 +11,13 @@
 #include "test/UnitTest/Test.h"
 #include <stddef.h>
 
-#define LZ(x) LIBC_NAMESPACE::stdc_leading_zeros_ull((x))
-
 TEST(LlvmLibcStdcLeadingZerosUllTest, Zero) {
-  EXPECT_EQ(LZ(0ULL), static_cast<unsigned long long>(ULLONG_WIDTH));
+  EXPECT_EQ(LIBC_NAMESPACE::stdc_leading_zeros_ull(0ULL),
+            static_cast<unsigned long long>(ULLONG_WIDTH));
 }
 
 TEST(LlvmLibcStdcLeadingZerosUllTest, OneHot) {
   for (unsigned i = 0U; i != ULLONG_WIDTH; ++i)
-    EXPECT_EQ(LZ(1ULL << i),
+    EXPECT_EQ(LIBC_NAMESPACE::stdc_leading_zeros_ull(1ULL << i),
               static_cast<unsigned long long>(ULLONG_WIDTH - i - 1));
 }
diff --git a/libc/test/src/stdbit/stdc_leading_zeros_us_test.cpp b/libc/test/src/stdbit/stdc_leading_zeros_us_test.cpp
index 8324f3a96922d2..b396a740e43b7c 100644
--- a/libc/test/src/stdbit/stdc_leading_zeros_us_test.cpp
+++ b/libc/test/src/stdbit/stdc_leading_zeros_us_test.cpp
@@ -10,13 +10,13 @@
 #include "src/stdbit/stdc_leading_zeros_us.h"
 #include "test/UnitTest/Test.h"
 
-#define LZ(x) LIBC_NAMESPACE::stdc_leading_zeros_us((x))
-
 TEST(LlvmLibcStdcLeadingZerosUsTest, Zero) {
-  EXPECT_EQ(LZ(0U), static_cast<unsigned short>(USHRT_WIDTH));
+  EXPECT_EQ(LIBC_NAMESPACE::stdc_leading_zeros_us(0U),
+            static_cast<unsigned short>(USHRT_WIDTH));
 }
 
 TEST(LlvmLibcStdcLeadingZerosUsTest, OneHot) {
   for (unsigned i = 0U; i != USHRT_WIDTH; ++i)
-    EXPECT_EQ(LZ(1U << i), static_cast<unsigned short>(USHRT_WIDTH - i - 1));
+    EXPECT_EQ(LIBC_NAMESPACE::stdc_leading_zeros_us(1U << i),
+              static_cast<unsigned short>(USHRT_WIDTH - i - 1));
 }

>From f30fddde040e1b664d3f1497cb41e31953effc49 Mon Sep 17 00:00:00 2001
From: Nick Desaulniers <ndesaulniers at google.com>
Date: Mon, 29 Jan 2024 09:38:33 -0800
Subject: [PATCH 5/8] fix cmake

---
 libc/test/include/CMakeLists.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libc/test/include/CMakeLists.txt b/libc/test/include/CMakeLists.txt
index 69a08822b06dc6..c07ec4ce54b182 100644
--- a/libc/test/include/CMakeLists.txt
+++ b/libc/test/include/CMakeLists.txt
@@ -22,8 +22,8 @@ add_libc_test(
   SRCS
     stdbit_test.cpp
   DEPENDS
-    libc.__support.CPP.limits
     libc.include.llvm-libc-macros.stdbit_macros
+    libc.src.__support.CPP.limits
     libc.src.stdbit.stdc_leading_zeros_uc
     libc.src.stdbit.stdc_leading_zeros_ui
     libc.src.stdbit.stdc_leading_zeros_ul

>From 3386377534329227a20f4924f882e63940f28ea0 Mon Sep 17 00:00:00 2001
From: Nick Desaulniers <ndesaulniers at google.com>
Date: Mon, 29 Jan 2024 10:24:15 -0800
Subject: [PATCH 6/8] change include test to only test our generated macro

---
 libc/test/include/CMakeLists.txt  | 10 ++++------
 libc/test/include/stdbit_test.cpp | 30 +++++++++++++++++++++---------
 2 files changed, 25 insertions(+), 15 deletions(-)

diff --git a/libc/test/include/CMakeLists.txt b/libc/test/include/CMakeLists.txt
index c07ec4ce54b182..4af3d669ded224 100644
--- a/libc/test/include/CMakeLists.txt
+++ b/libc/test/include/CMakeLists.txt
@@ -23,12 +23,10 @@ add_libc_test(
     stdbit_test.cpp
   DEPENDS
     libc.include.llvm-libc-macros.stdbit_macros
-    libc.src.__support.CPP.limits
-    libc.src.stdbit.stdc_leading_zeros_uc
-    libc.src.stdbit.stdc_leading_zeros_ui
-    libc.src.stdbit.stdc_leading_zeros_ul
-    libc.src.stdbit.stdc_leading_zeros_ull
-    libc.src.stdbit.stdc_leading_zeros_us
+    libc.include.stdbit
+    # Intentionally do not depend on libc.src.stdbit.*. The include test is
+    # simply testing the macros provided by stdbit.h, not the implementation of
+    # the underlying functions which the type generic macros may dispatch to.
   COMPILE_OPTIONS
     # stdbit is full of type generic macros implemented via C11 _Generic.
     -Wno-c11-extensions
diff --git a/libc/test/include/stdbit_test.cpp b/libc/test/include/stdbit_test.cpp
index c2e019d1096ea1..10ce492f6394f7 100644
--- a/libc/test/include/stdbit_test.cpp
+++ b/libc/test/include/stdbit_test.cpp
@@ -8,15 +8,27 @@
 
 #include "test/UnitTest/Test.h"
 
-#include "llvm-libc-macros/stdbit-macros.h"
-#include "src/__support/CPP/limits.h" // UINT_WIDTH
-#include "src/stdbit/stdc_leading_zeros_uc.h"
-#include "src/stdbit/stdc_leading_zeros_ui.h"
-#include "src/stdbit/stdc_leading_zeros_ul.h"
-#include "src/stdbit/stdc_leading_zeros_ull.h"
-#include "src/stdbit/stdc_leading_zeros_us.h"
+#include <stdbit.h>
+
+/*
+ * The intent of this test is validate that:
+ * 1. We provide the definition of the various type generic macros of stdbit.h.
+ * 2. It dispatches to the correct underlying function.
+ * Because unit tests build without public packaging, the object files produced
+ * do not contain non-namespaced symbols.
+ */
+
+unsigned char stdc_leading_zeros_uc(unsigned char) { return 0xAA; }
+unsigned short stdc_leading_zeros_us(unsigned short) { return 0xAB; }
+unsigned stdc_leading_zeros_ui(unsigned) { return 0xAC; }
+unsigned long stdc_leading_zeros_ul(unsigned long) { return 0xAD; }
+unsigned long long stdc_leading_zeros_ull(unsigned long long) { return 0xAF; }
 
 TEST(LlvmLibcStdbitTest, TypeGenericMacro) {
-  using namespace LIBC_NAMESPACE;
-  EXPECT_EQ(stdc_leading_zeros(0U), static_cast<unsigned>(UINT_WIDTH));
+  EXPECT_EQ(stdc_leading_zeros(static_cast<unsigned char>(0U)), static_cast<unsigned char>(0xAA));
+  EXPECT_EQ(stdc_leading_zeros(static_cast<unsigned short>(0U)),
+            static_cast<unsigned short>(0xAB));
+  EXPECT_EQ(stdc_leading_zeros(0U), static_cast<unsigned>(0xAC));
+  EXPECT_EQ(stdc_leading_zeros(0UL), static_cast<unsigned long>(0xAD));
+  EXPECT_EQ(stdc_leading_zeros(0ULL), static_cast<unsigned long long>(0xAF));
 }

>From dfbf115e640ef0b1d451c6f29222ab399239e4aa Mon Sep 17 00:00:00 2001
From: Nick Desaulniers <ndesaulniers at google.com>
Date: Mon, 29 Jan 2024 10:26:39 -0800
Subject: [PATCH 7/8] expand comment slightly

---
 libc/test/include/CMakeLists.txt | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libc/test/include/CMakeLists.txt b/libc/test/include/CMakeLists.txt
index 4af3d669ded224..766df1ab6da41e 100644
--- a/libc/test/include/CMakeLists.txt
+++ b/libc/test/include/CMakeLists.txt
@@ -28,6 +28,7 @@ add_libc_test(
     # simply testing the macros provided by stdbit.h, not the implementation of
     # the underlying functions which the type generic macros may dispatch to.
   COMPILE_OPTIONS
-    # stdbit is full of type generic macros implemented via C11 _Generic.
+    # stdbit.h is full of type generic macros implemented via C11 _Generic.
+    # Clang will produce -Wno-c11-extensions when using _Generic in C++ mode.
     -Wno-c11-extensions
 )

>From 0e7e10f7a8a66c97f594a45e8f5f190e63913fa1 Mon Sep 17 00:00:00 2001
From: Nick Desaulniers <ndesaulniers at google.com>
Date: Mon, 29 Jan 2024 10:27:40 -0800
Subject: [PATCH 8/8] formatting

---
 libc/test/include/stdbit_test.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libc/test/include/stdbit_test.cpp b/libc/test/include/stdbit_test.cpp
index 10ce492f6394f7..d20005cc31afa0 100644
--- a/libc/test/include/stdbit_test.cpp
+++ b/libc/test/include/stdbit_test.cpp
@@ -25,7 +25,8 @@ unsigned long stdc_leading_zeros_ul(unsigned long) { return 0xAD; }
 unsigned long long stdc_leading_zeros_ull(unsigned long long) { return 0xAF; }
 
 TEST(LlvmLibcStdbitTest, TypeGenericMacro) {
-  EXPECT_EQ(stdc_leading_zeros(static_cast<unsigned char>(0U)), static_cast<unsigned char>(0xAA));
+  EXPECT_EQ(stdc_leading_zeros(static_cast<unsigned char>(0U)),
+            static_cast<unsigned char>(0xAA));
   EXPECT_EQ(stdc_leading_zeros(static_cast<unsigned short>(0U)),
             static_cast<unsigned short>(0xAB));
   EXPECT_EQ(stdc_leading_zeros(0U), static_cast<unsigned>(0xAC));



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