[libc] implement stdc_leading_ones (C23) (#80082)

libc/config/linux/x86_64/entrypoints.txt

@@ -97,6 +97,11 @@ set(TARGET_LIBC_ENTRYPOINTS
     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_ones_uc
+    libc.src.stdbit.stdc_leading_ones_us
+    libc.src.stdbit.stdc_leading_ones_ui
+    libc.src.stdbit.stdc_leading_ones_ul
+    libc.src.stdbit.stdc_leading_ones_ull
 
     # stdlib.h entrypoints
     libc.src.stdlib.abs

libc/docs/stdbit.rst

@@ -36,11 +36,11 @@ stdc_leading_zeros_us        |check|
 stdc_leading_zeros_ui        |check|
 stdc_leading_zeros_ul        |check|
 stdc_leading_zeros_ull       |check|
-stdc_leading_ones_uc
-stdc_leading_ones_us
-stdc_leading_ones_ui
-stdc_leading_ones_ul
-stdc_leading_ones_ull
+stdc_leading_ones_uc         |check|
+stdc_leading_ones_us         |check|
+stdc_leading_ones_ui         |check|
+stdc_leading_ones_ul         |check|
+stdc_leading_ones_ull        |check|
 stdc_trailing_zeros_uc
 stdc_trailing_zeros_us
 stdc_trailing_zeros_ui
@@ -115,7 +115,7 @@ __STDC_ENDIAN_LITTLE__
 __STDC_ENDIAN_BIG__
 __STDC_ENDIAN_NATIVE__
 stdc_leading_zeros         |check|
-stdc_leading_ones
+stdc_leading_ones          |check|
 stdc_trailing_zeros
 stdc_trailing_ones
 stdc_first_leading_zero

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

@@ -25,6 +25,21 @@ inline unsigned long stdc_leading_zeros(unsigned long x) {
 inline unsigned long long stdc_leading_zeros(unsigned long long x) {
   return stdc_leading_zeros_ull(x);
 }
+inline unsigned char stdc_leading_ones(unsigned char x) {
+  return stdc_leading_ones_uc(x);
+}
+inline unsigned short stdc_leading_ones(unsigned short x) {
+  return stdc_leading_ones_us(x);
+}
+inline unsigned stdc_leading_ones(unsigned x) {
+  return stdc_leading_ones_ui(x);
+}
+inline unsigned long stdc_leading_ones(unsigned long x) {
+  return stdc_leading_ones_ul(x);
+}
+inline unsigned long long stdc_leading_ones(unsigned long long x) {
+  return stdc_leading_ones_ull(x);
+}
 #else
 #define stdc_leading_zeros(x)                                                  \
   _Generic((x),                                                                \
@@ -33,6 +48,13 @@ inline unsigned long long stdc_leading_zeros(unsigned long long x) {
       unsigned: stdc_leading_zeros_ui,                                         \
       unsigned long: stdc_leading_zeros_ul,                                    \
       unsigned long long: stdc_leading_zeros_ull)(x)
+#define stdc_leading_ones(x)                                                   \
+  _Generic((x),                                                                \
+      unsigned char: stdc_leading_ones_uc,                                     \
+      unsigned short: stdc_leading_ones_us,                                    \
+      unsigned: stdc_leading_ones_ui,                                          \
+      unsigned long: stdc_leading_ones_ul,                                     \
+      unsigned long long: stdc_leading_ones_ull)(x)
 #endif // __cplusplus
 
 #endif // __LLVM_LIBC_MACROS_STDBIT_MACROS_H

libc/spec/stdc.td

@@ -779,7 +779,12 @@ def StdC : StandardSpec<"stdc"> {
           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>]>
+          FunctionSpec<"stdc_leading_zeros_ull", RetValSpec<UnsignedLongLongType>, [ArgSpec<UnsignedLongLongType>]>,
+          FunctionSpec<"stdc_leading_ones_uc", RetValSpec<UnsignedCharType>, [ArgSpec<UnsignedCharType>]>,
+          FunctionSpec<"stdc_leading_ones_us", RetValSpec<UnsignedShortType>, [ArgSpec<UnsignedShortType>]>,
+          FunctionSpec<"stdc_leading_ones_ui", RetValSpec<UnsignedIntType>, [ArgSpec<UnsignedIntType>]>,
+          FunctionSpec<"stdc_leading_ones_ul", RetValSpec<UnsignedLongType>, [ArgSpec<UnsignedLongType>]>,
+          FunctionSpec<"stdc_leading_ones_ull", RetValSpec<UnsignedLongLongType>, [ArgSpec<UnsignedLongLongType>]>
       ] // Functions
   >;
 

libc/src/stdbit/CMakeLists.txt

@@ -47,3 +47,53 @@ add_entrypoint_object(
   DEPENDS
     libc.src.__support.CPP.bit
 )
+
+add_entrypoint_object(
+  stdc_leading_ones_uc
+  SRCS
+    stdc_leading_ones_uc.cpp
+  HDRS
+    stdc_leading_ones_uc.h
+  DEPENDS
+    libc.src.__support.CPP.bit
+)
+
+add_entrypoint_object(
+  stdc_leading_ones_us
+  SRCS
+    stdc_leading_ones_us.cpp
+  HDRS
+    stdc_leading_ones_us.h
+  DEPENDS
+    libc.src.__support.CPP.bit
+)
+
+add_entrypoint_object(
+  stdc_leading_ones_ui
+  SRCS
+    stdc_leading_ones_ui.cpp
+  HDRS
+    stdc_leading_ones_ui.h
+  DEPENDS
+    libc.src.__support.CPP.bit
+)
+
+add_entrypoint_object(
+  stdc_leading_ones_ul
+  SRCS
+    stdc_leading_ones_ul.cpp
+  HDRS
+    stdc_leading_ones_ul.h
+  DEPENDS
+    libc.src.__support.CPP.bit
+)
+
+add_entrypoint_object(
+  stdc_leading_ones_ull
+  SRCS
+    stdc_leading_ones_ull.cpp
+  HDRS
+    stdc_leading_ones_ull.h
+  DEPENDS
+    libc.src.__support.CPP.bit
+)

libc/src/stdbit/stdc_leading_ones_uc.cpp

@@ -0,0 +1,20 @@
+//===-- Implementation of stdc_leading_ones_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_ones_uc.h"
+
+#include "src/__support/CPP/bit.h"
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(unsigned char, stdc_leading_ones_uc, (unsigned char value)) {
+  return static_cast<unsigned char>(cpp::countl_one(value));
+}
+
+} // namespace LIBC_NAMESPACE

libc/src/stdbit/stdc_leading_ones_uc.h

@@ -0,0 +1,18 @@
+//===-- Implementation header for stdc_leading_ones_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_ONES_UC_H
+#define LLVM_LIBC_SRC_STDBIT_STDC_LEADING_ONES_UC_H
+
+namespace LIBC_NAMESPACE {
+
+unsigned char stdc_leading_ones_uc(unsigned char value);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_STDBIT_STDC_LEADING_ONES_UC_H

libc/src/stdbit/stdc_leading_ones_ui.cpp

@@ -0,0 +1,20 @@
+//===-- Implementation of stdc_leading_ones_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_ones_ui.h"
+
+#include "src/__support/CPP/bit.h"
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(unsigned, stdc_leading_ones_ui, (unsigned value)) {
+  return static_cast<unsigned>(cpp::countl_one(value));
+}
+
+} // namespace LIBC_NAMESPACE

libc/src/stdbit/stdc_leading_ones_ui.h

@@ -0,0 +1,18 @@
+//===-- Implementation header for stdc_leading_ones_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_ONES_UI_H
+#define LLVM_LIBC_SRC_STDBIT_STDC_LEADING_ONES_UI_H
+
+namespace LIBC_NAMESPACE {
+
+unsigned stdc_leading_ones_ui(unsigned value);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_STDBIT_STDC_LEADING_ONES_UI_H

libc/src/stdbit/stdc_leading_ones_ul.cpp

@@ -0,0 +1,20 @@
+//===-- Implementation of stdc_leading_ones_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_ones_ul.h"
+
+#include "src/__support/CPP/bit.h"
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(unsigned long, stdc_leading_ones_ul, (unsigned long value)) {
+  return static_cast<unsigned long>(cpp::countl_one(value));
+}
+
+} // namespace LIBC_NAMESPACE

libc/src/stdbit/stdc_leading_ones_ul.h

@@ -0,0 +1,18 @@
+//===-- Implementation header for stdc_leading_ones_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_ONES_UL_H
+#define LLVM_LIBC_SRC_STDBIT_STDC_LEADING_ONES_UL_H
+
+namespace LIBC_NAMESPACE {
+
+unsigned long stdc_leading_ones_ul(unsigned long value);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_STDBIT_STDC_LEADING_ONES_UL_H

libc/src/stdbit/stdc_leading_ones_ull.cpp

@@ -0,0 +1,21 @@
+//===-- Implementation of stdc_leading_ones_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_ones_ull.h"
+
+#include "src/__support/CPP/bit.h"
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(unsigned long long, stdc_leading_ones_ull,
+                   (unsigned long long value)) {
+  return static_cast<unsigned long long>(cpp::countl_one(value));
+}
+
+} // namespace LIBC_NAMESPACE

libc/src/stdbit/stdc_leading_ones_ull.h

@@ -0,0 +1,18 @@
+//===-- Implementation header for stdc_leading_ones_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_ONES_ULL_H
+#define LLVM_LIBC_SRC_STDBIT_STDC_LEADING_ONES_ULL_H
+
+namespace LIBC_NAMESPACE {
+
+unsigned long long stdc_leading_ones_ull(unsigned long long value);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_STDBIT_STDC_LEADING_ONES_ULL_H

libc/src/stdbit/stdc_leading_ones_us.cpp

@@ -0,0 +1,21 @@
+//===-- Implementation of stdc_leading_ones_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_ones_us.h"
+
+#include "src/__support/CPP/bit.h"
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(unsigned short, stdc_leading_ones_us,
+                   (unsigned short value)) {
+  return static_cast<unsigned short>(cpp::countl_one(value));
+}
+
+} // namespace LIBC_NAMESPACE

libc/src/stdbit/stdc_leading_ones_us.h

@@ -0,0 +1,18 @@
+//===-- Implementation header for stdc_leading_ones_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_ONES_US_H
+#define LLVM_LIBC_SRC_STDBIT_STDC_LEADING_ONES_US_H
+
+namespace LIBC_NAMESPACE {
+
+unsigned short stdc_leading_ones_us(unsigned short value);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_STDBIT_STDC_LEADING_ONES_US_H

libc/test/include/stdbit_test.cpp

@@ -23,8 +23,13 @@ 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; }
+unsigned char stdc_leading_ones_uc(unsigned char) { return 0xBA; }
+unsigned short stdc_leading_ones_us(unsigned short) { return 0xBB; }
+unsigned stdc_leading_ones_ui(unsigned) { return 0xBC; }
+unsigned long stdc_leading_ones_ul(unsigned long) { return 0xBD; }
+unsigned long long stdc_leading_ones_ull(unsigned long long) { return 0xBF; }
 
-TEST(LlvmLibcStdbitTest, TypeGenericMacro) {
+TEST(LlvmLibcStdbitTest, TypeGenericMacroLeadingZeros) {
   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)),
@@ -33,3 +38,13 @@ TEST(LlvmLibcStdbitTest, TypeGenericMacro) {
   EXPECT_EQ(stdc_leading_zeros(0UL), static_cast<unsigned long>(0xAD));
   EXPECT_EQ(stdc_leading_zeros(0ULL), static_cast<unsigned long long>(0xAF));
 }
+
+TEST(LlvmLibcStdbitTest, TypeGenericMacroLeadingOnes) {
+  EXPECT_EQ(stdc_leading_ones(static_cast<unsigned char>(0U)),
+            static_cast<unsigned char>(0xBA));
+  EXPECT_EQ(stdc_leading_ones(static_cast<unsigned short>(0U)),
+            static_cast<unsigned short>(0xBB));
+  EXPECT_EQ(stdc_leading_ones(0U), static_cast<unsigned>(0xBC));
+  EXPECT_EQ(stdc_leading_ones(0UL), static_cast<unsigned long>(0xBD));
+  EXPECT_EQ(stdc_leading_ones(0ULL), static_cast<unsigned long long>(0xBF));
+}