[libc] Add [l|ll]abs implementation.

Implement abs, labs and llabs with template.

Reviewed By: sivachandra

Differential Revision: https://reviews.llvm.org/D92626

8 files changed, 172 insertions, 0 deletions

diff --git a/libc/src/stdlib/CMakeLists.txt b/libc/src/stdlib/CMakeLists.txt
index 50b7421944dd..a599d8a59065 100644
--- a/libc/src/stdlib/CMakeLists.txt
+++ b/libc/src/stdlib/CMakeLists.txt
@@ -2,6 +2,12 @@ if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
   add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
 endif()
 
+add_header_library(
+  abs_utils
+  HDRS
+    abs_utils.h
+)
+
 add_entrypoint_object(
   _Exit
   ALIAS
@@ -20,3 +26,33 @@ add_entrypoint_object(
     libc.src.signal.raise
     ._Exit
 )
+
+add_entrypoint_object(
+  abs
+  SRCS
+    abs.cpp
+  HDRS
+    abs.h
+  DEPENDS
+    .abs_utils
+)
+
+add_entrypoint_object(
+  labs
+  SRCS
+    labs.cpp
+  HDRS
+    labs.h
+  DEPENDS
+    .abs_utils
+)
+
+add_entrypoint_object(
+  llabs
+  SRCS
+    llabs.cpp
+  HDRS
+    llabs.h
+  DEPENDS
+    .abs_utils
+)
diff --git a/libc/src/stdlib/abs.cpp b/libc/src/stdlib/abs.cpp
new file mode 100644
index 000000000000..74c47cdb242d
--- /dev/null
+++ b/libc/src/stdlib/abs.cpp
@@ -0,0 +1,20 @@
+//===-- Implementation of abs ---------------------------------------------===//
+//
+// 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/stdlib/abs.h"
+#include "src/__support/common.h"
+#include "src/stdlib/abs_utils.h"
+
+namespace __llvm_libc {
+
+int LLVM_LIBC_ENTRYPOINT(abs)(int n) {
+  // integer_abs from abs_utils.h.
+  return integer_abs(n);
+}
+
+} // namespace __llvm_libc
diff --git a/libc/src/stdlib/abs.h b/libc/src/stdlib/abs.h
new file mode 100644
index 000000000000..42ef7f885ed6
--- /dev/null
+++ b/libc/src/stdlib/abs.h
@@ -0,0 +1,18 @@
+//===-- Implementation header for abs ---------------------------*- 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_STDLIB_ABS_H
+#define LLVM_LIBC_SRC_STDLIB_ABS_H
+
+namespace __llvm_libc {
+
+int abs(int n);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_STDLIB_ABS_H
diff --git a/libc/src/stdlib/abs_utils.h b/libc/src/stdlib/abs_utils.h
new file mode 100644
index 000000000000..c0943fe0ee69
--- /dev/null
+++ b/libc/src/stdlib/abs_utils.h
@@ -0,0 +1,22 @@
+//===-- Utils for abs and friends -------------------------------*- 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_STDLIB_ABS_UTILS_H
+#define LLVM_LIBC_SRC_STDLIB_ABS_UTILS_H
+
+namespace __llvm_libc {
+
+template <typename T> static inline T integer_abs(T n) {
+  if (n < 0)
+    return -n;
+  return n;
+}
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_STDLIB_ABS_UTILS_H
diff --git a/libc/src/stdlib/labs.cpp b/libc/src/stdlib/labs.cpp
new file mode 100644
index 000000000000..427cb9d841ef
--- /dev/null
+++ b/libc/src/stdlib/labs.cpp
@@ -0,0 +1,20 @@
+//===-- Implementation of labs --------------------------------------------===//
+//
+// 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/stdlib/labs.h"
+#include "src/__support/common.h"
+#include "src/stdlib/abs_utils.h"
+
+namespace __llvm_libc {
+
+long LLVM_LIBC_ENTRYPOINT(labs)(long n) {
+  // integer_abs from abs_utils.h.
+  return integer_abs(n);
+}
+
+} // namespace __llvm_libc
diff --git a/libc/src/stdlib/labs.h b/libc/src/stdlib/labs.h
new file mode 100644
index 000000000000..0f0ea99dc22a
--- /dev/null
+++ b/libc/src/stdlib/labs.h
@@ -0,0 +1,18 @@
+//===-- Implementation header for labs --------------------------*- 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_STDLIB_LABS_H
+#define LLVM_LIBC_SRC_STDLIB_LABS_H
+
+namespace __llvm_libc {
+
+long labs(long n);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_STDLIB_LABS_H
diff --git a/libc/src/stdlib/llabs.cpp b/libc/src/stdlib/llabs.cpp
new file mode 100644
index 000000000000..8878ce41c76b
--- /dev/null
+++ b/libc/src/stdlib/llabs.cpp
@@ -0,0 +1,20 @@
+//===-- Implementation of llabs -------------------------------------------===//
+//
+// 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/stdlib/llabs.h"
+#include "src/__support/common.h"
+#include "src/stdlib/abs_utils.h"
+
+namespace __llvm_libc {
+
+long long LLVM_LIBC_ENTRYPOINT(llabs)(long long n) {
+  // integer_abs from abs_utils.h.
+  return integer_abs(n);
+}
+
+} // namespace __llvm_libc
diff --git a/libc/src/stdlib/llabs.h b/libc/src/stdlib/llabs.h
new file mode 100644
index 000000000000..f173431a14f1
--- /dev/null
+++ b/libc/src/stdlib/llabs.h
@@ -0,0 +1,18 @@
+//===-- Implementation header for llabs -------------------------*- 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_STDLIB_LLABS_H
+#define LLVM_LIBC_SRC_STDLIB_LLABS_H
+
+namespace __llvm_libc {
+
+long long llabs(long long n);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_STDLIB_LLABS_H