[libc] Add is_fixed_point type trait. (#81263)

lntue · web-flow · commit 1301bc46aea1 · 2024-02-14T14:44:09.000-05:00
diff --git a/libc/include/llvm-libc-macros/stdfix-macros.h b/libc/include/llvm-libc-macros/stdfix-macros.h
@@ -11,7 +11,7 @@
 
 #ifdef __clang__
 #if (!defined(__cplusplus) || (__clang_major__ >= 18))
-// _Fract and _Accum types are avaiable
+// _Fract and _Accum types are available
 #define LIBC_COMPILER_HAS_FIXED_POINT
 #endif // __cplusplus
 #endif // __clang__
diff --git a/libc/src/__support/CPP/CMakeLists.txt b/libc/src/__support/CPP/CMakeLists.txt
@@ -122,6 +122,7 @@ add_header_library(
     type_traits/is_convertible.h
     type_traits/is_destructible.h
     type_traits/is_enum.h
+    type_traits/is_fixed_point.h
     type_traits/is_floating_point.h
     type_traits/is_function.h
     type_traits/is_integral.h
@@ -155,6 +156,7 @@ add_header_library(
     libc.src.__support.macros.attributes
     libc.src.__support.macros.config
     libc.src.__support.macros.properties.float
+    libc.include.llvm-libc-macros.stdfix_macros
 )
 
 add_header_library(
diff --git a/libc/src/__support/CPP/type_traits.h b/libc/src/__support/CPP/type_traits.h
@@ -28,6 +28,7 @@
 #include "src/__support/CPP/type_traits/is_convertible.h"
 #include "src/__support/CPP/type_traits/is_destructible.h"
 #include "src/__support/CPP/type_traits/is_enum.h"
+#include "src/__support/CPP/type_traits/is_fixed_point.h"
 #include "src/__support/CPP/type_traits/is_floating_point.h"
 #include "src/__support/CPP/type_traits/is_function.h"
 #include "src/__support/CPP/type_traits/is_integral.h"
diff --git a/libc/src/__support/CPP/type_traits/is_fixed_point.h b/libc/src/__support/CPP/type_traits/is_fixed_point.h
@@ -0,0 +1,46 @@
+//===-- is_fixed_point type_traits ------------------------------*- 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___SUPPORT_CPP_TYPE_TRAITS_IS_FIXED_POINT_H
+#define LLVM_LIBC_SRC___SUPPORT_CPP_TYPE_TRAITS_IS_FIXED_POINT_H
+
+#include "src/__support/CPP/type_traits/is_same.h"
+#include "src/__support/CPP/type_traits/remove_cv.h"
+#include "src/__support/macros/attributes.h"
+
+#include "include/llvm-libc-macros/stdfix-macros.h"
+
+namespace LIBC_NAMESPACE::cpp {
+
+// is_fixed_point
+#ifdef LIBC_COMPILER_HAS_FIXED_POINT
+template <typename T> struct is_fixed_point {
+private:
+  template <typename Head, typename... Args>
+  LIBC_INLINE static constexpr bool __is_unqualified_any_of() {
+    return (... || is_same_v<remove_cv_t<Head>, Args>);
+  }
+
+public:
+  LIBC_INLINE_VAR static constexpr bool value = __is_unqualified_any_of<
+      T, short fract, fract, long fract, unsigned short fract, unsigned fract,
+      unsigned long fract, short accum, accum, long accum, unsigned short accum,
+      unsigned accum, unsigned long accum, short sat fract, sat fract,
+      long sat fract, unsigned short sat fract, unsigned sat fract,
+      unsigned long sat fract, short sat accum, sat accum, long sat accum,
+      unsigned short sat accum, unsigned sat accum, unsigned long sat accum>();
+};
+#else
+template <typename T> struct is_fixed_point : false_type {};
+#endif // LIBC_COMPILER_HAS_FIXED_POINT
+
+template <typename T>
+LIBC_INLINE_VAR constexpr bool is_fixed_point_v = is_fixed_point<T>::value;
+
+} // namespace LIBC_NAMESPACE::cpp
+
+#endif // LLVM_LIBC_SRC___SUPPORT_CPP_TYPE_TRAITS_IS_INTEGRAL_H
diff --git a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
@@ -296,6 +296,7 @@ libc_support_library(
         "src/__support/CPP/type_traits/is_convertible.h",
         "src/__support/CPP/type_traits/is_destructible.h",
         "src/__support/CPP/type_traits/is_enum.h",
+        "src/__support/CPP/type_traits/is_fixed_point.h",
         "src/__support/CPP/type_traits/is_floating_point.h",
         "src/__support/CPP/type_traits/is_function.h",
         "src/__support/CPP/type_traits/is_integral.h",
