[libc-commits] [libc] [libc][stdfix] Initial support for stdfix.h and fixed point arithmetic. (PR #81201)

Fri Feb 9 10:56:39 PST 2024

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@@ -0,0 +1,44 @@
+//===-- 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"
+#include "include/llvm-libc-types/stdfix_types.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_VAR 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>();
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PiJoules wrote:

We'll also want to cover the saturation equivalents of each of these.

https://github.com/llvm/llvm-project/pull/81201
