[libc-commits] [libc] [llvm] [libc][math] Refactor rint-nearbyint family to header-only (PR #195577)

[Muhammad Bassiouni via libc-commits]

================
@@ -0,0 +1,29 @@
+//===-- Implementation header for rint --------------------------*- 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_MATH_RINT_H
+#define LLVM_LIBC_SRC___SUPPORT_MATH_RINT_H
+
+#include "src/__support/FPUtil/NearestIntegerOperations.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+namespace math {
+
+LIBC_INLINE constexpr double rint(double x) {
+#ifdef __LIBC_USE_BUILTIN_CEIL_FLOOR_RINT_TRUNC
+  return __builtin_rint(x);
+#else
+  return fputil::round_using_current_rounding_mode(x);
+#endif
+}
----------------
bassiounix wrote:

```suggestion
LIBC_INLINE LIBC_CONSTEXPR double rint(double x) {
#if defined(__LIBC_USE_BUILTIN_CEIL_FLOOR_RINT_TRUNC) &&                       \
    !defined(LIBC_HAS_CONSTANT_EVALUATED)
  return __builtin_rint(x);
#else
  return fputil::round_using_current_rounding_mode(x);
#endif
}
```

https://github.com/llvm/llvm-project/pull/195577