1//===--- Round floating point to nearest integer on x86-64 ------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#ifndef LLVM_LIBC_SRC___SUPPORT_FPUTIL_X86_64_NEAREST_INTEGER_H
10#define LLVM_LIBC_SRC___SUPPORT_FPUTIL_X86_64_NEAREST_INTEGER_H
11
12#include "src/__support/common.h"
13#include "src/__support/macros/properties/architectures.h"
14
15#if !defined(LIBC_TARGET_ARCH_IS_X86_64)
16#error "Invalid include"
17#endif
18
19#if !defined(__SSE4_2__)
20#error "SSE4.2 instruction set is not supported"
21#endif
22
23#include <immintrin.h>
24
25namespace LIBC_NAMESPACE {
26namespace fputil {
27
28LIBC_INLINE float nearest_integer(float x) {
29 __m128 xmm = _mm_set_ss(w: x); // NOLINT
30 __m128 ymm =
31 _mm_round_ss(xmm, xmm, _MM_ROUND_NEAREST | _MM_FROUND_NO_EXC); // NOLINT
32 return ymm[0];
33}
34
35LIBC_INLINE double nearest_integer(double x) {
36 __m128d xmm = _mm_set_sd(w: x); // NOLINT
37 __m128d ymm =
38 _mm_round_sd(xmm, xmm, _MM_ROUND_NEAREST | _MM_FROUND_NO_EXC); // NOLINT
39 return ymm[0];
40}
41
42} // namespace fputil
43} // namespace LIBC_NAMESPACE
44
45#endif // LLVM_LIBC_SRC___SUPPORT_FPUTIL_X86_64_NEAREST_INTEGER_H
46

source code of libc/src/__support/FPUtil/x86_64/nearest_integer.h