_mm_rot_epi64

[Note: This document describes a pre-release version of Visual Studio 2010 SP1 and may be revised in any later version.]

Visual Studio 2010 SP1 is required.

Microsoft Specific

Generates the XOP instruction vprotq to rotate each of the quadwords in its first source by an amount specified in the second.

__m128i _mm_rot_epi64 (
   __m128i src,
   __m128i counts
);

Parameters

• [in] src
  A 128-bit parameter that contains two 64-bit unsigned integers.

• [in] counts
  A 128-bit parameter that contains sixteen 8-bit signed integers.

Return value

A 128-bit result r that contains two 64-bit unsigned integers.

r[i] := (counts[8*i] > 0) ? rotate_left(src[i], counts[8*i]) : 
                            rotate_right(src[i], -counts[8*i]);

Requirements

Header file <intrin.h>

Remarks

Each 64-bit unsigned integer value in src is rotated by the number of bits specified by the value in the byte of counts corresponding to its low-order byte, and the 64-bit unsigned integer result is stored as the corresponding value in the destination. If the value in counts is positive, the rotation is to the left (toward the most significant bit); otherwise, it is to the right. The other bytes of counts are ignored.

The vprotq instruction is part of the XOP family of instructions. Before you use this intrinsic, you must ensure that the processor supports this instruction. To determine hardware support for this instruction, call the __cpuid intrinsic with InfoType = 0x80000001 and check bit 11 of CPUInfo[2] (ECX). This bit is 1 when the instruction is supported, and 0 otherwise.

Example

#include <stdio.h>
#include <intrin.h>
int main()
{
    __m128i a, b, d;
    int i, j;
    unsigned __int64 temp;
    for (i = 0; i < 2; i++) {
        temp = 0;
        for (j = 0; j < 16; j++) {
            temp = temp << 4 | (8*i + j + 7) % 16;
        }
        a.m128i_u64[i] = temp;
        b.m128i_i8[8*i] = 21*i - 11;
    }
    printf_s("data:       ");
    for (i = 0; i < 2; i++) printf_s(" %016I64x", a.m128i_u64[i]);
    printf_s("\nrotated by  ");
    for (i = 0; i < 2; i++) printf_s(" %16d", b.m128i_i8[8*i]);
    d = _mm_rot_epi64(a, b);
    printf_s("\ngives       ");
    for (i = 0; i < 2; i++) printf_s(" %016I64x", d.m128i_u64[i]);
    printf_s("\n");
}

data:        789abcdef0123456 f0123456789abcde
rotated by                -11               10
gives        8acf13579bde0246 48d159e26af37bc0

See Also

Reference

_mm_rot_epi8

_mm_rot_epi16

_mm_rot_epi32

_mm_roti_epi64

_mm_shl_epi64

__cpuid, __cpuidex

XOP Intrinsics Added for Visual Studio 2010 SP1

Change History