通过

_rotl8、_rotl16

  • 项目

Microsoft 专用

通过指定的位位置数将输入值旋转到最高有效位 (MSB) 左侧。

语法

unsigned char _rotl8(
   unsigned char value,
   unsigned char shift
);
unsigned short _rotl16(
   unsigned short value,
   unsigned char shift
);

参数

value
[in] 要旋转的值。

shift
[in] 要旋转的位数。

返回值

旋转的值。

要求

Intrinsic 体系结构
_rotl8 x86、ARM、x64、ARM64
_rotl16 x86、ARM、x64、ARM64

头文件<intrin.h>

备注

不像左移操作，当执行向左旋转时，离开高端的高序位将移动到最低有效位位置。

示例

// rotl.cpp
#include <stdio.h>
#include <intrin.h>

#pragma intrinsic(_rotl8, _rotl16)

int main()
{
    unsigned char c = 'A', c1, c2;

    for (int i = 0; i < 8; i++)
    {
       printf_s("Rotating 0x%x left by %d bits gives 0x%x\n", c,
               i, _rotl8(c, i));
    }

    unsigned short s = 0x12;
    int nBit = 10;

    printf_s("Rotating unsigned short 0x%x left by %d bits gives 0x%x\n",
            s, nBit, _rotl16(s, nBit));
}

Rotating 0x41 left by 0 bits gives 0x41
Rotating 0x41 left by 1 bits gives 0x82
Rotating 0x41 left by 2 bits gives 0x5
Rotating 0x41 left by 3 bits gives 0xa
Rotating 0x41 left by 4 bits gives 0x14
Rotating 0x41 left by 5 bits gives 0x28
Rotating 0x41 left by 6 bits gives 0x50
Rotating 0x41 left by 7 bits gives 0xa0
Rotating unsigned short 0x12 left by 10 bits gives 0x4800

结束 Microsoft 专用

另请参阅

_rotr8, _rotr16
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