_rotl8, _rotl16

Microsoft 特定的

將輸入值依指定的位置數目，向左旋轉至最高有效位元 (MSB)。

語法

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

參數

value
[in]要旋轉的值。

shift
[in]要旋轉的位數。

傳回值

旋轉的值。

需求

內建	架構
_rotl8	x86、ARM、x64、ARM64
_rotl16	x86、ARM、x64、ARM64

標頭檔 < intrin.h>

備註

與左移作業不同的是，執行左旋轉時，從高端落下的高階位會移至最小有效位位置。

範例

// 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

END Microsoft 特定的

另請參閱

_rotr8、_rotr16
編譯器內建函式