# Shift Intrinsics

Intel® Streaming SIMD Extensions 2 (Intel® SSE2) intrinsics for integer shift operations are listed in this topic. The prototypes for Intel® SSE2 intrinsics are in the emmintrin.h header file.

To use these intrinsics, include the immintrin.h file as follows:

    #include <immintrin.h>

The results of each intrinsic operation are placed in registers. The information about what is placed in each register appears in the tables below, in the detailed explanation of each intrinsic. R, R0, R1...R7 represent the registers in which results are placed.

### Note

The count argument is one shift count that applies to all elements of the operand being shifted. It is not a vector shift count that shifts each element by a different amount.

Intrinsic | Operation | Shift Type | Corresponding Intel® SSE2 Instruction
--- | --- | --- | ---
_mm_slli_si128 | Shift left | Logical | PSLLDQ
_mm_slli_epi16 | Shift left | Logical | PSLLW
_mm_sll_epi16 | Shift left | Logical | PSLLW
_mm_slli_epi32 | Shift left | Logical | PSLLD
_mm_sll_epi32 | Shift left | Logical | PSLLD
_mm_slli_epi64 | Shift left | Logical | PSLLQ
_mm_sll_epi64 | Shift left | Logical | PSLLQ
_mm_srai_epi16 | Shift right | Arithmetic | PSRAW
_mm_sra_epi16 | Shift right | Arithmetic | PSRAW
_mm_srai_epi32 | Shift right | Arithmetic | PSRAD
_mm_sra_epi32 | Shift right | Arithmetic | PSRAD
_mm_srli_si128 | Shift right | Logical | PSRLDQ
_mm_srli_epi16 | Shift right | Logical | PSRLW
_mm_srl_epi16 | Shift right | Logical | PSRLW
_mm_srli_epi32 | Shift right | Logical | PSRLD
_mm_srl_epi32 | Shift right | Logical | PSRLD
_mm_srli_epi64 | Shift right | Logical | PSRLQ
_mm_srl_epi64 | Shift right | Logical | PSRLQ

## _mm_slli_si128

__m128i _mm_slli_si128(__m128i a, int imm);

Shifts the 128-bit value in a left by imm bytes while shifting in zeros. imm must be an immediate.

R
a << (imm * 8)

## _mm_slli_epi16

__m128i _mm_slli_epi16(__m128i a, int count);

Shifts the eight signed or unsigned 16-bit integers in a left by count bits while shifting in zeros.

R0 | R1 | ... | R7
--- | --- | --- | ---
a0 << count | a1 << count | ... | a7 << count

## _mm_sll_epi16

__m128i _mm_sll_epi16(__m128i a, __m128i count);

Shifts the eight signed or unsigned 16-bit integers in a left by count bits while shifting in zeros.

R0 | R1 | ... | R7
--- | --- | --- | ---
a0 << count | a1 << count | ... | a7 << count

## _mm_slli_epi32

__m128i _mm_slli_epi32(__m128i a, int count);

Shifts the four signed or unsigned 32-bit integers in a left by count bits while shifting in zeros.

R0 | R1 | R2 | R3
--- | --- | --- | ---
a0 << count | a1 << count | a2 << count | a3 << count

## _mm_sll_epi32

__m128i _mm_sll_epi32(__m128i a, __m128i count);

Shifts the four signed or unsigned 32-bit integers in a left by count bits while shifting in zeros.

R0 | R1 | R2 | R3
--- | --- | --- | ---
a0 << count | a1 << count | a2 << count | a3 << count

## _mm_slli_epi64

__m128i _mm_slli_epi64(__m128i a, int count);

Shifts the two signed or unsigned 64-bit integers in a left by count bits while shifting in zeros.

R0 | R1
--- | ---
a0 << count | a1 << count

## _mm_sll_epi64

__m128i _mm_sll_epi64(__m128i a, __m128i count);

Shifts the two signed or unsigned 64-bit integers in a left by count bits while shifting in zeros.

R0 | R1
--- | ---
a0 << count | a1 << count

## _mm_srai_epi16

__m128i _mm_srai_epi16(__m128i a, int count);

Shifts the eight signed 16-bit integers in a right by count bits while shifting in the sign bit.

R0 | R1 | ... | R7
--- | --- | --- | ---
a0 >> count | a1 >> count | ... | a7 >> count

## _mm_sra_epi16

__m128i _mm_sra_epi16(__m128i a, __m128i count);

Shifts the eight signed 16-bit integers in a right by count bits while shifting in the sign bit.

R0 | R1 | ... | R7
--- | --- | --- | ---
a0 >> count | a1 >> count | ... | a7 >> count

## _mm_srai_epi32

__m128i _mm_srai_epi32(__m128i a, int count);

Shifts the four signed 32-bit integers in a right by count bits while shifting in the sign bit.

R0 | R1 | R2 | R3
--- | --- | --- | ---
a0 >> count | a1 >> count | a2 >> count | a3 >> count

## _mm_sra_epi32

__m128i _mm_sra_epi32(__m128i a, __m128i count);

Shifts the four signed 32-bit integers in a right by count bits while shifting in the sign bit.

R0 | R1 | R2 | R3
--- | --- | --- | ---
a0 >> count | a1 >> count | a2 >> count | a3 >> count

## _mm_srli_si128

__m128i _mm_srli_si128(__m128i a, int imm);

Shifts the 128-bit value in a right by imm bytes while shifting in zeros. imm must be an immediate.

R
srl(a, imm*8)

## _mm_srli_epi16

__m128i _mm_srli_epi16(__m128i a, int count);

Shifts the eight signed or unsigned 16-bit integers in a right by count bits while shifting in zeros.

R0 | R1 | ... | R7
--- | --- | --- | ---
srl(a0, count) | srl(a1, count) | ... | srl(a7, count)

## _mm_srl_epi16

__m128i _mm_srl_epi16(__m128i a, __m128i count);

Shifts the eight signed or unsigned 16-bit integers in a right by count bits while shifting in zeros.

R0 | R1 | ... | R7
--- | --- | --- | ---
srl(a0, count) | srl(a1, count) | ... | srl(a7, count)

## _mm_srli_epi32

__m128i _mm_srli_epi32(__m128i a, int count);

Shifts the four signed or unsigned 32-bit integers in a right by count bits while shifting in zeros.

R0 | R1 | R2 | R3
--- | --- | --- | ---
srl(a0, count) | srl(a1, count) | srl(a2, count) | srl(a3, count)

## _mm_srl_epi32

__m128i _mm_srl_epi32(__m128i a, __m128i count);

Shifts the four signed or unsigned 32-bit integers in a right by count bits while shifting in zeros.

R0 | R1 | R2 | R3
--- | --- | --- | ---
srl(a0, count) | srl(a1, count) | srl(a2, count) | srl(a3, count)

## _mm_srli_epi64

__m128i _mm_srli_epi64(__m128i a, int count)

Shifts the two signed or unsigned 64-bit integers in a right by count bits while shifting in zeros.

R0 | R1
--- | ---
srl(a0, count) | srl(a1, count)

## _mm_srl_epi64

__m128i _mm_srl_epi64(__m128i a, __m128i count)

Shifts the two signed or unsigned 64-bit integers in a right by count bits while shifting in zeros.

R0 | R1
--- | ---
srl(a0, count) | srl(a1, count)

Parent topic: Integer Intrinsics