_mm_set1_epi8的干了什么？

在qemu中有#define SPLAT(p) _mm_set1_epi8(*(p))

那么，_mm_set1_epi8到底是干什么用的呢？下面这个说明文档说的很详细，算是个记录吧。

http://software.intel.com/sites/products/documentation/studio/composer/en-us/2011Update/compiler_c/intref_cls/common/intref_sse2_int_set.htm

Set Intrinsics

The Intel® Streaming SIMD Extensions 2 (Intel® SSE2) intrinsics for integer set operations are listed in this topic. These intrinsics are composite intrinsics because they require more than one instruction to implement them. The prototypes for the Intel® SSE2 intrinsics are in the emmintrin.h header file.

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...R15 represent the registers in which results are placed.（其实就是通过这些指令给寄存器赋值，利用了单指令多数据流的思想）

Intrinsic Name

Operation

Corresponding
Intel® SSE2 Instruction

_mm_set_epi64

Set two integer values

Composite

_mm_set_epi64x

Set two integer values

Composite

_mm_set_epi32

Set four integer values

Composite

_mm_set_epi16

Set eight integer values

Composite

_mm_set_epi8

Set sixteen integer values

Composite

_mm_set1_epi64

Set two integer values

Composite

_mm_set1_epi64x

Set two integer values

Composite

_mm_set1_epi32

Set four integer values

Composite

_mm_set1_epi16

Set eight integer values

Composite

_mm_set1_epi8

Set sixteen integer values

Composite

_mm_setr_epi64

Set two integer values in reverse order

Composite

_mm_setr_epi32

Set four integer values in reverse order

Composite

_mm_setr_epi16

Set eight integer values in reverse order

Composite

_mm_setr_epi8

Set sixteen integer values in reverse order

Composite

_mm_setzero_si128

Set to zero

Composite

__m128i _mm_set_epi64(__m64 q1, __m64 q0)

Sets the 2 64-bit integer values.

R0

R1

q0

q1

__m128i _mm_set_epi64x(__int64 b, __int64 a)

Sets the 2 64-bit integer values.

R0

R1

a

b

__m128i _mm_set_epi32(int i3, int i2, int i1, int i0)

Sets the 4 signed 32-bit integer values.

R0

R1

R2

R3

i0

i1

i2

i3

__m128i _mm_set_epi16(short w7, short w6, short w5, short w4, short w3, short w2, short w1, short w0)

Sets the 8 signed 16-bit integer values.

R0

R1

...

R7

w0

w1

...

w7

__m128i _mm_set_epi8(char b15, char b14, char b13, char b12, char b11, char b10, char b9, char b8, char b7, char b6, char b5, char b4, char b3, char b2, char b1, char b0)

Sets the 16 signed 8-bit integer values.

R0

R1

...

R15

b0

b1

...

b15

__m128i _mm_set1_epi64(__m64 q)

Sets the 2 64-bit integer values to q.

R0

R1

q

q

__m128i _mm_set1_epi64x(__int64 a)

Sets the 2 64-bit integer values to a.

R0

R1

a

a

__m128i _mm_set1_epi32(int i)

Sets the 4 signed 32-bit integer values to i.

R0

R1

R2

R3

i

i

i

i

__m128i _mm_set1_epi16(short w)

Sets the 8 signed 16-bit integer values to w.

R0

R1

...

R7

w

w

w

w

__m128i _mm_set1_epi8(char b)

Sets the 16 signed 8-bit integer values to b.

R0

R1

...

R15

b

b

b

b

__m128i _mm_setr_epi64(__m64 q0, __m64 q1)

Sets the 2 64-bit integer values in reverse order.

R0

R1

q0

q1

__m128i _mm_setr_epi32(int i0, int i1, int i2, int i3)

Sets the 4 signed 32-bit integer values in reverse order.

R0

R1

R2

R3

i0

i1

i2

i3

__m128i _mm_setr_epi16(short w0, short w1, short w2, short w3, short w4, short w5, short w6, short w7)

Sets the 8 signed 16-bit integer values in reverse order.

R0

R1

...

R7

w0

w1

...

w7

__m128i _mm_setr_epi8(char b15, char b14, char b13, char b12, char b11, char b10, char b9, char b8, char b7, char b6, char b5, char b4, char b3, char b2, char b1, char b0)

Sets the 16 signed 8-bit integer values in reverse order.

R0

R1

...

R15

b0

b1

...

b15

__m128i _mm_setzero_si128()

Sets the 128-bit value to zero.

R

0x0