_mm_haddw_epu8
Visual Studio 2010 SP1 is required.
Microsoft Specific
Generates the XOP instruction vphaddubw to perform an unsigned integer horizontal add of its source.
__m128i _mm_haddw_epu8 (
__m128i src
);
Parameters
- [in] src
A 128-bit parameter that contains sixteen 8-bit unsigned integers.
Return value
A 128-bit result r that contains eight 16-bit unsigned integers.
r[i] := src[2*i] + src[2*i+1];
Requirements
Intrinsic |
Architecture |
|---|---|
_mm_haddw_epu8 |
XOP |
Header file <intrin.h>
Remarks
Each of the eight even-odd indexed pairs of 8-bit unsigned integer values in src is added to produce a 16-bit unsigned integer result that is stored as the corresponding value in the destination.
The vphaddubw 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, d;
int i;
for (i = 0; i < 16; i++) {
a.m128i_i8[i] = i - 8;
}
// Note that this intrinsic treats negative values as unsigned
// So, e.g., -1 becomes 255
d = _mm_haddw_epu8(a);
for (i = 0; i < 8; i++) printf_s(" %d", d.m128i_i16[i]);
printf_s("\n");
}
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