_mm_haddd_epu8

[Note: This document describes a pre-release version of Visual Studio 2010 SP1 and may be revised in any later version.]

Visual Studio 2010 SP1 is required.

Microsoft Specific

Generates the XOP instruction vphaddubd to perform an unsigned integer horizontal add of its source.

__m128i _mm_haddd_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 four 32-bit unsigned integers.

r[i] := src[4*i] + src[4*i+1] + src[4*i+2] + src[4*i+3];

Requirements

Header file <intrin.h>

Remarks

Each of the four groups of four 8-bit unsigned integer values in src is added to produce a 32-bit unsigned integer result that is stored as the corresponding value in the destination. No overflow is possible in this instruction.

The vphaddubd 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 < 4; i++) {
        a.m128i_i8[i] = -128;
        a.m128i_i8[i+4] = i-128;
        a.m128i_i8[i+8] = 10*i;
        a.m128i_i8[i+12] = 127;
    }
    // Note that this intrinsic treats negative values as unsigned
    // So, e.g., -128 becomes +128
    d = _mm_haddd_epu8(a);
    for (i = 0; i < 4; i++) printf_s(" %u", d.m128i_u32[i]);
    printf_s("\n");
}

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See Also

Reference

_mm_haddw_epu8

_mm_haddq_epu8

_mm_haddd_epu16

_mm_haddd_epi8

__cpuid, __cpuidex

XOP Intrinsics Added for Visual Studio 2010 SP1

Change History