__m64_pavgsub2
Microsoft Specific
Emits the 2-byte form of the Parallel Average Subtract (pavgsub2) instruction.
__m64 __m64_pavgsub2(
__m64 a,
__m64 b
);
Parameters
[in] a
An __m64 union containing an array of four unsigned short integers, which are subtracted from.[in] b
An __m64 union containing an array of four unsigned short integers, which are subtracted.
Return Value
An __m64 union containing the array of results of (a[i]-b[i])/2 interpreted as 16-bit signed integers.
Requirements
Intrinsic |
Architecture |
|---|---|
__m64_pavgsub2 |
IPF |
Header file <intrin.h>
Remarks
The numbers in the input array b are subtracted from the numbers in the input array a. The result is an __m64 union containing an array of unsigned short integers with the result of (a[i] – b[i])/2, where i numbers the four unsigned integers in the source arrays. If fractional, the result of each average is rounded to the nearest odd integer.
Example
// pavgsub2.cpp
// processor: IPF
#include <stdio.h>
#include <intrin.h>
#pragma intrinsic(__m64_pavgsub2)
void print4u(unsigned __int16* ia)
{
printf_s("{ %8u, %8u, %8u, %8u }\n", ia[0], ia[1], ia[2], ia[3] );
}
void print4(__int16* ia)
{
printf_s("{ %8d, %8d, %8d, %8d }\n", ia[0], ia[1], ia[2], ia[3] );
}
int main()
{
__m64 m, n, result;
unsigned __int16 ra[4], i;
unsigned __int16 ma[4] = { 10, 100, 70, 10000 };
unsigned __int16 na[4] = { 1, 95, 50, 5000 };
for (i = 0; i < 4; i++)
{
m.m64_u16[i] = ma[i];
n.m64_u16[i] = na[i];
}
printf_s("a: \n");
print4u(ma);
printf_s("b: \n");
print4u(na);
printf_s("\n");
result = __m64_pavgsub2(m, n);
printf_s("Parallel Average Subtract (a[]-b[])/2 : \n");
print4(result.m64_i16);
printf_s("\n");
result = __m64_pavgsub2(n, m);
printf_s("Parallel Average Subtract (b[]-a[])/2 : \n");
print4(result.m64_i16);
printf_s("\n");
}
a:
{ 10, 100, 70, 10000 }
b:
{ 1, 95, 50, 5000 }
Parallel Average Subtract (a[]-b[])/2 :
{ 5, 3, 10, 2500 }
Parallel Average Subtract (b[]-a[])/2 :
{ -5, -3, -10, -2500 }