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Synopsis:
    #include <mmintrin.h>
    __m64 _m_packssdw(__m64 *m1, __m64 *m2);

Description:
    Convert signed packed double-words into signed packed words by packing
    (with signed saturation) the low-order words of the signed double-word
    elements from m1 and m2 into the respective signed words of the result.
    If the signed values in the word elements of m1 and m2 are smaller than
    0x8000, the result elements are clamped to 0x8000.  If the signed values
    in the word elements of m1 and m2 are larger than 0x7fff, the result
    elements are clamped to 0x7fff.


                 m2                  m1
         ---------------------   ---------------------
         | w3 : w2 | w1 : w0 |   | w3 : w2 | w1 : w0 |
         ---------------------   ---------------------
              |         |             |         |
              `--------.`---.     .---'.--------'
                       |    |     |    |
                       V    V     V    V
                     ---------------------
                     | w3 | w2 | w1 | w0 |
                     ---------------------
                             result


Returns:
    The result of packing, with signed saturation, 32-bit signed
    double-words into 16-bit signed words is returned.  is returned.

Example:
    #include <stdio.h>
    #include <mmintrin.h>

    #define AS_BYTES "%2.2x %2.2x %2.2x %2.2x " \
                     "%2.2x %2.2x %2.2x %2.2x"
    #define AS_WORDS "%4.4x %4.4x %4.4x %4.4x"
    #define AS_DWORDS "%8.8lx %8.8lx"

    __m64   a;
    __m64   b = { 0x0000567800001234 };
    __m64   c = { 0xfffffffe00010101 };

    void main()
      {
        a = _m_packssdw( b, c );
        printf( "m2="AS_DWORDS" "
                "m1="AS_DWORDS"\n"
                "mm="AS_WORDS"\n",
            c._32[1], c._32[0],
            b._32[1], b._32[0],
            a._16[3], a._16[2], a._16[1], a._16[0] );
      }

    produces the following:

    m2=fffffffe 00010101 m1=00005678 00001234
    mm=fffe 7fff 5678 1234

Classification:
    Intel

Systems:
    MACRO
See Also:
    _m_empty, _m_packsswb, _m_packuswb