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Re: Implementation of some string.h function using SSE2 instructions

Paweł Sikora wrote: 
        {
                __m128i m1 = *( __m128i* )( s1 );
                __m128i m2 = *( __m128i* )( s2 );
                __m128i r1 = not( _mm_cmpeq_epi8( m1, m2 ) );
                __m128i zero = { 0 };
                __m128i r2 = _mm_cmpeq_epi8( m1, zero );
                __m128i r3 = _mm_cmpeq_epi8( m2, zero );
                __m128i r = _mm_or_si128( r1, _mm_or_si128( r2, r3 ) );
                mask = _mm_movemask_epi8( r );
                if ( mask )
                {
                        unsigned index = __builtin_ffs( mask ) - 1;
                        return ( s1[ index ] - s2[ index ] );
                }
        }

BTW r3 isn't needed.

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