Commit 32ad48ab authored by Richard Henderson's avatar Richard Henderson
Browse files

target-alpha: Add vector implementation for CMPBGE 



While conditionalized on SSE2, it's a "portable" gcc generic vector
implementation, which could be enabled on other hosts.

Signed-off-by: default avatarRichard Henderson <rth@twiddle.net>
parent 8d8d324e

target-alpha/int_helper.c

+37 −0
Original line number Diff line number Diff line
@@ -60,6 +60,42 @@ uint64_t helper_zap(uint64_t val, uint64_t mask) 


uint64_t helper_cmpbge(uint64_t op1, uint64_t op2)

{

#if defined(__SSE2__)

    uint64_t r;



    /* The cmpbge instruction is heavily used in the implementation of

       every string function on Alpha.  We can do much better than either

       the default loop below, or even an unrolled version by using the

       native vector support.  */

    {

        typedef uint64_t Q __attribute__((vector_size(16)));

        typedef uint8_t B __attribute__((vector_size(16)));



        Q q1 = (Q){ op1, 0 };

        Q q2 = (Q){ op2, 0 };



        q1 = (Q)((B)q1 >= (B)q2);



        r = q1[0];

    }



    /* Select only one bit from each byte.  */

    r &= 0x0101010101010101;



    /* Collect the bits into the bottom byte.  */

    /* .......A.......B.......C.......D.......E.......F.......G.......H */

    r |= r >> (8 - 1);



    /* .......A......AB......BC......CD......DE......EF......FG......GH */

    r |= r >> (16 - 2);



    /* .......A......AB.....ABC....ABCD....BCDE....CDEF....DEFG....EFGH */

    r |= r >> (32 - 4);



    /* .......A......AB.....ABC....ABCD...ABCDE..ABCDEF.ABCDEFGABCDEFGH */

    /* Return only the low 8 bits.  */

    return r & 0xff;

#else

    uint8_t opa, opb, res;

    int i;
@@ -72,6 +108,7 @@ uint64_t helper_cmpbge(uint64_t op1, uint64_t op2) 
        }

    }

    return res;

#endif

}



uint64_t helper_minub8(uint64_t op1, uint64_t op2)