Commit d193a14a authored by Paolo Bonzini's avatar Paolo Bonzini Committed by Blue Swirl
Browse files

optimize: only write to state when clearing optimizer data 



The next patch will add to the TCG optimizer a field that should be
non-zero in the default case.  Thus, replace the memset of the
temps array with a loop.  Only the state field has to be up-to-date,
because others are not used except if the state is TCG_TEMP_COPY
or TCG_TEMP_CONST.

[rth: Extracted the loop to a function.]

Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarRichard Henderson <rth@twiddle.net>
Signed-off-by: default avatarBlue Swirl <blauwirbel@gmail.com>
parent 75f0585f

tcg/optimize.c

+14 −5
Original line number Diff line number Diff line
@@ -65,6 +65,15 @@ static void reset_temp(TCGArg temp) 
    temps[temp].state = TCG_TEMP_UNDEF;

}



/* Reset all temporaries, given that there are NB_TEMPS of them.  */

static void reset_all_temps(int nb_temps)

{

    int i;

    for (i = 0; i < nb_temps; i++) {

        temps[i].state = TCG_TEMP_UNDEF;

    }

}



static int op_bits(TCGOpcode op)

{

    const TCGOpDef *def = &tcg_op_defs[op];
@@ -482,7 +491,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr, 


    nb_temps = s->nb_temps;

    nb_globals = s->nb_globals;

    memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info));

    reset_all_temps(nb_temps);



    nb_ops = tcg_opc_ptr - s->gen_opc_buf;

    gen_args = args;
@@ -768,7 +777,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr, 
            tmp = do_constant_folding_cond(op, args[0], args[1], args[2]);

            if (tmp != 2) {

                if (tmp) {

                    memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info));

                    reset_all_temps(nb_temps);

                    s->gen_opc_buf[op_index] = INDEX_op_br;

                    gen_args[0] = args[3];

                    gen_args += 1;
@@ -861,7 +870,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr, 
            tmp = do_constant_folding_cond2(&args[0], &args[2], args[4]);

            if (tmp != 2) {

                if (tmp) {

                    memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info));

                    reset_all_temps(nb_temps);

                    s->gen_opc_buf[op_index] = INDEX_op_br;

                    gen_args[0] = args[5];

                    gen_args += 1;
@@ -875,7 +884,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr, 
                       && temps[args[3]].val == 0) {

                /* Simplify LT/GE comparisons vs zero to a single compare

                   vs the high word of the input.  */

                memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info));

                reset_all_temps(nb_temps);

                s->gen_opc_buf[op_index] = INDEX_op_brcond_i32;

                gen_args[0] = args[1];

                gen_args[1] = args[3];
@@ -940,7 +949,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr, 
               We trash everything if the operation is the end of a basic

               block, otherwise we only trash the output args.  */

            if (def->flags & TCG_OPF_BB_END) {

                memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info));

                reset_all_temps(nb_temps);

            } else {

                for (i = 0; i < def->nb_oargs; i++) {

                    reset_temp(args[i]);