Richard Henderson <r...@twiddle.net> writes:
> This is the same concept as, and same markup as, the
> early clobber markup in gcc.
With the proviso this is way in the (unfamiliar to me) guts of tcg:
Reviewed-by: Alex Bennée <alex.ben...@linaro.org>
>
> Signed-off-by: Richard Henderson <r...@twiddle.net>
> ---
> tcg/tcg.c | 34 ++++++++++++++++++++++------------
> tcg/tcg.h | 1 +
> 2 files changed, 23 insertions(+), 12 deletions(-)
>
> diff --git a/tcg/tcg.c b/tcg/tcg.c
> index aabf94f..27913f0 100644
> --- a/tcg/tcg.c
> +++ b/tcg/tcg.c
> @@ -1263,6 +1263,10 @@ void tcg_add_target_add_op_defs(const TCGTargetOpDef
> *tdefs)
> if (*ct_str == '\0')
> break;
> switch(*ct_str) {
> + case '&':
> + def->args_ct[i].ct |= TCG_CT_NEWREG;
> + ct_str++;
> + break;
> case 'i':
> def->args_ct[i].ct |= TCG_CT_CONST;
> ct_str++;
> @@ -2208,7 +2212,8 @@ static void tcg_reg_alloc_op(TCGContext *s,
> const TCGOpDef *def, TCGOpcode opc,
> const TCGArg *args, TCGLifeData arg_life)
> {
> - TCGRegSet allocated_regs;
> + TCGRegSet i_allocated_regs;
> + TCGRegSet o_allocated_regs;
> int i, k, nb_iargs, nb_oargs;
> TCGReg reg;
> TCGArg arg;
> @@ -2225,8 +2230,10 @@ static void tcg_reg_alloc_op(TCGContext *s,
> args + nb_oargs + nb_iargs,
> sizeof(TCGArg) * def->nb_cargs);
>
> + tcg_regset_set(i_allocated_regs, s->reserved_regs);
> + tcg_regset_set(o_allocated_regs, s->reserved_regs);
> +
> /* satisfy input constraints */
> - tcg_regset_set(allocated_regs, s->reserved_regs);
> for(k = 0; k < nb_iargs; k++) {
> i = def->sorted_args[nb_oargs + k];
> arg = args[i];
> @@ -2241,7 +2248,7 @@ static void tcg_reg_alloc_op(TCGContext *s,
> goto iarg_end;
> }
>
> - temp_load(s, ts, arg_ct->u.regs, allocated_regs);
> + temp_load(s, ts, arg_ct->u.regs, i_allocated_regs);
>
> if (arg_ct->ct & TCG_CT_IALIAS) {
> if (ts->fixed_reg) {
> @@ -2275,13 +2282,13 @@ static void tcg_reg_alloc_op(TCGContext *s,
> allocate_in_reg:
> /* allocate a new register matching the constraint
> and move the temporary register into it */
> - reg = tcg_reg_alloc(s, arg_ct->u.regs, allocated_regs,
> + reg = tcg_reg_alloc(s, arg_ct->u.regs, i_allocated_regs,
> ts->indirect_base);
> tcg_out_mov(s, ts->type, reg, ts->reg);
> }
> new_args[i] = reg;
> const_args[i] = 0;
> - tcg_regset_set_reg(allocated_regs, reg);
> + tcg_regset_set_reg(i_allocated_regs, reg);
> iarg_end: ;
> }
>
> @@ -2293,24 +2300,23 @@ static void tcg_reg_alloc_op(TCGContext *s,
> }
>
> if (def->flags & TCG_OPF_BB_END) {
> - tcg_reg_alloc_bb_end(s, allocated_regs);
> + tcg_reg_alloc_bb_end(s, i_allocated_regs);
> } else {
> if (def->flags & TCG_OPF_CALL_CLOBBER) {
> /* XXX: permit generic clobber register list ? */
> for (i = 0; i < TCG_TARGET_NB_REGS; i++) {
> if (tcg_regset_test_reg(tcg_target_call_clobber_regs, i)) {
> - tcg_reg_free(s, i, allocated_regs);
> + tcg_reg_free(s, i, i_allocated_regs);
> }
> }
> }
> if (def->flags & TCG_OPF_SIDE_EFFECTS) {
> /* sync globals if the op has side effects and might trigger
> an exception. */
> - sync_globals(s, allocated_regs);
> + sync_globals(s, i_allocated_regs);
> }
>
> /* satisfy the output constraints */
> - tcg_regset_set(allocated_regs, s->reserved_regs);
> for(k = 0; k < nb_oargs; k++) {
> i = def->sorted_args[k];
> arg = args[i];
> @@ -2318,6 +2324,10 @@ static void tcg_reg_alloc_op(TCGContext *s,
> ts = &s->temps[arg];
> if (arg_ct->ct & TCG_CT_ALIAS) {
> reg = new_args[arg_ct->alias_index];
> + } else if (arg_ct->ct & TCG_CT_NEWREG) {
> + reg = tcg_reg_alloc(s, arg_ct->u.regs,
> + i_allocated_regs | o_allocated_regs,
> + ts->indirect_base);
> } else {
> /* if fixed register, we try to use it */
> reg = ts->reg;
> @@ -2325,10 +2335,10 @@ static void tcg_reg_alloc_op(TCGContext *s,
> tcg_regset_test_reg(arg_ct->u.regs, reg)) {
> goto oarg_end;
> }
> - reg = tcg_reg_alloc(s, arg_ct->u.regs, allocated_regs,
> + reg = tcg_reg_alloc(s, arg_ct->u.regs, o_allocated_regs,
> ts->indirect_base);
> }
> - tcg_regset_set_reg(allocated_regs, reg);
> + tcg_regset_set_reg(o_allocated_regs, reg);
> /* if a fixed register is used, then a move will be done
> afterwards */
> if (!ts->fixed_reg) {
> if (ts->val_type == TEMP_VAL_REG) {
> @@ -2357,7 +2367,7 @@ static void tcg_reg_alloc_op(TCGContext *s,
> tcg_out_mov(s, ts->type, ts->reg, reg);
> }
> if (NEED_SYNC_ARG(i)) {
> - temp_sync(s, ts, allocated_regs, IS_DEAD_ARG(i));
> + temp_sync(s, ts, o_allocated_regs, IS_DEAD_ARG(i));
> } else if (IS_DEAD_ARG(i)) {
> temp_dead(s, ts);
> }
> diff --git a/tcg/tcg.h b/tcg/tcg.h
> index 5fd3733..ebfcefd 100644
> --- a/tcg/tcg.h
> +++ b/tcg/tcg.h
> @@ -851,6 +851,7 @@ void tcg_dump_op_count(FILE *f, fprintf_function
> cpu_fprintf);
>
> #define TCG_CT_ALIAS 0x80
> #define TCG_CT_IALIAS 0x40
> +#define TCG_CT_NEWREG 0x20 /* output requires a new register */
> #define TCG_CT_REG 0x01
> #define TCG_CT_CONST 0x02 /* any constant of register size */
--
Alex Bennée
