target/openrisc: Use tcg_constant_tl for dc->R0

The temp allocated for tcg_const_tl is auto-freed at branches,
but pure constants are not.  So we can remove the extra hoop
jumping in trans_l_swa.

Reviewed-by: Stafford Horne <shorne@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2021-07-08 14:12:09 -07:00
parent af42d35401
commit 4d10fa0ff9
1 changed files with 2 additions and 8 deletions

View File

@ -732,12 +732,6 @@ static bool trans_l_swa(DisasContext *dc, arg_store *a)
ea = tcg_temp_new();
tcg_gen_addi_tl(ea, cpu_R(dc, a->a), a->i);
/* For TB_FLAGS_R0_0, the branch below invalidates the temporary assigned
to cpu_regs[0]. Since l.swa is quite often immediately followed by a
branch, don't bother reallocating; finish the TB using the "real" R0.
This also takes care of RB input across the branch. */
dc->R0 = cpu_regs[0];
lab_fail = gen_new_label();
lab_done = gen_new_label();
tcg_gen_brcond_tl(TCG_COND_NE, ea, cpu_lock_addr, lab_fail);
@ -745,7 +739,7 @@ static bool trans_l_swa(DisasContext *dc, arg_store *a)
val = tcg_temp_new();
tcg_gen_atomic_cmpxchg_tl(val, cpu_lock_addr, cpu_lock_value,
cpu_regs[a->b], dc->mem_idx, MO_TEUL);
cpu_R(dc, a->b), dc->mem_idx, MO_TEUL);
tcg_gen_setcond_tl(TCG_COND_EQ, cpu_sr_f, val, cpu_lock_value);
tcg_temp_free(val);
@ -1601,7 +1595,7 @@ static void openrisc_tr_tb_start(DisasContextBase *db, CPUState *cs)
/* Allow the TCG optimizer to see that R0 == 0,
when it's true, which is the common case. */
if (dc->tb_flags & TB_FLAGS_R0_0) {
dc->R0 = tcg_const_tl(0);
dc->R0 = tcg_constant_tl(0);
} else {
dc->R0 = cpu_regs[0];
}