On Sun, Jun 20, 2021 at 02:32:47PM -0700, Richard Henderson wrote:
> By moving the code here, we can re-use other end-of-tb code,
> e.g. the evaluation of flags. Honor single stepping.
Hi Richard,
Unfortunately this patch seems to break one of the CRIS tests.
tests/tcg/cris/bare/check_xarith.s
I have an old image with the test-case built in the rootfs...
Best regards,
Edgar
>
> Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
> ---
> target/cris/translate.c | 82 ++++++++++++++++++++++-------------------
> 1 file changed, 45 insertions(+), 37 deletions(-)
>
> diff --git a/target/cris/translate.c b/target/cris/translate.c
> index 83b20162f1..0e925320b3 100644
> --- a/target/cris/translate.c
> +++ b/target/cris/translate.c
> @@ -55,6 +55,7 @@
> /* is_jmp field values */
> #define DISAS_JUMP DISAS_TARGET_0 /* only pc was modified dynamically */
> #define DISAS_UPDATE DISAS_TARGET_1 /* cpu state was modified dynamically */
> +#define DISAS_DBRANCH DISAS_TARGET_2 /* pc update for delayed branch */
>
> /* Used by the decoder. */
> #define EXTRACT_FIELD(src, start, end) \
> @@ -3219,43 +3220,8 @@ static void cris_tr_translate_insn(DisasContextBase
> *dcbase, CPUState *cs)
> * loop doing nothing for on this program location.
> */
> if (dc->delayed_branch && --dc->delayed_branch == 0) {
> - if (dc->base.tb->flags & 7) {
> - t_gen_movi_env_TN(dslot, 0);
> - }
> -
> - if (dc->cpustate_changed
> - || !dc->flagx_known
> - || (dc->flags_x != (dc->base.tb->flags & X_FLAG))) {
> - cris_store_direct_jmp(dc);
> - }
> -
> - if (dc->clear_locked_irq) {
> - dc->clear_locked_irq = 0;
> - t_gen_movi_env_TN(locked_irq, 0);
> - }
> -
> - if (dc->jmp == JMP_DIRECT_CC) {
> - TCGLabel *l1 = gen_new_label();
> - cris_evaluate_flags(dc);
> -
> - /* Conditional jmp. */
> - tcg_gen_brcondi_tl(TCG_COND_EQ, env_btaken, 0, l1);
> - gen_goto_tb(dc, 1, dc->jmp_pc);
> - gen_set_label(l1);
> - gen_goto_tb(dc, 0, dc->pc);
> - dc->base.is_jmp = DISAS_NORETURN;
> - dc->jmp = JMP_NOJMP;
> - } else if (dc->jmp == JMP_DIRECT) {
> - cris_evaluate_flags(dc);
> - gen_goto_tb(dc, 0, dc->jmp_pc);
> - dc->base.is_jmp = DISAS_NORETURN;
> - dc->jmp = JMP_NOJMP;
> - } else {
> - TCGv c = tcg_const_tl(dc->pc);
> - t_gen_cc_jmp(env_btarget, c);
> - tcg_temp_free(c);
> - dc->base.is_jmp = DISAS_JUMP;
> - }
> + dc->base.is_jmp = DISAS_DBRANCH;
> + return;
> }
>
> /* Force an update if the per-tb cpu state has changed. */
> @@ -3303,6 +3269,48 @@ static void cris_tr_tb_stop(DisasContextBase *dcbase,
> CPUState *cpu)
>
> cris_evaluate_flags(dc);
>
> + /* Evaluate delayed branch destination and fold to another is_jmp case.
> */
> + if (is_jmp == DISAS_DBRANCH) {
> + if (dc->base.tb->flags & 7) {
> + t_gen_movi_env_TN(dslot, 0);
> + }
> +
> + switch (dc->jmp) {
> + case JMP_DIRECT:
> + npc = dc->jmp_pc;
> + is_jmp = DISAS_TOO_MANY;
> + break;
> +
> + case JMP_DIRECT_CC:
> + /*
> + * Use a conditional branch if either taken or not-taken path
> + * can use goto_tb. If neither can, then treat it as indirect.
> + */
> + if (likely(!dc->base.singlestep_enabled)
> + && (use_goto_tb(dc, dc->jmp_pc) || use_goto_tb(dc, npc))) {
> + TCGLabel *not_taken = gen_new_label();
> +
> + tcg_gen_brcondi_tl(TCG_COND_EQ, env_btaken, 0, not_taken);
> + gen_goto_tb(dc, 1, dc->jmp_pc);
> + gen_set_label(not_taken);
> +
> + /* not-taken case handled below. */
> + is_jmp = DISAS_TOO_MANY;
> + break;
> + }
> + tcg_gen_movi_tl(env_btarget, dc->jmp_pc);
> + /* fall through */
> +
> + case JMP_INDIRECT:
> + t_gen_cc_jmp(env_btarget, tcg_constant_tl(npc));
> + is_jmp = DISAS_JUMP;
> + break;
> +
> + default:
> + g_assert_not_reached();
> + }
> + }
> +
> if (unlikely(dc->base.singlestep_enabled)) {
> switch (is_jmp) {
> case DISAS_TOO_MANY:
> --
> 2.25.1
>
