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[PATCH v2 09/11] target/cris: Move delayed branch handling to tb_stop
From: |
Richard Henderson |
Subject: |
[PATCH v2 09/11] target/cris: Move delayed branch handling to tb_stop |
Date: |
Sun, 20 Jun 2021 14:32:47 -0700 |
By moving the code here, we can re-use other end-of-tb code,
e.g. the evaluation of flags. Honor single stepping.
Signed-off-by: Richard Henderson <richard.henderson@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
- [PATCH v2 01/11] target/cris: Add DisasContextBase to DisasContext, (continued)
- [PATCH v2 01/11] target/cris: Add DisasContextBase to DisasContext, Richard Henderson, 2021/06/20
- [PATCH v2 03/11] target/cris: Mark exceptions as DISAS_NORETURN, Richard Henderson, 2021/06/20
- [PATCH v2 05/11] target/cris: Fix use_goto_tb, Richard Henderson, 2021/06/20
- [PATCH v2 02/11] target/cris: Replace DISAS_TB_JUMP with DISAS_NORETURN, Richard Henderson, 2021/06/20
- [PATCH v2 04/11] target/cris: Remove DISAS_SWI, Richard Henderson, 2021/06/20
- [PATCH v2 07/11] target/cris: Mark helper_raise_exception noreturn, Richard Henderson, 2021/06/20
- [PATCH v2 08/11] target/cris: Mark static arrays const, Richard Henderson, 2021/06/20
- [PATCH v2 09/11] target/cris: Move delayed branch handling to tb_stop,
Richard Henderson <=
- [PATCH v2 06/11] target/cris: Convert to TranslatorOps, Richard Henderson, 2021/06/20
- [PATCH v2 10/11] target/cris: Use tcg_gen_lookup_and_goto_ptr, Richard Henderson, 2021/06/20
- [PATCH v2 11/11] target/cris: Improve JMP_INDIRECT, Richard Henderson, 2021/06/20