Track direct jumps via dc->jmp_pc_imm. Use that in
preference to jmp_pc when possible. Emit goto_tb in
that case, and lookup_and_goto_tb otherwise.
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
target/openrisc/translate.c | 82 +++++++++++++++++++++----------------
1 file changed, 46 insertions(+), 36 deletions(-)
diff --git a/target/openrisc/translate.c b/target/openrisc/translate.c
index e566be6d3c..a8afb9a562 100644
--- a/target/openrisc/translate.c
+++ b/target/openrisc/translate.c
@@ -42,13 +42,16 @@
/* is_jmp field values */
#define DISAS_EXIT DISAS_TARGET_0 /* force exit to main loop */
-#define DISAS_UPDATE DISAS_TARGET_1 /* cpu state was modified dynamically */
+#define DISAS_JUMP DISAS_TARGET_1 /* exit via jmp_pc/jmp_pc_imm */
typedef struct DisasContext {
DisasContextBase base;
uint32_t mem_idx;
uint32_t tb_flags;
uint32_t delayed_branch;
+
+ /* If not -1, jmp_pc contains this value and so is a direct jump. */
+ target_ulong jmp_pc_imm;
} DisasContext;
/* Include the auto-generated decoder. */
@@ -164,34 +167,6 @@ static void check_ov64s(DisasContext *dc)
} \
} while (0)
-static inline bool use_goto_tb(DisasContext *dc, target_ulong dest)
-{
- if (unlikely(dc->base.singlestep_enabled)) {
- return false;
- }
-
-#ifndef CONFIG_USER_ONLY
- return (dc->base.tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK);
-#else
- return true;
-#endif
-}
-
-static void gen_goto_tb(DisasContext *dc, int n, target_ulong dest)
-{
- if (use_goto_tb(dc, dest)) {
- tcg_gen_movi_tl(cpu_pc, dest);
- tcg_gen_goto_tb(n);
- tcg_gen_exit_tb((uintptr_t)dc->base.tb + n);
- } else {
- tcg_gen_movi_tl(cpu_pc, dest);
- if (dc->base.singlestep_enabled) {
- gen_exception(dc, EXCP_DEBUG);
- }
- tcg_gen_exit_tb(0);
- }
-}
-
static void gen_ove_cy(DisasContext *dc)
{
if (dc->tb_flags & SR_OVE) {
@@ -655,6 +630,7 @@ static bool trans_l_j(DisasContext *dc, arg_l_j *a,
uint32_t insn)
LOG_DIS("l.j %d\n", a->n);
tcg_gen_movi_tl(jmp_pc, tmp_pc);
+ dc->jmp_pc_imm = tmp_pc;
dc->delayed_branch = 2;
return true;
}
@@ -669,6 +645,7 @@ static bool trans_l_jal(DisasContext *dc, arg_l_jal *a,
uint32_t insn)
/* Optimize jal being used to load the PC for PIC. */
if (tmp_pc != ret_pc) {
tcg_gen_movi_tl(jmp_pc, tmp_pc);
+ dc->jmp_pc_imm = tmp_pc;
dc->delayed_branch = 2;
}
return true;
@@ -1381,6 +1358,8 @@ static void
openrisc_tr_init_disas_context(DisasContextBase *dcb, CPUState *cs)
dc->mem_idx = cpu_mmu_index(env, false);
dc->tb_flags = dc->base.tb->flags;
dc->delayed_branch = (dc->tb_flags & TB_FLAGS_DFLAG) != 0;
+ dc->jmp_pc_imm = -1;
+
bound = -(dc->base.pc_first | TARGET_PAGE_MASK) / 4;
dc->base.max_insns = MIN(dc->base.max_insns, bound);
}
@@ -1437,10 +1416,7 @@ static void openrisc_tr_translate_insn(DisasContextBase
*dcbase, CPUState *cs)
if (dc->delayed_branch) {
dc->delayed_branch--;
if (!dc->delayed_branch) {
- tcg_gen_mov_tl(cpu_pc, jmp_pc);
- tcg_gen_discard_tl(jmp_pc);
- dc->base.is_jmp = DISAS_UPDATE;
- return;
+ dc->base.is_jmp = DISAS_JUMP;
}
}
}
@@ -1448,22 +1424,56 @@ static void openrisc_tr_translate_insn(DisasContextBase
*dcbase, CPUState *cs)
static void openrisc_tr_tb_stop(DisasContextBase *dcbase, CPUState *cs)
{
DisasContext *dc = container_of(dcbase, DisasContext, base);
+ target_ulong jmp_dest;
/* If we have already exited the TB, nothing following has effect. */
if (dc->base.is_jmp == DISAS_NORETURN) {
return;
}
+ /* Adjust the delayed branch state for the next TB. */
if ((dc->tb_flags & TB_FLAGS_DFLAG ? 1 : 0) != (dc->delayed_branch != 0)) {
tcg_gen_movi_i32(cpu_dflag, dc->delayed_branch != 0);
}
- tcg_gen_movi_tl(cpu_ppc, dc->base.pc_next - 4);
+ /* For DISAS_TOO_MANY, jump to the next insn. */
+ jmp_dest = dc->base.pc_next;
+ tcg_gen_movi_tl(cpu_ppc, jmp_dest - 4);
+
switch (dc->base.is_jmp) {
+ case DISAS_JUMP:
+ jmp_dest = dc->jmp_pc_imm;
+ if (jmp_dest == -1) {
+ /* The jump destination is indirect/computed; use jmp_pc. */
+ tcg_gen_mov_tl(cpu_pc, jmp_pc);
+ tcg_gen_discard_tl(jmp_pc);
+ if (unlikely(dc->base.singlestep_enabled)) {
+ gen_exception(dc, EXCP_DEBUG);
+ } else {
+ tcg_gen_lookup_and_goto_ptr ();
+ }
+ break;
+ }
+ /* The jump destination is direct; use jmp_pc_imm.
+ However, we will have stored into jmp_pc as well;
+ we know now that it wasn't needed. */
+ tcg_gen_discard_tl(jmp_pc);
+ /* fallthru */
+
case DISAS_TOO_MANY:
- gen_goto_tb(dc, 0, dc->base.pc_next);
+ if (unlikely(dc->base.singlestep_enabled)) {
+ tcg_gen_movi_tl(cpu_pc, jmp_dest);
+ gen_exception(dc, EXCP_DEBUG);
+ } else if ((dc->base.pc_first ^ jmp_dest) & TARGET_PAGE_MASK) {
+ tcg_gen_movi_tl(cpu_pc, jmp_dest);
+ tcg_gen_lookup_and_goto_ptr ();
+ } else {
+ tcg_gen_goto_tb(0);
+ tcg_gen_movi_tl(cpu_pc, jmp_dest);
+ tcg_gen_exit_tb((uintptr_t)dc->base.tb + 0);
+ }
break;
- case DISAS_UPDATE:
+
case DISAS_EXIT:
if (unlikely(dc->base.singlestep_enabled)) {
gen_exception(dc, EXCP_DEBUG);
--
2.17.0
