Drop from argument, since gbea has always been updated with
this address.  Add ilen argument for setting int_pgm_ilen.
Use update_cc_op before calling per_branch.

By raising the exception here, we need not call
per_check_exception later, which means we can clean up the
normal non-exception branch path.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/s390x/helper.h          |  2 +-
 target/s390x/tcg/misc_helper.c | 15 +++++++----
 target/s390x/tcg/translate.c   | 48 ++++++++++++----------------------
 3 files changed, 27 insertions(+), 38 deletions(-)

diff --git a/target/s390x/helper.h b/target/s390x/helper.h
index 96ab71e877..061b379065 100644
--- a/target/s390x/helper.h
+++ b/target/s390x/helper.h
@@ -360,7 +360,7 @@ DEF_HELPER_FLAGS_1(ptlb, TCG_CALL_NO_RWG, void, env)
 DEF_HELPER_FLAGS_1(purge, TCG_CALL_NO_RWG, void, env)
 DEF_HELPER_3(lra, i64, env, i64, i64)
 DEF_HELPER_FLAGS_3(per_check_exception, TCG_CALL_NO_WG, void, env, i64, i32)
-DEF_HELPER_FLAGS_3(per_branch, TCG_CALL_NO_RWG, void, env, i64, i64)
+DEF_HELPER_FLAGS_3(per_branch, TCG_CALL_NO_WG, void, env, i64, i32)
 DEF_HELPER_FLAGS_2(per_ifetch, TCG_CALL_NO_RWG, void, env, i64)
 DEF_HELPER_FLAGS_1(per_store_real, TCG_CALL_NO_RWG, void, env)
 DEF_HELPER_FLAGS_1(stfl, TCG_CALL_NO_RWG, void, env)
diff --git a/target/s390x/tcg/misc_helper.c b/target/s390x/tcg/misc_helper.c
index b7100c06c0..5b1c512367 100644
--- a/target/s390x/tcg/misc_helper.c
+++ b/target/s390x/tcg/misc_helper.c
@@ -625,13 +625,18 @@ static inline bool get_per_in_range(CPUS390XState *env, uint64_t addr)
     }
 }
 
-void HELPER(per_branch)(CPUS390XState *env, uint64_t from, uint64_t to)
+void HELPER(per_branch)(CPUS390XState *env, uint64_t dest, uint32_t ilen)
 {
-    if (!(env->cregs[9] & PER_CR9_CONTROL_BRANCH_ADDRESS)
-        || get_per_in_range(env, to)) {
-        env->per_address = from;
-        env->per_perc_atmid = PER_CODE_EVENT_BRANCH | get_per_atmid(env);
+    if ((env->cregs[9] & PER_CR9_CONTROL_BRANCH_ADDRESS)
+        && !get_per_in_range(env, dest)) {
+        return;
     }
+
+    env->psw.addr = dest;
+    env->int_pgm_ilen = ilen;
+    env->per_address = env->gbea;
+    env->per_perc_atmid = PER_CODE_EVENT_BRANCH | get_per_atmid(env);
+    per_raise_exception_log(env);
 }
 
 void HELPER(per_ifetch)(CPUS390XState *env, uint64_t addr)
diff --git a/target/s390x/tcg/translate.c b/target/s390x/tcg/translate.c
index a384192d15..4a6ef144b7 100644
--- a/target/s390x/tcg/translate.c
+++ b/target/s390x/tcg/translate.c
@@ -343,12 +343,11 @@ static void update_psw_addr(DisasContext *s)
     tcg_gen_movi_i64(psw_addr, s->base.pc_next);
 }
 
-static void per_branch(DisasContext *s, bool to_next)
+static void per_branch(DisasContext *s, TCGv_i64 dest)
 {
 #ifndef CONFIG_USER_ONLY
     if (s->base.tb->flags & FLAG_MASK_PER_BRANCH) {
-        TCGv_i64 next_pc = to_next ? tcg_constant_i64(s->pc_tmp) : psw_addr;
-        gen_helper_per_branch(tcg_env, gbea, next_pc);
+        gen_helper_per_branch(tcg_env, dest, tcg_constant_i32(s->ilen));
     }
 #endif
 }
@@ -637,9 +636,6 @@ static void gen_op_calc_cc(DisasContext *s)
 
 static bool use_goto_tb(DisasContext *s, uint64_t dest)
 {
-    if (unlikely(s->base.tb->flags & FLAG_MASK_PER_BRANCH)) {
-        return false;
-    }
     return translator_use_goto_tb(&s->base, dest);
 }
 
@@ -1081,37 +1077,38 @@ struct DisasInsn {
 
 static DisasJumpType help_goto_direct(DisasContext *s, uint64_t dest)
 {
+    update_cc_op(s);
     per_breaking_event(s);
+    per_branch(s, tcg_constant_i64(dest));
+
     if (dest == s->pc_tmp) {
-        per_branch(s, true);
         return DISAS_NEXT;
     }
     if (use_goto_tb(s, dest)) {
-        update_cc_op(s);
         tcg_gen_goto_tb(0);
         tcg_gen_movi_i64(psw_addr, dest);
         tcg_gen_exit_tb(s->base.tb, 0);
         return DISAS_NORETURN;
     } else {
         tcg_gen_movi_i64(psw_addr, dest);
-        per_branch(s, false);
-        return DISAS_PC_UPDATED;
+        return DISAS_PC_CC_UPDATED;
     }
 }
 
 static DisasJumpType help_goto_indirect(DisasContext *s, TCGv_i64 dest)
 {
+    update_cc_op(s);
     per_breaking_event(s);
     tcg_gen_mov_i64(psw_addr, dest);
-    per_branch(s, false);
-    return DISAS_PC_UPDATED;
+    per_branch(s, psw_addr);
+    return DISAS_PC_CC_UPDATED;
 }
 
 static DisasJumpType help_branch(DisasContext *s, DisasCompare *c,
                                  bool is_imm, int imm, TCGv_i64 cdest)
 {
     uint64_t dest = s->base.pc_next + (int64_t)imm * 2;
-    TCGLabel *lab, *over;
+    TCGLabel *lab;
 
     /* Take care of the special cases first.  */
     if (c->cond == TCG_COND_NEVER) {
@@ -1145,12 +1142,6 @@ static DisasJumpType help_branch(DisasContext *s, DisasCompare *c,
      * which avoids an otherwise unnecessary spill to the stack.
      */
     lab = gen_new_label();
-    if (s->base.tb->flags & FLAG_MASK_PER_BRANCH) {
-        over = gen_new_label();
-    } else {
-        over = NULL;
-    }
-
     if (c->is_64) {
         tcg_gen_brcond_i64(tcg_invert_cond(c->cond),
                            c->u.s64.a, c->u.s64.b, lab);
@@ -1166,13 +1157,11 @@ static DisasJumpType help_branch(DisasContext *s, DisasCompare *c,
     } else {
         tcg_gen_mov_i64(psw_addr, cdest);
     }
-    per_branch(s, false);
+    per_branch(s, psw_addr);
 
     if (is_imm && use_goto_tb(s, dest)) {
         tcg_gen_goto_tb(0);
         tcg_gen_exit_tb(s->base.tb, 0);
-    } else if (over) {
-        tcg_gen_br(over);
     } else {
         tcg_gen_lookup_and_goto_ptr();
     }
@@ -1184,15 +1173,9 @@ static DisasJumpType help_branch(DisasContext *s, DisasCompare *c,
     if (use_goto_tb(s, s->pc_tmp)) {
         tcg_gen_goto_tb(1);
         tcg_gen_exit_tb(s->base.tb, 1);
+        return DISAS_NORETURN;
     }
-
-    if (over) {
-        gen_set_label(over);
-        return DISAS_PC_UPDATED;
-    }
-
-    tcg_gen_lookup_and_goto_ptr();
-    return DISAS_NORETURN;
+    return DISAS_PC_CC_UPDATED;
 }
 
 /* ====================================================================== */
@@ -6374,7 +6357,8 @@ static DisasJumpType translate_one(CPUS390XState *env, DisasContext *s)
     }
 
 #ifndef CONFIG_USER_ONLY
-    if (s->base.tb->flags & FLAG_MASK_PER) {
+    if (s->base.tb->flags & (FLAG_MASK_PER_STORE_REAL |
+                             FLAG_MASK_PER_IFETCH)) {
         TCGv_i64 next_pc = psw_addr;
 
         if (ret == DISAS_NEXT || ret == DISAS_TOO_MANY) {
@@ -6404,7 +6388,7 @@ static void s390x_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
 
     dc->cc_op = CC_OP_DYNAMIC;
     dc->ex_value = dc->base.tb->cs_base;
-    dc->exit_to_mainloop = (dc->base.tb->flags & FLAG_MASK_PER) || dc->ex_value;
+    dc->exit_to_mainloop = dc->ex_value;
 }
 
 static void s390x_tr_tb_start(DisasContextBase *db, CPUState *cs)
-- 
2.34.1

On Wed, 2024-05-01 at 22:44 -0700, Richard Henderson wrote:
> Drop from argument, since gbea has always been updated with
> this address.  Add ilen argument for setting int_pgm_ilen.
> Use update_cc_op before calling per_branch.
> 
> By raising the exception here, we need not call
> per_check_exception later, which means we can clean up the
> normal non-exception branch path.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  target/s390x/helper.h          |  2 +-
>  target/s390x/tcg/misc_helper.c | 15 +++++++----
>  target/s390x/tcg/translate.c   | 48 ++++++++++++--------------------
> --
>  3 files changed, 27 insertions(+), 38 deletions(-)

[...]

>  static bool use_goto_tb(DisasContext *s, uint64_t dest)
>  {
> -    if (unlikely(s->base.tb->flags & FLAG_MASK_PER_BRANCH)) {
> -        return false;
> -    }

Why was this required in the first place and why can we remove it now?

On 5/22/24 15:45, Ilya Leoshkevich wrote:
> On Wed, 2024-05-01 at 22:44 -0700, Richard Henderson wrote:
>> Drop from argument, since gbea has always been updated with
>> this address.  Add ilen argument for setting int_pgm_ilen.
>> Use update_cc_op before calling per_branch.
>>
>> By raising the exception here, we need not call
>> per_check_exception later, which means we can clean up the
>> normal non-exception branch path.
>>
>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>> ---
>>   target/s390x/helper.h          |  2 +-
>>   target/s390x/tcg/misc_helper.c | 15 +++++++----
>>   target/s390x/tcg/translate.c   | 48 ++++++++++++--------------------
>> --
>>   3 files changed, 27 insertions(+), 38 deletions(-)
> 
> [...]
> 
>>   static bool use_goto_tb(DisasContext *s, uint64_t dest)
>>   {
>> -    if (unlikely(s->base.tb->flags & FLAG_MASK_PER_BRANCH)) {
>> -        return false;
>> -    }
> 
> Why was this required in the first place and why can we remove it now?
> 

This was required because of the structure of the code: the PER exception was only raised 
from translate_one, and therefore we could not allow the TB to end beforehand with goto_tb.

We can eliminate this now because we're raising the PER branch exception before attempting 
goto_tb.


r~