[PATCH v2 23/28] target/s390x: Remove use_exit_tb

[Richard Henderson <richard.henderson@linaro.org>]

We have not needed to end a TB for I/O since ba3e7926691
("icount: clean up cpu_can_io at the entry to the block").

In use_goto_tb, the check for singlestep_enabled is in the
generic translator_use_goto_tb.  In s390x_tr_tb_stop, the
check for singlestep_enabled is in the preceeding do_debug test.

Which leaves only FLAG_MASK_PER: fold that test alone into
the two callers of use_exit tb.

Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/s390x/translate.c | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/target/s390x/translate.c b/target/s390x/translate.c
index 117a890ecd..4742f59ca9 100644
--- a/target/s390x/translate.c
+++ b/target/s390x/translate.c
@@ -685,16 +685,9 @@ static void gen_op_calc_cc(DisasContext *s)
     set_cc_static(s);
 }
 
-static bool use_exit_tb(DisasContext *s)
-{
-    return s->base.singlestep_enabled ||
-            (tb_cflags(s->base.tb) & CF_LAST_IO) ||
-            (s->base.tb->flags & FLAG_MASK_PER);
-}
-
 static bool use_goto_tb(DisasContext *s, uint64_t dest)
 {
-    if (unlikely(use_exit_tb(s))) {
+    if (unlikely(s->base.tb->flags & FLAG_MASK_PER)) {
         return false;
     }
     return translator_use_goto_tb(&s->base, dest);
@@ -6634,7 +6627,7 @@ static void s390x_tr_tb_stop(DisasContextBase *dcbase, CPUState *cs)
         /* Exit the TB, either by raising a debug exception or by return.  */
         if (dc->do_debug) {
             gen_exception(EXCP_DEBUG);
-        } else if (use_exit_tb(dc) ||
+        } else if ((dc->base.tb->flags & FLAG_MASK_PER) ||
                    dc->base.is_jmp == DISAS_PC_STALE_NOCHAIN) {
             tcg_gen_exit_tb(NULL, 0);
         } else {
-- 
2.25.1