[Qemu-devel] [PULL 9/9] target/s390x: implement serialization in BRANCH CONDITION

[Richard Henderson <rth@twiddle.net>]

From: Aurelien Jarno <aurelien@aurel32.net>

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Message-Id: <20170509082800.10756-4-aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
---
 target/s390x/translate.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/target/s390x/translate.c b/target/s390x/translate.c
index 3a0a3ee..4c48c59 100644
--- a/target/s390x/translate.c
+++ b/target/s390x/translate.c
@@ -1518,6 +1518,21 @@ static ExitStatus op_bc(DisasContext *s, DisasOps *o)
     int imm = is_imm ? get_field(s->fields, i2) : 0;
     DisasCompare c;
 
+    /* BCR with R2 = 0 causes no branching */
+    if (have_field(s->fields, r2) && get_field(s->fields, r2) == 0) {
+        if (m1 == 14) {
+            /* Perform serialization */
+            /* FIXME: check for fast-BCR-serialization facility */
+            tcg_gen_mb(TCG_MO_ALL | TCG_BAR_SC);
+        }
+        if (m1 == 15) {
+            /* Perform serialization */
+            /* FIXME: perform checkpoint-synchronisation */
+            tcg_gen_mb(TCG_MO_ALL | TCG_BAR_SC);
+        }
+        return NO_EXIT;
+    }
+
     disas_jcc(s, &c, m1);
     return help_branch(s, &c, is_imm, imm, o->in2);
 }
-- 
2.9.3