[Qemu-devel] [PATCH 1/6] target/s390x: add BAL and BALR instructions

[Pavel Zbitskiy <pavel.zbitskiy@gmail.com>]

These instructions are provided for compatibility purposes and are
used only by old software, in the new code BAS and BASR are preferred.
The difference between the old and new instruction exists only in the
24-bit mode.

Signed-off-by: Pavel Zbitskiy <pavel.zbitskiy@gmail.com>
---
 target/s390x/insn-data.def |  3 +++
 target/s390x/translate.c   | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/target/s390x/insn-data.def b/target/s390x/insn-data.def
index 5c6f33ed9c..9c7b434fca 100644
--- a/target/s390x/insn-data.def
+++ b/target/s390x/insn-data.def
@@ -102,6 +102,9 @@
     D(0x9400, NI,      SI,    Z,   la1, i2_8u, new, 0, ni, nz64, MO_UB)
     D(0xeb54, NIY,     SIY,   LD,  la1, i2_8u, new, 0, ni, nz64, MO_UB)
 
+/* BRANCH AND LINK */
+    C(0x0500, BALR,    RR_a,  Z,   0, r2_nz, r1, 0, bal, 0)
+    C(0x4500, BAL,     RX_a,  Z,   0, a2, r1, 0, bal, 0)
 /* BRANCH AND SAVE */
     C(0x0d00, BASR,    RR_a,  Z,   0, r2_nz, r1, 0, bas, 0)
     C(0x4d00, BAS,     RX_a,  Z,   0, a2, r1, 0, bas, 0)
diff --git a/target/s390x/translate.c b/target/s390x/translate.c
index 57c03cbf58..efdc88e227 100644
--- a/target/s390x/translate.c
+++ b/target/s390x/translate.c
@@ -1463,6 +1463,38 @@ static DisasJumpType op_bas(DisasContext *s, DisasOps *o)
     }
 }
 
+static void save_link_info(TCGv_i64 out, uint64_t pc, uint64_t ilc)
+{
+    TCGv_i64 t;
+
+    tcg_gen_andi_i64(out, out, 0xffffffff00000000);
+    tcg_gen_ori_i64(out, out, (ilc << 30) | pc);
+    t = tcg_temp_new_i64();
+    tcg_gen_shri_i64(t, psw_mask, 16);
+    tcg_gen_andi_i64(t, t, 0x0f000000);
+    tcg_gen_or_i64(out, out, t);
+    tcg_gen_extu_i32_i64(t, cc_op);
+    tcg_gen_shli_i64(t, t, 28);
+    tcg_gen_or_i64(out, out, t);
+    tcg_temp_free_i64(t);
+}
+
+static DisasJumpType op_bal(DisasContext *s, DisasOps *o)
+{
+    if (s->base.tb->flags & FLAG_MASK_32) {
+        return op_bas(s, o);
+    }
+    gen_op_calc_cc(s);
+    save_link_info(o->out, s->pc_tmp, s->ilen / 2);
+    if (o->in2) {
+        tcg_gen_mov_i64(psw_addr, o->in2);
+        per_branch(s, false);
+        return DISAS_PC_UPDATED;
+    } else {
+        return DISAS_NEXT;
+    }
+}
+
 static DisasJumpType op_basi(DisasContext *s, DisasOps *o)
 {
     tcg_gen_movi_i64(o->out, pc_to_link_info(s, s->pc_tmp));
-- 
2.16.2.windows.1