From: Ilya Leoshkevich <iii@linux.ibm.com>

LAALG uses op_laa() and wout_addu64(). The latter expects cc_src to be
set, but the former does not do it. This can lead to assertion failures
if something sets cc_src to neither 0 nor 1 before.

Fix by introducing op_laa_addu64(), which sets cc_src, and using it for
LAALG.

Fixes: 4dba4d6fef61 ("target/s390x: Use atomic operations for LOAD AND OP")
Cc: qemu-stable@nongnu.org
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20231106093605.1349201-4-iii@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 target/s390x/tcg/insn-data.h.inc |  2 +-
 target/s390x/tcg/translate.c     | 19 +++++++++++++++++--
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/target/s390x/tcg/insn-data.h.inc b/target/s390x/tcg/insn-data.h.inc
index 0bfd88d3c3..2f07f39d9c 100644
--- a/target/s390x/tcg/insn-data.h.inc
+++ b/target/s390x/tcg/insn-data.h.inc
@@ -442,7 +442,7 @@
     D(0xebe8, LAAG,    RSY_a, ILA, r3, a2, new, in2_r1, laa, adds64, MO_TEUQ)
 /* LOAD AND ADD LOGICAL */
     D(0xebfa, LAAL,    RSY_a, ILA, r3_32u, a2, new, in2_r1_32, laa, addu32, MO_TEUL)
-    D(0xebea, LAALG,   RSY_a, ILA, r3, a2, new, in2_r1, laa, addu64, MO_TEUQ)
+    D(0xebea, LAALG,   RSY_a, ILA, r3, a2, new, in2_r1, laa_addu64, addu64, MO_TEUQ)
 /* LOAD AND AND */
     D(0xebf4, LAN,     RSY_a, ILA, r3_32s, a2, new, in2_r1_32, lan, nz32, MO_TESL)
     D(0xebe4, LANG,    RSY_a, ILA, r3, a2, new, in2_r1, lan, nz64, MO_TEUQ)
diff --git a/target/s390x/tcg/translate.c b/target/s390x/tcg/translate.c
index a0d6a2a35d..62ab2be8b1 100644
--- a/target/s390x/tcg/translate.c
+++ b/target/s390x/tcg/translate.c
@@ -2677,17 +2677,32 @@ static DisasJumpType op_kxb(DisasContext *s, DisasOps *o)
     return DISAS_NEXT;
 }
 
-static DisasJumpType op_laa(DisasContext *s, DisasOps *o)
+static DisasJumpType help_laa(DisasContext *s, DisasOps *o, bool addu64)
 {
     /* The real output is indeed the original value in memory;
        recompute the addition for the computation of CC.  */
     tcg_gen_atomic_fetch_add_i64(o->in2, o->in2, o->in1, get_mem_index(s),
                                  s->insn->data | MO_ALIGN);
     /* However, we need to recompute the addition for setting CC.  */
-    tcg_gen_add_i64(o->out, o->in1, o->in2);
+    if (addu64) {
+        tcg_gen_movi_i64(cc_src, 0);
+        tcg_gen_add2_i64(o->out, cc_src, o->in1, cc_src, o->in2, cc_src);
+    } else {
+        tcg_gen_add_i64(o->out, o->in1, o->in2);
+    }
     return DISAS_NEXT;
 }
 
+static DisasJumpType op_laa(DisasContext *s, DisasOps *o)
+{
+    return help_laa(s, o, false);
+}
+
+static DisasJumpType op_laa_addu64(DisasContext *s, DisasOps *o)
+{
+    return help_laa(s, o, true);
+}
+
 static DisasJumpType op_lan(DisasContext *s, DisasOps *o)
 {
     /* The real output is indeed the original value in memory;
-- 
2.41.0