[PATCH v2 1/2] target/s390x: Emulate CVDG

[Ilya Leoshkevich]

CVDG is the same as CVD, except that it converts 64 bits into 128,
rather than 32 into 64. Create a new helper, which uses Int128
wrappers.

Reported-by: Ido Plat <Ido.Plat@ibm.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 target/s390x/helper.h            |  1 +
 target/s390x/tcg/insn-data.h.inc |  1 +
 target/s390x/tcg/int_helper.c    | 21 +++++++++++++++++++++
 target/s390x/tcg/translate.c     |  8 ++++++++
 4 files changed, 31 insertions(+)

diff --git a/target/s390x/helper.h b/target/s390x/helper.h
index 05102578fc9..332a9a9c632 100644
--- a/target/s390x/helper.h
+++ b/target/s390x/helper.h
@@ -89,6 +89,7 @@ DEF_HELPER_FLAGS_2(sqeb, TCG_CALL_NO_WG, i64, env, i64)
 DEF_HELPER_FLAGS_2(sqdb, TCG_CALL_NO_WG, i64, env, i64)
 DEF_HELPER_FLAGS_2(sqxb, TCG_CALL_NO_WG, i128, env, i128)
 DEF_HELPER_FLAGS_1(cvd, TCG_CALL_NO_RWG_SE, i64, s32)
+DEF_HELPER_FLAGS_1(cvdg, TCG_CALL_NO_RWG_SE, i128, s64)
 DEF_HELPER_FLAGS_4(pack, TCG_CALL_NO_WG, void, env, i32, i64, i64)
 DEF_HELPER_FLAGS_4(pka, TCG_CALL_NO_WG, void, env, i64, i64, i32)
 DEF_HELPER_FLAGS_4(pku, TCG_CALL_NO_WG, void, env, i64, i64, i32)
diff --git a/target/s390x/tcg/insn-data.h.inc b/target/s390x/tcg/insn-data.h.inc
index 2f07f39d9cb..388dcb8dbbc 100644
--- a/target/s390x/tcg/insn-data.h.inc
+++ b/target/s390x/tcg/insn-data.h.inc
@@ -296,6 +296,7 @@
 /* CONVERT TO DECIMAL */
     C(0x4e00, CVD,     RX_a,  Z,   r1_o, a2, 0, 0, cvd, 0)
     C(0xe326, CVDY,    RXY_a, LD,  r1_o, a2, 0, 0, cvd, 0)
+    C(0xe32e, CVDG,    RXY_a, Z,   r1_o, a2, 0, 0, cvdg, 0)
 /* CONVERT TO FIXED */
     F(0xb398, CFEBR,   RRF_e, Z,   0, e2, new, r1_32, cfeb, 0, IF_BFP)
     F(0xb399, CFDBR,   RRF_e, Z,   0, f2, new, r1_32, cfdb, 0, IF_BFP)
diff --git a/target/s390x/tcg/int_helper.c b/target/s390x/tcg/int_helper.c
index eb8e6dd1b57..121e3006a65 100644
--- a/target/s390x/tcg/int_helper.c
+++ b/target/s390x/tcg/int_helper.c
@@ -118,6 +118,27 @@ uint64_t HELPER(cvd)(int32_t reg)
     return dec;
 }
 
+Int128 HELPER(cvdg)(int64_t reg)
+{
+    /* positive 0 */
+    Int128 dec = int128_make64(0x0c);
+    Int128 bin = int128_makes64(reg);
+    Int128 base = int128_make64(10);
+    int shift;
+
+    if (!int128_nonneg(bin)) {
+        bin = int128_neg(bin);
+        dec = int128_make64(0x0d);
+    }
+
+    for (shift = 4; (shift < 128) && int128_nz(bin); shift += 4) {
+        dec = int128_or(dec, int128_lshift(int128_remu(bin, base), shift));
+        bin = int128_divu(bin, base);
+    }
+
+    return dec;
+}
+
 uint64_t HELPER(popcnt)(uint64_t val)
 {
     /* Note that we don't fold past bytes. */
diff --git a/target/s390x/tcg/translate.c b/target/s390x/tcg/translate.c
index 8df00b7df9f..2d417337695 100644
--- a/target/s390x/tcg/translate.c
+++ b/target/s390x/tcg/translate.c
@@ -2233,6 +2233,14 @@ static DisasJumpType op_cvd(DisasContext *s, DisasOps *o)
     return DISAS_NEXT;
 }
 
+static DisasJumpType op_cvdg(DisasContext *s, DisasOps *o)
+{
+    TCGv_i128 t = tcg_temp_new_i128();
+    gen_helper_cvdg(t, o->in1);
+    tcg_gen_qemu_st_i128(t, o->in2, get_mem_index(s), MO_TE | MO_128);
+    return DISAS_NEXT;
+}
+
 static DisasJumpType op_ct(DisasContext *s, DisasOps *o)
 {
     int m3 = get_field(s, m3);
-- 
2.43.0