[PATCH v2 0/2] target/s390x: Emulate CVDG

[PATCH v2 0/2] target/s390x: Emulate CVDG

[Ilya Leoshkevich]

v1: https://lists.gnu.org/archive/html/qemu-devel/2024-01/msg02865.html
v1 -> v2: Fix !CONFIG_INT128 builds (Richard).

Hi,

Ido reported that we are missing the CVDG emulation (which is very
similar to the existing CVD emulation). This series adds it along with
a test.

Best regards,
Ilya

Ilya Leoshkevich (2):
  target/s390x: Emulate CVDG
  tests/tcg/s390x: Test CONVERT TO DECIMAL

 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 ++++++
 tests/tcg/s390x/Makefile.target  |  1 +
 tests/tcg/s390x/cvd.c            | 42 ++++++++++++++++++++++++++++++++
 6 files changed, 74 insertions(+)
 create mode 100644 tests/tcg/s390x/cvd.c

-- 
2.43.0

[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

[PATCH v2 2/2] tests/tcg/s390x: Test CONVERT TO DECIMAL

[Ilya Leoshkevich]

Check the CVD's and CVDG's corner cases.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 tests/tcg/s390x/Makefile.target |  1 +
 tests/tcg/s390x/cvd.c           | 42 +++++++++++++++++++++++++++++++++
 2 files changed, 43 insertions(+)
 create mode 100644 tests/tcg/s390x/cvd.c

diff --git a/tests/tcg/s390x/Makefile.target b/tests/tcg/s390x/Makefile.target
index 30994dcf9c2..04e4bddd83d 100644
--- a/tests/tcg/s390x/Makefile.target
+++ b/tests/tcg/s390x/Makefile.target
@@ -45,6 +45,7 @@ TESTS+=clc
 TESTS+=laalg
 TESTS+=add-logical-with-carry
 TESTS+=lae
+TESTS+=cvd
 
 cdsg: CFLAGS+=-pthread
 cdsg: LDFLAGS+=-pthread
diff --git a/tests/tcg/s390x/cvd.c b/tests/tcg/s390x/cvd.c
new file mode 100644
index 00000000000..4d12282c6aa
--- /dev/null
+++ b/tests/tcg/s390x/cvd.c
@@ -0,0 +1,42 @@
+/*
+ * Test the CONVERT TO DECIMAL instruction.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+#include <assert.h>
+#include <stdint.h>
+
+static uint64_t cvd(int32_t x)
+{
+    uint64_t ret;
+
+    asm("cvd %[x],%[ret]" : [ret] "=R" (ret) : [x] "r" (x));
+
+    return ret;
+}
+
+static __uint128_t cvdg(int64_t x)
+{
+    __uint128_t ret;
+
+    asm("cvdg %[x],%[ret]" : [ret] "=T" (ret) : [x] "r" (x));
+
+    return ret;
+}
+
+int main(void)
+{
+    __uint128_t m = (((__uint128_t)0x9223372036854775) << 16) | 0x8070;
+
+    assert(cvd(0) == 0xc);
+    assert(cvd(1) == 0x1c);
+    assert(cvd(-1) == 0x1d);
+    assert(cvd(0x7fffffff) == 0x2147483647c);
+    assert(cvd(-0x7fffffff) == 0x2147483647d);
+
+    assert(cvdg(0) == 0xc);
+    assert(cvdg(1) == 0x1c);
+    assert(cvdg(-1) == 0x1d);
+    assert(cvdg(0x7fffffffffffffff) == (m | 0xc));
+    assert(cvdg(-0x7fffffffffffffff) == (m | 0xd));
+}
-- 
2.43.0

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

[Richard Henderson]

On 1/25/24 22:29, Ilya Leoshkevich wrote:
> 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(+)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~