[Qemu-devel] [PATCH v1 07/41] s390x/tcg: Implement VECTOR AVERAGE

[David Hildenbrand <david@redhat.com>]

Handle 32/64-bit elements via gvec expansion and the 8/16 bits via
ool helpers.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 target/s390x/helper.h           |  2 ++
 target/s390x/insn-data.def      |  2 ++
 target/s390x/translate_vx.inc.c | 63 +++++++++++++++++++++++++++++++++
 target/s390x/vec_int_helper.c   | 16 +++++++++
 4 files changed, 83 insertions(+)

diff --git a/target/s390x/helper.h b/target/s390x/helper.h
index e1847e8877..2b6b716909 100644
--- a/target/s390x/helper.h
+++ b/target/s390x/helper.h
@@ -148,6 +148,8 @@ DEF_HELPER_FLAGS_4(vstl, TCG_CALL_NO_WG, void, env, cptr, i64, i64)
 /* === Vector Integer Instructions === */
 DEF_HELPER_FLAGS_4(gvec_vacc128, TCG_CALL_NO_RWG, void, ptr, cptr, cptr, i32)
 DEF_HELPER_FLAGS_5(gvec_vaccc128, TCG_CALL_NO_RWG, void, ptr, cptr, cptr, cptr, i32)
+DEF_HELPER_FLAGS_4(gvec_vavg8, TCG_CALL_NO_RWG, void, ptr, cptr, cptr, i32)
+DEF_HELPER_FLAGS_4(gvec_vavg16, TCG_CALL_NO_RWG, void, ptr, cptr, cptr, i32)
 
 #ifndef CONFIG_USER_ONLY
 DEF_HELPER_3(servc, i32, env, i64, i64)
diff --git a/target/s390x/insn-data.def b/target/s390x/insn-data.def
index 456d5597ca..6f8b42e327 100644
--- a/target/s390x/insn-data.def
+++ b/target/s390x/insn-data.def
@@ -1068,6 +1068,8 @@
     F(0xe768, VN,      VRR_c, V,   0, 0, 0, 0, vn, 0, IF_VEC)
 /* VECTOR AND WITH COMPLEMENT */
     F(0xe769, VNC,     VRR_c, V,   0, 0, 0, 0, vnc, 0, IF_VEC)
+/* VECTOR AVERAGE */
+    F(0xe7f2, VAVG,    VRR_c, V,   0, 0, 0, 0, vavg, 0, IF_VEC)
 
 #ifndef CONFIG_USER_ONLY
 /* COMPARE AND SWAP AND PURGE */
diff --git a/target/s390x/translate_vx.inc.c b/target/s390x/translate_vx.inc.c
index aaa247e855..50e03bf151 100644
--- a/target/s390x/translate_vx.inc.c
+++ b/target/s390x/translate_vx.inc.c
@@ -256,6 +256,17 @@ static void zero_vec(uint8_t reg)
     tcg_gen_gvec_dup8i(vec_full_reg_offset(reg), 16, 16, 0);
 }
 
+static void gen_addi2_i64(TCGv_i64 dl, TCGv_i64 dh, TCGv_i64 al, TCGv_i64 ah,
+                          uint64_t b)
+{
+    TCGv_i64 bl = tcg_const_i64(b);
+    TCGv_i64 bh = tcg_const_i64(0);
+
+    tcg_gen_add2_i64(dl, dh, al, ah, bl, bh);
+    tcg_temp_free_i64(bl);
+    tcg_temp_free_i64(bh);
+}
+
 static DisasJumpType op_vge(DisasContext *s, DisasOps *o)
 {
     const uint8_t es = s->insn->data;
@@ -1149,3 +1160,55 @@ static DisasJumpType op_vnc(DisasContext *s, DisasOps *o)
                   get_field(s->fields, v2), get_field(s->fields, v3));
     return DISAS_NEXT;
 }
+
+static void gen_avg_i32(TCGv_i32 d, TCGv_i32 a, TCGv_i32 b)
+{
+    TCGv_i64 t0 = tcg_temp_new_i64();
+    TCGv_i64 t1 = tcg_temp_new_i64();
+
+    tcg_gen_ext_i32_i64(t0, a);
+    tcg_gen_ext_i32_i64(t1, b);
+    tcg_gen_add_i64(t0, t0, t1);
+    tcg_gen_addi_i64(t0, t0, 1);
+    tcg_gen_shri_i64(t0, t0, 1);
+    tcg_gen_extrl_i64_i32(d, t0);
+
+    tcg_temp_free(t0);
+    tcg_temp_free(t1);
+}
+
+static void gen_avg_i64(TCGv_i64 dl, TCGv_i64 al, TCGv_i64 bl)
+{
+    TCGv_i64 dh = tcg_temp_new_i64();
+    TCGv_i64 ah = tcg_temp_new_i64();
+    TCGv_i64 bh = tcg_temp_new_i64();
+
+    /* extending the sign by one bit is sufficient */
+    tcg_gen_extract_i64(ah, al, 63, 1);
+    tcg_gen_extract_i64(bh, bl, 63, 1);
+    tcg_gen_add2_i64(dl, dh, al, ah, bl, bh);
+    gen_addi2_i64(dl, dh, dl, dh, 1);
+    tcg_gen_extract2_i64(dl, dl, dh, 1);
+
+    tcg_temp_free_i64(dh);
+    tcg_temp_free_i64(ah);
+    tcg_temp_free_i64(bh);
+}
+static DisasJumpType op_vavg(DisasContext *s, DisasOps *o)
+{
+    const uint8_t es = get_field(s->fields, m4);
+    static const GVecGen3 g[4] = {
+        { .fno = gen_helper_gvec_vavg8, },
+        { .fno = gen_helper_gvec_vavg16, },
+        { .fni4 = gen_avg_i32, },
+        { .fni8 = gen_avg_i64, },
+    };
+
+    if (es > ES_64) {
+        gen_program_exception(s, PGM_SPECIFICATION);
+        return DISAS_NORETURN;
+    }
+    gen_gvec_3(get_field(s->fields, v1), get_field(s->fields, v2),
+               get_field(s->fields, v3), &g[es]);
+    return DISAS_NEXT;
+}
diff --git a/target/s390x/vec_int_helper.c b/target/s390x/vec_int_helper.c
index 97fc559da0..149cfaaeae 100644
--- a/target/s390x/vec_int_helper.c
+++ b/target/s390x/vec_int_helper.c
@@ -61,3 +61,19 @@ void HELPER(gvec_vaccc128)(void *v1, const void *v2, const void *v3,
     dst->doubleword[0] = 0;
     dst->doubleword[1] = carry;
 }
+
+#define DEF_VAVG(BITS)                                                         \
+void HELPER(gvec_vavg##BITS)(void *v1, const void *v2, const void *v3,         \
+                             uint32_t desc)                                    \
+{                                                                              \
+    int i;                                                                     \
+                                                                               \
+    for (i = 0; i < (128 / BITS); i++) {                                       \
+        const int32_t a = (int##BITS##_t)s390_vec_read_element##BITS(v2, i);   \
+        const int32_t b = (int##BITS##_t)s390_vec_read_element##BITS(v3, i);   \
+                                                                               \
+        s390_vec_write_element##BITS(v1, i, (a + b + 1) >> 1);                 \
+    }                                                                          \
+}
+DEF_VAVG(8)
+DEF_VAVG(16)
-- 
2.20.1