[Qemu-devel] [PATCH v3 02/40] s390x/tcg: Implement VECTOR ADD COMPUTE CARRY

[David Hildenbrand <david@redhat.com>]

128-bit handling courtesy of Richard H.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 target/s390x/insn-data.def      |  2 +
 target/s390x/translate_vx.inc.c | 94 +++++++++++++++++++++++++++++++++
 2 files changed, 96 insertions(+)

diff --git a/target/s390x/insn-data.def b/target/s390x/insn-data.def
index 74a0ccc770..f0e62b9aa8 100644
--- a/target/s390x/insn-data.def
+++ b/target/s390x/insn-data.def
@@ -1058,6 +1058,8 @@
 
 /* VECTOR ADD */
     F(0xe7f3, VA,      VRR_c, V,   0, 0, 0, 0, va, 0, IF_VEC)
+/* VECTOR ADD COMPUTE CARRY */
+    F(0xe7f1, VACC,    VRR_c, V,   0, 0, 0, 0, vacc, 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 2f84ea0511..312c5f67be 100644
--- a/target/s390x/translate_vx.inc.c
+++ b/target/s390x/translate_vx.inc.c
@@ -136,6 +136,9 @@ static void get_vec_element_ptr_i64(TCGv_ptr ptr, uint8_t reg, TCGv_i64 enr,
     tcg_temp_free_i64(tmp);
 }
 
+#define gen_gvec_3(v1, v2, v3, gen) \
+    tcg_gen_gvec_3(vec_full_reg_offset(v1), vec_full_reg_offset(v2), \
+                   vec_full_reg_offset(v3), 16, 16, gen)
 #define gen_gvec_3_ool(v1, v2, v3, data, fn) \
     tcg_gen_gvec_3_ool(vec_full_reg_offset(v1), vec_full_reg_offset(v2), \
                        vec_full_reg_offset(v3), 16, 16, data, fn)
@@ -985,3 +988,94 @@ static DisasJumpType op_va(DisasContext *s, DisasOps *o)
                   get_field(s->fields, v3));
     return DISAS_NEXT;
 }
+
+static void gen_acc(TCGv_i64 d, TCGv_i64 a, TCGv_i64 b, uint8_t es)
+{
+    const uint8_t msb_bit_nr = NUM_VEC_ELEMENT_BITS(es) - 1;
+    TCGv_i64 msb_mask = tcg_const_i64(dup_const(es, 1ull << msb_bit_nr));
+    TCGv_i64 t1 = tcg_temp_new_i64();
+    TCGv_i64 t2 = tcg_temp_new_i64();
+    TCGv_i64 t3 = tcg_temp_new_i64();
+
+    /* Calculate the carry into the MSB, ignoring the old MSBs */
+    tcg_gen_andc_i64(t1, a, msb_mask);
+    tcg_gen_andc_i64(t2, b, msb_mask);
+    tcg_gen_add_i64(t1, t1, t2);
+    /* Calculate the MSB without any carry into it */
+    tcg_gen_xor_i64(t3, a, b);
+    /* Calculate the carry out of the MSB in the MSB bit position */
+    tcg_gen_and_i64(d, a, b);
+    tcg_gen_and_i64(t1, t1, t3);
+    tcg_gen_or_i64(d, d, t1);
+    /* Isolate and shift the carry into position */
+    tcg_gen_and_i64(d, d, msb_mask);
+    tcg_gen_shri_i64(d, d, msb_bit_nr);
+
+    tcg_temp_free_i64(t1);
+    tcg_temp_free_i64(t2);
+    tcg_temp_free_i64(t3);
+}
+
+static void gen_acc8_i64(TCGv_i64 d, TCGv_i64 a, TCGv_i64 b)
+{
+    gen_acc(d, a, b, ES_8);
+}
+
+static void gen_acc16_i64(TCGv_i64 d, TCGv_i64 a, TCGv_i64 b)
+{
+    gen_acc(d, a, b, ES_16);
+}
+
+static void gen_acc32_i64(TCGv_i64 d, TCGv_i64 a, TCGv_i64 b)
+{
+    gen_acc(d, a, b, ES_32);
+}
+
+static void gen_acc_i64(TCGv_i64 d, TCGv_i64 a, TCGv_i64 b)
+{
+    TCGv_i64 t = tcg_temp_new_i64();
+
+    tcg_gen_add_i64(t, a, b);
+    tcg_gen_setcond_i64(TCG_COND_LTU, d, t, b);
+    tcg_temp_free_i64(t);
+}
+
+static void gen_acc2_i64(TCGv_i64 dl, TCGv_i64 dh, TCGv_i64 al,
+                         TCGv_i64 ah, TCGv_i64 bl, TCGv_i64 bh)
+{
+    TCGv_i64 th = tcg_temp_new_i64();
+    TCGv_i64 tl = tcg_temp_new_i64();
+    TCGv_i64 zero = tcg_const_i64(0);
+
+    tcg_gen_add2_i64(tl, th, al, zero, bl, zero);
+    tcg_gen_add2_i64(tl, th, th, zero, ah, zero);
+    tcg_gen_add2_i64(tl, dl, tl, th, bh, zero);
+    tcg_gen_mov_i64(dh, zero);
+
+    tcg_temp_free_i64(th);
+    tcg_temp_free_i64(tl);
+    tcg_temp_free_i64(zero);
+}
+
+static DisasJumpType op_vacc(DisasContext *s, DisasOps *o)
+{
+    const uint8_t es = get_field(s->fields, m4);
+    static const GVecGen3 g[4] = {
+        { .fni8 = gen_acc8_i64, },
+        { .fni8 = gen_acc16_i64, },
+        { .fni8 = gen_acc32_i64, },
+        { .fni8 = gen_acc_i64, },
+    };
+
+    if (es > ES_128) {
+        gen_program_exception(s, PGM_SPECIFICATION);
+        return DISAS_NORETURN;
+    } else if (es == ES_128) {
+        gen_gvec128_3_i64(gen_acc2_i64, get_field(s->fields, v1),
+                          get_field(s->fields, v2), get_field(s->fields, v3));
+        return DISAS_NEXT;
+    }
+    gen_gvec_3(get_field(s->fields, v1), get_field(s->fields, v2),
+               get_field(s->fields, v3), &g[es]);
+    return DISAS_NEXT;
+}
-- 
2.20.1