s390x/tcg: Implement VECTOR SUBTRACT WITH BORROW COMPUTE BORROW INDICATION

Mostly courtesy of Richard H.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Hildenbrand <david@redhat.com>

2 files changed, 36 insertions, 0 deletions

diff --git a/target/s390x/insn-data.def b/target/s390x/insn-data.def
index a60d8531dc..a8d90517f6 100644
--- a/target/s390x/insn-data.def
+++ b/target/s390x/insn-data.def
@@ -1180,6 +1180,8 @@
     F(0xe7f5, VSCBI,   VRR_c, V,   0, 0, 0, 0, vscbi, 0, IF_VEC)
 /* VECTOR SUBTRACT WITH BORROW INDICATION */
     F(0xe7bf, VSBI,    VRR_d, V,   0, 0, 0, 0, vsbi, 0, IF_VEC)
+/* VECTOR SUBTRACT WITH BORROW COMPUTE BORROW INDICATION */
+    F(0xe7bd, VSBCBI,  VRR_d, V,   0, 0, 0, 0, vsbcbi, 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 66a938a909..85cd5f03b3 100644
--- a/target/s390x/translate_vx.inc.c
+++ b/target/s390x/translate_vx.inc.c
@@ -2218,3 +2218,37 @@ static DisasJumpType op_vsbi(DisasContext *s, DisasOps *o)
                       get_field(s->fields, v4));
     return DISAS_NEXT;
 }
+
+static void gen_sbcbi2_i64(TCGv_i64 dl, TCGv_i64 dh, TCGv_i64 al, TCGv_i64 ah,
+                           TCGv_i64 bl, TCGv_i64 bh, TCGv_i64 cl, TCGv_i64 ch)
+{
+    TCGv_i64 th = tcg_temp_new_i64();
+    TCGv_i64 tl = tcg_temp_new_i64();
+    TCGv_i64 zero = tcg_const_i64(0);
+
+    tcg_gen_andi_i64(tl, cl, 1);
+    tcg_gen_sub2_i64(tl, th, al, zero, tl, zero);
+    tcg_gen_sub2_i64(tl, th, tl, th, bl, zero);
+    tcg_gen_andi_i64(th, th, 1);
+    tcg_gen_sub2_i64(tl, th, ah, zero, th, zero);
+    tcg_gen_sub2_i64(tl, th, tl, th, bh, zero);
+    tcg_gen_andi_i64(dl, th, 1);
+    tcg_gen_mov_i64(dh, zero);
+
+    tcg_temp_free_i64(tl);
+    tcg_temp_free_i64(th);
+    tcg_temp_free_i64(zero);
+}
+
+static DisasJumpType op_vsbcbi(DisasContext *s, DisasOps *o)
+{
+    if (get_field(s->fields, m5) != ES_128) {
+        gen_program_exception(s, PGM_SPECIFICATION);
+        return DISAS_NORETURN;
+    }
+
+    gen_gvec128_4_i64(gen_sbcbi2_i64, get_field(s->fields, v1),
+                      get_field(s->fields, v2), get_field(s->fields, v3),
+                      get_field(s->fields, v4));
+    return DISAS_NEXT;
+}