[PULL 26/28] tcg/s390x: Implement TCG_TARGET_HAS_sat_vec

[Richard Henderson <richard.henderson@linaro.org>]

The unsigned saturations are handled via generic code
using min/max.  The signed saturations are expanded using
double-sized arithmetic and a saturating pack.

Since all operations are done via expansion, do not
actually set TCG_TARGET_HAS_sat_vec.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 tcg/s390x/tcg-target.opc.h |  3 ++
 tcg/s390x/tcg-target.c.inc | 63 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 66 insertions(+)

diff --git a/tcg/s390x/tcg-target.opc.h b/tcg/s390x/tcg-target.opc.h
index 67afc82a93..0eb2350fb3 100644
--- a/tcg/s390x/tcg-target.opc.h
+++ b/tcg/s390x/tcg-target.opc.h
@@ -10,3 +10,6 @@
  * emitted by tcg_expand_vec_op.  For those familiar with GCC internals,
  * consider these to be UNSPEC with names.
  */
+DEF(s390_vuph_vec, 1, 1, 0, IMPLVEC)
+DEF(s390_vupl_vec, 1, 1, 0, IMPLVEC)
+DEF(s390_vpks_vec, 1, 2, 0, IMPLVEC)
diff --git a/tcg/s390x/tcg-target.c.inc b/tcg/s390x/tcg-target.c.inc
index 3b8fc62cd7..965d9ab54c 100644
--- a/tcg/s390x/tcg-target.c.inc
+++ b/tcg/s390x/tcg-target.c.inc
@@ -291,7 +291,10 @@ typedef enum S390Opcode {
     VRRc_VNO    = 0xe76b,
     VRRc_VO     = 0xe76a,
     VRRc_VOC    = 0xe76f,
+    VRRc_VPKS   = 0xe797,   /* we leave the m5 cs field 0 */
     VRRc_VS     = 0xe7f7,
+    VRRa_VUPH   = 0xe7d7,
+    VRRa_VUPL   = 0xe7d6,
     VRRc_VX     = 0xe76d,
     VRRf_VLVGP  = 0xe762,
 
@@ -2800,6 +2803,16 @@ static void tcg_out_vec_op(TCGContext *s, TCGOpcode opc,
         }
         break;
 
+    case INDEX_op_s390_vuph_vec:
+        tcg_out_insn(s, VRRa, VUPH, a0, a1, vece);
+        break;
+    case INDEX_op_s390_vupl_vec:
+        tcg_out_insn(s, VRRa, VUPL, a0, a1, vece);
+        break;
+    case INDEX_op_s390_vpks_vec:
+        tcg_out_insn(s, VRRc, VPKS, a0, a1, a2, vece);
+        break;
+
     case INDEX_op_mov_vec:   /* Always emitted via tcg_out_mov.  */
     case INDEX_op_dup_vec:   /* Always emitted via tcg_out_dup_vec.  */
     default:
@@ -2842,6 +2855,9 @@ int tcg_can_emit_vec_op(TCGOpcode opc, TCGType type, unsigned vece)
         return -1;
     case INDEX_op_mul_vec:
         return vece < MO_64;
+    case INDEX_op_ssadd_vec:
+    case INDEX_op_sssub_vec:
+        return vece < MO_64 ? -1 : 0;
     default:
         return 0;
     }
@@ -2897,6 +2913,43 @@ static void expand_vec_cmp(TCGType type, unsigned vece, TCGv_vec v0,
     }
 }
 
+static void expand_vec_sat(TCGType type, unsigned vece, TCGv_vec v0,
+                           TCGv_vec v1, TCGv_vec v2, TCGOpcode add_sub_opc)
+{
+    TCGv_vec h1 = tcg_temp_new_vec(type);
+    TCGv_vec h2 = tcg_temp_new_vec(type);
+    TCGv_vec l1 = tcg_temp_new_vec(type);
+    TCGv_vec l2 = tcg_temp_new_vec(type);
+
+    tcg_debug_assert (vece < MO_64);
+
+    /* Unpack with sign-extension. */
+    vec_gen_2(INDEX_op_s390_vuph_vec, type, vece,
+              tcgv_vec_arg(h1), tcgv_vec_arg(v1));
+    vec_gen_2(INDEX_op_s390_vuph_vec, type, vece,
+              tcgv_vec_arg(h2), tcgv_vec_arg(v2));
+
+    vec_gen_2(INDEX_op_s390_vupl_vec, type, vece,
+              tcgv_vec_arg(l1), tcgv_vec_arg(v1));
+    vec_gen_2(INDEX_op_s390_vupl_vec, type, vece,
+              tcgv_vec_arg(l2), tcgv_vec_arg(v2));
+
+    /* Arithmetic on a wider element size. */
+    vec_gen_3(add_sub_opc, type, vece + 1, tcgv_vec_arg(h1),
+              tcgv_vec_arg(h1), tcgv_vec_arg(h2));
+    vec_gen_3(add_sub_opc, type, vece + 1, tcgv_vec_arg(l1),
+              tcgv_vec_arg(l1), tcgv_vec_arg(l2));
+
+    /* Pack with saturation. */
+    vec_gen_3(INDEX_op_s390_vpks_vec, type, vece + 1,
+              tcgv_vec_arg(v0), tcgv_vec_arg(h1), tcgv_vec_arg(l1));
+
+    tcg_temp_free_vec(h1);
+    tcg_temp_free_vec(h2);
+    tcg_temp_free_vec(l1);
+    tcg_temp_free_vec(l2);
+}
+
 void tcg_expand_vec_op(TCGOpcode opc, TCGType type, unsigned vece,
                        TCGArg a0, ...)
 {
@@ -2920,6 +2973,13 @@ void tcg_expand_vec_op(TCGOpcode opc, TCGType type, unsigned vece,
         tcg_temp_free_vec(t0);
         break;
 
+    case INDEX_op_ssadd_vec:
+        expand_vec_sat(type, vece, v0, v1, v2, INDEX_op_add_vec);
+        break;
+    case INDEX_op_sssub_vec:
+        expand_vec_sat(type, vece, v0, v1, v2, INDEX_op_sub_vec);
+        break;
+
     default:
         g_assert_not_reached();
     }
@@ -3080,6 +3140,8 @@ static TCGConstraintSetIndex tcg_target_op_def(TCGOpcode op)
     case INDEX_op_sari_vec:
     case INDEX_op_shli_vec:
     case INDEX_op_shri_vec:
+    case INDEX_op_s390_vuph_vec:
+    case INDEX_op_s390_vupl_vec:
         return C_O1_I1(v, v);
     case INDEX_op_add_vec:
     case INDEX_op_sub_vec:
@@ -3099,6 +3161,7 @@ static TCGConstraintSetIndex tcg_target_op_def(TCGOpcode op)
     case INDEX_op_smin_vec:
     case INDEX_op_umax_vec:
     case INDEX_op_umin_vec:
+    case INDEX_op_s390_vpks_vec:
         return C_O1_I2(v, v, v);
     case INDEX_op_rotls_vec:
     case INDEX_op_shls_vec:
-- 
2.25.1