target/arm: Implement SVE2 bitwise shift right and accumulate

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210525010358.152808-22-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

target/arm/sve.decode

@@ -1253,3 +1253,11 @@ UABALT          01000101 .. 0 ..... 1100 11 ..... .....  @rda_rn_rm
 # ADC and SBC decoded via size in helper dispatch.
 ADCLB           01000101 .. 0 ..... 11010 0 ..... .....  @rda_rn_rm
 ADCLT           01000101 .. 0 ..... 11010 1 ..... .....  @rda_rn_rm
+
+## SVE2 bitwise shift right and accumulate
+
+# TODO: Use @rda and %reg_movprfx here.
+SSRA            01000101 .. 0 ..... 1110 00 ..... .....  @rd_rn_tszimm_shr
+USRA            01000101 .. 0 ..... 1110 01 ..... .....  @rd_rn_tszimm_shr
+SRSRA           01000101 .. 0 ..... 1110 10 ..... .....  @rd_rn_tszimm_shr
+URSRA           01000101 .. 0 ..... 1110 11 ..... .....  @rd_rn_tszimm_shr

target/arm/translate-sve.c

@@ -6394,3 +6394,37 @@ static bool trans_ADCLT(DisasContext *s, arg_rrrr_esz *a)
 {
     return do_adcl(s, a, true);
 }
+
+static bool do_sve2_fn2i(DisasContext *s, arg_rri_esz *a, GVecGen2iFn *fn)
+{
+    if (a->esz < 0 || !dc_isar_feature(aa64_sve2, s)) {
+        return false;
+    }
+    if (sve_access_check(s)) {
+        unsigned vsz = vec_full_reg_size(s);
+        unsigned rd_ofs = vec_full_reg_offset(s, a->rd);
+        unsigned rn_ofs = vec_full_reg_offset(s, a->rn);
+        fn(a->esz, rd_ofs, rn_ofs, a->imm, vsz, vsz);
+    }
+    return true;
+}
+
+static bool trans_SSRA(DisasContext *s, arg_rri_esz *a)
+{
+    return do_sve2_fn2i(s, a, gen_gvec_ssra);
+}
+
+static bool trans_USRA(DisasContext *s, arg_rri_esz *a)
+{
+    return do_sve2_fn2i(s, a, gen_gvec_usra);
+}
+
+static bool trans_SRSRA(DisasContext *s, arg_rri_esz *a)
+{
+    return do_sve2_fn2i(s, a, gen_gvec_srsra);
+}
+
+static bool trans_URSRA(DisasContext *s, arg_rri_esz *a)
+{
+    return do_sve2_fn2i(s, a, gen_gvec_ursra);
+}