target/arm: Implement SVE2 XAR

In addition, use the same vector generator interface for AdvSIMD.
This fixes a bug in which the AdvSIMD insn failed to clear the
high bits of the SVE register.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210525010358.152808-44-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 104 insertions, 0 deletions

diff --git a/target/arm/translate-sve.c b/target/arm/translate-sve.c
index 13f84d14d3..ba39ff84a5 100644
--- a/target/arm/translate-sve.c
+++ b/target/arm/translate-sve.c
@@ -340,6 +340,110 @@ static bool trans_BIC_zzz(DisasContext *s, arg_rrr_esz *a)
     return do_zzz_fn(s, a, tcg_gen_gvec_andc);
 }
 
+static void gen_xar8_i64(TCGv_i64 d, TCGv_i64 n, TCGv_i64 m, int64_t sh)
+{
+    TCGv_i64 t = tcg_temp_new_i64();
+    uint64_t mask = dup_const(MO_8, 0xff >> sh);
+
+    tcg_gen_xor_i64(t, n, m);
+    tcg_gen_shri_i64(d, t, sh);
+    tcg_gen_shli_i64(t, t, 8 - sh);
+    tcg_gen_andi_i64(d, d, mask);
+    tcg_gen_andi_i64(t, t, ~mask);
+    tcg_gen_or_i64(d, d, t);
+    tcg_temp_free_i64(t);
+}
+
+static void gen_xar16_i64(TCGv_i64 d, TCGv_i64 n, TCGv_i64 m, int64_t sh)
+{
+    TCGv_i64 t = tcg_temp_new_i64();
+    uint64_t mask = dup_const(MO_16, 0xffff >> sh);
+
+    tcg_gen_xor_i64(t, n, m);
+    tcg_gen_shri_i64(d, t, sh);
+    tcg_gen_shli_i64(t, t, 16 - sh);
+    tcg_gen_andi_i64(d, d, mask);
+    tcg_gen_andi_i64(t, t, ~mask);
+    tcg_gen_or_i64(d, d, t);
+    tcg_temp_free_i64(t);
+}
+
+static void gen_xar_i32(TCGv_i32 d, TCGv_i32 n, TCGv_i32 m, int32_t sh)
+{
+    tcg_gen_xor_i32(d, n, m);
+    tcg_gen_rotri_i32(d, d, sh);
+}
+
+static void gen_xar_i64(TCGv_i64 d, TCGv_i64 n, TCGv_i64 m, int64_t sh)
+{
+    tcg_gen_xor_i64(d, n, m);
+    tcg_gen_rotri_i64(d, d, sh);
+}
+
+static void gen_xar_vec(unsigned vece, TCGv_vec d, TCGv_vec n,
+                        TCGv_vec m, int64_t sh)
+{
+    tcg_gen_xor_vec(vece, d, n, m);
+    tcg_gen_rotri_vec(vece, d, d, sh);
+}
+
+void gen_gvec_xar(unsigned vece, uint32_t rd_ofs, uint32_t rn_ofs,
+                  uint32_t rm_ofs, int64_t shift,
+                  uint32_t opr_sz, uint32_t max_sz)
+{
+    static const TCGOpcode vecop[] = { INDEX_op_rotli_vec, 0 };
+    static const GVecGen3i ops[4] = {
+        { .fni8 = gen_xar8_i64,
+          .fniv = gen_xar_vec,
+          .fno = gen_helper_sve2_xar_b,
+          .opt_opc = vecop,
+          .vece = MO_8 },
+        { .fni8 = gen_xar16_i64,
+          .fniv = gen_xar_vec,
+          .fno = gen_helper_sve2_xar_h,
+          .opt_opc = vecop,
+          .vece = MO_16 },
+        { .fni4 = gen_xar_i32,
+          .fniv = gen_xar_vec,
+          .fno = gen_helper_sve2_xar_s,
+          .opt_opc = vecop,
+          .vece = MO_32 },
+        { .fni8 = gen_xar_i64,
+          .fniv = gen_xar_vec,
+          .fno = gen_helper_gvec_xar_d,
+          .opt_opc = vecop,
+          .vece = MO_64 }
+    };
+    int esize = 8 << vece;
+
+    /* The SVE2 range is 1 .. esize; the AdvSIMD range is 0 .. esize-1. */
+    tcg_debug_assert(shift >= 0);
+    tcg_debug_assert(shift <= esize);
+    shift &= esize - 1;
+
+    if (shift == 0) {
+        /* xar with no rotate devolves to xor. */
+        tcg_gen_gvec_xor(vece, rd_ofs, rn_ofs, rm_ofs, opr_sz, max_sz);
+    } else {
+        tcg_gen_gvec_3i(rd_ofs, rn_ofs, rm_ofs, opr_sz, max_sz,
+                        shift, &ops[vece]);
+    }
+}
+
+static bool trans_XAR(DisasContext *s, arg_rrri_esz *a)
+{
+    if (a->esz < 0 || !dc_isar_feature(aa64_sve2, s)) {
+        return false;
+    }
+    if (sve_access_check(s)) {
+        unsigned vsz = vec_full_reg_size(s);
+        gen_gvec_xar(a->esz, vec_full_reg_offset(s, a->rd),
+                     vec_full_reg_offset(s, a->rn),
+                     vec_full_reg_offset(s, a->rm), a->imm, vsz, vsz);
+    }
+    return true;
+}
+
 static bool do_sve2_zzzz_fn(DisasContext *s, arg_rrrr_esz *a, GVecGen4Fn *fn)
 {
     if (!dc_isar_feature(aa64_sve2, s)) {