Re: [Qemu-devel] [PATCH v3 40/40] s390x/tcg: Implement VECTOR TEST UNDER MASK

[David Hildenbrand <david@redhat.com>]

On 02.05.19 16:10, David Hildenbrand wrote:
> Let's return the cc value directly via cpu_env. Unfortunately there
> isn't a simple way to calculate the value lazily - one would have to
> calculate and store e.g. the population count of the mask and the
> result so it can be evaluated in a cc helper.
> 
> But as VTM only sets the cc, we can assume the value will be needed soon
> either way.
> 
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>  target/s390x/helper.h           |  1 +
>  target/s390x/insn-data.def      |  2 ++
>  target/s390x/translate_vx.inc.c | 11 +++++++++++
>  target/s390x/vec_int_helper.c   | 18 ++++++++++++++++++
>  4 files changed, 32 insertions(+)
> 
> diff --git a/target/s390x/helper.h b/target/s390x/helper.h
> index 2cb1f369bd..7755a96c33 100644
> --- a/target/s390x/helper.h
> +++ b/target/s390x/helper.h
> @@ -209,6 +209,7 @@ DEF_HELPER_FLAGS_4(gvec_vsra, TCG_CALL_NO_RWG, void, ptr, cptr, i64, i32)
>  DEF_HELPER_FLAGS_4(gvec_vsrl, TCG_CALL_NO_RWG, void, ptr, cptr, i64, i32)
>  DEF_HELPER_FLAGS_4(gvec_vscbi8, TCG_CALL_NO_RWG, void, ptr, cptr, cptr, i32)
>  DEF_HELPER_FLAGS_4(gvec_vscbi16, TCG_CALL_NO_RWG, void, ptr, cptr, cptr, i32)
> +DEF_HELPER_4(gvec_vtm, void, ptr, cptr, env, i32)
>  
>  #ifndef CONFIG_USER_ONLY
>  DEF_HELPER_3(servc, i32, env, i64, i64)
> diff --git a/target/s390x/insn-data.def b/target/s390x/insn-data.def
> index a52db41388..e61475bdc4 100644
> --- a/target/s390x/insn-data.def
> +++ b/target/s390x/insn-data.def
> @@ -1188,6 +1188,8 @@
>      F(0xe767, VSUMQ,   VRR_c, V,   0, 0, 0, 0, vsumq, 0, IF_VEC)
>  /* VECTOR SUM ACROSS WORD */
>      F(0xe764, VSUM,    VRR_c, V,   0, 0, 0, 0, vsum, 0, IF_VEC)
> +/* VECTOR TEST UNDER MASK */
> +    F(0xe7d8, VTM,     VRR_a, V,   0, 0, 0, 0, vtm, 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 23eca2b332..e12ba00a13 100644
> --- a/target/s390x/translate_vx.inc.c
> +++ b/target/s390x/translate_vx.inc.c
> @@ -191,6 +191,9 @@ static void get_vec_element_ptr_i64(TCGv_ptr ptr, uint8_t reg, TCGv_i64 enr,
>  #define gen_gvec_2i_ool(v1, v2, c, data, fn) \
>      tcg_gen_gvec_2i_ool(vec_full_reg_offset(v1), vec_full_reg_offset(v2), \
>                          c, 16, 16, data, fn)
> +#define gen_gvec_2_ptr(v1, v2, ptr, data, fn) \
> +    tcg_gen_gvec_2_ptr(vec_full_reg_offset(v1), vec_full_reg_offset(v2), \
> +                       ptr, 16, 16, data, fn)
>  #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)
> @@ -2338,3 +2341,11 @@ static DisasJumpType op_vsum(DisasContext *s, DisasOps *o)
>      tcg_temp_free_i32(tmp);
>      return DISAS_NEXT;
>  }
> +
> +static DisasJumpType op_vtm(DisasContext *s, DisasOps *o)
> +{
> +    gen_gvec_2_ptr(get_field(s->fields, v1), get_field(s->fields, v2),
> +                   cpu_env, 0, gen_helper_gvec_vtm);
> +    set_cc_static(s);
> +    return DISAS_NEXT;
> +}
> diff --git a/target/s390x/vec_int_helper.c b/target/s390x/vec_int_helper.c
> index 09137dab99..3e8837e09a 100644
> --- a/target/s390x/vec_int_helper.c
> +++ b/target/s390x/vec_int_helper.c
> @@ -583,3 +583,21 @@ void HELPER(gvec_vscbi##BITS)(void *v1, const void *v2, const void *v3,        \
>  }
>  DEF_VSCBI(8)
>  DEF_VSCBI(16)
> +
> +void HELPER(gvec_vtm)(void *v1, const void *v2, CPUS390XState *env,
> +                      uint32_t desc)
> +{
> +    S390Vector tmp;
> +
> +    s390_vec_and(&tmp, v1, v2);
> +    if (s390_vec_is_zero(&tmp)) {
> +        /* Selected bits all zeros; or all mask bits zero */
> +        env->cc_op = 0;
> +    } else if (s390_vec_equal(&tmp, v2)) {
> +        /* Selected bits all ones */
> +        env->cc_op = 3;
> +    } else {
> +        /* Selected bits a mix of zeros and ones */
> +        env->cc_op = 1;
> +    }
> +}
> 


This hunk got lost in follow-up patches:

diff --git a/target/s390x/vec_int_helper.c b/target/s390x/vec_int_helper.c
index 09137dab99..68eaae407b 100644
--- a/target/s390x/vec_int_helper.c
+++ b/target/s390x/vec_int_helper.c
@@ -28,6 +28,19 @@ static void s390_vec_xor(S390Vector *res, const
S390Vector *a,
     res->doubleword[1] = a->doubleword[1] ^ b->doubleword[1];
 }

+static void s390_vec_and(S390Vector *res, const S390Vector *a,
+                         const S390Vector *b)
+{
+    res->doubleword[0] = a->doubleword[0] & b->doubleword[0];
+    res->doubleword[1] = a->doubleword[1] & b->doubleword[1];
+}
+
+static bool s390_vec_equal(const S390Vector *a, const S390Vector *b)
+{
+    return a->doubleword[0] == b->doubleword[0] &&
+           a->doubleword[1] == b->doubleword[1];
+}
+
 static void s390_vec_shl(S390Vector *d, const S390Vector *a, uint64_t
count)
 {
     uint64_t tmp;


-- 

Thanks,

David / dhildenb