| Message ID | 20190411100836.646-38-david@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | s390x/tcg: Vector Instruction Support Part 2 | expand |
On 4/11/19 12:08 AM, David Hildenbrand wrote: > +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_gvec_4_ool(get_field(s->fields, v1), get_field(s->fields, v2), > + get_field(s->fields, v3), get_field(s->fields, v4), 0, > + gen_helper_gvec_vsbcbi128); > + return DISAS_NEXT; > +} Reviewed-by: Richard Henderson <richard.henderson@linaro.org> I'm sure this can be done similarly to add with carry compute carry, but it's harder to reason with sub2. Something like 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(tl, th, 1); tcg_gen_sub2_i64(tl, th, ah, zero, tl, zero); tcg_gen_sub2_i64(tl, th, tl, th, bh, zero); tcg_gen_andi_i64(tl, th, 1); /* result in tl */ r~
On 13.04.19 08:11, Richard Henderson wrote: > On 4/11/19 12:08 AM, David Hildenbrand wrote: >> +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_gvec_4_ool(get_field(s->fields, v1), get_field(s->fields, v2), >> + get_field(s->fields, v3), get_field(s->fields, v4), 0, >> + gen_helper_gvec_vsbcbi128); >> + return DISAS_NEXT; >> +} > > > Reviewed-by: Richard Henderson <richard.henderson@linaro.org> > > I'm sure this can be done similarly to add with carry compute carry, but it's > harder to reason with sub2. Something like > > 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(tl, th, 1); > tcg_gen_sub2_i64(tl, th, ah, zero, tl, zero); > tcg_gen_sub2_i64(tl, th, tl, th, bh, zero); > tcg_gen_andi_i64(tl, th, 1); > /* result in tl */ Indeed, looks good to me. The only thing to care about is to convert -1 to 1, so we get a proper borrow. Thanks!
diff --git a/target/s390x/helper.h b/target/s390x/helper.h index 33e3e003f8..d040e4cd07 100644 --- a/target/s390x/helper.h +++ b/target/s390x/helper.h @@ -233,6 +233,7 @@ 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_FLAGS_4(gvec_vscbi128, TCG_CALL_NO_RWG, void, ptr, cptr, cptr, i32) +DEF_HELPER_FLAGS_5(gvec_vsbcbi128, TCG_CALL_NO_RWG, void, ptr, cptr, cptr, cptr, 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 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 3f60b97654..fd232ba6c3 100644 --- a/target/s390x/translate_vx.inc.c +++ b/target/s390x/translate_vx.inc.c @@ -2212,3 +2212,16 @@ static DisasJumpType op_vsbi(DisasContext *s, DisasOps *o) get_field(s->fields, v4)); return DISAS_NEXT; } + +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_gvec_4_ool(get_field(s->fields, v1), get_field(s->fields, v2), + get_field(s->fields, v3), get_field(s->fields, v4), 0, + gen_helper_gvec_vsbcbi128); + return DISAS_NEXT; +} diff --git a/target/s390x/vec_int_helper.c b/target/s390x/vec_int_helper.c index 699b399a26..95686e79fd 100644 --- a/target/s390x/vec_int_helper.c +++ b/target/s390x/vec_int_helper.c @@ -803,3 +803,19 @@ void HELPER(gvec_vscbi128)(void *v1, const void *v2, const void *v3, dst->doubleword[0] = 0; dst->doubleword[1] = s390_vec_sub(&tmp, v2, v3); } + +void HELPER(gvec_vsbcbi128)(void *v1, const void *v2, const void *v3, + const void *v4, uint32_t desc) +{ + const S390Vector old_borrow = { + .doubleword[0] = 0, + .doubleword[1] = ((S390Vector *)v4)->doubleword[1] & 1, + }; + S390Vector tmp, *dst = v1; + bool borrow; + + borrow = s390_vec_sub(&tmp, v2, v3); + borrow |= s390_vec_sub(&tmp, &tmp, &old_borrow); + dst->doubleword[0] = 0; + dst->doubleword[1] = borrow; +}
Reuse s390_vec_sub() to perform two 128-bit subtraction, calculating the borrow. 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 | 13 +++++++++++++ target/s390x/vec_int_helper.c | 16 ++++++++++++++++ 4 files changed, 32 insertions(+)