From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: david@redhat.com
Subject: [PATCH v3 3/4] target/s390x: Improve cc computation for SUBTRACT LOGICAL
Date: Mon, 14 Dec 2020 16:13:55 -0600 [thread overview]
Message-ID: <20201214221356.68039-4-richard.henderson@linaro.org> (raw)
In-Reply-To: <20201214221356.68039-1-richard.henderson@linaro.org>
The resulting cc is only dependent on the result and the carry-out.
Carry-out and borrow-out are inverses, so are trivially converted.
With tcg ops, it is easier to compute borrow-out than carry-out, so
save result and borrow-out rather than the inputs.
Borrow-out for 64-bit inputs is had via tcg_gen_sub2_i64 directly
into cc_src. Borrow-out for 32-bit inputs is had via extraction
from a normal 64-bit sub (with zero-extended inputs).
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
target/s390x/internal.h | 3 +--
target/s390x/cc_helper.c | 40 ++++++---------------------
target/s390x/helper.c | 3 +--
target/s390x/translate.c | 55 +++++++++++++++-----------------------
target/s390x/insn-data.def | 24 ++++++++---------
5 files changed, 43 insertions(+), 82 deletions(-)
diff --git a/target/s390x/internal.h b/target/s390x/internal.h
index f5f3ae063e..4077047494 100644
--- a/target/s390x/internal.h
+++ b/target/s390x/internal.h
@@ -161,6 +161,7 @@ enum cc_op {
CC_OP_NZ, /* env->cc_dst != 0 */
CC_OP_ADDU, /* dst != 0, src = carry out (0,1) */
+ CC_OP_SUBU, /* dst != 0, src = borrow out (0,-1) */
CC_OP_LTGT_32, /* signed less/greater than (32bit) */
CC_OP_LTGT_64, /* signed less/greater than (64bit) */
@@ -171,7 +172,6 @@ enum cc_op {
CC_OP_ADD_64, /* overflow on add (64bit) */
CC_OP_SUB_64, /* overflow on subtraction (64bit) */
- CC_OP_SUBU_64, /* overflow on unsigned subtraction (64bit) */
CC_OP_SUBB_64, /* overflow on unsigned sub-borrow (64bit) */
CC_OP_ABS_64, /* sign eval on abs (64bit) */
CC_OP_NABS_64, /* sign eval on nabs (64bit) */
@@ -179,7 +179,6 @@ enum cc_op {
CC_OP_ADD_32, /* overflow on add (32bit) */
CC_OP_SUB_32, /* overflow on subtraction (32bit) */
- CC_OP_SUBU_32, /* overflow on unsigned subtraction (32bit) */
CC_OP_SUBB_32, /* overflow on unsigned sub-borrow (32bit) */
CC_OP_ABS_32, /* sign eval on abs (64bit) */
CC_OP_NABS_32, /* sign eval on nabs (64bit) */
diff --git a/target/s390x/cc_helper.c b/target/s390x/cc_helper.c
index cd2c5c4b39..c7728d1225 100644
--- a/target/s390x/cc_helper.c
+++ b/target/s390x/cc_helper.c
@@ -129,6 +129,11 @@ static uint32_t cc_calc_addu(uint64_t carry_out, uint64_t result)
return (result != 0) + 2 * carry_out;
}
+static uint32_t cc_calc_subu(uint64_t borrow_out, uint64_t result)
+{
+ return cc_calc_addu(borrow_out + 1, result);
+}
+
static uint32_t cc_calc_add_64(int64_t a1, int64_t a2, int64_t ar)
{
if ((a1 > 0 && a2 > 0 && ar < 0) || (a1 < 0 && a2 < 0 && ar > 0)) {
@@ -159,19 +164,6 @@ static uint32_t cc_calc_sub_64(int64_t a1, int64_t a2, int64_t ar)
}
}
-static uint32_t cc_calc_subu_64(uint64_t a1, uint64_t a2, uint64_t ar)
-{
- if (ar == 0) {
- return 2;
- } else {
- if (a2 > a1) {
- return 1;
- } else {
- return 3;
- }
- }
-}
-
static uint32_t cc_calc_subb_64(uint64_t a1, uint64_t a2, uint64_t ar)
{
int borrow_out;
@@ -245,19 +237,6 @@ static uint32_t cc_calc_sub_32(int32_t a1, int32_t a2, int32_t ar)
}
}
-static uint32_t cc_calc_subu_32(uint32_t a1, uint32_t a2, uint32_t ar)
-{
- if (ar == 0) {
- return 2;
- } else {
- if (a2 > a1) {
- return 1;
- } else {
- return 3;
- }
- }
-}
-
static uint32_t cc_calc_subb_32(uint32_t a1, uint32_t a2, uint32_t ar)
{
int borrow_out;
@@ -462,15 +441,15 @@ static uint32_t do_calc_cc(CPUS390XState *env, uint32_t cc_op,
case CC_OP_ADDU:
r = cc_calc_addu(src, dst);
break;
+ case CC_OP_SUBU:
+ r = cc_calc_subu(src, dst);
+ break;
case CC_OP_ADD_64:
r = cc_calc_add_64(src, dst, vr);
break;
case CC_OP_SUB_64:
r = cc_calc_sub_64(src, dst, vr);
break;
- case CC_OP_SUBU_64:
- r = cc_calc_subu_64(src, dst, vr);
- break;
case CC_OP_SUBB_64:
r = cc_calc_subb_64(src, dst, vr);
break;
@@ -493,9 +472,6 @@ static uint32_t do_calc_cc(CPUS390XState *env, uint32_t cc_op,
case CC_OP_SUB_32:
r = cc_calc_sub_32(src, dst, vr);
break;
- case CC_OP_SUBU_32:
- r = cc_calc_subu_32(src, dst, vr);
- break;
case CC_OP_SUBB_32:
r = cc_calc_subb_32(src, dst, vr);
break;
diff --git a/target/s390x/helper.c b/target/s390x/helper.c
index 4f4561bc64..fa3aa500e5 100644
--- a/target/s390x/helper.c
+++ b/target/s390x/helper.c
@@ -396,6 +396,7 @@ const char *cc_name(enum cc_op cc_op)
[CC_OP_STATIC] = "CC_OP_STATIC",
[CC_OP_NZ] = "CC_OP_NZ",
[CC_OP_ADDU] = "CC_OP_ADDU",
+ [CC_OP_SUBU] = "CC_OP_SUBU",
[CC_OP_LTGT_32] = "CC_OP_LTGT_32",
[CC_OP_LTGT_64] = "CC_OP_LTGT_64",
[CC_OP_LTUGTU_32] = "CC_OP_LTUGTU_32",
@@ -404,13 +405,11 @@ const char *cc_name(enum cc_op cc_op)
[CC_OP_LTGT0_64] = "CC_OP_LTGT0_64",
[CC_OP_ADD_64] = "CC_OP_ADD_64",
[CC_OP_SUB_64] = "CC_OP_SUB_64",
- [CC_OP_SUBU_64] = "CC_OP_SUBU_64",
[CC_OP_SUBB_64] = "CC_OP_SUBB_64",
[CC_OP_ABS_64] = "CC_OP_ABS_64",
[CC_OP_NABS_64] = "CC_OP_NABS_64",
[CC_OP_ADD_32] = "CC_OP_ADD_32",
[CC_OP_SUB_32] = "CC_OP_SUB_32",
- [CC_OP_SUBU_32] = "CC_OP_SUBU_32",
[CC_OP_SUBB_32] = "CC_OP_SUBB_32",
[CC_OP_ABS_32] = "CC_OP_ABS_32",
[CC_OP_NABS_32] = "CC_OP_NABS_32",
diff --git a/target/s390x/translate.c b/target/s390x/translate.c
index d1d97e4696..40add1df1f 100644
--- a/target/s390x/translate.c
+++ b/target/s390x/translate.c
@@ -601,11 +601,9 @@ static void gen_op_calc_cc(DisasContext *s)
/* FALLTHRU */
case CC_OP_ADD_64:
case CC_OP_SUB_64:
- case CC_OP_SUBU_64:
case CC_OP_SUBB_64:
case CC_OP_ADD_32:
case CC_OP_SUB_32:
- case CC_OP_SUBU_32:
case CC_OP_SUBB_32:
local_cc_op = tcg_const_i32(s->cc_op);
break;
@@ -656,6 +654,7 @@ static void gen_op_calc_cc(DisasContext *s)
case CC_OP_TM_64:
case CC_OP_SLA_32:
case CC_OP_SLA_64:
+ case CC_OP_SUBU:
case CC_OP_NZ_F128:
case CC_OP_VC:
case CC_OP_MULS_64:
@@ -664,11 +663,9 @@ static void gen_op_calc_cc(DisasContext *s)
break;
case CC_OP_ADD_64:
case CC_OP_SUB_64:
- case CC_OP_SUBU_64:
case CC_OP_SUBB_64:
case CC_OP_ADD_32:
case CC_OP_SUB_32:
- case CC_OP_SUBU_32:
case CC_OP_SUBB_32:
/* 3 arguments */
gen_helper_calc_cc(cc_op, cpu_env, local_cc_op, cc_src, cc_dst, cc_vr);
@@ -843,6 +840,7 @@ static void disas_jcc(DisasContext *s, DisasCompare *c, uint32_t mask)
break;
case CC_OP_ADDU:
+ case CC_OP_SUBU:
switch (mask) {
case 8 | 2: /* result == 0 */
cond = TCG_COND_EQ;
@@ -850,33 +848,11 @@ static void disas_jcc(DisasContext *s, DisasCompare *c, uint32_t mask)
case 4 | 1: /* result != 0 */
cond = TCG_COND_NE;
break;
- case 8 | 4: /* no carry */
- cond = TCG_COND_EQ;
+ case 8 | 4: /* !carry (borrow) */
+ cond = old_cc_op == CC_OP_ADDU ? TCG_COND_EQ : TCG_COND_NE;
break;
- case 2 | 1: /* carry */
- cond = TCG_COND_NE;
- break;
- default:
- goto do_dynamic;
- }
- account_inline_branch(s, old_cc_op);
- break;
-
- case CC_OP_SUBU_32:
- case CC_OP_SUBU_64:
- /* Note that CC=0 is impossible; treat it as dont-care. */
- switch (mask & 7) {
- case 2: /* zero -> op1 == op2 */
- cond = TCG_COND_EQ;
- break;
- case 4 | 1: /* !zero -> op1 != op2 */
- cond = TCG_COND_NE;
- break;
- case 4: /* borrow (!carry) -> op1 < op2 */
- cond = TCG_COND_LTU;
- break;
- case 2 | 1: /* !borrow (carry) -> op1 >= op2 */
- cond = TCG_COND_GEU;
+ case 2 | 1: /* carry (!borrow) */
+ cond = old_cc_op == CC_OP_ADDU ? TCG_COND_NE : TCG_COND_EQ;
break;
default:
goto do_dynamic;
@@ -911,7 +887,6 @@ static void disas_jcc(DisasContext *s, DisasCompare *c, uint32_t mask)
break;
case CC_OP_LTGT_32:
case CC_OP_LTUGTU_32:
- case CC_OP_SUBU_32:
c->is_64 = false;
c->u.s32.a = tcg_temp_new_i32();
tcg_gen_extrl_i64_i32(c->u.s32.a, cc_src);
@@ -928,7 +903,6 @@ static void disas_jcc(DisasContext *s, DisasCompare *c, uint32_t mask)
break;
case CC_OP_LTGT_64:
case CC_OP_LTUGTU_64:
- case CC_OP_SUBU_64:
c->u.s64.a = cc_src;
c->u.s64.b = cc_dst;
c->g1 = c->g2 = true;
@@ -943,6 +917,7 @@ static void disas_jcc(DisasContext *s, DisasCompare *c, uint32_t mask)
break;
case CC_OP_ADDU:
+ case CC_OP_SUBU:
c->is_64 = true;
c->u.s64.b = tcg_const_i64(0);
c->g1 = true;
@@ -1446,6 +1421,9 @@ static void compute_carry(DisasContext *s)
case CC_OP_ADDU:
/* The carry value is already in cc_src (1,0). */
break;
+ case CC_OP_SUBU:
+ tcg_gen_addi_i64(cc_src, cc_src, 1);
+ break;
default:
gen_op_calc_cc(s);
/* fall through */
@@ -4761,6 +4739,13 @@ static DisasJumpType op_sub(DisasContext *s, DisasOps *o)
return DISAS_NEXT;
}
+static DisasJumpType op_subu64(DisasContext *s, DisasOps *o)
+{
+ tcg_gen_movi_i64(cc_src, 0);
+ tcg_gen_sub2_i64(o->out, cc_src, o->in1, cc_src, o->in2, cc_src);
+ return DISAS_NEXT;
+}
+
static DisasJumpType op_subb(DisasContext *s, DisasOps *o)
{
DisasCompare cmp;
@@ -5312,12 +5297,14 @@ static void cout_subs64(DisasContext *s, DisasOps *o)
static void cout_subu32(DisasContext *s, DisasOps *o)
{
- gen_op_update3_cc_i64(s, CC_OP_SUBU_32, o->in1, o->in2, o->out);
+ tcg_gen_sari_i64(cc_src, o->out, 32);
+ tcg_gen_ext32u_i64(cc_dst, o->out);
+ gen_op_update2_cc_i64(s, CC_OP_SUBU, cc_src, cc_dst);
}
static void cout_subu64(DisasContext *s, DisasOps *o)
{
- gen_op_update3_cc_i64(s, CC_OP_SUBU_64, o->in1, o->in2, o->out);
+ gen_op_update2_cc_i64(s, CC_OP_SUBU, cc_src, o->out);
}
static void cout_subb32(DisasContext *s, DisasOps *o)
diff --git a/target/s390x/insn-data.def b/target/s390x/insn-data.def
index e380723dcd..7ff3e7e517 100644
--- a/target/s390x/insn-data.def
+++ b/target/s390x/insn-data.def
@@ -900,21 +900,21 @@
C(0xb9c9, SHHHR, RRF_a, HW, r2_sr32, r3_sr32, new, r1_32h, sub, subs32)
C(0xb9d9, SHHLR, RRF_a, HW, r2_sr32, r3, new, r1_32h, sub, subs32)
/* SUBTRACT LOGICAL */
- C(0x1f00, SLR, RR_a, Z, r1, r2, new, r1_32, sub, subu32)
- C(0xb9fb, SLRK, RRF_a, DO, r2, r3, new, r1_32, sub, subu32)
- C(0x5f00, SL, RX_a, Z, r1, m2_32u, new, r1_32, sub, subu32)
- C(0xe35f, SLY, RXY_a, LD, r1, m2_32u, new, r1_32, sub, subu32)
- C(0xb90b, SLGR, RRE, Z, r1, r2, r1, 0, sub, subu64)
- C(0xb91b, SLGFR, RRE, Z, r1, r2_32u, r1, 0, sub, subu64)
- C(0xb9eb, SLGRK, RRF_a, DO, r2, r3, r1, 0, sub, subu64)
- C(0xe30b, SLG, RXY_a, Z, r1, m2_64, r1, 0, sub, subu64)
- C(0xe31b, SLGF, RXY_a, Z, r1, m2_32u, r1, 0, sub, subu64)
+ C(0x1f00, SLR, RR_a, Z, r1_32u, r2_32u, new, r1_32, sub, subu32)
+ C(0xb9fb, SLRK, RRF_a, DO, r2_32u, r3_32u, new, r1_32, sub, subu32)
+ C(0x5f00, SL, RX_a, Z, r1_32u, m2_32u, new, r1_32, sub, subu32)
+ C(0xe35f, SLY, RXY_a, LD, r1_32u, m2_32u, new, r1_32, sub, subu32)
+ C(0xb90b, SLGR, RRE, Z, r1, r2, r1, 0, subu64, subu64)
+ C(0xb91b, SLGFR, RRE, Z, r1, r2_32u, r1, 0, subu64, subu64)
+ C(0xb9eb, SLGRK, RRF_a, DO, r2, r3, r1, 0, subu64, subu64)
+ C(0xe30b, SLG, RXY_a, Z, r1, m2_64, r1, 0, subu64, subu64)
+ C(0xe31b, SLGF, RXY_a, Z, r1, m2_32u, r1, 0, subu64, subu64)
/* SUBTRACT LOCICAL HIGH */
C(0xb9cb, SLHHHR, RRF_a, HW, r2_sr32, r3_sr32, new, r1_32h, sub, subu32)
- C(0xb9db, SLHHLR, RRF_a, HW, r2_sr32, r3, new, r1_32h, sub, subu32)
+ C(0xb9db, SLHHLR, RRF_a, HW, r2_sr32, r3_32u, new, r1_32h, sub, subu32)
/* SUBTRACT LOGICAL IMMEDIATE */
- C(0xc205, SLFI, RIL_a, EI, r1, i2_32u, new, r1_32, sub, subu32)
- C(0xc204, SLGFI, RIL_a, EI, r1, i2_32u, r1, 0, sub, subu64)
+ C(0xc205, SLFI, RIL_a, EI, r1_32u, i2_32u, new, r1_32, sub, subu32)
+ C(0xc204, SLGFI, RIL_a, EI, r1, i2_32u, r1, 0, subu64, subu64)
/* SUBTRACT LOGICAL WITH BORROW */
C(0xb999, SLBR, RRE, Z, r1, r2, new, r1_32, subb, subb32)
C(0xb989, SLBGR, RRE, Z, r1, r2, r1, 0, subb, subb64)
--
2.25.1
next prev parent reply other threads:[~2020-12-14 22:19 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-14 22:13 [PATCH v3 0/4] target/s390x: Improve carry computation Richard Henderson
2020-12-14 22:13 ` [PATCH v3 1/4] target/s390x: Improve cc computation for ADD LOGICAL Richard Henderson
2020-12-14 22:13 ` [PATCH v3 2/4] target/s390x: Improve ADD LOGICAL WITH CARRY Richard Henderson
2020-12-14 22:13 ` Richard Henderson [this message]
2020-12-14 22:13 ` [PATCH v3 4/4] target/s390x: Improve SUB LOGICAL WITH BORROW Richard Henderson
2020-12-16 14:44 ` [PATCH v3 0/4] target/s390x: Improve carry computation David Hildenbrand
2020-12-16 17:09 ` Cornelia Huck
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