qemu/target/s390x/cc_helper.c
Richard Henderson a2db06da7d target/s390x: Improve cc computation for SUBTRACT LOGICAL
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>
Message-Id: <20201214221356.68039-4-richard.henderson@linaro.org>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2020-12-21 18:11:33 +01:00

571 lines
12 KiB
C

/*
* S/390 condition code helper routines
*
* Copyright (c) 2009 Ulrich Hecht
* Copyright (c) 2009 Alexander Graf
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "cpu.h"
#include "internal.h"
#include "tcg_s390x.h"
#include "exec/exec-all.h"
#include "exec/helper-proto.h"
#include "qemu/host-utils.h"
/* #define DEBUG_HELPER */
#ifdef DEBUG_HELPER
#define HELPER_LOG(x...) qemu_log(x)
#else
#define HELPER_LOG(x...)
#endif
static uint32_t cc_calc_ltgt_32(int32_t src, int32_t dst)
{
if (src == dst) {
return 0;
} else if (src < dst) {
return 1;
} else {
return 2;
}
}
static uint32_t cc_calc_ltgt0_32(int32_t dst)
{
return cc_calc_ltgt_32(dst, 0);
}
static uint32_t cc_calc_ltgt_64(int64_t src, int64_t dst)
{
if (src == dst) {
return 0;
} else if (src < dst) {
return 1;
} else {
return 2;
}
}
static uint32_t cc_calc_ltgt0_64(int64_t dst)
{
return cc_calc_ltgt_64(dst, 0);
}
static uint32_t cc_calc_ltugtu_32(uint32_t src, uint32_t dst)
{
if (src == dst) {
return 0;
} else if (src < dst) {
return 1;
} else {
return 2;
}
}
static uint32_t cc_calc_ltugtu_64(uint64_t src, uint64_t dst)
{
if (src == dst) {
return 0;
} else if (src < dst) {
return 1;
} else {
return 2;
}
}
static uint32_t cc_calc_tm_32(uint32_t val, uint32_t mask)
{
uint32_t r = val & mask;
if (r == 0) {
return 0;
} else if (r == mask) {
return 3;
} else {
return 1;
}
}
static uint32_t cc_calc_tm_64(uint64_t val, uint64_t mask)
{
uint64_t r = val & mask;
if (r == 0) {
return 0;
} else if (r == mask) {
return 3;
} else {
int top = clz64(mask);
if ((int64_t)(val << top) < 0) {
return 2;
} else {
return 1;
}
}
}
static uint32_t cc_calc_nz(uint64_t dst)
{
return !!dst;
}
static uint32_t cc_calc_addu(uint64_t carry_out, uint64_t result)
{
g_assert(carry_out <= 1);
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)) {
return 3; /* overflow */
} else {
if (ar < 0) {
return 1;
} else if (ar > 0) {
return 2;
} else {
return 0;
}
}
}
static uint32_t cc_calc_sub_64(int64_t a1, int64_t a2, int64_t ar)
{
if ((a1 > 0 && a2 < 0 && ar < 0) || (a1 < 0 && a2 > 0 && ar > 0)) {
return 3; /* overflow */
} else {
if (ar < 0) {
return 1;
} else if (ar > 0) {
return 2;
} else {
return 0;
}
}
}
static uint32_t cc_calc_subb_64(uint64_t a1, uint64_t a2, uint64_t ar)
{
int borrow_out;
if (ar != a1 - a2) { /* difference means borrow-in */
borrow_out = (a2 >= a1);
} else {
borrow_out = (a2 > a1);
}
return (ar != 0) + 2 * !borrow_out;
}
static uint32_t cc_calc_abs_64(int64_t dst)
{
if ((uint64_t)dst == 0x8000000000000000ULL) {
return 3;
} else if (dst) {
return 2;
} else {
return 0;
}
}
static uint32_t cc_calc_nabs_64(int64_t dst)
{
return !!dst;
}
static uint32_t cc_calc_comp_64(int64_t dst)
{
if ((uint64_t)dst == 0x8000000000000000ULL) {
return 3;
} else if (dst < 0) {
return 1;
} else if (dst > 0) {
return 2;
} else {
return 0;
}
}
static uint32_t cc_calc_add_32(int32_t a1, int32_t a2, int32_t ar)
{
if ((a1 > 0 && a2 > 0 && ar < 0) || (a1 < 0 && a2 < 0 && ar > 0)) {
return 3; /* overflow */
} else {
if (ar < 0) {
return 1;
} else if (ar > 0) {
return 2;
} else {
return 0;
}
}
}
static uint32_t cc_calc_sub_32(int32_t a1, int32_t a2, int32_t ar)
{
if ((a1 > 0 && a2 < 0 && ar < 0) || (a1 < 0 && a2 > 0 && ar > 0)) {
return 3; /* overflow */
} else {
if (ar < 0) {
return 1;
} else if (ar > 0) {
return 2;
} else {
return 0;
}
}
}
static uint32_t cc_calc_subb_32(uint32_t a1, uint32_t a2, uint32_t ar)
{
int borrow_out;
if (ar != a1 - a2) { /* difference means borrow-in */
borrow_out = (a2 >= a1);
} else {
borrow_out = (a2 > a1);
}
return (ar != 0) + 2 * !borrow_out;
}
static uint32_t cc_calc_abs_32(int32_t dst)
{
if ((uint32_t)dst == 0x80000000UL) {
return 3;
} else if (dst) {
return 2;
} else {
return 0;
}
}
static uint32_t cc_calc_nabs_32(int32_t dst)
{
return !!dst;
}
static uint32_t cc_calc_comp_32(int32_t dst)
{
if ((uint32_t)dst == 0x80000000UL) {
return 3;
} else if (dst < 0) {
return 1;
} else if (dst > 0) {
return 2;
} else {
return 0;
}
}
/* calculate condition code for insert character under mask insn */
static uint32_t cc_calc_icm(uint64_t mask, uint64_t val)
{
if ((val & mask) == 0) {
return 0;
} else {
int top = clz64(mask);
if ((int64_t)(val << top) < 0) {
return 1;
} else {
return 2;
}
}
}
static uint32_t cc_calc_sla_32(uint32_t src, int shift)
{
uint32_t mask = ((1U << shift) - 1U) << (32 - shift);
uint32_t sign = 1U << 31;
uint32_t match;
int32_t r;
/* Check if the sign bit stays the same. */
if (src & sign) {
match = mask;
} else {
match = 0;
}
if ((src & mask) != match) {
/* Overflow. */
return 3;
}
r = ((src << shift) & ~sign) | (src & sign);
if (r == 0) {
return 0;
} else if (r < 0) {
return 1;
}
return 2;
}
static uint32_t cc_calc_sla_64(uint64_t src, int shift)
{
uint64_t mask = ((1ULL << shift) - 1ULL) << (64 - shift);
uint64_t sign = 1ULL << 63;
uint64_t match;
int64_t r;
/* Check if the sign bit stays the same. */
if (src & sign) {
match = mask;
} else {
match = 0;
}
if ((src & mask) != match) {
/* Overflow. */
return 3;
}
r = ((src << shift) & ~sign) | (src & sign);
if (r == 0) {
return 0;
} else if (r < 0) {
return 1;
}
return 2;
}
static uint32_t cc_calc_flogr(uint64_t dst)
{
return dst ? 2 : 0;
}
static uint32_t cc_calc_lcbb(uint64_t dst)
{
return dst == 16 ? 0 : 3;
}
static uint32_t cc_calc_vc(uint64_t low, uint64_t high)
{
if (high == -1ull && low == -1ull) {
/* all elements match */
return 0;
} else if (high == 0 && low == 0) {
/* no elements match */
return 3;
} else {
/* some elements but not all match */
return 1;
}
}
static uint32_t cc_calc_muls_32(int64_t res)
{
const int64_t tmp = res >> 31;
if (!res) {
return 0;
} else if (tmp && tmp != -1) {
return 3;
} else if (res < 0) {
return 1;
}
return 2;
}
static uint64_t cc_calc_muls_64(int64_t res_high, uint64_t res_low)
{
if (!res_high && !res_low) {
return 0;
} else if (res_high + (res_low >> 63) != 0) {
return 3;
} else if (res_high < 0) {
return 1;
}
return 2;
}
static uint32_t do_calc_cc(CPUS390XState *env, uint32_t cc_op,
uint64_t src, uint64_t dst, uint64_t vr)
{
uint32_t r = 0;
switch (cc_op) {
case CC_OP_CONST0:
case CC_OP_CONST1:
case CC_OP_CONST2:
case CC_OP_CONST3:
/* cc_op value _is_ cc */
r = cc_op;
break;
case CC_OP_LTGT0_32:
r = cc_calc_ltgt0_32(dst);
break;
case CC_OP_LTGT0_64:
r = cc_calc_ltgt0_64(dst);
break;
case CC_OP_LTGT_32:
r = cc_calc_ltgt_32(src, dst);
break;
case CC_OP_LTGT_64:
r = cc_calc_ltgt_64(src, dst);
break;
case CC_OP_LTUGTU_32:
r = cc_calc_ltugtu_32(src, dst);
break;
case CC_OP_LTUGTU_64:
r = cc_calc_ltugtu_64(src, dst);
break;
case CC_OP_TM_32:
r = cc_calc_tm_32(src, dst);
break;
case CC_OP_TM_64:
r = cc_calc_tm_64(src, dst);
break;
case CC_OP_NZ:
r = cc_calc_nz(dst);
break;
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_SUBB_64:
r = cc_calc_subb_64(src, dst, vr);
break;
case CC_OP_ABS_64:
r = cc_calc_abs_64(dst);
break;
case CC_OP_NABS_64:
r = cc_calc_nabs_64(dst);
break;
case CC_OP_COMP_64:
r = cc_calc_comp_64(dst);
break;
case CC_OP_MULS_64:
r = cc_calc_muls_64(src, dst);
break;
case CC_OP_ADD_32:
r = cc_calc_add_32(src, dst, vr);
break;
case CC_OP_SUB_32:
r = cc_calc_sub_32(src, dst, vr);
break;
case CC_OP_SUBB_32:
r = cc_calc_subb_32(src, dst, vr);
break;
case CC_OP_ABS_32:
r = cc_calc_abs_32(dst);
break;
case CC_OP_NABS_32:
r = cc_calc_nabs_32(dst);
break;
case CC_OP_COMP_32:
r = cc_calc_comp_32(dst);
break;
case CC_OP_MULS_32:
r = cc_calc_muls_32(dst);
break;
case CC_OP_ICM:
r = cc_calc_icm(src, dst);
break;
case CC_OP_SLA_32:
r = cc_calc_sla_32(src, dst);
break;
case CC_OP_SLA_64:
r = cc_calc_sla_64(src, dst);
break;
case CC_OP_FLOGR:
r = cc_calc_flogr(dst);
break;
case CC_OP_LCBB:
r = cc_calc_lcbb(dst);
break;
case CC_OP_VC:
r = cc_calc_vc(src, dst);
break;
case CC_OP_NZ_F32:
r = set_cc_nz_f32(dst);
break;
case CC_OP_NZ_F64:
r = set_cc_nz_f64(dst);
break;
case CC_OP_NZ_F128:
r = set_cc_nz_f128(make_float128(src, dst));
break;
default:
cpu_abort(env_cpu(env), "Unknown CC operation: %s\n", cc_name(cc_op));
}
HELPER_LOG("%s: %15s 0x%016lx 0x%016lx 0x%016lx = %d\n", __func__,
cc_name(cc_op), src, dst, vr, r);
return r;
}
uint32_t calc_cc(CPUS390XState *env, uint32_t cc_op, uint64_t src, uint64_t dst,
uint64_t vr)
{
return do_calc_cc(env, cc_op, src, dst, vr);
}
uint32_t HELPER(calc_cc)(CPUS390XState *env, uint32_t cc_op, uint64_t src,
uint64_t dst, uint64_t vr)
{
return do_calc_cc(env, cc_op, src, dst, vr);
}
#ifndef CONFIG_USER_ONLY
void HELPER(load_psw)(CPUS390XState *env, uint64_t mask, uint64_t addr)
{
load_psw(env, mask, addr);
cpu_loop_exit(env_cpu(env));
}
void HELPER(sacf)(CPUS390XState *env, uint64_t a1)
{
HELPER_LOG("%s: %16" PRIx64 "\n", __func__, a1);
switch (a1 & 0xf00) {
case 0x000:
env->psw.mask &= ~PSW_MASK_ASC;
env->psw.mask |= PSW_ASC_PRIMARY;
break;
case 0x100:
env->psw.mask &= ~PSW_MASK_ASC;
env->psw.mask |= PSW_ASC_SECONDARY;
break;
case 0x300:
env->psw.mask &= ~PSW_MASK_ASC;
env->psw.mask |= PSW_ASC_HOME;
break;
default:
HELPER_LOG("unknown sacf mode: %" PRIx64 "\n", a1);
tcg_s390_program_interrupt(env, PGM_SPECIFICATION, GETPC());
}
}
#endif