1 /*
2 * S/390 integer helper routines
3 *
4 * Copyright (c) 2009 Ulrich Hecht
5 * Copyright (c) 2009 Alexander Graf
6 *
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
19 */
20
21 #include "qemu/osdep.h"
22 #include "cpu.h"
23 #include "s390x-internal.h"
24 #include "tcg_s390x.h"
25 #include "exec/exec-all.h"
26 #include "qemu/host-utils.h"
27 #include "exec/helper-proto.h"
28 #include "exec/cpu_ldst.h"
29
30 /* #define DEBUG_HELPER */
31 #ifdef DEBUG_HELPER
32 #define HELPER_LOG(x...) qemu_log(x)
33 #else
34 #define HELPER_LOG(x...)
35 #endif
36
37 /* 64/32 -> 32 signed division */
HELPER(divs32)38 uint64_t HELPER(divs32)(CPUS390XState *env, int64_t a, int64_t b64)
39 {
40 int32_t b = b64;
41 int64_t q, r;
42
43 if (b == 0) {
44 tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
45 }
46
47 q = a / b;
48 r = a % b;
49
50 /* Catch non-representable quotient. */
51 if (q != (int32_t)q) {
52 tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
53 }
54
55 return deposit64(q, 32, 32, r);
56 }
57
58 /* 64/32 -> 32 unsigned division */
HELPER(divu32)59 uint64_t HELPER(divu32)(CPUS390XState *env, uint64_t a, uint64_t b64)
60 {
61 uint32_t b = b64;
62 uint64_t q, r;
63
64 if (b == 0) {
65 tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
66 }
67
68 q = a / b;
69 r = a % b;
70
71 /* Catch non-representable quotient. */
72 if (q != (uint32_t)q) {
73 tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
74 }
75
76 return deposit64(q, 32, 32, r);
77 }
78
79 /* 64/64 -> 64 signed division */
HELPER(divs64)80 Int128 HELPER(divs64)(CPUS390XState *env, int64_t a, int64_t b)
81 {
82 /* Catch divide by zero, and non-representable quotient (MIN / -1). */
83 if (b == 0 || (b == -1 && a == (1ll << 63))) {
84 tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
85 }
86 return int128_make128(a / b, a % b);
87 }
88
89 /* 128 -> 64/64 unsigned division */
HELPER(divu64)90 Int128 HELPER(divu64)(CPUS390XState *env, uint64_t ah, uint64_t al, uint64_t b)
91 {
92 if (b != 0) {
93 uint64_t r = divu128(&al, &ah, b);
94 if (ah == 0) {
95 return int128_make128(al, r);
96 }
97 }
98 /* divide by zero or overflow */
99 tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
100 }
101
HELPER(cvb)102 void HELPER(cvb)(CPUS390XState *env, uint32_t r1, uint64_t dec)
103 {
104 int64_t pow10 = 1, bin = 0;
105 int digit, sign;
106
107 sign = dec & 0xf;
108 if (sign < 0xa) {
109 tcg_s390_data_exception(env, 0, GETPC());
110 }
111 dec >>= 4;
112
113 while (dec) {
114 digit = dec & 0xf;
115 if (digit > 0x9) {
116 tcg_s390_data_exception(env, 0, GETPC());
117 }
118 dec >>= 4;
119 bin += digit * pow10;
120 pow10 *= 10;
121 }
122
123 if (sign == 0xb || sign == 0xd) {
124 bin = -bin;
125 }
126
127 /* R1 is updated even on fixed-point-divide exception. */
128 env->regs[r1] = (env->regs[r1] & 0xffffffff00000000ULL) | (uint32_t)bin;
129 if (bin != (int32_t)bin) {
130 tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
131 }
132 }
133
HELPER(cvbg)134 uint64_t HELPER(cvbg)(CPUS390XState *env, Int128 dec)
135 {
136 uint64_t dec64[] = {int128_getlo(dec), int128_gethi(dec)};
137 int64_t bin = 0, pow10, tmp;
138 int digit, i, sign;
139
140 sign = dec64[0] & 0xf;
141 if (sign < 0xa) {
142 tcg_s390_data_exception(env, 0, GETPC());
143 }
144 dec64[0] >>= 4;
145 pow10 = (sign == 0xb || sign == 0xd) ? -1 : 1;
146
147 for (i = 1; i < 20; i++) {
148 digit = dec64[i >> 4] & 0xf;
149 if (digit > 0x9) {
150 tcg_s390_data_exception(env, 0, GETPC());
151 }
152 dec64[i >> 4] >>= 4;
153 /*
154 * Prepend the next digit and check for overflow. The multiplication
155 * cannot overflow, since, conveniently, the int64_t limits are
156 * approximately +-9.2E+18. If bin is zero, the addition cannot
157 * overflow. Otherwise bin is known to have the same sign as the rhs
158 * addend, in which case overflow happens if and only if the result
159 * has a different sign.
160 */
161 tmp = bin + pow10 * digit;
162 if (bin && ((tmp ^ bin) < 0)) {
163 tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
164 }
165 bin = tmp;
166 pow10 *= 10;
167 }
168
169 g_assert(!dec64[0]);
170 if (dec64[1]) {
171 tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
172 }
173
174 return bin;
175 }
176
HELPER(cvd)177 uint64_t HELPER(cvd)(int32_t reg)
178 {
179 /* positive 0 */
180 uint64_t dec = 0x0c;
181 int64_t bin = reg;
182 int shift;
183
184 if (bin < 0) {
185 bin = -bin;
186 dec = 0x0d;
187 }
188
189 for (shift = 4; (shift < 64) && bin; shift += 4) {
190 dec |= (bin % 10) << shift;
191 bin /= 10;
192 }
193
194 return dec;
195 }
196
HELPER(cvdg)197 Int128 HELPER(cvdg)(int64_t reg)
198 {
199 /* positive 0 */
200 Int128 dec = int128_make64(0x0c);
201 Int128 bin = int128_makes64(reg);
202 Int128 base = int128_make64(10);
203 int shift;
204
205 if (!int128_nonneg(bin)) {
206 bin = int128_neg(bin);
207 dec = int128_make64(0x0d);
208 }
209
210 for (shift = 4; (shift < 128) && int128_nz(bin); shift += 4) {
211 dec = int128_or(dec, int128_lshift(int128_remu(bin, base), shift));
212 bin = int128_divu(bin, base);
213 }
214
215 return dec;
216 }
217
HELPER(popcnt)218 uint64_t HELPER(popcnt)(uint64_t val)
219 {
220 /* Note that we don't fold past bytes. */
221 val = (val & 0x5555555555555555ULL) + ((val >> 1) & 0x5555555555555555ULL);
222 val = (val & 0x3333333333333333ULL) + ((val >> 2) & 0x3333333333333333ULL);
223 val = (val + (val >> 4)) & 0x0f0f0f0f0f0f0f0fULL;
224 return val;
225 }
226