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 "internal.h"
24#include "exec/exec-all.h"
25#include "qemu/host-utils.h"
26#include "exec/helper-proto.h"
27
28/* #define DEBUG_HELPER */
29#ifdef DEBUG_HELPER
30#define HELPER_LOG(x...) qemu_log(x)
31#else
32#define HELPER_LOG(x...)
33#endif
34
35/* 64/32 -> 32 signed division */
36int64_t HELPER(divs32)(CPUS390XState *env, int64_t a, int64_t b64)
37{
38 int32_t ret, b = b64;
39 int64_t q;
40
41 if (b == 0) {
42 s390_program_interrupt(env, PGM_FIXPT_DIVIDE, ILEN_AUTO, GETPC());
43 }
44
45 ret = q = a / b;
46 env->retxl = a % b;
47
48 /* Catch non-representable quotient. */
49 if (ret != q) {
50 s390_program_interrupt(env, PGM_FIXPT_DIVIDE, ILEN_AUTO, GETPC());
51 }
52
53 return ret;
54}
55
56/* 64/32 -> 32 unsigned division */
57uint64_t HELPER(divu32)(CPUS390XState *env, uint64_t a, uint64_t b64)
58{
59 uint32_t ret, b = b64;
60 uint64_t q;
61
62 if (b == 0) {
63 s390_program_interrupt(env, PGM_FIXPT_DIVIDE, ILEN_AUTO, GETPC());
64 }
65
66 ret = q = a / b;
67 env->retxl = a % b;
68
69 /* Catch non-representable quotient. */
70 if (ret != q) {
71 s390_program_interrupt(env, PGM_FIXPT_DIVIDE, ILEN_AUTO, GETPC());
72 }
73
74 return ret;
75}
76
77/* 64/64 -> 64 signed division */
78int64_t HELPER(divs64)(CPUS390XState *env, int64_t a, int64_t b)
79{
80 /* Catch divide by zero, and non-representable quotient (MIN / -1). */
81 if (b == 0 || (b == -1 && a == (1ll << 63))) {
82 s390_program_interrupt(env, PGM_FIXPT_DIVIDE, ILEN_AUTO, GETPC());
83 }
84 env->retxl = a % b;
85 return a / b;
86}
87
88/* 128 -> 64/64 unsigned division */
89uint64_t HELPER(divu64)(CPUS390XState *env, uint64_t ah, uint64_t al,
90 uint64_t b)
91{
92 uint64_t ret;
93 /* Signal divide by zero. */
94 if (b == 0) {
95 s390_program_interrupt(env, PGM_FIXPT_DIVIDE, ILEN_AUTO, GETPC());
96 }
97 if (ah == 0) {
98 /* 64 -> 64/64 case */
99 env->retxl = al % b;
100 ret = al / b;
101 } else {
102 /* ??? Move i386 idivq helper to host-utils. */
103#ifdef CONFIG_INT128
104 __uint128_t a = ((__uint128_t)ah << 64) | al;
105 __uint128_t q = a / b;
106 env->retxl = a % b;
107 ret = q;
108 if (ret != q) {
109 s390_program_interrupt(env, PGM_FIXPT_DIVIDE, ILEN_AUTO, GETPC());
110 }
111#else
112 /* 32-bit hosts would need special wrapper functionality - just abort if
113 we encounter such a case; it's very unlikely anyways. */
114 cpu_abort(env_cpu(env), "128 -> 64/64 division not implemented\n");
115#endif
116 }
117 return ret;
118}
119
120uint64_t HELPER(cvd)(int32_t reg)
121{
122 /* positive 0 */
123 uint64_t dec = 0x0c;
124 int64_t bin = reg;
125 int shift;
126
127 if (bin < 0) {
128 bin = -bin;
129 dec = 0x0d;
130 }
131
132 for (shift = 4; (shift < 64) && bin; shift += 4) {
133 dec |= (bin % 10) << shift;
134 bin /= 10;
135 }
136
137 return dec;
138}
139
140uint64_t HELPER(popcnt)(uint64_t val)
141{
142 /* Note that we don't fold past bytes. */
143 val = (val & 0x5555555555555555ULL) + ((val >> 1) & 0x5555555555555555ULL);
144 val = (val & 0x3333333333333333ULL) + ((val >> 2) & 0x3333333333333333ULL);
145 val = (val + (val >> 4)) & 0x0f0f0f0f0f0f0f0fULL;
146 return val;
147}
148