xref: /openbmc/qemu/target/s390x/tcg/int_helper.c (revision 6016b7b4)
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 
29 /* #define DEBUG_HELPER */
30 #ifdef DEBUG_HELPER
31 #define HELPER_LOG(x...) qemu_log(x)
32 #else
33 #define HELPER_LOG(x...)
34 #endif
35 
36 /* 64/32 -> 32 signed division */
37 int64_t HELPER(divs32)(CPUS390XState *env, int64_t a, int64_t b64)
38 {
39     int32_t ret, b = b64;
40     int64_t q;
41 
42     if (b == 0) {
43         tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
44     }
45 
46     ret = q = a / b;
47     env->retxl = a % b;
48 
49     /* Catch non-representable quotient.  */
50     if (ret != q) {
51         tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
52     }
53 
54     return ret;
55 }
56 
57 /* 64/32 -> 32 unsigned division */
58 uint64_t HELPER(divu32)(CPUS390XState *env, uint64_t a, uint64_t b64)
59 {
60     uint32_t ret, b = b64;
61     uint64_t q;
62 
63     if (b == 0) {
64         tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
65     }
66 
67     ret = q = a / b;
68     env->retxl = a % b;
69 
70     /* Catch non-representable quotient.  */
71     if (ret != q) {
72         tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
73     }
74 
75     return ret;
76 }
77 
78 /* 64/64 -> 64 signed division */
79 int64_t HELPER(divs64)(CPUS390XState *env, int64_t a, int64_t b)
80 {
81     /* Catch divide by zero, and non-representable quotient (MIN / -1).  */
82     if (b == 0 || (b == -1 && a == (1ll << 63))) {
83         tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
84     }
85     env->retxl = a % b;
86     return a / b;
87 }
88 
89 /* 128 -> 64/64 unsigned division */
90 uint64_t HELPER(divu64)(CPUS390XState *env, uint64_t ah, uint64_t al,
91                         uint64_t b)
92 {
93     uint64_t ret;
94     /* Signal divide by zero.  */
95     if (b == 0) {
96         tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
97     }
98     if (ah == 0) {
99         /* 64 -> 64/64 case */
100         env->retxl = al % b;
101         ret = al / b;
102     } else {
103         /* ??? Move i386 idivq helper to host-utils.  */
104 #ifdef CONFIG_INT128
105         __uint128_t a = ((__uint128_t)ah << 64) | al;
106         __uint128_t q = a / b;
107         env->retxl = a % b;
108         ret = q;
109         if (ret != q) {
110             tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
111         }
112 #else
113         /* 32-bit hosts would need special wrapper functionality - just abort if
114            we encounter such a case; it's very unlikely anyways. */
115         cpu_abort(env_cpu(env), "128 -> 64/64 division not implemented\n");
116 #endif
117     }
118     return ret;
119 }
120 
121 uint64_t HELPER(cvd)(int32_t reg)
122 {
123     /* positive 0 */
124     uint64_t dec = 0x0c;
125     int64_t bin = reg;
126     int shift;
127 
128     if (bin < 0) {
129         bin = -bin;
130         dec = 0x0d;
131     }
132 
133     for (shift = 4; (shift < 64) && bin; shift += 4) {
134         dec |= (bin % 10) << shift;
135         bin /= 10;
136     }
137 
138     return dec;
139 }
140 
141 uint64_t HELPER(popcnt)(uint64_t val)
142 {
143     /* Note that we don't fold past bytes. */
144     val = (val & 0x5555555555555555ULL) + ((val >> 1) & 0x5555555555555555ULL);
145     val = (val & 0x3333333333333333ULL) + ((val >> 2) & 0x3333333333333333ULL);
146     val = (val + (val >> 4)) & 0x0f0f0f0f0f0f0f0fULL;
147     return val;
148 }
149