target/s390x/int_helper.c

   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 "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 }