qemu

FORK: QEMU emulator
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int_helper.c (3954B)

      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 }