cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
Log | Files | Refs | Submodules | LICENSE | sfeed.txt

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 */
     37int64_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 */
     58uint64_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 */
     79int64_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 */
     90uint64_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
    121uint64_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
    141uint64_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}