cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
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vax_helper.c (8431B)

      1/*
      2 *  Helpers for vax floating point instructions.
      3 *
      4 *  Copyright (c) 2007 Jocelyn Mayer
      5 *
      6 * This library is free software; you can redistribute it and/or
      7 * modify it under the terms of the GNU Lesser General Public
      8 * License as published by the Free Software Foundation; either
      9 * version 2.1 of the License, or (at your option) any later version.
     10 *
     11 * This library is distributed in the hope that it will be useful,
     12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
     13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     14 * Lesser General Public License for more details.
     15 *
     16 * You should have received a copy of the GNU Lesser General Public
     17 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
     18 */
     19
     20#include "qemu/osdep.h"
     21#include "cpu.h"
     22#include "exec/exec-all.h"
     23#include "exec/helper-proto.h"
     24#include "fpu/softfloat.h"
     25
     26#define FP_STATUS (env->fp_status)
     27
     28
     29/* F floating (VAX) */
     30static uint64_t float32_to_f(float32 fa)
     31{
     32    uint64_t r, exp, mant, sig;
     33    CPU_FloatU a;
     34
     35    a.f = fa;
     36    sig = ((uint64_t)a.l & 0x80000000) << 32;
     37    exp = (a.l >> 23) & 0xff;
     38    mant = ((uint64_t)a.l & 0x007fffff) << 29;
     39
     40    if (exp == 255) {
     41        /* NaN or infinity */
     42        r = 1; /* VAX dirty zero */
     43    } else if (exp == 0) {
     44        if (mant == 0) {
     45            /* Zero */
     46            r = 0;
     47        } else {
     48            /* Denormalized */
     49            r = sig | ((exp + 1) << 52) | mant;
     50        }
     51    } else {
     52        if (exp >= 253) {
     53            /* Overflow */
     54            r = 1; /* VAX dirty zero */
     55        } else {
     56            r = sig | ((exp + 2) << 52);
     57        }
     58    }
     59
     60    return r;
     61}
     62
     63static float32 f_to_float32(CPUAlphaState *env, uintptr_t retaddr, uint64_t a)
     64{
     65    uint32_t exp, mant_sig;
     66    CPU_FloatU r;
     67
     68    exp = ((a >> 55) & 0x80) | ((a >> 52) & 0x7f);
     69    mant_sig = ((a >> 32) & 0x80000000) | ((a >> 29) & 0x007fffff);
     70
     71    if (unlikely(!exp && mant_sig)) {
     72        /* Reserved operands / Dirty zero */
     73        dynamic_excp(env, retaddr, EXCP_OPCDEC, 0);
     74    }
     75
     76    if (exp < 3) {
     77        /* Underflow */
     78        r.l = 0;
     79    } else {
     80        r.l = ((exp - 2) << 23) | mant_sig;
     81    }
     82
     83    return r.f;
     84}
     85
     86uint32_t helper_f_to_memory(uint64_t a)
     87{
     88    uint32_t r;
     89    r =  (a & 0x00001fffe0000000ull) >> 13;
     90    r |= (a & 0x07ffe00000000000ull) >> 45;
     91    r |= (a & 0xc000000000000000ull) >> 48;
     92    return r;
     93}
     94
     95uint64_t helper_memory_to_f(uint32_t a)
     96{
     97    uint64_t r;
     98    r =  ((uint64_t)(a & 0x0000c000)) << 48;
     99    r |= ((uint64_t)(a & 0x003fffff)) << 45;
    100    r |= ((uint64_t)(a & 0xffff0000)) << 13;
    101    if (!(a & 0x00004000)) {
    102        r |= 0x7ll << 59;
    103    }
    104    return r;
    105}
    106
    107/* ??? Emulating VAX arithmetic with IEEE arithmetic is wrong.  We should
    108   either implement VAX arithmetic properly or just signal invalid opcode.  */
    109
    110uint64_t helper_addf(CPUAlphaState *env, uint64_t a, uint64_t b)
    111{
    112    float32 fa, fb, fr;
    113
    114    fa = f_to_float32(env, GETPC(), a);
    115    fb = f_to_float32(env, GETPC(), b);
    116    fr = float32_add(fa, fb, &FP_STATUS);
    117    return float32_to_f(fr);
    118}
    119
    120uint64_t helper_subf(CPUAlphaState *env, uint64_t a, uint64_t b)
    121{
    122    float32 fa, fb, fr;
    123
    124    fa = f_to_float32(env, GETPC(), a);
    125    fb = f_to_float32(env, GETPC(), b);
    126    fr = float32_sub(fa, fb, &FP_STATUS);
    127    return float32_to_f(fr);
    128}
    129
    130uint64_t helper_mulf(CPUAlphaState *env, uint64_t a, uint64_t b)
    131{
    132    float32 fa, fb, fr;
    133
    134    fa = f_to_float32(env, GETPC(), a);
    135    fb = f_to_float32(env, GETPC(), b);
    136    fr = float32_mul(fa, fb, &FP_STATUS);
    137    return float32_to_f(fr);
    138}
    139
    140uint64_t helper_divf(CPUAlphaState *env, uint64_t a, uint64_t b)
    141{
    142    float32 fa, fb, fr;
    143
    144    fa = f_to_float32(env, GETPC(), a);
    145    fb = f_to_float32(env, GETPC(), b);
    146    fr = float32_div(fa, fb, &FP_STATUS);
    147    return float32_to_f(fr);
    148}
    149
    150uint64_t helper_sqrtf(CPUAlphaState *env, uint64_t t)
    151{
    152    float32 ft, fr;
    153
    154    ft = f_to_float32(env, GETPC(), t);
    155    fr = float32_sqrt(ft, &FP_STATUS);
    156    return float32_to_f(fr);
    157}
    158
    159
    160/* G floating (VAX) */
    161static uint64_t float64_to_g(float64 fa)
    162{
    163    uint64_t r, exp, mant, sig;
    164    CPU_DoubleU a;
    165
    166    a.d = fa;
    167    sig = a.ll & 0x8000000000000000ull;
    168    exp = (a.ll >> 52) & 0x7ff;
    169    mant = a.ll & 0x000fffffffffffffull;
    170
    171    if (exp == 2047) {
    172        /* NaN or infinity */
    173        r = 1; /* VAX dirty zero */
    174    } else if (exp == 0) {
    175        if (mant == 0) {
    176            /* Zero */
    177            r = 0;
    178        } else {
    179            /* Denormalized */
    180            r = sig | ((exp + 1) << 52) | mant;
    181        }
    182    } else {
    183        if (exp >= 2045) {
    184            /* Overflow */
    185            r = 1; /* VAX dirty zero */
    186        } else {
    187            r = sig | ((exp + 2) << 52);
    188        }
    189    }
    190
    191    return r;
    192}
    193
    194static float64 g_to_float64(CPUAlphaState *env, uintptr_t retaddr, uint64_t a)
    195{
    196    uint64_t exp, mant_sig;
    197    CPU_DoubleU r;
    198
    199    exp = (a >> 52) & 0x7ff;
    200    mant_sig = a & 0x800fffffffffffffull;
    201
    202    if (!exp && mant_sig) {
    203        /* Reserved operands / Dirty zero */
    204        dynamic_excp(env, retaddr, EXCP_OPCDEC, 0);
    205    }
    206
    207    if (exp < 3) {
    208        /* Underflow */
    209        r.ll = 0;
    210    } else {
    211        r.ll = ((exp - 2) << 52) | mant_sig;
    212    }
    213
    214    return r.d;
    215}
    216
    217uint64_t helper_g_to_memory(uint64_t a)
    218{
    219    uint64_t r;
    220    r =  (a & 0x000000000000ffffull) << 48;
    221    r |= (a & 0x00000000ffff0000ull) << 16;
    222    r |= (a & 0x0000ffff00000000ull) >> 16;
    223    r |= (a & 0xffff000000000000ull) >> 48;
    224    return r;
    225}
    226
    227uint64_t helper_memory_to_g(uint64_t a)
    228{
    229    uint64_t r;
    230    r =  (a & 0x000000000000ffffull) << 48;
    231    r |= (a & 0x00000000ffff0000ull) << 16;
    232    r |= (a & 0x0000ffff00000000ull) >> 16;
    233    r |= (a & 0xffff000000000000ull) >> 48;
    234    return r;
    235}
    236
    237uint64_t helper_addg(CPUAlphaState *env, uint64_t a, uint64_t b)
    238{
    239    float64 fa, fb, fr;
    240
    241    fa = g_to_float64(env, GETPC(), a);
    242    fb = g_to_float64(env, GETPC(), b);
    243    fr = float64_add(fa, fb, &FP_STATUS);
    244    return float64_to_g(fr);
    245}
    246
    247uint64_t helper_subg(CPUAlphaState *env, uint64_t a, uint64_t b)
    248{
    249    float64 fa, fb, fr;
    250
    251    fa = g_to_float64(env, GETPC(), a);
    252    fb = g_to_float64(env, GETPC(), b);
    253    fr = float64_sub(fa, fb, &FP_STATUS);
    254    return float64_to_g(fr);
    255}
    256
    257uint64_t helper_mulg(CPUAlphaState *env, uint64_t a, uint64_t b)
    258{
    259    float64 fa, fb, fr;
    260
    261    fa = g_to_float64(env, GETPC(), a);
    262    fb = g_to_float64(env, GETPC(), b);
    263    fr = float64_mul(fa, fb, &FP_STATUS);
    264    return float64_to_g(fr);
    265}
    266
    267uint64_t helper_divg(CPUAlphaState *env, uint64_t a, uint64_t b)
    268{
    269    float64 fa, fb, fr;
    270
    271    fa = g_to_float64(env, GETPC(), a);
    272    fb = g_to_float64(env, GETPC(), b);
    273    fr = float64_div(fa, fb, &FP_STATUS);
    274    return float64_to_g(fr);
    275}
    276
    277uint64_t helper_sqrtg(CPUAlphaState *env, uint64_t a)
    278{
    279    float64 fa, fr;
    280
    281    fa = g_to_float64(env, GETPC(), a);
    282    fr = float64_sqrt(fa, &FP_STATUS);
    283    return float64_to_g(fr);
    284}
    285
    286uint64_t helper_cmpgeq(CPUAlphaState *env, uint64_t a, uint64_t b)
    287{
    288    float64 fa, fb;
    289
    290    fa = g_to_float64(env, GETPC(), a);
    291    fb = g_to_float64(env, GETPC(), b);
    292
    293    if (float64_eq_quiet(fa, fb, &FP_STATUS)) {
    294        return 0x4000000000000000ULL;
    295    } else {
    296        return 0;
    297    }
    298}
    299
    300uint64_t helper_cmpgle(CPUAlphaState *env, uint64_t a, uint64_t b)
    301{
    302    float64 fa, fb;
    303
    304    fa = g_to_float64(env, GETPC(), a);
    305    fb = g_to_float64(env, GETPC(), b);
    306
    307    if (float64_le(fa, fb, &FP_STATUS)) {
    308        return 0x4000000000000000ULL;
    309    } else {
    310        return 0;
    311    }
    312}
    313
    314uint64_t helper_cmpglt(CPUAlphaState *env, uint64_t a, uint64_t b)
    315{
    316    float64 fa, fb;
    317
    318    fa = g_to_float64(env, GETPC(), a);
    319    fb = g_to_float64(env, GETPC(), b);
    320
    321    if (float64_lt(fa, fb, &FP_STATUS)) {
    322        return 0x4000000000000000ULL;
    323    } else {
    324        return 0;
    325    }
    326}
    327
    328uint64_t helper_cvtqf(CPUAlphaState *env, uint64_t a)
    329{
    330    float32 fr = int64_to_float32(a, &FP_STATUS);
    331    return float32_to_f(fr);
    332}
    333
    334uint64_t helper_cvtgf(CPUAlphaState *env, uint64_t a)
    335{
    336    float64 fa;
    337    float32 fr;
    338
    339    fa = g_to_float64(env, GETPC(), a);
    340    fr = float64_to_float32(fa, &FP_STATUS);
    341    return float32_to_f(fr);
    342}
    343
    344uint64_t helper_cvtgq(CPUAlphaState *env, uint64_t a)
    345{
    346    float64 fa = g_to_float64(env, GETPC(), a);
    347    return float64_to_int64_round_to_zero(fa, &FP_STATUS);
    348}
    349
    350uint64_t helper_cvtqg(CPUAlphaState *env, uint64_t a)
    351{
    352    float64 fr;
    353    fr = int64_to_float64(a, &FP_STATUS);
    354    return float64_to_g(fr);
    355}