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      1 /*
      2  * Utility compute operations used by translated code.
      3  *
      4  * Copyright (c) 2003 Fabrice Bellard
      5  * Copyright (c) 2007 Aurelien Jarno
      6  *
      7  * Permission is hereby granted, free of charge, to any person obtaining a copy
      8  * of this software and associated documentation files (the "Software"), to deal
      9  * in the Software without restriction, including without limitation the rights
     10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     11  * copies of the Software, and to permit persons to whom the Software is
     12  * furnished to do so, subject to the following conditions:
     13  *
     14  * The above copyright notice and this permission notice shall be included in
     15  * all copies or substantial portions of the Software.
     16  *
     17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
     20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
     21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
     22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
     23  * THE SOFTWARE.
     24  */
     25 
     26 #include <stdlib.h>
     27 #include <stdint.h>
     28 #include "host-utils.h"
     29 
     30 //#define DEBUG_MULDIV
     31 
     32 /* Long integer helpers */
     33 #if !defined(__x86_64__)
     34 static void add128 (uint64_t *plow, uint64_t *phigh, uint64_t a, uint64_t b)
     35 {
     36     *plow += a;
     37     /* carry test */
     38     if (*plow < a)
     39         (*phigh)++;
     40     *phigh += b;
     41 }
     42 
     43 static void neg128 (uint64_t *plow, uint64_t *phigh)
     44 {
     45     *plow = ~*plow;
     46     *phigh = ~*phigh;
     47     add128(plow, phigh, 1, 0);
     48 }
     49 
     50 static void mul64 (uint64_t *plow, uint64_t *phigh, uint64_t a, uint64_t b)
     51 {
     52     uint32_t a0, a1, b0, b1;
     53     uint64_t v;
     54 
     55     a0 = a;
     56     a1 = a >> 32;
     57 
     58     b0 = b;
     59     b1 = b >> 32;
     60 
     61     v = (uint64_t)a0 * (uint64_t)b0;
     62     *plow = v;
     63     *phigh = 0;
     64 
     65     v = (uint64_t)a0 * (uint64_t)b1;
     66     add128(plow, phigh, v << 32, v >> 32);
     67 
     68     v = (uint64_t)a1 * (uint64_t)b0;
     69     add128(plow, phigh, v << 32, v >> 32);
     70 
     71     v = (uint64_t)a1 * (uint64_t)b1;
     72     *phigh += v;
     73 }
     74 
     75 /* Unsigned 64x64 -> 128 multiplication */
     76 void mulu64 (uint64_t *plow, uint64_t *phigh, uint64_t a, uint64_t b)
     77 {
     78     mul64(plow, phigh, a, b);
     79 #if defined(DEBUG_MULDIV)
     80     printf("mulu64: 0x%016llx * 0x%016llx = 0x%016llx%016llx\n",
     81            a, b, *phigh, *plow);
     82 #endif
     83 }
     84 
     85 /* Signed 64x64 -> 128 multiplication */
     86 void muls64 (uint64_t *plow, uint64_t *phigh, int64_t a, int64_t b)
     87 {
     88     int sa, sb;
     89 
     90     sa = (a < 0);
     91     if (sa)
     92         a = -a;
     93     sb = (b < 0);
     94     if (sb)
     95         b = -b;
     96     mul64(plow, phigh, a, b);
     97     if (sa ^ sb) {
     98         neg128(plow, phigh);
     99     }
    100 #if defined(DEBUG_MULDIV)
    101     printf("muls64: 0x%016llx * 0x%016llx = 0x%016llx%016llx\n",
    102            a, b, *phigh, *plow);
    103 #endif
    104 }
    105 #endif /* !defined(__x86_64__) */
    106