Annotation of qemu/host-utils.c, revision 1.1.1.2

1.1       root        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: 
1.1.1.2 ! root       26: #include <stdlib.h>
        !            27: #include <stdint.h>
1.1       root       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__) */

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