]> git.proxmox.com Git - qemu.git/blob - host-utils.c
Fix memory corruption reported by Julian Seward
[qemu.git] / host-utils.c
1 /*
2 * Utility compute operations used by translated code.
3 *
4 * Copyright (c) 2007 Aurelien Jarno
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24
25 #include "vl.h"
26
27 /* Signed 64x64 -> 128 multiplication */
28
29 void muls64(int64_t *phigh, int64_t *plow, int64_t a, int64_t b)
30 {
31 #if defined(__x86_64__)
32 __asm__ ("imul %0\n\t"
33 : "=d" (*phigh), "=a" (*plow)
34 : "a" (a), "0" (b)
35 );
36 #else
37 int64_t ph;
38 uint64_t pm1, pm2, pl;
39
40 pl = (uint64_t)((uint32_t)a) * (uint64_t)((uint32_t)b);
41 pm1 = (a >> 32) * (uint32_t)b;
42 pm2 = (uint32_t)a * (b >> 32);
43 ph = (a >> 32) * (b >> 32);
44
45 ph += (int64_t)pm1 >> 32;
46 pm1 = (uint64_t)((uint32_t)pm1) + pm2 + (pl >> 32);
47
48 *phigh = ph + ((int64_t)pm1 >> 32);
49 *plow = (pm1 << 32) + (uint32_t)pl;
50 #endif
51 }
52
53 /* Unsigned 64x64 -> 128 multiplication */
54 void mulu64(uint64_t *phigh, uint64_t *plow, uint64_t a, uint64_t b)
55 {
56 #if defined(__x86_64__)
57 __asm__ ("mul %0\n\t"
58 : "=d" (*phigh), "=a" (*plow)
59 : "a" (a), "0" (b)
60 );
61 #else
62 uint64_t ph, pm1, pm2, pl;
63
64 pl = (uint64_t)((uint32_t)a) * (uint64_t)((uint32_t)b);
65 pm1 = (a >> 32) * (uint32_t)b;
66 pm2 = (uint32_t)a * (b >> 32);
67 ph = (a >> 32) * (b >> 32);
68
69 ph += pm1 >> 32;
70 pm1 = (uint64_t)((uint32_t)pm1) + pm2 + (pl >> 32);
71
72 *phigh = ph + (pm1 >> 32);
73 *plow = (pm1 << 32) + (uint32_t)pl;
74 #endif
75 }