ths | 69d3572 | 2007-05-16 11:59:40 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Utility compute operations used by translated code. |
| 3 | * |
ths | e494ead | 2007-10-25 23:00:03 +0000 | [diff] [blame] | 4 | * Copyright (c) 2003 Fabrice Bellard |
ths | 69d3572 | 2007-05-16 11:59:40 +0000 | [diff] [blame] | 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 | |
Peter Maydell | aafd758 | 2016-01-29 17:49:55 +0000 | [diff] [blame^] | 26 | #include "qemu/osdep.h" |
Paolo Bonzini | 1de7afc | 2012-12-17 18:20:00 +0100 | [diff] [blame] | 27 | #include "qemu/host-utils.h" |
ths | 69d3572 | 2007-05-16 11:59:40 +0000 | [diff] [blame] | 28 | |
ths | e494ead | 2007-10-25 23:00:03 +0000 | [diff] [blame] | 29 | /* Long integer helpers */ |
Richard Henderson | ff7a1eb | 2013-02-16 12:47:00 -0800 | [diff] [blame] | 30 | static inline void mul64(uint64_t *plow, uint64_t *phigh, |
| 31 | uint64_t a, uint64_t b) |
ths | 69d3572 | 2007-05-16 11:59:40 +0000 | [diff] [blame] | 32 | { |
Richard Henderson | ff7a1eb | 2013-02-16 12:47:00 -0800 | [diff] [blame] | 33 | typedef union { |
| 34 | uint64_t ll; |
| 35 | struct { |
| 36 | #ifdef HOST_WORDS_BIGENDIAN |
| 37 | uint32_t high, low; |
| 38 | #else |
| 39 | uint32_t low, high; |
| 40 | #endif |
| 41 | } l; |
| 42 | } LL; |
| 43 | LL rl, rm, rn, rh, a0, b0; |
| 44 | uint64_t c; |
ths | 69d3572 | 2007-05-16 11:59:40 +0000 | [diff] [blame] | 45 | |
Richard Henderson | ff7a1eb | 2013-02-16 12:47:00 -0800 | [diff] [blame] | 46 | a0.ll = a; |
| 47 | b0.ll = b; |
ths | e494ead | 2007-10-25 23:00:03 +0000 | [diff] [blame] | 48 | |
Richard Henderson | ff7a1eb | 2013-02-16 12:47:00 -0800 | [diff] [blame] | 49 | rl.ll = (uint64_t)a0.l.low * b0.l.low; |
| 50 | rm.ll = (uint64_t)a0.l.low * b0.l.high; |
| 51 | rn.ll = (uint64_t)a0.l.high * b0.l.low; |
| 52 | rh.ll = (uint64_t)a0.l.high * b0.l.high; |
ths | e494ead | 2007-10-25 23:00:03 +0000 | [diff] [blame] | 53 | |
Richard Henderson | ff7a1eb | 2013-02-16 12:47:00 -0800 | [diff] [blame] | 54 | c = (uint64_t)rl.l.high + rm.l.low + rn.l.low; |
| 55 | rl.l.high = c; |
| 56 | c >>= 32; |
| 57 | c = c + rm.l.high + rn.l.high + rh.l.low; |
| 58 | rh.l.low = c; |
| 59 | rh.l.high += (uint32_t)(c >> 32); |
ths | e494ead | 2007-10-25 23:00:03 +0000 | [diff] [blame] | 60 | |
Richard Henderson | ff7a1eb | 2013-02-16 12:47:00 -0800 | [diff] [blame] | 61 | *plow = rl.ll; |
| 62 | *phigh = rh.ll; |
ths | e494ead | 2007-10-25 23:00:03 +0000 | [diff] [blame] | 63 | } |
| 64 | |
ths | 69d3572 | 2007-05-16 11:59:40 +0000 | [diff] [blame] | 65 | /* Unsigned 64x64 -> 128 multiplication */ |
ths | e494ead | 2007-10-25 23:00:03 +0000 | [diff] [blame] | 66 | void mulu64 (uint64_t *plow, uint64_t *phigh, uint64_t a, uint64_t b) |
ths | 69d3572 | 2007-05-16 11:59:40 +0000 | [diff] [blame] | 67 | { |
ths | e494ead | 2007-10-25 23:00:03 +0000 | [diff] [blame] | 68 | mul64(plow, phigh, a, b); |
ths | e494ead | 2007-10-25 23:00:03 +0000 | [diff] [blame] | 69 | } |
ths | 69d3572 | 2007-05-16 11:59:40 +0000 | [diff] [blame] | 70 | |
ths | e494ead | 2007-10-25 23:00:03 +0000 | [diff] [blame] | 71 | /* Signed 64x64 -> 128 multiplication */ |
| 72 | void muls64 (uint64_t *plow, uint64_t *phigh, int64_t a, int64_t b) |
| 73 | { |
Richard Henderson | ff7a1eb | 2013-02-16 12:47:00 -0800 | [diff] [blame] | 74 | uint64_t rh; |
ths | 69d3572 | 2007-05-16 11:59:40 +0000 | [diff] [blame] | 75 | |
Richard Henderson | ff7a1eb | 2013-02-16 12:47:00 -0800 | [diff] [blame] | 76 | mul64(plow, &rh, a, b); |
| 77 | |
| 78 | /* Adjust for signs. */ |
| 79 | if (b < 0) { |
| 80 | rh -= a; |
ths | e494ead | 2007-10-25 23:00:03 +0000 | [diff] [blame] | 81 | } |
Richard Henderson | ff7a1eb | 2013-02-16 12:47:00 -0800 | [diff] [blame] | 82 | if (a < 0) { |
| 83 | rh -= b; |
| 84 | } |
| 85 | *phigh = rh; |
ths | 69d3572 | 2007-05-16 11:59:40 +0000 | [diff] [blame] | 86 | } |
Tom Musta | 98d1eb2 | 2014-01-07 10:05:51 -0600 | [diff] [blame] | 87 | |
| 88 | /* Unsigned 128x64 division. Returns 1 if overflow (divide by zero or */ |
| 89 | /* quotient exceeds 64 bits). Otherwise returns quotient via plow and */ |
| 90 | /* remainder via phigh. */ |
| 91 | int divu128(uint64_t *plow, uint64_t *phigh, uint64_t divisor) |
| 92 | { |
| 93 | uint64_t dhi = *phigh; |
| 94 | uint64_t dlo = *plow; |
| 95 | unsigned i; |
| 96 | uint64_t carry = 0; |
| 97 | |
| 98 | if (divisor == 0) { |
| 99 | return 1; |
| 100 | } else if (dhi == 0) { |
| 101 | *plow = dlo / divisor; |
| 102 | *phigh = dlo % divisor; |
| 103 | return 0; |
| 104 | } else if (dhi > divisor) { |
| 105 | return 1; |
| 106 | } else { |
| 107 | |
| 108 | for (i = 0; i < 64; i++) { |
| 109 | carry = dhi >> 63; |
| 110 | dhi = (dhi << 1) | (dlo >> 63); |
| 111 | if (carry || (dhi >= divisor)) { |
| 112 | dhi -= divisor; |
| 113 | carry = 1; |
| 114 | } else { |
| 115 | carry = 0; |
| 116 | } |
| 117 | dlo = (dlo << 1) | carry; |
| 118 | } |
| 119 | |
| 120 | *plow = dlo; |
| 121 | *phigh = dhi; |
| 122 | return 0; |
| 123 | } |
| 124 | } |
Tom Musta | e44259b | 2014-01-07 10:05:52 -0600 | [diff] [blame] | 125 | |
| 126 | int divs128(int64_t *plow, int64_t *phigh, int64_t divisor) |
| 127 | { |
| 128 | int sgn_dvdnd = *phigh < 0; |
| 129 | int sgn_divsr = divisor < 0; |
| 130 | int overflow = 0; |
| 131 | |
| 132 | if (sgn_dvdnd) { |
| 133 | *plow = ~(*plow); |
| 134 | *phigh = ~(*phigh); |
| 135 | if (*plow == (int64_t)-1) { |
| 136 | *plow = 0; |
| 137 | (*phigh)++; |
| 138 | } else { |
| 139 | (*plow)++; |
| 140 | } |
| 141 | } |
| 142 | |
| 143 | if (sgn_divsr) { |
| 144 | divisor = 0 - divisor; |
| 145 | } |
| 146 | |
| 147 | overflow = divu128((uint64_t *)plow, (uint64_t *)phigh, (uint64_t)divisor); |
| 148 | |
| 149 | if (sgn_dvdnd ^ sgn_divsr) { |
| 150 | *plow = 0 - *plow; |
| 151 | } |
| 152 | |
| 153 | if (!overflow) { |
| 154 | if ((*plow < 0) ^ (sgn_dvdnd ^ sgn_divsr)) { |
| 155 | overflow = 1; |
| 156 | } |
| 157 | } |
| 158 | |
| 159 | return overflow; |
| 160 | } |
| 161 | |