Thomas Chou | 8d52ea6 | 2010-05-15 06:00:05 +0800 | [diff] [blame] | 1 | /* longlong.h -- definitions for mixed size 32/64 bit arithmetic. |
| 2 | Copyright (C) 1991, 1992, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2004, |
| 3 | 2005 Free Software Foundation, Inc. |
| 4 | |
| 5 | This definition file is free software; you can redistribute it |
| 6 | and/or modify it under the terms of the GNU General Public |
| 7 | License as published by the Free Software Foundation; either |
| 8 | version 2, or (at your option) any later version. |
| 9 | |
| 10 | This definition file is distributed in the hope that it will be |
| 11 | useful, but WITHOUT ANY WARRANTY; without even the implied |
| 12 | warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| 13 | See the GNU General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU General Public License |
| 16 | along with this program; if not, write to the Free Software |
| 17 | Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| 18 | Boston, MA 02110-1301, USA. */ |
| 19 | |
| 20 | /* You have to define the following before including this file: |
| 21 | |
| 22 | UWtype -- An unsigned type, default type for operations (typically a "word") |
| 23 | UHWtype -- An unsigned type, at least half the size of UWtype. |
| 24 | UDWtype -- An unsigned type, at least twice as large a UWtype |
| 25 | W_TYPE_SIZE -- size in bits of UWtype |
| 26 | |
| 27 | UQItype -- Unsigned 8 bit type. |
| 28 | SItype, USItype -- Signed and unsigned 32 bit types. |
| 29 | DItype, UDItype -- Signed and unsigned 64 bit types. |
| 30 | |
| 31 | On a 32 bit machine UWtype should typically be USItype; |
| 32 | on a 64 bit machine, UWtype should typically be UDItype. */ |
| 33 | |
| 34 | #define __BITS4 (W_TYPE_SIZE / 4) |
| 35 | #define __ll_B ((UWtype) 1 << (W_TYPE_SIZE / 2)) |
| 36 | #define __ll_lowpart(t) ((UWtype) (t) & (__ll_B - 1)) |
| 37 | #define __ll_highpart(t) ((UWtype) (t) >> (W_TYPE_SIZE / 2)) |
| 38 | |
| 39 | #ifndef W_TYPE_SIZE |
| 40 | #define W_TYPE_SIZE 32 |
| 41 | #define UWtype USItype |
| 42 | #define UHWtype USItype |
| 43 | #define UDWtype UDItype |
| 44 | #endif |
| 45 | |
| 46 | extern const UQItype __clz_tab[256]; |
| 47 | |
| 48 | /* Define auxiliary asm macros. |
| 49 | |
| 50 | 1) umul_ppmm(high_prod, low_prod, multiplier, multiplicand) multiplies two |
| 51 | UWtype integers MULTIPLIER and MULTIPLICAND, and generates a two UWtype |
| 52 | word product in HIGH_PROD and LOW_PROD. |
| 53 | |
| 54 | 2) __umulsidi3(a,b) multiplies two UWtype integers A and B, and returns a |
| 55 | UDWtype product. This is just a variant of umul_ppmm. |
| 56 | |
| 57 | 3) udiv_qrnnd(quotient, remainder, high_numerator, low_numerator, |
| 58 | denominator) divides a UDWtype, composed by the UWtype integers |
| 59 | HIGH_NUMERATOR and LOW_NUMERATOR, by DENOMINATOR and places the quotient |
| 60 | in QUOTIENT and the remainder in REMAINDER. HIGH_NUMERATOR must be less |
| 61 | than DENOMINATOR for correct operation. If, in addition, the most |
| 62 | significant bit of DENOMINATOR must be 1, then the pre-processor symbol |
| 63 | UDIV_NEEDS_NORMALIZATION is defined to 1. |
| 64 | |
| 65 | 4) sdiv_qrnnd(quotient, remainder, high_numerator, low_numerator, |
| 66 | denominator). Like udiv_qrnnd but the numbers are signed. The quotient |
| 67 | is rounded towards 0. |
| 68 | |
| 69 | 5) count_leading_zeros(count, x) counts the number of zero-bits from the |
| 70 | msb to the first nonzero bit in the UWtype X. This is the number of |
| 71 | steps X needs to be shifted left to set the msb. Undefined for X == 0, |
| 72 | unless the symbol COUNT_LEADING_ZEROS_0 is defined to some value. |
| 73 | |
| 74 | 6) count_trailing_zeros(count, x) like count_leading_zeros, but counts |
| 75 | from the least significant end. |
| 76 | |
| 77 | 7) add_ssaaaa(high_sum, low_sum, high_addend_1, low_addend_1, |
| 78 | high_addend_2, low_addend_2) adds two UWtype integers, composed by |
| 79 | HIGH_ADDEND_1 and LOW_ADDEND_1, and HIGH_ADDEND_2 and LOW_ADDEND_2 |
| 80 | respectively. The result is placed in HIGH_SUM and LOW_SUM. Overflow |
| 81 | (i.e. carry out) is not stored anywhere, and is lost. |
| 82 | |
| 83 | 8) sub_ddmmss(high_difference, low_difference, high_minuend, low_minuend, |
| 84 | high_subtrahend, low_subtrahend) subtracts two two-word UWtype integers, |
| 85 | composed by HIGH_MINUEND_1 and LOW_MINUEND_1, and HIGH_SUBTRAHEND_2 and |
| 86 | LOW_SUBTRAHEND_2 respectively. The result is placed in HIGH_DIFFERENCE |
| 87 | and LOW_DIFFERENCE. Overflow (i.e. carry out) is not stored anywhere, |
| 88 | and is lost. |
| 89 | |
| 90 | If any of these macros are left undefined for a particular CPU, |
| 91 | C macros are used. */ |
| 92 | |
| 93 | /* The CPUs come in alphabetical order below. |
| 94 | |
| 95 | Please add support for more CPUs here, or improve the current support |
| 96 | for the CPUs below! |
| 97 | (E.g. WE32100, IBM360.) */ |
| 98 | |
| 99 | /* Snipped per CPU support */ |
| 100 | |
| 101 | /* If this machine has no inline assembler, use C macros. */ |
| 102 | |
| 103 | #if !defined (add_ssaaaa) |
| 104 | #define add_ssaaaa(sh, sl, ah, al, bh, bl) \ |
| 105 | do { \ |
| 106 | UWtype __x; \ |
| 107 | __x = (al) + (bl); \ |
| 108 | (sh) = (ah) + (bh) + (__x < (al)); \ |
| 109 | (sl) = __x; \ |
| 110 | } while (0) |
| 111 | #endif |
| 112 | |
| 113 | #if !defined (sub_ddmmss) |
| 114 | #define sub_ddmmss(sh, sl, ah, al, bh, bl) \ |
| 115 | do { \ |
| 116 | UWtype __x; \ |
| 117 | __x = (al) - (bl); \ |
| 118 | (sh) = (ah) - (bh) - (__x > (al)); \ |
| 119 | (sl) = __x; \ |
| 120 | } while (0) |
| 121 | #endif |
| 122 | |
| 123 | /* If we lack umul_ppmm but have smul_ppmm, define umul_ppmm in terms of |
| 124 | smul_ppmm. */ |
| 125 | #if !defined (umul_ppmm) && defined (smul_ppmm) |
| 126 | #define umul_ppmm(w1, w0, u, v) \ |
| 127 | do { \ |
| 128 | UWtype __w1; \ |
| 129 | UWtype __xm0 = (u), __xm1 = (v); \ |
| 130 | smul_ppmm (__w1, w0, __xm0, __xm1); \ |
| 131 | (w1) = __w1 + (-(__xm0 >> (W_TYPE_SIZE - 1)) & __xm1) \ |
| 132 | + (-(__xm1 >> (W_TYPE_SIZE - 1)) & __xm0); \ |
| 133 | } while (0) |
| 134 | #endif |
| 135 | |
| 136 | /* If we still don't have umul_ppmm, define it using plain C. */ |
| 137 | #if !defined (umul_ppmm) |
| 138 | #define umul_ppmm(w1, w0, u, v) \ |
| 139 | do { \ |
| 140 | UWtype __x0, __x1, __x2, __x3; \ |
| 141 | UHWtype __ul, __vl, __uh, __vh; \ |
| 142 | \ |
| 143 | __ul = __ll_lowpart (u); \ |
| 144 | __uh = __ll_highpart (u); \ |
| 145 | __vl = __ll_lowpart (v); \ |
| 146 | __vh = __ll_highpart (v); \ |
| 147 | \ |
| 148 | __x0 = (UWtype) __ul * __vl; \ |
| 149 | __x1 = (UWtype) __ul * __vh; \ |
| 150 | __x2 = (UWtype) __uh * __vl; \ |
| 151 | __x3 = (UWtype) __uh * __vh; \ |
| 152 | \ |
| 153 | __x1 += __ll_highpart (__x0);/* this can't give carry */ \ |
| 154 | __x1 += __x2; /* but this indeed can */ \ |
| 155 | if (__x1 < __x2) /* did we get it? */ \ |
| 156 | __x3 += __ll_B; /* yes, add it in the proper pos. */ \ |
| 157 | \ |
| 158 | (w1) = __x3 + __ll_highpart (__x1); \ |
| 159 | (w0) = __ll_lowpart (__x1) * __ll_B + __ll_lowpart (__x0); \ |
| 160 | } while (0) |
| 161 | #endif |
| 162 | |
| 163 | #if !defined (__umulsidi3) |
| 164 | #define __umulsidi3(u, v) \ |
| 165 | ({DWunion __w; \ |
| 166 | umul_ppmm (__w.s.high, __w.s.low, u, v); \ |
| 167 | __w.ll; }) |
| 168 | #endif |
| 169 | |
| 170 | /* Define this unconditionally, so it can be used for debugging. */ |
| 171 | #define __udiv_qrnnd_c(q, r, n1, n0, d) \ |
| 172 | do { \ |
| 173 | UWtype __d1, __d0, __q1, __q0; \ |
| 174 | UWtype __r1, __r0, __m; \ |
| 175 | __d1 = __ll_highpart (d); \ |
| 176 | __d0 = __ll_lowpart (d); \ |
| 177 | \ |
| 178 | __r1 = (n1) % __d1; \ |
| 179 | __q1 = (n1) / __d1; \ |
| 180 | __m = (UWtype) __q1 * __d0; \ |
| 181 | __r1 = __r1 * __ll_B | __ll_highpart (n0); \ |
| 182 | if (__r1 < __m) \ |
| 183 | { \ |
| 184 | __q1--, __r1 += (d); \ |
| 185 | if (__r1 >= (d)) /* i.e. we didn't get carry when adding to __r1 */\ |
| 186 | if (__r1 < __m) \ |
| 187 | __q1--, __r1 += (d); \ |
| 188 | } \ |
| 189 | __r1 -= __m; \ |
| 190 | \ |
| 191 | __r0 = __r1 % __d1; \ |
| 192 | __q0 = __r1 / __d1; \ |
| 193 | __m = (UWtype) __q0 * __d0; \ |
| 194 | __r0 = __r0 * __ll_B | __ll_lowpart (n0); \ |
| 195 | if (__r0 < __m) \ |
| 196 | { \ |
| 197 | __q0--, __r0 += (d); \ |
| 198 | if (__r0 >= (d)) \ |
| 199 | if (__r0 < __m) \ |
| 200 | __q0--, __r0 += (d); \ |
| 201 | } \ |
| 202 | __r0 -= __m; \ |
| 203 | \ |
| 204 | (q) = (UWtype) __q1 * __ll_B | __q0; \ |
| 205 | (r) = __r0; \ |
| 206 | } while (0) |
| 207 | |
| 208 | /* If the processor has no udiv_qrnnd but sdiv_qrnnd, go through |
| 209 | __udiv_w_sdiv (defined in libgcc or elsewhere). */ |
| 210 | #if !defined (udiv_qrnnd) && defined (sdiv_qrnnd) |
| 211 | #define udiv_qrnnd(q, r, nh, nl, d) \ |
| 212 | do { \ |
| 213 | USItype __r; \ |
| 214 | (q) = __udiv_w_sdiv (&__r, nh, nl, d); \ |
| 215 | (r) = __r; \ |
| 216 | } while (0) |
| 217 | #endif |
| 218 | |
| 219 | /* If udiv_qrnnd was not defined for this processor, use __udiv_qrnnd_c. */ |
| 220 | #if !defined (udiv_qrnnd) |
| 221 | #define UDIV_NEEDS_NORMALIZATION 1 |
| 222 | #define udiv_qrnnd __udiv_qrnnd_c |
| 223 | #endif |
| 224 | |
| 225 | #if !defined (count_leading_zeros) |
| 226 | #define count_leading_zeros(count, x) \ |
| 227 | do { \ |
| 228 | UWtype __xr = (x); \ |
| 229 | UWtype __a; \ |
| 230 | \ |
| 231 | if (W_TYPE_SIZE <= 32) \ |
| 232 | { \ |
| 233 | __a = __xr < ((UWtype)1<<2*__BITS4) \ |
| 234 | ? (__xr < ((UWtype)1<<__BITS4) ? 0 : __BITS4) \ |
| 235 | : (__xr < ((UWtype)1<<3*__BITS4) ? 2*__BITS4 : 3*__BITS4); \ |
| 236 | } \ |
| 237 | else \ |
| 238 | { \ |
| 239 | for (__a = W_TYPE_SIZE - 8; __a > 0; __a -= 8) \ |
| 240 | if (((__xr >> __a) & 0xff) != 0) \ |
| 241 | break; \ |
| 242 | } \ |
| 243 | \ |
| 244 | (count) = W_TYPE_SIZE - (__clz_tab[__xr >> __a] + __a); \ |
| 245 | } while (0) |
| 246 | #define COUNT_LEADING_ZEROS_0 W_TYPE_SIZE |
| 247 | #endif |
| 248 | |
| 249 | #if !defined (count_trailing_zeros) |
| 250 | /* Define count_trailing_zeros using count_leading_zeros. The latter might be |
| 251 | defined in asm, but if it is not, the C version above is good enough. */ |
| 252 | #define count_trailing_zeros(count, x) \ |
| 253 | do { \ |
| 254 | UWtype __ctz_x = (x); \ |
| 255 | UWtype __ctz_c; \ |
| 256 | count_leading_zeros (__ctz_c, __ctz_x & -__ctz_x); \ |
| 257 | (count) = W_TYPE_SIZE - 1 - __ctz_c; \ |
| 258 | } while (0) |
| 259 | #endif |
| 260 | |
| 261 | #ifndef UDIV_NEEDS_NORMALIZATION |
| 262 | #define UDIV_NEEDS_NORMALIZATION 0 |
| 263 | #endif |