arch/mips/include/asm/div64.h

   1 /*
   2  * Copyright (C) 2000, 2004, 2021  Maciej W. Rozycki
   3  * Copyright (C) 2003, 07 Ralf Baechle (ralf@linux-mips.org)
   4  *
   5  * This file is subject to the terms and conditions of the GNU General Public
   6  * License.  See the file "COPYING" in the main directory of this archive
   7  * for more details.
   8  */
   9 #ifndef __ASM_DIV64_H
  10 #define __ASM_DIV64_H
  11
  12 #include <asm/bitsperlong.h>
  13
  14 #if BITS_PER_LONG == 32
  15
  16 /*
  17  * No traps on overflows for any of these...
  18  */
  19
  20 #define do_div64_32(res, high, low, base) ({                            \
  21         unsigned long __cf, __tmp, __tmp2, __i;                         \
  22         unsigned long __quot32, __mod32;                                \
  23                                                                         \
  24         __asm__(                                                        \
  25         "       .set    push                                    \n"     \
  26         "       .set    noat                                    \n"     \
  27         "       .set    noreorder                               \n"     \
  28         "       move    %2, $0                                  \n"     \
  29         "       move    %3, $0                                  \n"     \
  30         "       b       1f                                      \n"     \
  31         "        li     %4, 0x21                                \n"     \
  32         "0:                                                     \n"     \
  33         "       sll     $1, %0, 0x1                             \n"     \
  34         "       srl     %3, %0, 0x1f                            \n"     \
  35         "       or      %0, $1, %5                              \n"     \
  36         "       sll     %1, %1, 0x1                             \n"     \
  37         "       sll     %2, %2, 0x1                             \n"     \
  38         "1:                                                     \n"     \
  39         "       bnez    %3, 2f                                  \n"     \
  40         "        sltu   %5, %0, %z6                             \n"     \
  41         "       bnez    %5, 3f                                  \n"     \
  42         "2:                                                     \n"     \
  43         "        addiu  %4, %4, -1                              \n"     \
  44         "       subu    %0, %0, %z6                             \n"     \
  45         "       addiu   %2, %2, 1                               \n"     \
  46         "3:                                                     \n"     \
  47         "       bnez    %4, 0b                                  \n"     \
  48         "        srl    %5, %1, 0x1f                            \n"     \
  49         "       .set    pop"                                            \
  50         : "=&r" (__mod32), "=&r" (__tmp),                               \
  51           "=&r" (__quot32), "=&r" (__cf),                               \
  52           "=&r" (__i), "=&r" (__tmp2)                                   \
  53         : "Jr" (base), "0" (high), "1" (low));                          \
  54                                                                         \
  55         (res) = __quot32;                                               \
  56         __mod32;                                                        \
  57 })
  58
  59 #define __div64_32(n, base) ({                                          \
  60         unsigned long __upper, __low, __high, __radix;                  \
  61         unsigned long long __modquot;                                   \
  62         unsigned long long __quot;                                      \
  63         unsigned long long __div;                                       \
  64         unsigned long __mod;                                            \
  65                                                                         \
  66         __div = (*n);                                                   \
  67         __radix = (base);                                               \
  68                                                                         \
  69         __high = __div >> 32;                                           \
  70         __low = __div;                                                  \
  71         __upper = __high;                                               \
  72                                                                         \
  73         if (__high) {                                                   \
  74                 __asm__("divu   $0, %z1, %z2"                           \
  75                 : "=x" (__modquot)                                      \
  76                 : "Jr" (__high), "Jr" (__radix));                       \
  77                 __upper = __modquot >> 32;                              \
  78                 __high = __modquot;                                     \
  79         }                                                               \
  80                                                                         \
  81         __mod = do_div64_32(__low, __upper, __low, __radix);            \
  82                                                                         \
  83         __quot = __high;                                                \
  84         __quot = __quot << 32 | __low;                                  \
  85         (*n) = __quot;                                                  \
  86         __mod;                                                          \
  87 })
  88
  89 #endif /* BITS_PER_LONG == 32 */
  90
  91 #include <asm-generic/div64.h>
  92
  93 #endif /* __ASM_DIV64_H */