StdLib/LibC/StdLib/Xdiv.c

   1 /** @file
   2   The div, ldiv, and lldiv, functions compute numer / denom and
   3   numer % denom in a single operation.
   4
   5   The div, ldiv, and lldiv functions return a structure of type div_t, ldiv_t,
   6   and lldiv_t, respectively, comprising both the quotient and the remainder.
   7   The structures shall contain (in either order) the members quot
   8   (the quotient) and rem (the remainder), each of which has the same type as
   9   the arguments numer and denom. If either part of the result cannot be
  10   represented, the behavior is undefined.
  11
  12   Copyright (c) 2010, Intel Corporation. All rights reserved.<BR>
  13   This program and the accompanying materials are licensed and made available under
  14   the terms and conditions of the BSD License that accompanies this distribution.
  15   The full text of the license may be found at
  16   http://opensource.org/licenses/bsd-license.php.
  17
  18   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  19   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  20 **/
  21 #include  <LibConfig.h>
  22 #include  <sys/EfiCdefs.h>
  23
  24 #include  <Library/BaseLib.h>
  25 #include  <stdlib.h>          /* div_t, ldiv_t, lldiv_t */
  26
  27 /* DivS64x64Remainder will write the remainder as a 64-bit value, so we store
  28    it first into bigrem and then into r.rem.  This avoids writing the remainder
  29    beyond the end of the div_t structure.
  30 */
  31 div_t
  32 div(int num, int denom)
  33 {
  34   div_t r;
  35   INT64 bigrem;
  36
  37   r.quot = (int)DivS64x64Remainder( (INT64)num, (INT64)denom, &bigrem);
  38   r.rem  = (int)bigrem;
  39
  40   return (r);
  41 }
  42
  43 /* DivS64x64Remainder will write the remainder as a 64-bit value, so we store
  44    it first into bigrem and then into r.rem.  This avoids writing the remainder
  45    beyond the end of the div_t structure.
  46 */
  47 ldiv_t
  48 ldiv(long num, long denom)
  49 {
  50   ldiv_t r;
  51   INT64 bigrem;
  52
  53   r.quot = (long)DivS64x64Remainder( (INT64)num, (INT64)denom, &bigrem);
  54   r.rem  = (long)bigrem;
  55
  56   return (r);
  57 }
  58
  59 /* DivS64x64Remainder will write the remainder as a 64-bit value, so we store
  60    it first into bigrem and then into r.rem.  This avoids writing the remainder
  61    beyond the end of the div_t structure if r.rem is narrower than 64-bits.
  62
  63    Even though most implementations make long long 64 bits wide, we still go
  64    through bigrem, just-in-case.
  65 */
  66 lldiv_t
  67 lldiv(long long num, long long denom)
  68 {
  69   lldiv_t r;
  70   INT64 bigrem;
  71
  72   r.quot = (long long)DivS64x64Remainder( (INT64)num, (INT64)denom, &bigrem);
  73   r.rem  = (long long)bigrem;
  74
  75   return (r);
  76 }