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      1 /* ===-- modti3.c - Implement __modti3 -------------------------------------===
      2  *
      3  *                     The LLVM Compiler Infrastructure
      4  *
      5  * This file is dual licensed under the MIT and the University of Illinois Open
      6  * Source Licenses. See LICENSE.TXT for details.
      7  *
      8  * ===----------------------------------------------------------------------===
      9  *
     10  * This file implements __modti3 for the compiler_rt library.
     11  *
     12  * ===----------------------------------------------------------------------===
     13  */
     14 
     15 #include "int_lib.h"
     16 
     17 #if __x86_64
     18 
     19 tu_int __udivmodti4(tu_int a, tu_int b, tu_int* rem);
     20 
     21 /*Returns: a % b */
     22 
     23 ti_int
     24 __modti3(ti_int a, ti_int b)
     25 {
     26     const int bits_in_tword_m1 = (int)(sizeof(ti_int) * CHAR_BIT) - 1;
     27     ti_int s = b >> bits_in_tword_m1;  /* s = b < 0 ? -1 : 0 */
     28     b = (b ^ s) - s;                   /* negate if s == -1 */
     29     s = a >> bits_in_tword_m1;         /* s = a < 0 ? -1 : 0 */
     30     a = (a ^ s) - s;                   /* negate if s == -1 */
     31     ti_int r;
     32     __udivmodti4(a, b, (tu_int*)&r);
     33     return (r ^ s) - s;                /* negate if s == -1 */
     34 }
     35 
     36 #endif
     37