llvm/compiler-rt/lib/builtins/int_div_impl.inc

//===-- int_div_impl.inc - Integer division ---------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Helpers used by __udivsi3, __umodsi3, __udivdi3, and __umodsi3.
//
//===----------------------------------------------------------------------===//

#define clz(a) …

// Adapted from Figure 3-40 of The PowerPC Compiler Writer's Guide
static __inline fixuint_t __udivXi3(fixuint_t n, fixuint_t d) { … }

// Mostly identical to __udivXi3 but the return values are different.
static __inline fixuint_t __umodXi3(fixuint_t n, fixuint_t d) { … }

#ifdef COMPUTE_UDIV
static __inline fixint_t __divXi3(fixint_t a, fixint_t b) { … }
#endif // COMPUTE_UDIV

#ifdef ASSIGN_UMOD
static __inline fixint_t __modXi3(fixint_t a, fixint_t b) {
  const int N = (int)(sizeof(fixint_t) * CHAR_BIT) - 1;
  fixint_t s = b >> N;                              // s = b < 0 ? -1 : 0
  fixuint_t b_u = (fixuint_t)(b ^ s) + (-s);        // negate if s == -1
  s = a >> N;                                       // s = a < 0 ? -1 : 0
  fixuint_t a_u = (fixuint_t)(a ^ s) + (-s);        // negate if s == -1
  fixuint_t res;
  ASSIGN_UMOD(res, a_u, b_u);
  return (res ^ s) + (-s);                          // negate if s == -1
}
#endif // ASSIGN_UMOD