llvm/compiler-rt/lib/builtins/udivmodti4.c

//===-- udivmodti4.c - Implement __udivmodti4 -----------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This file implements __udivmodti4 for the compiler_rt library.
//
//===----------------------------------------------------------------------===//

#include "int_lib.h"

#ifdef CRT_HAS_128BIT

// Returns the 128 bit division result by 64 bit. Result must fit in 64 bits.
// Remainder stored in r.
// Taken and adjusted from libdivide libdivide_128_div_64_to_64 division
// fallback. For a correctness proof see the reference for this algorithm
// in Knuth, Volume 2, section 4.3.1, Algorithm D.
UNUSED
static inline du_int udiv128by64to64default(du_int u1, du_int u0, du_int v,
                                            du_int *r) { … }

static inline du_int udiv128by64to64(du_int u1, du_int u0, du_int v,
                                     du_int *r) { … }

// Effects: if rem != 0, *rem = a % b
// Returns: a / b

COMPILER_RT_ABI tu_int __udivmodti4(tu_int a, tu_int b, tu_int *rem) { … }

#endif // CRT_HAS_128BIT