divti3.c
1.18 KB
//===-- divti3.c - Implement __divti3 -------------------------------------===//
//
// 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 __divti3 for the compiler_rt library.
//
//===----------------------------------------------------------------------===//
#include "int_lib.h"
#ifdef CRT_HAS_128BIT
// Returns: a / b
COMPILER_RT_ABI ti_int __divti3(ti_int a, ti_int b) {
const int bits_in_tword_m1 = (int)(sizeof(ti_int) * CHAR_BIT) - 1;
ti_int s_a = a >> bits_in_tword_m1; // s_a = a < 0 ? -1 : 0
ti_int s_b = b >> bits_in_tword_m1; // s_b = b < 0 ? -1 : 0
a = (a ^ s_a) - s_a; // negate if s_a == -1
b = (b ^ s_b) - s_b; // negate if s_b == -1
s_a ^= s_b; // sign of quotient
return (__udivmodti4(a, b, (tu_int *)0) ^ s_a) - s_a; // negate if s_a == -1
}
#endif // CRT_HAS_128BIT