diff options
Diffstat (limited to 'lib/builtins/mulodi4.c')
-rw-r--r-- | lib/builtins/mulodi4.c | 93 |
1 files changed, 42 insertions, 51 deletions
diff --git a/lib/builtins/mulodi4.c b/lib/builtins/mulodi4.c index d2fd7db2bcd3..23f5571ac468 100644 --- a/lib/builtins/mulodi4.c +++ b/lib/builtins/mulodi4.c @@ -1,58 +1,49 @@ -/*===-- mulodi4.c - Implement __mulodi4 -----------------------------------=== - * - * The LLVM Compiler Infrastructure - * - * This file is dual licensed under the MIT and the University of Illinois Open - * Source Licenses. See LICENSE.TXT for details. - * - * ===----------------------------------------------------------------------=== - * - * This file implements __mulodi4 for the compiler_rt library. - * - * ===----------------------------------------------------------------------=== - */ +//===-- mulodi4.c - Implement __mulodi4 -----------------------------------===// +// +// 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 __mulodi4 for the compiler_rt library. +// +//===----------------------------------------------------------------------===// #include "int_lib.h" -/* Returns: a * b */ +// Returns: a * b -/* Effects: sets *overflow to 1 if a * b overflows */ +// Effects: sets *overflow to 1 if a * b overflows -COMPILER_RT_ABI di_int -__mulodi4(di_int a, di_int b, int* overflow) -{ - const int N = (int)(sizeof(di_int) * CHAR_BIT); - const di_int MIN = (di_int)1 << (N-1); - const di_int MAX = ~MIN; - *overflow = 0; - di_int result = a * b; - if (a == MIN) - { - if (b != 0 && b != 1) - *overflow = 1; - return result; - } - if (b == MIN) - { - if (a != 0 && a != 1) - *overflow = 1; - return result; - } - di_int sa = a >> (N - 1); - di_int abs_a = (a ^ sa) - sa; - di_int sb = b >> (N - 1); - di_int abs_b = (b ^ sb) - sb; - if (abs_a < 2 || abs_b < 2) - return result; - if (sa == sb) - { - if (abs_a > MAX / abs_b) - *overflow = 1; - } - else - { - if (abs_a > MIN / -abs_b) - *overflow = 1; - } +COMPILER_RT_ABI di_int __mulodi4(di_int a, di_int b, int *overflow) { + const int N = (int)(sizeof(di_int) * CHAR_BIT); + const di_int MIN = (di_int)1 << (N - 1); + const di_int MAX = ~MIN; + *overflow = 0; + di_int result = a * b; + if (a == MIN) { + if (b != 0 && b != 1) + *overflow = 1; return result; + } + if (b == MIN) { + if (a != 0 && a != 1) + *overflow = 1; + return result; + } + di_int sa = a >> (N - 1); + di_int abs_a = (a ^ sa) - sa; + di_int sb = b >> (N - 1); + di_int abs_b = (b ^ sb) - sb; + if (abs_a < 2 || abs_b < 2) + return result; + if (sa == sb) { + if (abs_a > MAX / abs_b) + *overflow = 1; + } else { + if (abs_a > MIN / -abs_b) + *overflow = 1; + } + return result; } |