xref: /openbsd-src/gnu/llvm/compiler-rt/lib/builtins/subvti3.c (revision 3cab2bb3f667058bece8e38b12449a63a9d73c4b)
1*3cab2bb3Spatrick //===-- subvti3.c - Implement __subvti3 -----------------------------------===//
2*3cab2bb3Spatrick //
3*3cab2bb3Spatrick // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4*3cab2bb3Spatrick // See https://llvm.org/LICENSE.txt for license information.
5*3cab2bb3Spatrick // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6*3cab2bb3Spatrick //
7*3cab2bb3Spatrick //===----------------------------------------------------------------------===//
8*3cab2bb3Spatrick //
9*3cab2bb3Spatrick // This file implements __subvti3 for the compiler_rt library.
10*3cab2bb3Spatrick //
11*3cab2bb3Spatrick //===----------------------------------------------------------------------===//
12*3cab2bb3Spatrick 
13*3cab2bb3Spatrick #include "int_lib.h"
14*3cab2bb3Spatrick 
15*3cab2bb3Spatrick #ifdef CRT_HAS_128BIT
16*3cab2bb3Spatrick 
17*3cab2bb3Spatrick // Returns: a - b
18*3cab2bb3Spatrick 
19*3cab2bb3Spatrick // Effects: aborts if a - b overflows
20*3cab2bb3Spatrick 
__subvti3(ti_int a,ti_int b)21*3cab2bb3Spatrick COMPILER_RT_ABI ti_int __subvti3(ti_int a, ti_int b) {
22*3cab2bb3Spatrick   ti_int s = (tu_int)a - (tu_int)b;
23*3cab2bb3Spatrick   if (b >= 0) {
24*3cab2bb3Spatrick     if (s > a)
25*3cab2bb3Spatrick       compilerrt_abort();
26*3cab2bb3Spatrick   } else {
27*3cab2bb3Spatrick     if (s <= a)
28*3cab2bb3Spatrick       compilerrt_abort();
29*3cab2bb3Spatrick   }
30*3cab2bb3Spatrick   return s;
31*3cab2bb3Spatrick }
32*3cab2bb3Spatrick 
33*3cab2bb3Spatrick #endif // CRT_HAS_128BIT
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