blob: 32ea54c6630196c9d527501fa251f3c01be20e9f (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
|
// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
using System;
using System.Runtime.CompilerServices;
#pragma warning disable 472
public class Bug7907
{
int _position = 10;
[MethodImpl(MethodImplOptions.NoInlining)]
public static int G(int z, ref int r)
{
r -= z;
return 1;
}
[MethodImpl(MethodImplOptions.NoInlining)]
public int F0(int count)
{
int initialCount = count;
_position += G(_position, ref count);
if (initialCount == count)
{
count--;
}
return initialCount - count;
}
[MethodImpl(MethodImplOptions.NoInlining)]
public int F1(int count)
{
// " != null" is known to be true - just to remove control flow
// since that by itself may force spilling and mask the bug
count -= (_position += G(_position, ref count)) != null ? count : 1;
return count;
}
public static int Main(string[] args)
{
int result0 = new Bug7907().F0(10);
int result1 = new Bug7907().F1(10);
Console.WriteLine("R0={0} R1={1}", result0, result1);
return (result0 == 10 && result1 == 10 ? 100 : -1);
}
}
|
