Integer overflow occurs when the result of an operation is larger than the maximal value that can be represented by the underlying integer type.
Questions tagged [integer-overflow]
1056 questions
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votes
4 answers
Bit-shifting left and discarding bits
Let's consider the function (one of possible implementations of it) which would zero out right N bits of an unsigned short value (or any other unsigned integral type). The possible implementation could look like following:
template
SergeyA
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4 answers
Creating a custom int that would enforce always being in a specified range; how to get past integer overflows?
As in the title. As an exercise, I wanted to create an int that would enforce constraints on its value and would disallow being set to values outside its specified range.
Here is how I tried to approach this:
#include
#include…
user4385532
6
votes
4 answers
C++ integer overflow
I'm just starting to teach myself C++, and have begun learning about integer overflow. Out of curiosity I wrote some tests just to see what occurs with certain integer values.
Here's my program:
#include
int main()
{
int x(0);
…
Zack Downs
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Why is checked arithmetic in .NET sometimes faster than unckecked?
Why is it when I turn on "check for arithmetic underflow/overflow" under C# Project Properties > Build > Advanced, that the following code runs faster (138 ms) than if I turn the option off (141 ms)?
Test Run #1: 138ms with checked arithmetic, 141ms…
Edward Brey
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3 answers
Python prevent overflow errors while handling large floating point numbers and integers
I am working on a python program to calculate numbers in the Fibonacci sequence. Here is my code:
import math
def F(n):
return ((1+math.sqrt(5))**n-(1-math.sqrt(5))**n)/(2**n*math.sqrt(5))
def fib(n):
for i in range(n):
print…
Progo
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How can both (i + 1) < ii and (i + 1) > ii both be true?
I'm currently learning C program But I came across some weird behavior
I expected one result but two results is printed like this
$ ./a.out
yes1 0x80000000
yes3 0x80000000
How could possible that?
I can't understand the result.
OS : x86_64 Ubuntu…
mug896
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Does the C standard make an guarantees about the relationship between INT_MIN and INT_MAX?
For example, in both 2's and 1's complement, INT_MAX*-1 is a valid number. Is this guaranteed? Are there any other guarantees? Could INT_MIN be -1 or 0 on any architecture, for example? Is there anything we can know about (INT_MAX + INT_MIN)? Can we…
Drew
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6
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2 answers
What would happen if I were to make more references to Objects than 32 bits can account for?
So I just learned when you declare a variable of type Object ( i.e. Object a; ), a 32-bit space is allocated for that variable. Inside this variable/reference, there is a memory address to an actual Object.
Now let's pretend I have a large enough…
Kacy Raye
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Can I detect integer overflow flaws with valgrind?
Can I detect integer overflow flaws with valgrind? and which tool in it can do that?
Syrena
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Is overflow defined for VHDL numeric_std signed/unsigned
If I have an unsigned(MAX downto 0) containing the value 2**MAX - 1, do the VHDL (87|93|200X) standards define what happens when I increment it by one? (Or, similarly, when I decrement it by one from zero?)
detly
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Can I prevent a integer overflow in C# using an unsigned right shift?
I want alwaysPositive to be assigned a positive number with all possible values for lareValue1 and largeValue2 (these are at least 1).
The following statement causes a buffer overflow:
int alwaysPositive = (largeValue1 + largeValue2) / 2;
I know I…
Paco
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2 answers
Why does initializing a negatively-sized array cause an overflow exception?
I was unit testing in C#, and I found the following code gives an overflow exception:
using System;
public class Program
{
public static void Main()
{
int i = 0;
Console.WriteLine(new float[i - 1]);
…
ADAMJR
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5
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128 bit (a * b) / c in Rust with phantom overflow protection
Let a, b, and c be 128 bit numbers. A phantom overflow happens when the intermediary value a * b overflows 128 bits. However the final product after division numerator / c fits inside 128 bits.
For 64 bit and smaller numbers, one can cast to 128…
secretshardul
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Stopping integer overflow in ASP.NET
We use Acunetix at work to do security scans on our applications. Recently we came across the following Integer Vulnerabilities error below:
From what I can tell, it looks like the report is telling us that we are not stopping integer overflow…
ryanulit
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Can `unsigned int x; scanf("%u",&x);` really cause undefined behavior?
For once I thought I found a good use for sscanf() but after reading about how it handles integers, it appears not. Having a string that should look like this: 123,456,678 I thought I could safely and concisely parse it with this code:
unsigned int…
pipe
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