Integer overflow occurs when the result of an operation is larger than the maximal value that can be represented by the underlying integer type.
0
votes
1answer
10 views
Overflow Error When Diving Large Numbers In Python
I am trying to use a code to look for Wilson Primes for a bit of fun and to get me back into the swing of coding, however, I found that when I try to divide 172! +1 By 173 it gives me an Overflow ...
1
vote
0answers
36 views
How to prevent integer overflow on an addition? [duplicate]
I would like to add x to y (where y is an attribute of class A)
void A::f1(char x)
{
y += x;
}
However, there is a risk of overflow. I think (I have not tested them) the following two functions ...
5
votes
1answer
82 views
F# Performance Impact of Checked Calcs?
Is there a performance impact from using the Checked module? I've tested it out with sequences of type int and see no noticeable difference. Sometimes the checked version is faster and sometimes ...
-1
votes
0answers
25 views
why numeric overflow isn't an exception in java [duplicate]
Numeric overflow is a potential risk, because we may get a wrong result during runtime.
So why not design the numeric overflow as an exception in Java Language ?
int x=Integer.MAX_VALUE;
x++;
System....
1
vote
2answers
87 views
C++ literal integer type
Do literal expressions have types too ?
long long int a = 2147483647+1 ;
long long int b = 2147483648+1 ;
std::cout << a << ',' << b ; // -2147483648,2147483649
1
vote
0answers
18 views
nclass * nsamples in random forest is higher than the largest number supported by Integer type
I'm running random forest on a dataset with nsample = 20,379,102 and 5 features. The target feature is categorical with nclass = 107,189 levels. I receive the following error:
Error in integer(nclass ...
5
votes
3answers
48 views
short int Integer wrap around / short int inversion in c not understood, difference between assignment and prints
The following code fragment
short int k = -32768;
printf("%d \n", -k);
k=-k;
printf("%d \n", k);
prints
32768
-32768
I would assume that both prints are equal.
Can somebody explain what the ...
2
votes
2answers
66 views
Java integer overflow
I'm totally new to Java and I'm implementing a simple function to convert string to integer on Leetcode.
public int myAtoi(String str) {
if(str.length() == 0){
return 0;
}
str = ...
-1
votes
1answer
24 views
atomic AddUint32 overflow
I'm using the below code to get unique IDs within process:
for i := 0; i < 10; i++ {
go func() {
for {
atomic.AddUint32(&counter, 1)
time.Sleep(time....
go
3
votes
2answers
134 views
What is the standard rule on arithmetic operations when storing temporary values to a certain data type?
I had some code which I did a long time ago (I was using visual studio 2003 back then). Now I'm using gcc and some values are overflowing, I took a look at what was happening and it kind of surprises ...
2
votes
0answers
32 views
numpy memmap read error memory mapped size must be positive
I am reading a large binary file in partitions.
Each partition is mapped using numpy.memmap.
The file consist of 1M rows, where a row is 198 2-byte integers.
A partition is 1000 rows long.
Below ...
3
votes
2answers
55 views
Overflow detection when subtracting 2 longs
I have been going through Apache's common math libs Link
In the below code snippet lines A, B, C doesn't make sense to me. Can someone shed some light on this ?
public static long subAndCheck(long a,...
0
votes
2answers
40 views
Increment (overflow) Short.MAX_VALUE to zero, not Short.MIN_VALUE
I'm working on a 'tabindex' defect in an application that works fine in Firefox and Chrome, but not Internet Explorer.
The 'tabindex' is set through a JSP by a static 'int', which is incremented each ...
0
votes
1answer
76 views
C# vs Java overflow checking crazy performanse deviation
I am trying to measure time difference between checked and unchecked integer overflow in Java and C#.
I have noticed that checked Java code gets faster and faster while C# doesn't. Why is that?
...
0
votes
1answer
19 views
How many bits are available for JS-style “integer” math now?
While solving my previous question I faced even more funny thing.
Try integer math (yes, I know they aren't "too integer" inside) to see how much bits are available:
var n = 0xffffffff;
// loop over ...
0
votes
4answers
38 views
JavaScript integer shift safety: (n << 1) != (n * 2)
Digging JS just discovered something new to me:
n = 0xffffffff
4294967295
n
4294967295
n << 1
-2
n * 2
8589934590
(n << 1) == (n * 2)
false
n + 1
4294967296
This is console output of ...
-1
votes
1answer
39 views
Why might signed overflow occur when changing division to right-shift?
When optimising, GCC sometimes tells me
assuming signed overflow does not occur when simplifying / or % to >> or &
[-Wstrict-overflow]
I failed to make a reproducible test-case for ...
0
votes
1answer
25 views
SQL Datediff overflow - Null overflows
I am running a datediff to return microsecond diffs between two timestamps, so I believe the greatest gap that can be handled pre-overflow is about 33 minutes.
There are going to be a number of ...
2
votes
0answers
16 views
BitmapSource rendering glitch due to large width, probable overflow
I've got a bitmap that's 827852 pixels wide by 1 pixel high in a Bitmap object.
When converting the bitmap to a BitmapSource for rendering in WPF, the following artifacts appear in the UI:
The black ...
1
vote
4answers
193 views
Java finding the midpoint between two integers
I'm attempting to find the integer midpoint between two integers. For example mid(2,3) would be 2, not 2.5. I had the below which works fine, but i'd like to work with numbers from MIN_VALUE to ...
1
vote
3answers
83 views
Using ARM Cortex SysTick for calculating elapsed time; what happens when SysTick counter rolls over?
I'm currently auditing an online edX course about embedded systems, and learning about using the SysTick timer to calculate elapsed time.
Picture of logic I'm referring to
Code of logic I'm ...
0
votes
2answers
42 views
elisp: number can't get greater than (expt 2 60)?
In a previous post, someone shows that you can express any number in elisp because it switchs over to big_nums automatically.
But when I call (setq long_max (expt 2 60)), I get
1152921504606846976
...
2
votes
1answer
56 views
New to VBA- runtime error 6, script stops at blank cells instead of looping
Recently started working with VBA. Youtube and this forum have been excellent help so far. However, my problem is this:
Private Sub CommandButton1_Click()
Dim i As Integer
i = 1
Do ...
4
votes
3answers
171 views
What happens when >> operator is trying to input a value bigger than a variable can contain?
I'm pulling numbers from a text file and filling an array of type int with them.
I'm inserting the values into the array while looping through the .txt file with those lines of code (where k is the ...
4
votes
1answer
155 views
Is over/underflow an undefined behavior at execution time?
I was reading about undefined behavior, and I'm not sure if it's a compile-time only feature, or if it can occurs at execution-time.
I understand this example well (this is extracted from the ...
1
vote
2answers
93 views
Arithmetic overflow occurred
I am trying to run below statement in Sybase 15.5, but I am getting "Arithmetic overflow occurred " error:
declare @TradeId BIGINT
select @TradeId=(20170103-19950000)*10000
select @TradeId
Please ...
0
votes
2answers
77 views
What datatype to use for 40 digit integers in java
For example
first number = 123456.....40 digits
second number = 123456.....40digits
Then I need to store the number
third = first * second;
after that I need to print third and again I need to ...
5
votes
2answers
301 views
Panicked at 'attempt to subtract with overflow' when cycling backwards though a list
I am writing a cycle method for a list that moves an index either forwards or backwards. The following code is used to cycle backwards:
(i-1)%list_length
In this case, i is of the type usize, ...
0
votes
0answers
25 views
G++ ignores comparison at -O2
This code here runs fine on -O but fails to exit on -O2 and -Os.
#include <iostream>
int main() {
int ctr = 2000000000;
while (ctr++ > 0) {
if (ctr % 100000000 == 0) {
...
0
votes
1answer
17 views
Having an issue with large integer addition in JavaScript
I'm just making a very simple program to convert binary numbers to decimal and vice versa. In doing the decimal to binary conversion, I realized I was running across a weird error when I try and add ...
0
votes
3answers
110 views
Why isn't overflow checked by default
I found some questions on SO about checking operations before executions for over/underflow behavior. It seems that there are ways to do this quite easy. So why isn't there an option to automatically ...
-1
votes
1answer
77 views
Signed integer overflow: 999999999 * 10 cannot be represented in type 'int' Error
Why is there a runtime error? I made range2 a long long.
Code:
/*VARIABLES FOR WHILE LOOP*/
long long range1 = 9;
int length = 1;
/*FIND NUM'S LENGTH*/
while (NUM > range1)
{
long ...
-3
votes
1answer
43 views
Implementing / enforcing wraparound arithmetic in C [closed]
The C standard says that overflow in arithmetic is undefined.
I would like to know how to implement wraparound arithmetic in a performance-friendly way. This means that overflow checking solutions ...
2
votes
2answers
87 views
is this bit field of size one actually overflowing when assigning 1?
I have written some code with bit fields that I thought should work, but it seems like GCC disagrees. Did I miss something or did I actually find a bug in GCC?
After simplifying my code, the testcase ...
0
votes
1answer
50 views
Swift 3 uint64 overflows when trying to assign 64 bit integer
I'm trying to implement bitboards in Swift and am trying to store a 64bit integer into a UInt64 and get an overflow error.
var white_queen_bb:uint64 = ...
0
votes
1answer
48 views
Swift: Overriding NSObject hash Without Overflow Crash
Using Swift 3, I have some NSObject subclasses that I am overriding the hash property and isEqual() functions for. (I want the classes to be able to be used as keys in a dictionary, and I want an ...
0
votes
1answer
51 views
What is the size of an integer in Eiffel? How does it handle overflow?
In Eiffel, what is the size of an INTEGER type?
I was not able to find it, except here, where it is claimed that the size is 32 bits.
In this case, how does Eiffel handle overflow? Is it undefined ...
0
votes
0answers
33 views
Checking for overflow before casting to Sequence.IndexDistance
I'd like to call Collection's
func index(_ i: Self.Index,
offsetBy n: Self.IndexDistance,
limitedBy limit: Self.Index) -> Self.Index?
method with a user-supplied offset.
...
0
votes
1answer
115 views
Go print large number
I am currently doing the Go Lang tutorial, "Numeric Constants" to be precise. The example code starts with the following statement:
const (
// Create a huge number by shifting a 1 bit left 100 ...
0
votes
1answer
371 views
MIPS overflow exception
I have read through a couple of posts here on overflow exception for MIPS signed and unsigned addition, but it is still not clear to me.
1) What is meant by an overflow exception and when does it ...
3
votes
3answers
42 views
The effect of assigning parameter types on integer overflow
I am having difficulty of understanding the behavior of the java in the following scenario. For example, I have a multiply method, which simply multiplies two int value and print the result to the ...
81
votes
11answers
10k views
At what point in the loop does integer overflow become undefined behavior?
This is an example to illustrate my question which involves some much more complicated code that I can't post here.
#include <stdio.h>
int main()
{
int a = 0;
for (int i = 0; i < 3; ...
0
votes
1answer
42 views
2^n - 1 without overflowing a long
This is for a C89 project, in which LONG_IS_64BIT is defined if (and only if) a long is 64-bit, that is, contains all the integers from -2^63-1 to 2^63-1. Otherwise (by the C standard) it contains all ...
2
votes
5answers
95 views
Perform 64 bit calculations in 64 bit executable
I am using MinGW64 (with the -m64 flag) with Code::Blocks and want to know how to perform 64 bit calculations without having to using something like:
int64_t test = int64_t(2123123123) * 17;
If I ...
-2
votes
2answers
110 views
Reverse Integer Catch overflow C++
Hello I am trying a simple reverse integer operation in c++. Code below:
#include <iostream>
#include <algorithm>
#include <climits>
using namespace std;
class RevInteger {
...
0
votes
2answers
41 views
How does a processor(esp. ARM) interpret an overflow result at later stage in execution when the result is wirtten back to memory
Since processors follow the convention of representing numbers as 2's complement how do they know whether the number resulted from an addition of two positive numbers is still positive and not ...
0
votes
1answer
137 views
When do I have to check for integer overflow?
I have been researching about integer overflowing, and I ended creating a function that checks for integer overflows and underflows:
#include <exception>
#include <limits>
int safe_add(...
0
votes
1answer
84 views
JavaScript integer overflow workaround
I need to perform arithmetical operations with large numbers in JS, in this particular case it is:
(1827116622 / 6) * 251772294
The expected result is 76669557221078478 but I am getting ...
2
votes
4answers
88 views
If we add one to the largest re-presentable integer, is the result negative?
This program is asking the C implementation to answer a simple question:
If we check the largest re-presentable integer INT_MAX < 0 and print it.
printf ("%d\n", (INT_MAX) < 0);
So, ...
0
votes
1answer
510 views
Will an integer overflow in Python? [duplicate]
In languages such as Java, the integer value will overflow once it is larger than Integer.MAX_VALUE or when it is less than Integer.MIN_VALUE. I have seen posts where using a Long datatype was ...
