Is there a general way to check for an overflow or an underflow of a given data type (uint32, int etc.)? I am doing something like this: uint32 a,b,c; ... //initialize a,b,c if(b < c) { a -= (c - b) } When I print a after some iterations, it displays a large number like: 4294963846. ...
Microsoft already says, in the documentation for GetTickCount, that you could never compare tick counts to check if an interval has passed. e.g.: Incorrect (pseudo-code): DWORD endTime = GetTickCount + 10000; //10 s from now ... if (GetTickCount > endTime) break; The above code is bad because it is suceptable to rollover of the ...
i have bit of code that causes an underflow: var t1, t2, delta: DWORD: begin t1 := 0xffffff00; t2 := 0x00000037; delta := (t2 - t1); The subtraction itself does generate an overflow (underflow), but i don't want Delphi to throw an EIntOverflow exception. So i try disabling the generation of overflow checking code by disa...
I'm working on a verification-tool for some VHDL-Code in MATLAB/Octave. Therefore I need data types which generate "real" overflows: intmax('int32') + 1 ans = -2147483648 Later on, it would be helpful if I can define the bit width of a variable, but that is not so important right now. When I build a C-like example, where a variable g...
I am trying to find the linear trend line for a set of data. The set contains pairs of dates (x values) and scores (y values). I am using a version of this code as the basis of my algorithm. The results I am getting are off by a few orders of magnitude. I assume that there is some problem with round off error or overflow because I am us...
I am implementing a database application and I will use both JavaDB and MySQL as database. I have an ID column in my tables that has integer as type and I use the databases auto_increment-function for the value. But what happens when I get more than 2 (or 4) billion posts and integer is not enough? Is the integer overflowed and continue...
How can one add two long values in Java so that if the result overflows then it is clamped to the range Long.MIN_VALUE..Long.MAX_VALUE? For adding ints one can perform the arithmetic in long precision and cast the result back to an int, e.g.: int saturatedAdd(int x, int y) { long sum = (long) x + (long) y; long clampedSum = Math.ma...
Possible Duplicate: Best way to detect integer overflow in C/C++ There's (1): // assume x,y are non-negative if(x > max - y) error; And (2): // assume x,y are non-negative int sum = x + y; if(sum < x || sum < y) error; Whichs is preferred or is there a better way. ...
What is an integer overflow error? Why do i care about such an error? What are some methods of avoiding or preventing it? ...
I want to multiply two numbers, and detect if there was an overflow. What is the simplest way to do that? ...
I have read in many places that integer overflow is well-defined in C unlike the signed counterpart. Is underflow the same? For example: unsigned int x = -1; // Does x == UINT_MAX? Thanks. I can't recall where, but i read somewhere that arithmetic on unsigned integral types is modular, so if that were the case then -1 == UINT_MAX m...
This the part of my OpenGL code, I am getting an error for : struct Ball { float x; float y; float rot; float dir; bool rmv; Ball* next; }; Ball* curBall; void addBall() { if (balls==NULL) { balls=new Ball; balls->next=NULL; curBall=balls; } else { curBall->next=new Ball; ...
Does anyone have a detailed explanation on how integers can be exploited? I have been reading a lot about the concept, and I understand what an it is, and I understand buffer overflows, but I dont understand how one could modify memory reliably, or in a way to modify application flow, by making an integer larger than its defined memory.....
In VBA you can Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long) to provide yourself with a sleep routine. However, the Long that must be passed to the routine appears to overflow for values in excess of 32000 milliseconds. Is there a way to sleep for longer periods of time without the complexity of stringing together s...
I've been experimenting with BCrypt, and found the following. If it matters, I'm running ruby 1.9.2dev (2010-04-30 trunk 27557) [i686-linux] require 'bcrypt' # bcrypt-ruby gem, version 2.1.2 @long_string_1 = 'f287ed6548e91475d06688b481ae8612fa060b2d402fdde8f79b7d0181d6a27d8feede46b833ecd9633b10824259ebac13b077efb7c24563fce0000670834215...
In the following C++ code, 32767 + 1 = -32768. #include <iostream> int main(){ short var = 32767; var++; std::cout << var; std::cin.get(); } Is there any way to just leave "var" as 32767, without errors? ...
Hi Guys, I need to deal with a counter that gives me ticks for my application. The counter is 32bits so what i need to know is how to deal with it when it wraps. for example: I have a function that returns a (timestamp + shifttime) and i have another function that will return 1 or 0 depending whether or not the time has elapsed, but t...
Hello all I've a for loop which keeps incrementing an integer value till the loop completes. So if the limit n is a double variable and the incremented variable 'i' is an integer, i gets incremented beyond its limits. double total = 0; double number = hugetValue; for (int i = 1; i <= number; i++) { total = total + i; } return...
What is the proper way to deal with character values which when casted to an unsigned char fall between {INT_MAX + 1 ... UCHAR_MAX} where UCHAR_MAX is greater than INT_MAX. int is_digit(char c) { unsigned char uchar = c; if(uchar > INT_MAX) return MAYBE; return isdigit((int)uchar) ? YES : NO; } ...
Why in C# is Example A valid, compilable and will just wrap while examples B will not compile? A int val = 0; val = val + Int32.MaxValue +2; or int val = Int32.MaxValue; val++; B int val = 0; val = 2147483647 + 1; or int val = 0; int val = Int32.MaxValue + 1; I know by default that arithmetic exceptions are not checked by de...