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The register width of a processor determines the range of values that can be represented in its registers. Though the vast majority of computers can perform multiple-precision arithmetic on operands in memory, allowing numbers to be arbitrarily long and overflow to be avoided, the register width limits the sizes of numbers that can be operated on (e.g., added or subtracted) using a single ...
The problem is similar in nature to the year 2000 problem, the difference being the Year 2000 problem had to do with base 10 numbers, whereas the Year 2038 problem involves base 2 numbers. Analogous storage constraints will be reached in 2106 , where systems storing Unix time as an unsigned (rather than signed) 32-bit integer will overflow on 7 ...
The problem with the code is it does not check for integer overflow on the addition operation. If the sum of x and y is greater than the maximum possible value of an unsigned int , the addition operation will overflow and perhaps result in a value less than or equal to MAX, even though the sum of x and y is greater than MAX.
On 5 January 1975, the 12-bit field that had been used for dates in the TOPS-10 operating system for DEC PDP-10 computers overflowed, in a bug known as "DATE75". The field value was calculated by taking the number of years since 1964, multiplying by 12, adding the number of months since January, multiplying by 31, and adding the number of days since the start of the month; putting 2 12 − 1 ...
Canaries or canary words or stack cookies are known values that are placed between a buffer and control data on the stack to monitor buffer overflows. When the buffer overflows, the first data to be corrupted will usually be the canary, and a failed verification of the canary data will therefore alert of an overflow, which can then be handled, for example, by invalidating the corrupted data.
An example, suppose we add 127 and 127 using 8-bit registers. 127+127 is 254, but using 8-bit arithmetic the result would be 1111 1110 binary, which is the two's complement encoding of −2, a negative number. A negative sum of positive operands (or vice versa) is an overflow.
Example: 16 bit signed integer: 30000 + 30000 = −5536. The example given here of a negative number resulting from addition is an example of a signed integer overflow, but its usage immediately after the statement about C programming behavior is contradictory.
ALGOL 68 leaves intentionally undefined what happens in case of integer overflow, the integer bit representation, and the degree of numerical accuracy for floating point. Both official reports included some advanced features that were not part of the standard language. These were indicated with an ℵ and considered effectively private.