How do modern processors perform whole arithmetic operations?

This Wikipedia page mentions computation complexity of different mathematical operations, including addition, subtraction, multiplication and division. I'd like to focus on these four. First of all, every of the mentioned operations has its complexit

An efficient way to divide the RGB values ​​into C

I'm writing some software for a 32-bit cortex M0 microcontroller in C and I'm doing alot of manipulations with 32-bit RGB values. They are handled in a 32-bit integer format like 0x00BBRRGG. I want to be able to do math with them without worrying abo

Tip to divide a constant (power of two) by an integer

NOTE This is a theoretical question. I'm happy with the performance of my actual code as it is. I'm just curious about whether there is an alternative. Is there a trick to do an integer division of a constant value, which is itself an integer power o

What can Bool return to C99?

What is bool guaranteed to return as? Can I rely on a bool type to always be interpreted as 0 or 1? If bool's numerical interpretation isn't reliable in C99 is there a standard where it is? Are there any things I should look out for in LLVM, GCC, or

Establishment of a school division on 32-bit blocks on x86

Say i got two big numbers (defined below), and i want to implement division on them by falling back to x86 avaliable arithmetic 0008768376 - 1653656387 - 0437673667 - 0123767614 - 1039873878 - 2231712290 / 0038768167 - 3276287672 - 1665265628 C=A/B T

How to compare two whole objects?

Integer i = new Integer(0); Integer j = new Integer(0); while(i <= j && j <= i && i !=j ){ System.out.println(i); } Why does this while loop execute? I understand that i != j. But separately, both i <= j and j <= i returns true

How to find the average of two numbers that take place?

I have an int that represents numbers in the range [0, 8[ that wraps around: 2 1 3 0 4 7 5 6 Now I need to find the average of two numbers like this, so that for example the average of 7 and 0 would be 7.5, the average of 7 and 2 would be 0.5, the av

Exact sum of a long set

In order to get the exact sum of a long[] I'm using the following snippet. public static BigInteger sum(long[] a) { long low = 0; long high = 0; for (final long x : a) { low += (x & 0xFFFF_FFFFL); high += (x >> 32); } return BigInteger.valueOf(h

Perl-int () decrementing an integer

Before I get flamed, I want to say I do understand floating point numbers and things of the sort, but that doesn't seem to be my issue. To simplify things, I'm trying to determine if a number has more than 2 decimal places. I'm doing this by multiply

Define division using Haskell

I decided it would be cool to learn Haskell by recreating arithmetic using only the Succ function, or other functions I've defined, and the Integer number type. So far I've managed to (re)create Add, Subtract, and Multiply, only for Integers. I've cr

Java8 unsigned arithmetic

Java 8 is widely reported to have library support for unsigned integers. However, there seem to be no articles explaining how to use it and how much is possible. Some functions like Integer.CompareUnsigned are easy enough to find and seem to do what

Java Beginner Programmer Arithmetic Error

I've recently embarked into Java programming and consider myself a programming novice. It seem that I'm having an issue with my source code arithmetic. I have verified all the nested if-else statements and they all work up to the final else statement

Is the arithmetic overrun equivalent to the modulo operation?

I need to do modulo 256 arithmetic in C. So can I simply do unsigned char i; i++; instead of int i; i=(i+1)%256; No. There is nothing that guarantees that unsigned char has eight bits. Use uint8_t from <stdint.h>, and you'll be perfectly fine. This

How to check if an int is even

This is likely an easy solution that is simply eluding me. Specifically, I am creating locations on a canvas dynamically using a sin() function for equidistant points on a circle. Once these points are created, I am animating a shape moving from one

Keyboard Type Conversion

I want to get numbers entered from my Arduino keypad (which are of type 'char') converted to type 'int' so I can use them in variables and use math. For instance, if I press key "5", how do i put it into a variable "keyPressed" and do

Strange integer overflow logic

For the following code I get an overflow but sadly I cannot seem to understand why. std::int8_t smallValue = -1; unsigned int value = 500; std::uint8_t anotherSmallValue = 1; auto test = smallValue * value * anotherSmallValue; Afterwards test is a qu

Java Scientific Calculator Regular Expression

What will be the regular expression in java for like this expression (3+2)+23/12-(43/54) in which left parentheses is create than user will be able to put right one and if left parentheses is not created than user will not able to put right parenthes

Ambiguity in long integer arithmetic?

Have a look at the following piece of code: #include <stdio.h> int main(void) { int a; a = 2147483647; printf("a + 1 = %d \t sizeof (a + 1) = %lu\n", a + 1, sizeof (a + 1)); printf("a + 1L = %ld \t sizeof (a + 1L) = %lu\n", a + 1

Why int int more uint returns?

int plus unsigned int returns an unsigned int. Should it be so? Consider this code: #include <boost/static_assert.hpp> #include <boost/typeof/typeof.hpp> #include <boost/type_traits/is_same.hpp> class test { static const int si = 0; stat

The defined behavior of unsigned integer subtraction?

I have come across code from someone who appears to believe there is a problem subtracting an unsigned integer from another integer of the same type when the result would be negative. So that code like this would be incorrect even if it happens to wo

How to store an arbitrarily large integer value in memory?

I have to store an integer value that is larger than the maximum value for the long datatype. How would I store and manipulate this value in memory? Please illustrate it through an example, if possible.Think about storing a numbers as sequences of de