I am working on writing my own operating system. So far, my code exceeds 512 bytes, which is too large to fit in a simple boot sector.
Clearly, fixed-width integral types should be used when the size is important.However, I read (Insomniac Games style guide), that "int" should be preferred for loop counters / function args / return codes / ect when the size isn't important - the rationale given was that fixed-width types can preclude certain...
An x86 CPU have some instructions that deal with integers and floating-point numbers.For example: the INC instruction increments an integer (which can be stored in memory or in a register) by 1, so the INC instruction "knows" that it should interpret the bits that it is manipulating as an integer....
Consider the following simple program:It takes an (optional) string on the command line and prints it, with / characters replaced by _. This replacement functionality is implemented by the c_repl function1. For example, a.out foo/bar prints:
Does the x86 standard include Mnemonics or does it just define the opcodes?If it does not include them, is there another standard for the different assemblers?
I'm currently working on a homework problem that asks me to find out the number of machine code instructions that are executed when running a short program I wrote in C.
Let's say you want to find the first occurrence of a value1 in a sorted array. For small arrays (where things like binary search don't pay off), you can achieve this by simply counting the number of values less than that value: the result is the index you are after.
In numerical computation, it is often needed to scale numbers to be in safe range.For example, computing Euclidean distance: sqrt(a^2+b^2). Here, if magnitude of a or b is too small/large, then underflow/overflow can happen.
In Delphi math.pas unit there is a procedure DivMod that i want to convert it into inline and optimize it for divisor to be always 10 . But I dont know details of Pentagon ASM . What is the conversion of bellow procedure
I was wondering if it is possible to decode x86-64 instructions in reverse?I need this for a runtime dissembler. Users can point to a random location in memory and then should be able to scroll upwards and see what instructions came before the specified address.